do i have low compression pistons already??

[Reno]

hey guys, i was wondering if i have low compression pistons... well i have 2 friends with completely stock ka's and mine has a fidanza flywheel 2.5 exhaust electric fans and cheep cone intake . With their cars you can feel the torque all the time, but on mine you don't feel anything until you hit 4k and even at that rpm its a little bit.. When i purchased this car back in 06 the motor looked extremely clean and i noticed a new exhaust manifold gasket and a hole under my radio.. a hole for wiring of some sort , maybe some pods, gauges etc. right on my steering column there are 2 small holes where something was drilled (i think an afr meter) i even did a full tune up and to no avail.. is there any way to check without dropping the oil pan or removing the head? because its my dd..

basically my car feels like a non vtec honda... thx guys

[tramp_drift240]

[ilovesideways]

[tramp_drift240]

well, depending on the price of the car, and who you actually got it from...

i have an easier time believing that youve got really crappy rings or perhaps imperfections on the cylinder walls from some idiot driving like a dummy. all those drilled holes and stuff are from crappy AFR and other pointless gauges for the "cool street racer" look.

i doubt youve got low comp pistons.

[Crautz240]

basically my car feels like a non vtec honda... thx guys

[Chris28]

My car feels exactly the same way. With the clutch in the engine revs freely, hks hi power makes it sound awesome, but when I actually drive it takes soooo long for the car to get up to speed. I timed it at like 12 seconds for 0 to 60 haha, it really sucks. I did a compression test and found my cylinder 3 was horribly low, even after a tune up (new plugs, wires, cleaned maf, seafoam, engine restore when I put new oil in) it still sucked. Your best bet is a rebuild, which is why my engine is on a stand in my garage now. My engine looks really clean too, even under my valve cover everything is a nice gold, no gunk at all. It's something with your rings or cylinder walls. Order oversize pistons if you are going to rebuild.

[tramp_drift240]

^

said it already, or summed it up already.

and only order oversized pistons if you actually make the effort to get your block bored out.

you might just be able to get new rings and fix the problem, or perhaps just hone the cylinder walls.

three possibilities. my DE's bored .020 over. or, .5mm over.

[Reno]

i forgot to mention the my compression was tested and came back

150-154-151-150

o btw i paid 2500 2 years ago and it was a trade with cash for a built sr20det.(blown)

basically the guy who sold it to me was waiting for the title lol..

[Reno]

and my friends who have beaten me 1 of the cars compression is 91-92-90-121

[ilovesideways]

could be a fuel problem, check your fuel filter. Could be multitude of things however your compression is still in the okay range.

[Cone Junky]

Maybe it was a ka-t before, and the guy removed all the boost goodies before selling it to you.

Although your compression ratio seems perfectly fine, so maybe you have some fuel/spark management problem.

Have you checked your timing? Maybe it is retarded too far...

[Gabes13]

my first thought was head gasket, but your comp. numbers are pretty square. any smoke? if not, i would assume it would be definitely something with your rings... like tramp has already said

[janda240sx]

My car kinda does the same thing. My new engine only has 40K on it. You can feel the power all throughout the rpms but once it 4k it feels like it just takes off. My compresion #'s are 160 across all four.

[slyedog240sx]

My car kinda does the same thing. My new engine only has 40K on it. You can feel the power all throughout the rpms but once it 4k it feels like it just takes off. My compresion #'s are 160 across all four.

dang those are some low #'s.Did you open the throttlebody when you did the test?Should be in the 170's.My origional stock engine has 148,000 on it now ,and mine are still 170's across the board.

[ScrapMetal]

Yea, my 98 DE with 80K miles was averaging almost 180 across.

[ilovesideways]

My 90, stock (has been rebuilt) motor is 178, 181, 180, 181

[janda240sx]

dang those are some low #'s.Did you open the throttlebody when you did the test?Should be in the 170's.My origional stock engine has 148,000 on it now ,and mine are still 170's across the board.

actually I didn't open the throttle and i didn't unhook the injectors. I just removed the plugs. It gives a low number when you do it like that. IF I done the right way it would be about 180 across all.

[Reno]

Maybe it was a ka-t before, and the guy removed all the boost goodies before selling it to you.

Although your compression ratio seems perfectly fine, so maybe you have some fuel/spark management problem.

Have you checked your timing? Maybe it is retarded too far...

Maybe it was a ka-t before, and the guy removed all the boost goodies before selling it to you.

Although your compression ratio seems perfectly fine, so maybe you have some fuel/spark management problem.

Have you checked your timing? Maybe it is retarded too far...

yea my timing was @ 23 degrees originally now its @ 25... still feels slow... and i did a complete tuneup still... how do i check my spark??/fuel and i blow blue smoke... valve seals??

[Two-Fortee]

and my friends who have beaten me 1 of the cars compression is 91-92-90-121

ummm what? Theres no way thats right....not if its running properly....I think he did the test wrong...

[Reno]

a shop that does work for titan measured it, mine too

[jesse53]

mine was doin the same thing i tried everything, new plugs, cap and rotor, tps and nothin worked. i got a can of seafoam ran that through and timed it correctly and it runs great now.definitely try checking your timing mine was a little off and that made all the difference.

[White Comet]

i agree with tramp about teh rings. and while this isnt the culprit, you're always gonna lose a little low end with a freer flowing exhaust

[driftersdad]

do you know if all is equal? are your rearend gears the same? The other ways would be to cc the head for displacement or to find out how tight the motor is, do a leak down on the motor and figure the percentage of blowby your friend with compression of 90's I think is a false reading,gauge bad or something 60 to 70 psi drop is to much to allow motor to start and run unless supercharged(not turbocharged)

[Reno]

whoops, forgot about this thread, well my friends who had low compression on both motors... both of them blew LOL now im faster than both of them LOL.

but anyway, car is still slow. yup yup yup.

you think timing could be off a tooth? or 4

but maybe this would help. weather i feather the throttle or floor it it acclerates at the same rate, so it doesn't matter if i floor it, it does the same

dear god i hope its the timing

[OM3GA]