so my local shop just did a compression test on my car. i was planning on turboing it very soon and wanted to make sure of a health engine before i did anything.
well it sucks balls.

my compression

cyl 1 220
cyl 2 230
cyl 3 210
cyl 4 180


what do you guys think about it.
i know cyl 4 is reading kinda low but the odd thing is the car runs very smooth and i dont even notice a diff when i campared it to a friends s2000 in driving feel and accel power.

my car is a 02 with 125k miles. from what ppl are telling me i should try a topend cleaner to see if maybe one of the valves on cyl 4 has some buildup around the vavles and not closing properly

just wanted to see what you guys think and get any advice. i might just build my engine but not really looking for crazy hp even when i turbo im only looking for maybe 400whp at most off of a gt30r

 

400whp means youre basically doubling the power from stock.

 

u can try something like seafoam, but dont get your hopes up. might be time for a rebuild. you would need to do a leakdown test to see where the problem is.

 

i wouldnt worry too much. if your car feels great then dont worry about the numbers. however if your turboing it may lead to problems. you could try a top end cleaner and an oil flush and retest but it just sounds like normal wear on a high mileage engine.

 

yeah a top end cleaner is what im planning next to see how it goes and redo a compression and leak down test.

if its the rings i might just build it. im just trying no to do any over kill when i do it.

if it is the rings im still debating on what i should do. if the pistons and rods look good should i just replace the rings and do a 3mm hg or should i go for some lower commpression pistons while i have the engine cracked open. im leaning trards the low comp pistons as they will not cost much more then a 3mm hg and they will be out anyways when new rings get put in.

its not that i want to go cheap or anything. money isnt that important as this is my toy and dd during the summer when it nice out. i have a wrx for winter and people carrying. but i just dont want to overkill to much on anything as the engine will see 10-12 psi most of the time and maybe a bit more on high boost if and when i take it to the track.
if i went with a 3mmhg i might just get new stock rods and pistons as they are pretty cheap. or i would go with low comp pistons and maybe new aftermarket rods with w reg hg.
if i went with low comp pistons i would need to resleeve as well correct?? well even if i didnt need to i might as well lol. but im just feeling that is over kill. because from what i have read on here a 3mm hg can be taken to 400 hp without much problem and some have gone much higher then that to the 500 hp range.


hmmm maybe i should have started this in the fi section.

 

Drop some oil in cyl 4. Then,take the compression. If the compression goes higher than 180, for sure the ring is bad.

400hp? that's a lot of zhyte. Turboeng a hi-compression engine without
lowering the compression is asking for trouble.

The rest of your compression is fine but not great in a turbo spec.
The s2000 engine is not meant for turbo. I think you should hone the cylinders, install a new rings then use a thicker head gasket. Although this is a half ass job, but far better than what you did (installing a turbo without lowering it).

 

what is a topend cleaner?

 

i'd say sleeve the motor and get some low comp pistons

 

Please stop posting false information. Please.

 

I will be glad and will apologize if you tell me which false statement.

...explain

No single word like your post.