What happens when your Timing Belt goes?

[Oz87Si]

g'day Boys

My 87Si is at 188,000 km's and its common knowledge that in most Honda's you change the timing belt before you hit 100,000km's. I'm guessing the previous owner probs did it around 90-95,000 km's. I'm about to get my clutch done and I'll do the timing belt at the same time (will cost me $850 all up).

Just wondering about what happens if the belt snaps before it's changed as I'm getting a little vervous about the Km's and the belt letting go soon. Plus, if I launch the car in 2nd from say 2000rpm to about 5000rpm, the engine sometimes stops pulling for a split second sometimes as if it misses a few revs or something....

Can the car get seriously fucked up if the belt snaps while you're driving?

Cheers

[TheMagi]

the valves risk hitting the pistons if the belt should break.

[Strugglebucket]

Dude, replace that belt and replace it NOW. Mine was doing the same thing like it would miss every once and a while if you were driving at steady rpm. That little jump on the tach it does is because a section of the teeth are stripped out. If you don't wanna break down and have to rebuild the head, fix it now. :werd:

[FatDave]

if you're really lucky the belt will strip a few teeth at low rpm and the engine will die with no damage done, if you're not so lucky the belt will snap and the pistons will slam into the valves and make a nice boat anchor out of the head

[accordlxi2.0]

umm this has been a big debate.
the engine is NON-INTERFERANCE.
if the belt snap's the engine's fine.
i had a friend who dogged his 3g, everyday and did'nt change the belt at all.
it lasted for a while.
well doggig as usual it snapped.
he cranked quite a few time's too.
it was the belt which was really worn, and we replaced it, it started ranned too.


a few guy's on this board had the belt's break, replaced it , it was fine . . .

[mr eff]

yeah i've heard the engines are non-interference, meaning if the belt snapped you shouldn't damage the valvetrain. of course, don't let it break to find out... get the thing replaced while you're doing the clutch!

[TheMagi]

yeah i've heard the engines are non-interference, meaning if the belt snapped you shouldn't damage the valvetrain. of course, don't let it break to find out... get the thing replaced while you're doing the clutch!
I thought it was in interferance motor

[johnwc723]

hmm i think that honda engines are interference, i have heard of people messing up their engines when the timing belt breaks, one of my friends had a lude with the a20a4 and his timing belt broke and many of the valves got bent (maybe holes in the pistons too i dont remember) and he just gave up on it

sometimes people get lucky when the timing belt breaks in our cars and no major damage (or even noticable damage) happens, id replace the belt tho if you can!

[HondaBoy]

ok, well yes, its an interferance motor. think of it like this. your T belt breaks, the crank is still turing pushing the pistons up and down, but your cam shaft has stopped not letting the valves open and close with the pistons up and down run. you can get lucky as a few people have to where it broke just at the right time where the valves were not fully open. thats how they didnt bend the valve. moral of the story, its worth every penny you have to replace that damn T belt. and as your replacing the T belt, go ahead and replace the water pump and the other belts of the engine. believe me the water pump will like to go out on you many times after changing the T belt. actually if you change the alternator belt which also runs the water pump sometimes soon after that the water pump will go out when its pretty old.

[locknload68]

Yes it's an interference motor. I talked to a mechanic at Honda's Civic plant about my timing belt breaking and he was amazed that no valves got messed up. He said every one that he has seen has had internal engine damage.

[accordlxi2.0]

then why did my friend's 3g start up okay.
and some of the people on this board said thier's was fine . . .

plus i heard that 90 and up accord's ARE.
i don't know . . . . .

[rideredorgohome]

ok well it is really easy to take the cover off to check it. get a haynes manual at Auto Zone or something and it will tell you what it looks like when it needs to be replaced. any worn edges, fraying etc will indicate it is time to change it. i would not recommend changing it yourself, unless u r a mechanic. the engine is an interference engine. the belt was one of the first things i did when i first got the car for safety's sake. don't forgrt that our cars have power steering as well and not only can you punch a few holes in the pistons but when u lose power u will also lose steering. :ugh:

[Oyvind Ryeng]

The car will steer fine without pressure from the PS-pump. A little hard, but it would still steer.

[rideredorgohome]

The car will steer fine without pressure from the PS-pump. A little hard, but it would still steer.
I meant to put "power" in there Steering without it is not fun and almost dangerous IMO at lower speeds

[Neuspeed87lx]

my timing belt snapped..... not good things happened.... dont like it snap .... replace it now and save the trouble

[KoNEY]

well, what does "interference" mean?? and what is this talk of '90 on up accords being "non-interference"??

[Oyvind Ryeng]

Interfering= The piston will hit the valves if they are open when piston gets to TDC.
Non-interfering= The piston will not hit the open valves at TDC.

[Ludi Mali]

I thought all hondas were interference, as are a majority of cars, they're cheaper to produce. Thats the one thing i loved about my 87 camry, non-interference=no stress :)

[accordlxi2.0]

by sean
"for the last fucking time the a20a is not an interfernce engine. i dont know when where or how it got around that it was but the bullshit stops here. put a belt on it youll be fine "


sorry sean i had too,peep's are confused again.

[AccordAddict]

its an interference engine, im sure of it :kekeke: , j/k :lol: . im glad the owner before me put a new belt on :D .

[accordlxi2.0]

i have a confession to make i never replaced neither t- belt's, cause they looked new, i gotta check this one though . .

[Oyvind Ryeng]

Is the A20 NOT an interfering engine? Are you guys absolutely sure about this? This is news to me!

[accordlxi2.0]

nope, plus one person knew the clearance's and he said they would'nt touch.
plus, one guy at my job, an acura owner say's that also what contribute's to prevent the engine from hitting if the . . .
oh my head hurt's wait . . .
okay you know on the block then the piston, then the top of the block, well if the piston does'nt surpass that or does'nt reach to the top then that's a non- interference engine.
i've seen the diff between a interfernce and non-interference
a mitsubishi galant (poor engine)
and a a20a3 whoa!@

[Oyvind Ryeng]

okay you know on the block then the piston, then the top of the block, well if the piston does'nt surpass that or does'nt reach to the top then that's a non- interference engine.
Are you thinking about the deck height?

Anyway, if the cam does not lift the valves high enough to make them come into contact with the piston @ TDC, it's all fun 'n' games. That means one doesn't even have to change the t-belt or tensioner to prevent engine damage.

[accordlxi2.0]

umm yea, but i'm glad that's over with, you know this should be a sticky.

something like:

ALL NEW MEMBER'S ( OR ALL MEMBER'S) A20 SERIES ENGINE'S ARE NOT INTERFERENCE.

[njpeter]

consider the possibilities of a broken timing belt. it's not that hard fellas, maybe you'll need a trip to a friendly garage to bust the crank nut, but for cripes, anybody check the cost of towing recently? Not to mention the embarassment of causing a huge traffic jam.

I have timing belts and tires in the same class, change when questionable , and damm the expense

I busted a belt at 70mph, no head damage, and try to change belts at least once every 60-70k miles ( I've run some of em to 80-100k).

I believe the 89 engine for some reason can go 80k miles on a belt, pre 89's rated at 60k. Checking the fit of the belt on the top pulley reveals worn teeth, but typically oil contamination is a reason to change the belt, that crap seeps in everywhere in time.

My daily driver just turned 200k this week

[88Accord-DX]

I have got to bring this thread back! I see people looking at it & probably wondering WTF?

I'm pretty sure that the A20A1 & A20A3 is a "interface" engine. Meaning that the valves will contact the top of the piston if you break a timing belt. Or if you turn the crank with the belt off the cam.

[njpeter]

I have got to bring this thread back! I see people looking at it & probably wondering WTF?

I'm pretty sure that the A20A1 & A20A3 is a "interface" engine. Meaning that the valves will contact the top of the piston if you break a timing belt. Or if you turn the crank with the belt off the cam.

well sure or not, mine survived tossing some teeth at highway speed, so I guess I can color myself lucky. Had I ruined the head, I would have likely gone back to a big block v8 or something else.

Speaking of which, I've got a couple of complete accords and parts for sale, local pickup only. Hurt my back badly..and I'm pretty much out of the fix-it game for a while, so I'm selling off my fleet to any reasonable buyers ( except the daily driver 88-lx) Bergen country area.

[88Accord-DX]

I think I need to wait & see once I pull the head off & see if it has the recess in the pistons for the valve. A lot of pistons have the recess in the top of the piston to give the valve some clearance.

[Oldblueaccord]

I think I need to wait & see once I pull the head off & see if it has the recess in the pistons for the valve. A lot of pistons have the recess in the top of the piston to give the valve some clearance.

I was idling mine once without the damper on and the timing belt slipped off. I was looking for an oil leak near the front of the motor. No damage, BUT I wouldnt rule out it not happening.Best way is to clay up the motor and see what the distances are. Somebody here swore they milled a bunch off there block till the pistons where positive (above deck) and ran there motor that way. I dont think we have pop up(dome) pistons least from the pictures i have seen here so far.


wp

[carotman]

Our pistons do have the notches for the valves.

[Blkblurr]

by sean
"for the last fucking time the a20a is not an interfernce engine. i dont know when where or how it got around that it was but the bullshit stops here. put a belt on it youll be fine "


sorry sean i had too,peep's are confused again.

You are correct. It is a NON INTERFERENCE engine. I just called by buddy at the Anna engine plant here in Ohio and he confirmed it. Other things can cause damage that look like a broken belt issue. A valve can come loose and cause a piston crash. The load it puts on a worn or old belt can cause it to break. This type of failure would be diagnosed as a broken timing belt and since the valve hit the piston, it must be interference. I asked him to get me a list of engines Honda produces that are and aren't interference. He said he would try but no promises.

[Blkblurr]

I think I need to wait & see once I pull the head off & see if it has the recess in the pistons for the valve. A lot of pistons have the recess in the top of the piston to give the valve some clearance.

My A20A3 has recesses in the piston for the valves. I posted pics on this forum several months ago showing the tops of my pistons when I rebuilt my head and valve train.

[Blkblurr]

I found the pic but it didn't show up here. I'll try again.

[Blkblurr]

Hope this works
http://img224.imageshack.us/img224/1717/p5040950crop2wa.th.jpg (http://img224.imageshack.us/my.php?image=p5040950crop2wa.jpg)

[ICEMAN707]

i still doubt the a20 is a non interferance engine. the pistons are at deck height on TDC. what makes you think there will be room there for an open valve? why do you think timing alignment is important when changing the timing belt? other than bent valves and destroyed pistons, you can also damage the engine by way of detonation when the compressed cylinder gasses shoot back into the open intake valve instead of out the exhaust valve into the exhaust manifold, and blow your intake manifold, valve cover, and head, etc. in any case, a snapped timing belt=damaged engine. just cus you could start it by way of luck, doesn't mean the damage hasn't been done. don't tell me the engine still purrs like kitten after that happens. LOL.

higher compression pistons, VTEC lobe, and mild to wild cam profiles certainly affect the way the engine is....certainly won't be non-interferance anymore, that's for sure.

[Blkblurr]

i still doubt the a20 is a non interferance engine. the pistons are at deck height on TDC. what makes you think there will be room there for an open valve? why do you think timing alignment is important when changing the timing belt? other than bent valves and destroyed pistons, you can also damage the engine by way of detonation when the compressed cylinder gasses shoot back into the open intake valve instead of out the exhaust valve into the exhaust manifold, and blow your intake manifold, valve cover, and head, etc. in any case, a snapped timing belt=damaged engine. just cus you could start it by way of luck, doesn't mean the damage hasn't been done. don't tell me the engine still purrs like kitten after that happens. LOL.

higher compression pistons, VTEC lobe, and mild to wild cam profiles certainly affect the way the engine is....certainly won't be non-interferance anymore, that's for sure.

The next time you replace your timing belt. put your engine at TDC, take the belt off and rotate the cam gear 360 deg. You will not hit anything. I have done it. This engine is a NON- INTERFERENCE engine. Did you see my post above? I got this from the plant that built the engines. I live in Dayton, Oh which is 40 miles from the engine plant in Anna. The company I work for builds equipment for them. Did you see the pic I posted showing the recesses in the piston? Do you think Honda put those there for fun?

[ICEMAN707]

well, i did say "i doubt". which means im not sure. i still wouldn't want a belt break on me just to find out though, that's for sure.

[logic]

I can guarantee you guys the 86-89 accords are NON-Interference engines in stock form. All accords before 86 were interference engines so the timing belt MUST be replaced between 60k mi. and 80k mi. unless you want new heads. I don't have experience with 90 & later so I can't comment on those, however I would like to know before I get around to swapping my motor. There is no way I'm going back to an interfering motor!!!

The difference between Interfereing and NON-Interfering is simply wether the pistons will hit the valves if the valves are completely open when the piston reaches TDC. What causes an engine to Interfering or NON-Interfering is complex because it is derived from many different things. How close the pistons come to the top of the deck, whether the pistons have indentations in the top, how far the valves open, and how far they drop below the bottom of the head (if they do).

The reason I stated stock in my first statement is because modificatins can change that, if you change your cam to a cam that opens the valves farther than the stock one or if you mill your head & block more that a thousanth or two, use a thinner head gasket, change crank rods or pistons to increase stroke, or any combination of the above, you could make your non-interfering engine interfering...

[Blkblurr]

I can guarantee you guys the 86-89 accords are NON-Interference engines in stock form. All accords before 86 were interference engines so the timing belt MUST be replaced between 60k mi. and 80k mi. unless you want new heads. I don't have experience with 90 & later so I can't comment on those, however I would like to know before I get around to swapping my motor. There is no way I'm going back to an interfering motor!!!

The difference between Interfereing and NON-Interfering is simply wether the pistons will hit the valves if the valves are completely open when the piston reaches TDC. What causes an engine to Interfering or NON-Interfering is complex because it is derived from many different things. How close the pistons come to the top of the deck, whether the pistons have indentations in the top, how far the valves open, and how far they drop below the bottom of the head (if they do).

The reason I stated stock in my first statement is because modificatins can change that, if you change your cam to a cam that opens the valves farther than the stock one or if you mill your head & block more that a thousanth or two, use a thinner head gasket, change crank rods or pistons to increase stroke, or any combination of the above, you could make your non-interfering engine interfering...
Well put!

[system-f]

Hmm...so has anyone had any engine damage from breaking a timing belt? I still don't believe this is a non-interference engine. I am about to do a timing belt and oil pump and am going to see if I can get the piston to hit a valve...

http://texasnissantrucks.com/upload/system-f/honda_belt.jpg

[cardoc33]

I spent 14 years as a honda mechanic and have seen broken timing belts go both ways. Some people got lucky, others...well, "That will be $800.00 Ma'am."
My AutoData timing belt book says it's an Interference engine, so I wouldn't take chances. Do the belt and tensioner and seals.
If I remember correctly, Honda had an issue with timing belts in '85 or '86. Rated them for 90k, but they began to break around 60k. They issued a bulliten to re-rate them for 60k replacement. I think Honda ended up doing some free valve jobs over that one. ;)

[Blkblurr]

The old engines in the second gen were interference engines. The post above does not state what engines are identified as interference! Just sizes. If the A20A3 for 89 is an interference engine, then someone please tell me how I can rotate the valve train 360 degrees or more with the cylinder at TDC and not hit anything??????? Of course the timing belt is removed. :dunno:

[Blkblurr]

What happened to all you interference engine guys? Especially the ex Honda techs. What no answer to my question???

[NJC]

I can guarantee you guys the 86-89 accords are NON-Interference engines in stock form. All accords before 86 were interference engines so the timing belt MUST be replaced between 60k mi. and 80k mi. unless you want new heads. I don't have experience with 90 & later so I can't comment on those, however I would like to know before I get around to swapping my motor. There is no way I'm going back to an interfering motor!!!


I just had a t-belt break on an '84 Accord 12V 1.6L @ ~20mph. No damage.

[buds302]

well someone go outside and try it out!!!!!! cause this going back and forth is bullshit!!! just go out there take the belt off and crank the engine by hand!!! it it stops moving then it hits the piston!!!!simple as that!! common sense people! if you dont know try it out!!

[Soundy]

Kinda makes me miss my gold ol' GLC with its dual-width timing CHAIN. Now THAT'S heavy-duty!

[lamontlamont]

I tried to be a cheap skate and let my car go to about 90k miles with out changing the timing belt. The belt lost about six inches worth of belt teeth while cruising at 70mph. Right away i knew what the problem was. the only thing that upset me was that they towed my car and i had to pay 140 dollars for the tow. i installed a new belt and it runs fine. i would guess this is a NON interferrence engine just like the guy said. also, why would they cut the clearance marks into the piston if it is interferrence..... My tip is to just change the belt and dont be cheap. its easy to do it your self. you just need to get the crank pulley bolt off. i used a park bicycle bottom bracket lock ring tool to hold the pulley and a 18"breaker bar and a pipe to get extra leverage. Make sure u spray it down with liquid wrench first.

[cardoc33]

What happened to all you interference engine guys? Especially the ex Honda techs. What no answer to my question???

Just relating what my Autodata book says and my past expeirance. No need to flame.
Really, this is all just academic. Just change the belt if you think it's old and avoid the $140.00 tow bills and possibly more.

[w261w261]

gates.com has a list of timing belt applications. The catalog says the 86-89 accord is an interference engine.

[Oldblueaccord]

I tried to be a cheap skate and let my car go to about 90k miles with out changing the timing belt. The belt lost about six inches worth of belt teeth while cruising at 70mph. Right away i knew what the problem was. the only thing that upset me was that they towed my car and i had to pay 140 dollars for the tow. i installed a new belt and it runs fine. i would guess this is a NON interferrence engine just like the guy said. also, why would they cut the clearance marks into the piston if it is interferrence..... My tip is to just change the belt and dont be cheap. its easy to do it your self. you just need to get the crank pulley bolt off. i used a park bicycle bottom bracket lock ring tool to hold the pulley and a 18"breaker bar and a pipe to get extra leverage. Make sure u spray it down with liquid wrench first.

I went a 100k on my last one. I think back then the belts just didnt last as long but now there so popular there made better and thus last longer.

wp

[86-accord-lxi]

I have the original owners manual for my 86 lxi.
It says that the engine IS an interferance engine.

[88Accord-DX]

Here is what my Chiltons manual says about timing belts.

**Warning***
Severe engine damage will occur if the timing belt should break. Honda uses an "interface" engine design. If the timing belt breaks, the valves will contact the pistons & likely become damaged.

On models through 89, Honda does not specify a recommended inspection or replacement interval. However, since these engines utilize an "interface" design, it is highly recommended to at least inspect the timing belt at 60,000 mile intervals. It is even better idea to replace the timing belt at these intervals.
Replacing the timing belt before its recommended interval is a wise choice. It is far less expensive to replace the belt than to repair the engine damage which results from the belt breaking.

Straight out of Chilton

[blahblahblah]

wow...long one here...I think its an interferance motor..I just broke my belt...But I think I got lucky...How would I know without removing the head...I was just shifting into 2nd when it broke so it was at vary low rpms if it matters.....

[88Accord-DX]

Put a new timing belt back on blahblahblah, then do a compression test with a "compression gauge". That'll let you know if you have a bent valve without removing the head.

[blahblahblah]

Ok...But I was going to have a shop do the belt...I got the new water pump and tensioner on. Im a little lost on puttung the new belt on tho. All I have is the "how to" from here.....

[88Accord-DX]

You need to take that water pulley off, that is it.

First thing first, make sure you have the TDC on #1 cylinder compression stroke before removing the belt!! You can stick a long peice of (stiff) wire down the spark plug hole & rotate the crankshaft pulley bolt to find it. The piston should be at the top & the distributor rotor should point at #1 spark plug wire. I recommend you pull your cam out so not to bend a valve while finding TDC while turning the crank over. I say that cause your belt has broke & your cam & crank probably isn't lined up right.

Here is what my Chiltons says from the belt install starting point.
1. Double check the position of the engine. The timing pointer must be alighned with the white mark on the flywheel; the cam pulley must set so the small dot or the word UP is vertical & the marks on the edges of the pulley are alighned with the surface of the head.
2. Fit the belt to the engine & slide it onto the cam pulley.
3. Loosen the adjusting bolt slowly, allowing the adjuster to move against the belt. Tighten the adjuster bolt temporarily.
4. Install the lower timing belt cover.
5. Install the crankshaft pulley & key.
6. Adjust the timing tensioner. Loosen the adjusting bolt. Rotate the crankshsft counterclockwise until the camshaft pulley has moved 3 teeth. Tighten the adjusting bolt to 31 ft. lbs.
7. Install the water pump & pulley. Tighten the pulley bolts to 9 ft. lbs.
8. Install the drive belts, tension them properly & secure the alternator.
9. Install the upper timing belt cover & the valve cover.
10. Start the engine, allowing it to idle. Listen for belt rubbing or slapping the covers.

There you go, good luck with it.

[JpSaNaB]

Hi everyone, I broke my timming belt 4 days ago, installed a new one the next day and the car is running fine, no damage at all. The car is an 89 accord EX (without pop-up lights) with an A20A2 engine. So I guess its a non-interference. :bowrofl:

[visionguru]

Hi everyone, I broke my timming belt 4 days ago, installed a new one the next day and the car is running fine, no damage at all. The car is an 89 accord EX (without pop-up lights) with an A20A2 engine. So I guess its a non-interference. :bowrofl:
Sounds good.
How fast were you going when it snapped?
How old was the belt? (in mileage & time)
Have you checked out the broken belt? Was it worn or looks new?

[StressSolutions]

I meant to put "power" in there Steering without it is not fun and almost dangerous IMO at lower speeds

I used to drive city bus, once had to drive one all shift with PS not working! Quite a workout, made me appreciate that power steering, for sure.

[Mars]

what exactly will the car do when it snaps?
asumning your pistons dont plow into the drivetrain.

I was drving from tyler to dallas yesterday (100mi) and on the way to get on the highway, she just died at idle. i tried to crank her to no avail, so we pulled her over and got some starting fluid. a couple shots in the carb and she was running. i did notice that power steering had been off and on while driving it (i remember someone saying a tbelt could affect ps), but so i got it running, and im cruising down i20 at like, 70, and she starts stuttering and just dies on me. the tach is doing all kindsa wierd crap, sitting at 0 while the engine is revving (had her in nuetral) and jumping around randomly. i got her pulled over into a little road, where she wouldnt start period. just crank. if she did stutter and try to fire she would make kind of a whirring noise that ive never heard before. could this be a tbelt?

EDIT: It had been sitting at my fiances house for about 5 days, and it had rained. Maybe condensation got into something?

[JpSaNaB]

Sounds good.
How fast were you going when it snapped?
How old was the belt? (in mileage & time)
Have you checked out the broken belt? Was it worn or looks new?

I had just shifted down into 2nd, so, about 30mph, Im not sure how old the belt was, I think it was 4 years and maybe 35000 miles, and I didn't see it broken because I took the car to a friend's place since I was fearing the worst :violin:

[Bglad420]

boom bitch

[88Accord-DX]

what exactly will the car do when it snaps?
People get different results from breaking the timing belt. Some have valve damage, some don't. I think it depends if your r.p.m.s are around 5,000 compaired to 2,000 cause of a little valve float at higher R.P.M.s...


if she did stutter and try to fire she would make kind of a whirring noise that ive never heard before. could this be a tbelt?
There is two things to look for. Either take the dizzy cap off & look for the rotor spinning. You can take the top timing cover off & see if the belt broke.

[Blkblurr]

I know this is an old topic but I haven't heard any good answers to how I was able to rotate my valve trane over and over again with my #1 piston at TDC without hitting the piston. This is the test that proves if it's truely interference or not. I had .008 milled off the head when I rebuilt the head and of course it didn't hit. Regardless of what is published about this engine my 89 does not hit valve to piston with the timing belt removed. Now it's possible for the valves to hit if the head is mill too much or the cam lift has increased but with the stock engine I have in my 89 SE-i with .008 milled, it's not.

[lamontlamont]

my belt broke on me twice . once from a seized tension pulley one from worn out belt. my car ran fine and like th elast poster i had my piston at dead top center and rotated the cam gear and no touching. also a guy showed me this trick. you dont have to take off the distributor just take off the oil cap and look to see if the rocker arms are moving when y ou crank to tell if its a broken belt.

[Cant Stop]

and the debate rages on
as for cheaper to build no not true interferance motors tend to have more compression than non-intereference motors
my mom had a pinto and that was definitely a non-interferance motor,if our pistons have half moons in the top corresponding to the valve placement then it is a interference type motor ,closer the piston is to the top the more compression it usually has.

[2ndGenGuy]

I can guarantee you guys the 86-89 accords are NON-Interference engines in stock form. All accords before 86 were interference engines so the timing belt MUST be replaced between 60k mi. and 80k mi. unless you want new heads.

Hmm.. I don't know if you're correct about the pre-86 Accords. My 84 broke a belt clean off when I dropped to 3rd gear on the highway. The car just lost power all of a sudden, and I ran it through all the gears trying to figure out what had happened. Coasted for probably a half mile with the car in gear, pistons cranking in the block the whole time. I even spent about 5 minutes trying to turn the engine over.

I had it towed to a mechanic and he just replaced the belt, said I was lucky that it's a NON-interference engine. It was about 100k miles ago. Oh crap, I just realized it's time for a new belt! :)

[aerokid1987]

Wow great thread! Should definitely be a sticky! Moderator???

[accord upset]

in the gates timeing belt guide it says it is. but i have yet to see an a20 have the piston hit the valves. i work on cars all day its my job. ive also broke a timing belt on the freeway once no damage.

[DBMaster]

The Gates book also says my change interval is 60K miles when it is definitely 90K miles. So, even the Gates book can be wrong. The debate rages on.

[Blkblurr]

No debate as far as I am concerned. No amount of discussion can be a replacement for experience rebuilding the cylinder head and trying the procedure I mentioned earlier. :cheers:

[Soundy]

Yeah, I don't really see the point of debate... replace your timing belt at the specified intervals, and you simply will never (well, almost never) have to worry about whether your engine is an interference type or not. I mean, what are we talking about otherwise? "I want to run my car as long as I can until my timing belt breaks, so I need to know if it will damage my engine or not"??? D-uh!

As for the interval... if someone does follow the Gates book and change it at 60k instead of 90k, well, no harm done... if it were the other way around and the belt broke within that intervening 30k, I can see where there might be a small issue!

[lostforawhile]

have we ever settled this debate? I broke a belt at 70 miles an hour and 6500 rpms,no damage whatsoever. when I had the engine apart, I put a valve all the way down to the retainer with a piston at tdc, it had to have the retainer at valve guide level before it would hit the piston, the valve never gets that low unless the spring disinigrates or something. I wonder if there is a difference between the very early a20 which is the BS series,or the later a20. my book shows some different specs for them. I think the a20 has slightly higher compression or something,could that account for the difference.

[88Accord-DX]

I've talk to a Honda tech about these cars & timing belts. He said that all Honda vehicles with a timing belt are interference design engines. So, if you don't have damage done breaking the belt, than consider it a plus. No debate here.

[newaccorddriver]

I've talk to a Honda tech about these cars & timing belts. He said that all Honda vehicles with a timing belt are interference design engines. So, if you don't have damage done breaking the belt, than consider it a plus. No debate here.

im assembling an engine within the next couple days or so, since ill be putting on the head and everything anyways, ill check it out

[Blkblurr]

This is such an old debate and their is always someone on here that says " They talked to a Honda mechanic or tech and they said it was an interference engine. Anyone on here that has replaced a timing belt or done head work and rotated the engine over several times without the timing belt in place knows that it is a NON-interferece engine no matter how many Honda techs say otherwise. Maybe if you've had the head shaved it would become interference or made valve/ piston mods but we are talking stock here.

[MessyHonda]

This is such an old debate and their is always someone on here that says " They talked to a Honda mechanic or tech and they said it was an interference engine. Anyone on here that has replaced a timing belt or done head work and rotated the engine over several times without the timing belt in place knows that it is a NON-interferece engine no matter how many Honda techs say otherwise. Maybe if you've had the head shaved it would become interference or made valve/ piston mods but we are talking stock here.


yeah on my uncles 89 lx the timing belt went...then they just put a new belt and it lasted another 4 years. till he junked it

[88Accord-DX]

There is allways someone that has "turned the engine over without the timing belt on" ... Never fails. I guess that Gates, Alldata, Chiltons, Mitchell, Honda techs & everything published saying it's Interference design engine forgot to "turn the engine over without the timing belt. :bong:

Here is an example of INTERFERNCE below. I've seen about 8-10 (3 gen. accords) on ebay being sold from bending valves.


Hello all I might as well introduce myself, My name is Josh I own a 1988 Honda accord lX w/ carb, I have owned it for over a year and whoever I baught it from decided to bypass the Cooling fans and I over heated the thing :rant: so it still ran ok (or so I thought) and I was driving and downshifted into second at 55 MPH (not smart) anyways the car died I started it back up it died again and wouldnt start back up, long story short I took it to a shop and they told me I just broke my timing belt and it could be replaced by the next day (Smart me didnt know that when 3geezs break belts it also bends valves) so I said go ahead and do it, well got 3 minutes down the road from the shop and it happened again took it back, the belt broke again!, turns out I had a melted camshaft :wtf: so had the head rebuilt and about 3000 miles of drive it started smoking horibbly (Bottom end Fried! :gun: ) so I got a nissian maxima 93 nice car really was until started misfiring after only driving it 4000 miles, fuel injectors fried... Replaced them without replacing o rings, about 3 days later it burned up :rant: F***, but I still had the 3geez so now it is undergoing engine rebuild and much more.. will post pics next

[Blkblurr]

There is allways someone that has "turned the engine over without the timing belt on" ... Never fails. I guess that Gates, Alldata, Chiltons, Mitchell, Honda techs & everything published saying it's Interference design engine forgot to "turn the engine over without the timing belt. :bong:

Here is an example of INTERFERNCE below. I've seen about 8-10 (3 gen. accords) on ebay being sold from bending valves.
Try it yourself then. Stop trusting manuals we know to be wrong in that regard. Once you do, you will be on the other side of this ongoing and old debate.

[tuxdreamerx]

yeah when my timing belt went it bent the hell out of the valves dont take the chance....

[lostforawhile]

this has got to be proof there is a difference between the early bs series and the a20. I don't care what the book says,when I was replacing my valve stem seals, I was able to drop all three valves all the way down to the retainer groove at the top of the valve stem before it hit the piston. and the piston was at top dead center. the valve never moves that much in use,even if it was floating. as far as haynes and chiltons,they are not going to risk liability by sayings it's not an inference engine. I believe the other post about it breaking a valve and snapping the belt,if a valve should jam in there the first thing thats going to go is the belt,then the engine gets taken apart, someone sees the broken belt and bent valve,and assumes it all backwards,when it was the valve that caused the belt to snap. I'm just going by what i saw with my own two eyes. remember the books that are written for a bunch of different hondas have a lot of general info. and what about the guy who worked at the engine plant and said they aren't interference? I would think he knows.

[Blkblurr]

this has got to be proof there is a difference between the early bs series and the a20. I don't care what the book says,when I was replacing my valve stem seals, I was able to drop all three valves all the way down to the retainer groove at the top of the valve stem before it hit the piston. and the piston was at top dead center. the valve never moves that much in use,even if it was floating. as far as haynes and chiltons,they are not going to risk liability by sayings it's not an inference engine. I believe the other post about it breaking a valve and snapping the belt,if a valve should jam in there the first thing thats going to go is the belt,then the engine gets taken apart, someone sees the broken belt and bent valve,and assumes it all backwards,when it was the valve that caused the belt to snap. I'm just going by what i saw with my own two eyes. remember the books that are written for a bunch of different hondas have a lot of general info. and what about the guy who worked at the engine plant and said they aren't interference? I would think he knows.That guys is me. The company I work for builds machines for the engine plant in Anna, Ohio. My job is to manage these projects from specifications to a finished working system. We also build test rigs for the engines and heads with valve tranes installed.

[lostforawhile]

all right do you know the difference between the bs series and the a20 series? my book shows minor spec differences internally between the two engines. could this account for the debate here? I know some of these cars were built in the US and some in Japan, mine is a japanese car. were there maby two different engines at the beginning of the production run?

[Blkblurr]

The interference tag has been put on the engine because the valves extend into the piston area but the pistons have cresent dishes in them to stop the damage. None of the Accord engine are damaging interference engines from the factory as built. If you modify the engine by changing pistons or valves you can cause damage. This is why Honda calls them interference engines. Anyone that has had a valve bent has had this happen due to other causes. I milled my head by .008" and the valve still does not hit. It is not possible to end up with a good unbent valve during a timing belt break if the engine is a damaging interference engine. If you understand the physics of the valve trane and the lower piston/ crank trane you would know that at any normal operating speed, the valves will hit the piston if the timing belt breaks if the engine is a true damaging interference engine. There are four possibilites of valve damage per engine cycle and the engine cannot stop fast enough to stop it from getting through many cycles before it comes to a stop especially manual trannys. If the engines were damaging interference engines, you would have nearly 100% failure during a timing belt break. I have rebuilt the top end of my engine and performed the very test I mentioned before. I wish I had recorded it when I did this so I could post it. Maybe then this debate would end.

[lostforawhile]

thank you !! somebody please make this a sticky,thats the most common sense answer i've heard yet. I forgot any engine that has the valves go into the piston area is an interference engine,even if clearance has been milled for the valves.

[Civic Accord Honda]

ok i am not reading 3 padges of posts but i will tell you this
in are 1987 Accord Hatchback Dx we broke the timing belt in it 2 times and the car was fine did need a tow truck tho lol

[Estimated Prophet]

Well all is well that ends well - who wants ice cream?

[RamThis]

Those "little cutouts" or "crescent cutouts" are technically called Valve Reliefs.

If you can put a piston to TDC, and turn the camshaft, and the valve face does not contact the piston face, it's non interference, period.

As for whether the A20A is or is not, I have no idea. I will know eventually when I get back into my resto project and start rebuilding my A20A3 engine. This is something I'd like to know about the engine really. Would be nice to know if I need to be really concerned about belt replacement intervals or if it's not that major of a concern.



I hate to ask it, but does anyone know if the B18C1 engine is interference or not? I have that engine in my 96 Integra GSR and am soon to replace the timing belt. The belt might have been done at 75K, might not, we dont know what the dealership did at that service interval. But the car has 140K on it and I worry about it every day until I can get that damn thing changed, wondering if it has 65K on it or if it has 140K on it. BIG frickin difference LOL.

[88Accord-DX]

I had a couple days to think about why some people are bending valves even though these motors are labeled "interference". I can agree with it being non-interference with rebuilding mine & seeing the valve releifs. Generally, the releifs on tops of the piston are for compression, not so much for a valve releif.

To me, looking at the top of numerous pistons with high milage on them. I think that the valve releifs are being filled in with carbon deposites along with a good amount on the bottom of the valves, causing bending on valves.

[Blkblurr]

It's possible. Could also be mods to the engine such as a cam with more lift, a shaved head from having too much warpage, a broken valve spring or a seized valve due to no lubrication.

[lostforawhile]

what also could be causing a lot of this are retainers that have broken, if the valve gets bent a lot of times no one will be able to tell if the retainer broke or not. if it breaks the valve drops down into the cyl. always replace your retainers when rebuilding. also when you are done with the cyl head work,hit the top of each valve stem(lightly) to see if the retainer is seated,this can also help set it.

[DDRaptor]

sorry to revie an old thread mine broke while driving an i had no idea what had happened. i stepped out the car and i checked oil, trans fluid, msd coil, dis, plug wires, plugs and i tried starting it 2 times and i saw something moving from the spark plug holes, luckly after about $450 I got a new belt but i think my timing is off i'm still tring to figure out how i can check it

so i lucked out i thought my valves had bent would have been a nice way to get new valves, springs, and seals outta my dad. but shes so slow now i can't even beat a 4g stock which i used to do real easily. :(

[Blkblurr]

Sounds like your timing is off. Do you have a timing light? Maybe take it back to the shop that did the work and have them check it. take a copy of the manual with you that describes how to check it. Is it carbed or FI? Carbed timing is 24-26 degrees and FI is 15 degrees

[DDRaptor]

carb and how much does a timing light go for,

is it possible that the belt was loose and it just advanced itself until it finally broke???

even if was able to check the timing and all that is'nt that really hard to do, i know how to do ign cause easy to reach.

cause i'm not going back to that shop they used the wrong freaking spark plugs, and also broke the tip of my msd causing me to buy a new one.

[Blkblurr]

Once the new belt was put on the timing was set by how the new belt was installed. My timing light cost around $60 but that was a while ago.

[DDRaptor]

how much of a difference does does 1 tooth off make???

[Blkblurr]

Big diff. You need to be on the money with the belt.

[DDRaptor]

so if used to keep/pass 4th gen with ease they stock around 120 and i have a carb 98hp-19years of aging. i would mean that i had to be at least running 110-115 before the belt was changed and that guy had a stick i have an auto, so i defintly have to invest in checking my belt.

what are the tools needed to adjust tooth??
since you said the timing for carbs is within 24-26 what's the safest/most agressive timing that can be placed, and is listed somewhere on the car.

thanks alot sorry for the all the questions.

[Blkblurr]

Take the valve cover off to check timing. Put piston #1 at TDC. Check flywheel timing mark to make sure it's at TDC. I take the plugs out to make it easy to rotate the engine. You can get to the crank through the drivers side wheel well after taking off the tire and rotate the engine using a socket and extention and a ratchet or breaker bar. Rotate it CCW to get to TDC on piston 1. I use a piece of wire to make sure the piston is at the top of it's stroke. Now look at the cam gear and make sure the line in the gear is lined up with the top of the cylinder head. See manual. If it is you are on the correct tooth / belt position with respect to the crank and cam shaft.

[Blkblurr]

Double post

[DDRaptor]

ok does'nt sound to difficult but do you have picture of what tdc and the cam gear being aligned looks like, and also how do i know what tdc looks like at piston 1, which i'm assuming is the furthest away from the dizzy.

i'll probably just buy a few valve gaskets and open it and take pictures before touching anything.

[DDRaptor]

whats the difference between the timing lights, inductive, advance, digital

cause they have diferent prices at autozone, starting at 40, 70; 100

[88Accord-DX]

whats the difference between the timing lights, inductive, advance, digital
cause they have diferent prices at autozone, starting at 40, 70; 100
Some of the high end advance timing lights can check any type of electronic/vacuum/centrifugal advance mechanisms. Also, they can check the timing at higher RPMS. On the digital ones, they can have a tachometer reading, advance reading, & timing light.
A simple inductive timing light is about all you need for these cars.

[DDRaptor]

sweet i love my accord all the things necessary are very cheap and simple.
parts are cheap too. :)

[a20aaccord]

my t balt broke while engine was doing 900rpm no damage done:)

[blh1983]

About 2 years ago I had an '87 LX-i that snapped a timing belt, and the mechanic put a new one on and the car was ready for the road again! Car ran better than it did before the belt broke.

[DDRaptor]

I have been able to learn how to adjust my belt but everytime i set it to the correct tooth, i tighten the tensioner and then rotate the crankshaft it's always off between 17-23 teeth behind where i placed it and i don't know why. keep in my i have'nt removed and drivebelts or anything of the like.

edit. sorry for reviveing the old thread did'nt see a need to start a new one.

[Toneloc5145]

I have been able to learn how to adjust my belt but everytime i set it to the correct tooth, i tighten the tensioner and then rotate the crankshaft it's always off between 17-23 teeth behind where i placed it and i don't know why. keep in my i have'nt removed and drivebelts or anything of the like.

edit. sorry for reviveing the old thread did'nt see a need to start a new one.

Well here is what I did. I put the timing belt on the crankshaft, but left it off of the camshaft sprocket. I then turned the crank until i saw the "marking" through the flywheel window. That will be TDC for the crank. Once that lined up perfectly, I rotated the Camshaft sprocket so that it was at TDC (when the "UP" is completely 90 degrees). Then try to put the belt on the camshaft sprocket, and then tighten the belt. You may be on or two teeth off, but the car will still run. It will just drive differently.

[DDRaptor]

heresy the thing i already have the belt marked where i need it im just trying to get that marked 1 tooth in front of the up so she can run the way she used to be but every time i set it on the correct tooth when i turn the crank i roatation the mark is off by exactly 23 teeth and i cant advance it by 23 because the crank binds, so im like so confused.

[Toneloc5145]

heresy the thing i already have the belt marked where i need it im just trying to get that marked 1 tooth in front of the up so she can run the way she used to be but every time i set it on the correct tooth when i turn the crank i roatation the mark is off by exactly 23 teeth and i cant advance it by 23 because the crank binds, so im like so confused.

Its hard for me to understand what you just said, but I think I have the idea. I would say screw the mark where you need it and just start from scratch. If you start from scratch, you may be able to get the car to run even better then it did before. Just try it.

[DDRaptor]

no timing light. :(

[88Accord-DX]

The reason your off 17-23 teeth is cause your making just one revolution with the crankshaft. You need to make 2 revolutions with the crankshaft bolt if your checking to see if the marks line up back at TDC #1 compression stroke.

What you been looking at is TDC on the exhaust stroke.

[DDRaptor]

yes your right i took off the dizzy cap and saw the rotor backwardsandfigured my mistake, now i just don't have a spark.

[shawnmos]

The interference tag has been put on the engine because the valves extend into the piston area but the pistons have cresent dishes in them to stop the damage. None of the Accord engine are damaging interference engines from the factory as built. If you modify the engine by changing pistons or valves you can cause damage. This is why Honda calls them interference engines. Anyone that has had a valve bent has had this happen due to other causes. I milled my head by .008" and the valve still does not hit. It is not possible to end up with a good unbent valve during a timing belt break if the engine is a damaging interference engine. If you understand the physics of the valve trane and the lower piston/ crank trane you would know that at any normal operating speed, the valves will hit the piston if the timing belt breaks if the engine is a true damaging interference engine. There are four possibilites of valve damage per engine cycle and the engine cannot stop fast enough to stop it from getting through many cycles before it comes to a stop especially manual trannys. If the engines were damaging interference engines, you would have nearly 100% failure during a timing belt break. I have rebuilt the top end of my engine and performed the very test I mentioned before. I wish I had recorded it when I did this so I could post it. Maybe then this debate would end.

Thanks for this info!!! This should be stickied somewhere. It would be nice if the Haynes manuals could be updated with the correct information.