ok I went to Honda to check some stuff out and this may be interesting to most:
1987 is the only year to have the A18a1
1985-1986 had the ET-2
checked the part numbers and they share the same valve springs
ok I went to Honda to check some stuff out and this may be interesting to most:
1987 is the only year to have the A18a1
1985-1986 had the ET-2
checked the part numbers and they share the same valve springs
When you say 'they' share the same springs, are you talking the A18A1 and ET2 only? ...are are they the same as some of the BT, BS, and A20 springs too? Also, exhaust, intake or both?Originally Posted by rustlude87
-Mark D.
So bs is the same as a a3 correct mark? cause thats what i got but i always say i have a a3 since thats what i was told
200+ ALL MOTOR LS VTEC
haha, so great you're asking me this today and not 2 days ago. I had either completely forgotten about the BS/BT variants, or somehow never knew it. But John helped me out with that just the other day.
The BS is from the '86 dx/lx 3G, and is the equivalent to the A20A1.
The BT is from the '86 lx-i 3G, and is the equivalent to the A20A3.
However, I do not know of any differences with the block itself, but more-so with the head. Even the head casting (PJ0 / HF-#) appears the same between the two as well. The differences lie in the cam, and top bracket for the rockers from what I can tell. The top bracket difference is specifically for the change in dizzy's from the carb'd to the injected models.
-Mark D.
i got bt my bad lol mark....BUt i noticed on the a1 head even thou its carb, gots ports like if it was made for FI...i was like what lol...But good to know.
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Yep, and it's those little bastard injector cavity 'bumps' that cause some turbulence with the air as it passes through the runners on my DCOE manifold and into the intake ports on the head. DAMN them for doing that. ...now I need to either dig out the runners on the manny to smooth out that transition, or just get the head welded up so I have an oval instead of a diseased oval for an intake port.
-Mark D.
Shouldnt be a prob for a shop that can weld and youll should be set
200+ ALL MOTOR LS VTEC
nope not hard to do thats what i did!
FYI
Smeado
^^ that right there is great info. Who made that chart?
I did, i used a bathroom scale, caliper, and an accordion jack. I'm guessing I probably have about a 5% error on the calculations. I noticed that the stock springs only have a seated pressure of 40 lbs which seems pretty weak. I was looking at the valve springs on the ferrara site and they all have a seat of about 70 Pounds or more. I don't know. but its a pretty interesting chart either way. Too bad i don't have my A18 head with me or i could check those valves too.
Smeado
nice, the bisi springs on that chart is both the outter + the inner correct?
yup.
kthx
all i wanted to kno. I guess i dont have to worry about valve float(again) then lol.
So what you guys are saying, and correct me if im wrong, is that in order to run full bisi valve springs without wearing out bearings super fast, you need to run the installed height pretty high to prevent valve bounce? Thats pretty upsetting news
well, with the stock installed height (based on Smeado's graph), the stock is somewhere around 40 lbs, while bisi is somewhere near 90 lbs. That's not terrible, but because they're a linear spring, their weight at 35-40mm height is significantly higher than stock. While that and the higher rate at installed height will help avoid bounce, you do still run that risk far more than with stockers.
I can't be certain (yet) but I believe the A18 exhaust inner/outer springs are wound in the opposite direction of the A20 exhaust, so using the A18 inners could work great with the Bisi outers. I'll take more pics soon and see if I can tap the brain of someone with an A18 head to verify this.
All that said, I personally would worry about the added stressed imposed by the Bisi springs, and worry about the journals/bearings excessively wearing, added friction on the cam lobes, stress on the valve stems and heads from the increased spring rates. ...and the list goes on.
To me, a great setup is looking like the Bisi outers with A18 (pending specs) or A20 inners. It's a slightly stiffer spring setup that should allow us to rev a bit higher before float, and should keep the stresses to a more tolerable level.
-Mark D.
I kno the stock a20 inners will fit with the bisi outers on the exhaust so yea.
btw, I am finally gonna be switching out the retainers. I finally got the time to do so.
If you want any pics of anything special lmk and ill try my best.
No they wind the same as the A20 and other honda ones. below is an ET2 head.
PS. this is the setup i used to measure the valve spring rates. A bit Getto but it worked fantastic.
looks like my head i have now...my BS
200+ ALL MOTOR LS VTEC
Damn thats a shame looks like you guys bummed out on the ET valve springs as well they are definately not the same ones as i have on my ET and A18 heads! bummer!
fyi everyone, i couldn't get my retainers changed out. I need a good valve spring compressor tool.
btw, i Called bisi yesterday and spoke with the tech department and informed them about the year split on the heads and their springs only working with the 86-87 retainers+seats.
good to know....so yeah i might have to pick up a valve compressor tool also
1989 Honda Accord LX-i
B18c1 swap since 7/2011
175whp and 132tq
Redzone tuned
I got a reply from Bisi the other day and I'll post it up. This was before Tdurr informed him of the difference in heads.
David,
We will address your concerns in the order posed:
1. We are working on a no-slip cam gear for the A-series, and should hit the marker late next month
2. Using the exhaust retainers on the intake are fine. The fitment was tested without failure on both the intake and exhaust, but we find the lighter stock exhaust retainers appealing.
3. If there is a need for custom chromoly (or the more expensive titanium) retainers we can do so with a minimum count of 20 sets. The chromoly retainer set of 12 can be manufactured for $160 a set, and the titanium for $240 a set.
Thank you for your interest in Bisimoto Engineering's technology.
Thats good to know...
200+ ALL MOTOR LS VTEC
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