okay so I bought this 92 gs hatch that is pretty clean, but has 328k miles on it, yes that is a lot of miles.

the previous owner told me that the owner before him swapped the engine with a lower miles b18a1 (OBD-1) and tranny. looking inside the valve cover it looks nice... not burnt not old.

I have been working on simple maintainance stuff like fluids, leaks, etc...

last night I went to change spark plugs and check compression and this is what resulted:

cyl1 cyl2 cyl3 cyl4
150 130 90 150

and the spark plug hole in cyl3 is now stripped because the last person to change plugs must have torqued those things down close to 50ft-lbs and no anti-seize and I couldn't get the tester to screw in very much so it leaked gas and crap out the hole when I tested that one.

the helms manual says that optimal compression should be 185 psi with no less than 28 psi difference between cylinders.

any suggestions that come to mind?

after last night I decided I want to consider an ls-vtec conversion. I have never seen them as a bulletproof way to do things, especially when it comes to high revving on a block that originally redlines at 6800 heh.... any words of advise there?

thanks!

ps: do jdm b18a1 engines' serial numbers start with a 30xxxxxx?

 

Try and do a leak down test to see where your compression is being lost. As for ls/vtec just make sure u do it right and you can probally rev decently high and make good power *edit*-theres plenty of good write ups on lsv on HT. As for your question about the A1 i cant help ya other then that the engine code stamp should be B18A1. Good luck

 

Did you do it at WOT?

And, you said gas was leaking because it couldn't seal? You need to disable the fuel injection before doing a compression test. And if it can't seal then obviously it will be low compression.

 

Minus cylinder 3, your results look decent (for a 90 model w/ 320k on the chassis and unknown on the motor....i mean, its not like its a new $20k car w/ 15k on it), so try to fix the spark plug seal (ie new head) and rock it out. LS/vtecs can be very reliable if done properly.

 

as far as lsvtec goes I would do my best to do it right, and there are tons of conversion kits available, but as far as "doing it right" would that include any bottom end stuff? if I were to do it I would try to stick to a budget so that the cost would be less than going for a gsr swap or something...

and yes I was doing the compression test at wot.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by aaronhume &raquo;</TD></TR><TR><TD CLASS="quote">as far as lsvtec goes I would do my best to do it right, and there are tons of conversion kits available, but as far as "doing it right" would that include any bottom end stuff? if I were to do it I would try to stick to a budget so that the cost would be less than going for a gsr swap or something...

and yes I was doing the compression test at wot.
</TD></TR></TABLE>

Bottom end stuff depends on how high you want to rev it. Stock LS rev limiter of 7k (6800+200 before fuel cut), you'll be fine just rebuilding the bottom end w/ stock/oem parts to make sure its in top notch shape. Past 7k and you should upgrade to ARP rod bolts (or aftermarket rods) and get a main girdle. I would also suggest getting some pistons to raise compression up a bit as well....assuming its not going to be FI'd.

 

hmm... sounds like that would be the way to go.. too bad I'd have to pull the engine heh... I was hoping lsvtec could be done without needing the engine out

 

You can do it without taking the engine out although its much easier to work on with it out. Just sucks having oil dripping in you face when under it.

 

ya I can see how that could work.. so what if I left the pistons alone and just did the rod bolts underneath? I am pretty sure this is a low miles engine... its very very clean in side... I did some compression claculator stuff to determine that my CR would be either 9.55 or 9.73 to 1 depending on if its a B16 head or GSR head... otherwise if I used PR3 pistons the cr would jump to 11.59 with the gsr head or 11.32 with b16 head... is it really worth all the extra time and expense?


edit: fixed cr ratio


Modified by aaronhume at 2:34 PM 1/11/2007

 

I'm pretty sure with your compression results, a good hone and new rings would be very beneficial. You can still do that with just taking the head off though. Also, your compression w/ PR3 pistons is off (11.59 w/ GSR head and 10.16 w/ B16 head doesnt add up).

 

hmm... well I have never actually rebuilt an engine but would be up for the challenge given the time and tools... can it be done with just those cylinder honing tools? and how do you know when you've done enough? and if you just do a light honing do you have to get the oversised pistons?

ps. the calculator I used for figuring compression is:
http://www.c-speedracing.com/h...c.php

edit: my bad its 11.32 for that last post... not 10.16 I copied taht from something else.

 

You'll need the dingle-berry hone and if you do it correctly (and have a decent block to start with) you can still rock out with the 81.00mm pistons. I think the correct term for the hone Im talking about is a flex hone.

http://cgi.ebay.com/ebaymotors...ZWDVW

 

alright....

as far as changing pistons go, ever heard of NCR pistons? they have tons of OEM type honda pistons on ebay .... PR3 pistons and rings for $150 opposed to honda pr3's for $170 plus another 130 for rings....

I know sometimes you get what you pay for... but I do not try to waste money when I can get a comparable part for less...

after finding the complete ls/vtec page on here and a price guide for it I came up with something around $3000 to do the conversion minus machine shop work.

also, it looks like tuning would be a pain and expensive... what are recommendations that would cost less than $400? (400 = wideband o2, and ostrich emulator, ecu chipping+datalogging) is there an ecu that works good enough to not need much tuning?

thanks!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by aaronhume &raquo;</TD></TR><TR><TD CLASS="quote">alright....

as far as changing pistons go, ever heard of NCR pistons? they have tons of OEM type honda pistons on ebay .... PR3 pistons and rings for $150 opposed to honda pr3's for $170 plus another 130 for rings....

I know sometimes you get what you pay for... but I do not try to waste money when I can get a comparable part for less...

after finding the complete ls/vtec page on here and a price guide for it I came up with something around $3000 to do the conversion minus machine shop work.

also, it looks like tuning would be a pain and expensive... what are recommendations that would cost less than $400? (400 = wideband o2, and ostrich emulator, ecu chipping+datalogging) is there an ecu that works good enough to not need much tuning?

thanks!</TD></TR></TABLE>

For pistons, PM RSMACHINES
http://www.rsmachines.net/company.html
He sells OEM Cast pistons for nearly the same prices you found on ebay, and hes a trusted sponsor on here; I bought my supertech valvetrain from him and he helped me out a lot. As far as tuning, The best cost effective method would be to use http://www.phearble.net or equiv. site and get them to make a basemap to your setup, then take it to a local tuner just to get the AFRs tweaked.

 

nice sites... btw its http://www.phearable.net and I didn't see any pricing on rsmachines.net to check through... is there a honda-tech user name I should be looking up for more information? thanks!

so it seems I may not end up doing an ls/vtec conversion but instead maybe lightly building this motor, by getting a head off ebay and maybe a block in the area and rebuilding, but using good enough stuff so an ls/vtec changeover could be done quite easily... maybe.

 

well, I finally got around to a leak down test, and heres my report:

on the three cylinders I checked (not the stripped one) I applied a max of 100psi to each chamber at the cyl TDC and I heard the same noise on all of them- through the oil passages through the head meaning its leaking around the piston rings.

my question, how much is too much noise to be heard? it would slowly leak until the pressure is zero. is it supposed to hold pressure constant? or is it assumed it will leak a little?

 

Yes, its going to leak, thats a given...do a search on yahoo for leak down tester or something like that and you'll see the tool you need to get the % of leakdown.