Did a compression test not to long ago, they came out 230psi across the board on a 93 vtec with 60k...That is higher than the Honda manual said the upper most tolerance could be..I have came to the conclusion I have some carbon build up..My question is does an increase in carbon build up actually make your car faster? I know its not wonderful for you motor...but if it increases the compression inside the cylinder than shouldn't it?

 

What does your manual list for the tolerances? In theory, if you have less combustion chamber volume you would gain more horsepower. But I doubt this is the case when it comes to carbon build up. Keep in mind having large deposits can attribute to poor flow patterns and even lead to hot spots. It all really depends how much carbon build up we are talking here and where it is accumulating at specifically.

 

Yea, thats REALLY high for an H22, certainly a 1993 one

 

whats a good why to remove carbon, if that is what causes the higher compression?

 

My buddys 93 H22A1 came out with just about the same numbers. I think its normal....nothin to worry about until the numbers are inconsistent.

 

actually it IS the case when it comes to carbon build up. It actually does make the car faster. It's been dyno proven. Now, it's not good in all cases, if it builds up on the valve seats it causes them to not seal/seat correctly. But since your compression is evenly distributed, and nice and high, you have nothing but to be happy with your faster motor

 

a buddy of mine had a turbo Toyota MR2 which posted really high compression numbers, somewhere around the 210-215 range and thats on a car that is supposed to have a 8.5 - 1 C/R. They estimated that his car was around the 10 -1 C/R because of the build up and the owner just decided to replace the pistons.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Kidd_Stylez &raquo;</TD></TR><TR><TD CLASS="quote">
a buddy of mine had a turbo Toyota MR2 which posted really high compression numbers, somewhere around the 210-215 range and thats on a car that is supposed to have a 8.5 - 1 C/R. They estimated that his car was around the 10 -1 C/R because of the build up and the owner just decided to replace the pistons.</TD></TR></TABLE>

I think thats a little extreme.....doubt its even possible to have that much buildup.

 

my h23a1 with 180000 miles ran 169 175 180 155 its a champ!

 

both of my previous jdm h22a's had compression numbers around 235,240 or so...but that was a jdm motor....

 

My H23 puts out 195 across the board. 114k

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CHK4TIX &raquo;</TD></TR><TR><TD CLASS="quote">whats a good why to remove carbon, if that is what causes the higher compression?</TD></TR></TABLE>

some octane boosters contain "carbon removing" agents. Or if you can find it, C-foam (or sea-foam, not sure on spelling) for fuel injected vehicles.

 

The manual says

Nominal 185 psi
Minimum 135 psi
Maximum Variation 28 psi

The test was done at 250 rpm at WOT

 

if you're still thinking it's bad.. don't. Don't worry about it. Just make sure you're putting in high octane fuel, and that your plugs are changed regularly, and you won't get an overcarbonized chamber. The part that REALLY matters, is the vairance between the cylinders. You don't want more than +- 5 per cylinder generally.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Prelude Styl &raquo;</TD></TR><TR><TD CLASS="quote">My H23 puts out 195 across the board. 114k</TD></TR></TABLE>


Hey, I'm 195 across the board with 107,000 miles on my h23a

 

Nah I'm not too worried..Im rebuilding this winter.. My plugs are changed more than routinely, and I always run 94 octane fuel. The whole reason i did the test was to run some nawwwzzz, but the damn NMU is screwed up right now..waiting for a call about that as I type.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 93preludevtec &raquo;</TD></TR><TR><TD CLASS="quote">

some octane boosters contain "carbon removing" agents. Or if you can find it, C-foam (or sea-foam, not sure on spelling) for fuel injected vehicles.</TD></TR></TABLE>

Your right it's sea foam and carquest has it
but i'm not sure if your supposed to put it in if your about
to rebuild your engine, kind of like engine restorer

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by symba &raquo;</TD></TR><TR><TD CLASS="quote">
Hey, I'm 195 across the board with 107,000 miles on my h23a</TD></TR></TABLE>

Seems like that's the right number for us H23 guys.

 

201k and 145 across, no nos
were talkin boss hoss lol j/k

 

You're serious right? 145 across. If so, I'd try another compressiont tester. I'd be willing to bet that those numbers jump up 40-50 psi each!~ The variance is the important part, and you don't have any apparently. Try another tester. I used a tester once that tested 50 psi low and got your numbers.