On my 2001 ITR, my Compression tested 180 in cylinders 1,2, and 4 and 160 in #3 cylinder. It appears to be a leaking piston ring from seeing all the black spots on the bumper. I know some people pull the pistons with the block still in the car but i plan on just pulling everything out and do it the right way. My ideal plan is to purchase some JDM ITR pistons and run a 2 layer mugen head gasket. My question is that after resurfacing the head will i have to worry about clearance with my valves? or should i be okay..

 

160 is still with in specs. Low but within specs of others.
You need to stay within 20% so about 32psi(or 36psi, not sure if to use high or low number) varience
Since you are only 20psi off, you are within the limit for ethire calculation.
Just so you know you don't HAVE to rebuild. Although it will be a rewarding and fun learning experience.

 

well i'm just not satisfied with the performance... Even before i knew there was a compression issue i knew i was losing power.. and if there's something hindering my motors performance i feel like i want to get it fixed.... i still feel like i want to pull the motor out anyways, so would i have to worry about clearance, keeping in mind of everything i said above?

 

If your thinking about going with a thinner head gasket, then you might want to use a set of cam gears to correct the timing belt difference. I could be wrong.

 

fella at the rollers told me my car was down 20bhp, so compression had to be checked,it came out at 225 on each pot,when i went to restart the distributor was w*nked, now its a nightmare trying to get rebuild bits, its a 97 jdm itr & honda ireland r not the most helpfull when it comes to imports

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dc2quick &raquo;</TD></TR><TR><TD CLASS="quote">My question is that after resurfacing the head will i have to worry about clearance with my valves? or should i be okay..</TD></TR></TABLE>

You shouldn't have any clearance issues, but as Rob suggested, you'll probably want to purchase a set of adjustable cam sprockets to allow you to compensate for the resulting change in cam timing.

 

I just read your bumper is covered in black spots which concerned me because my rear bumper is COVERED in black spots.... are my piston rings messed?? maybei should get a compression test done??

Either way, when it comes to performance . I was at the dragstrip and i beat 02-03 RSX-S's with Hondata #4 reflashes/Exhaust/headers/intake/suspension , tires.. all the goodies by .2 tenths of a second.. so i guess my performance isn't hindered?

 

well i knew i was always running rich before my comp test but after my comp test when told my #3 cylinder was down to 160, the tech at honda told me that a good sign that my piston rings are leaking is from the black spots on my rear bumper... My car still runs strong and pulls hard but i know my car and i know when it's losing power.

 

I would have the valves adjusted, then do a compression and leak down test.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Rdriver &raquo;</TD></TR><TR><TD CLASS="quote">I would have the valves adjusted, then do a compression and leak down test.

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I was about to say, your oil rings might be bad, but that wont affect compression too much, more likely your valvestem seals, but a leakdown will help pinpoint the problem.

And Rob is correct. I'm milled 4 thousandths off my head and roughly the same off my block, stock thickness HG and I'm off 1/2 tooth at TDC with stock sprockets. You will need adjustable gears to correct the difference.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ITRIK &raquo;</TD></TR><TR><TD CLASS="quote">I just read your bumper is covered in black spots which concerned me because my rear bumper is COVERED in black spots.... are my piston rings messed?? maybei should get a compression test done??

Either way, when it comes to performance . I was at the dragstrip and i beat 02-03 RSX-S's with Hondata #4 reflashes/Exhaust/headers/intake/suspension , tires.. all the goodies by .2 tenths of a second.. so i guess my performance isn't hindered?</TD></TR></TABLE>

Yeah that's a fine way to measure your car's performance

Dude! put it on a dyno and get the #s along with all the avalible info. then see how she is running.

 

I would love to put the car on a dyno, but why pay all that money when i know it's running like crap, i'd rather spend the time tunning it on a dyno to its max potential. But i think it's time to rebuild anyways. I need something to do and i guess this would be the perfect opportunity

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dc2quick &raquo;</TD></TR><TR><TD CLASS="quote">I would love to put the car on a dyno, but why pay all that money when i know it's running like crap, I'd rather spend the time tuning it on a dyno to its max potential. But i think it's time to rebuild anyways. I need something to do and i guess this would be the perfect opportunity</TD></TR></TABLE>

Read this again:
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Bbasso &raquo;</TD></TR><TR><TD CLASS="quote"> put it on a dyno and get the #s along with all the available info. then see how she is running.</TD></TR></TABLE>

A good tuner will be able to show you EXACTLY what is up or down with your car on a Dyno.

 

Well right now i'm in the process of buying the pistons.... what i'm stuck with is deciding whether to get standard or oversized... Now a few fellas i know were trying to tell me to get .25mm over since i decided to go with the JDM ITR pistons. From what i understood from other people if i try to put std pistons back in on a motor with 50k, that's leaking from the pistons on a compression loss i'm going to have a gap if i try to put std sized pistons back in.... i don't want to go oversized if i really don't need to, but would it be suggested that i go oversized to make up the difference on cylinder wall loss? Is it a type of situation where you can say "it couldn't hurt to go oversized, and just bore it out to size"? or do most think that it should be fairly safe to put std pistons back in?