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mushroom_toy
07-20-2007, 04:30 AM
Well finally did a compression test, and I was wondering if yall think the compression on my engine would hold up good enough for low boost. Cyl. #1 is at 155 Cyl. #2 is at 168 Cyl. #3 is at 173 Cyl. #4 is at 175 on a 393,xxx mile engine. I was thinking I might go ahead and rebuild the head but I'm not sure yet.

2oodoor
07-20-2007, 04:45 AM
update your counter, you got 2K more miles now !
Sounds like you at least need to refresh the head, but turbo on that many miles may take out the rings if the head job doesnt. Just from what I have seen the A20 bottom end holds up much better than D series do when you refresh the head.
If I had it to do again I would have just put in new rings and rod bearings only when I had the head off mine last summer. It is holding up well but it is always in mind when I push it.
There is the color code and number stamp thing to be awarre of on the bearings, see the online manual.

shepherd79
07-20-2007, 08:53 AM
that is big varience in compression. you need at least 175psi or more for healthy motor if you are going to turbo.
I say rebuild is must in your case. while you have motor apart you may as well stick forged pistons and H beam rods to be more forgiving on street tunning.

mushroom_toy
07-20-2007, 08:58 AM
^Would do that if I was made of money lol. XD Probably just end up rebuilding the head later on down the road before the turbo.

MessyHonda
07-20-2007, 11:36 AM
if you want do it. i bet you can run like 4-6 psi....just remember it might blow some rings.

Legend_master
07-20-2007, 12:47 PM
that is big varience in compression. you need at least 175psi or more for healthy motor if you are going to turbo.
I say rebuild is must in your case. while you have motor apart you may as well stick forged pistons and H beam rods to be more forgiving on street tunning.


I agree, it doesnt sound like a very healthy motor. Sounds like you need to rebuild the bottom end.

AccordEpicenter
07-20-2007, 02:30 PM
It could be a headgasket leak from the sounds of it also. Does the car overheat at all or use coolant? Id say you should get at least 165psi or so to boost it so id find out what is going on with the motor before you boost it

88Accord-DX
07-20-2007, 05:12 PM
You have the maximum variation on compression readings. Here is the tool you need to use to see what work needs done. Need to have some compressed air to look at the readings & too see where air is leaking from. LEAK DOWN TESTER..

http://i2.ebayimg.com/03/i/000/a3/98/f9bd_1.JPG

RamThis
10-24-2007, 09:08 PM
I know nothing about Turbo's, but I do know your compression readings are showing that you have problems with the engine, whether it be bad valve seats, blown head gasket, or bad rings, or cracked head, there are two tools that can help you.

One is the aforementioned leak down tester. To use it youll have to put the engine on TDC on compression stroke, lock down the crank, thread in the leak down tester's hose to the spark plug hole, and pressurize the cylinder. It will show you the percentage of leakage from the cylinder, and by listening, you can tell where the leaking is coming from, whether you hear it coming through the exhaust valve, hear air coming from the dipstick tube, hear it gurgling out the radiator opening, or blowing out the carburetor, it can pinpoint the place that it's leaking from the most.

Another quick test is to use a Stant coolant system pressure tester. You can buy these online. I have one. You simply put this on your radiator filler neck like the cap goes on, pump up the pressure until the guage reads in the correct range, and let it set. the guage should not move at all. If it bleeds off pressure, start looking for leaks because there definitely is one somewhere. It helped me find leaks on my Acura and my Ram before.

mushroom_toy
10-25-2007, 12:24 PM
Lol you dug up a thread. XD Yeah im waiting till after rebuild to turbo so no need to test anymore, cause i have 397k on my engine. :) If it ever dies i will rebuild then turbo.

tuxdreamerx
10-27-2007, 04:15 PM
Well finally did a compression test, and I was wondering if yall think the compression on my engine would hold up good enough for low boost. Cyl. #1 is at 155 Cyl. #2 is at 168 Cyl. #3 is at 173 Cyl. #4 is at 175 on a 393,xxx mile engine. I was thinking I might go ahead and rebuild the head but I'm not sure yet.

before I did a full engine rebuild I rebuilt just the head and the head job took out my rings and a chunk of my piston so I wouldnt just to the head you should considor a full rebuild. if you have a strong top end and a weak bottom end the bottom end will take a shit mine did after 500 miles on the rebuilt head..