lenn

about 6k mi on a new motor with JRSC since day 1.

Finally got around to doing a compression test, about 6k miles on the motor:

Cylinders left to right
225, 215, 220, 220

Looked at cylinder 1's plug (#1 is the closest to distributor right?), although it had the best compression, the plug looked... well terrible... what is my engine trying to tell me?



and I found this weird gunk on the compression tester (the end that screws into the plug thread), i'm thinking nothing to worry about and its probably carbon or something, but how would it have transferred over to the tool?



btw, arias 10:1 (stock compression), supertec oversized valves, JRSC, although it shouldn't make any difference in my results.

CivicEJ1

B18C1CYA

the # 1 your refering to is #4 , the plug has some strange deposite on it , not shure what it is , got pics of the others ????

mattssi

My guess would be that the plug saw some lean conditions. What sort of management are you using?

Dunc

Ummm you say your supercharged right? And the porclein on the plug looks like it has pieces missing......could that be from detonation??? Either way, definitely a new set of plugs haha.

Syner-G-Racing LLC

its a deposite (not pieces missing from the porcelin) and if you had detonation you would see shinny metal like lines and so forth.
looking at the compression tester and the black deposite on the collar of the spark plug I would say that it looks like a sloppy oil change where oil spilled into the spark plug well or the spark plug well grommits are old and allowed a little oil to squeeze out into the spark plug well...then when you changed the spark plug the oil ran into the cyliner or you could have a little squeezing by the piston rings due the super charger. the wet stuff on the compression tester looks like a mix of either oil and carbon sludge or oil and coolant. I realy need to see the other plugs and the engine setup etc. but for now change the plugs and let it idle for 5 min, then take it for a mile of stop and go driving and then get on it from a stop and a 40 roll dropping in 2nd and then check the plug, you will get a better reading with out the deposites.

lenn

I am using the JR EMS (piece of crap) with the JR BTC and FMU. I also have an untuned AFC connected.

All of my other plugs were easy to read and looked fine, not deposits, slight browning of the ceramic so I didnt take any pictures of them.

It seems like chipped porcelain, but under the "chipping" is... well... more porcelain that looks normal. The car idles and runs really well, my plugs are gapped ~.35, although i hear I can even be at ~.32. I can confirm that i found small telltale signs of detonation on the other plugs (mainly cyl #1, now that I have the cylinders figured out).

Syner-G:
Detonation makes the ceramic part of the plugs have little aluminum specs, I've never seen lines before, but yea, i should probably be getting new plugs to see how they turn out. I think you're supposed to put on the new plugs, then romp on the car, take to redline and pull the key immediately, and pull the plugs to inspect without restarting the motor. You're supposed to do that because if the car is detonating under load, the combustion heat/pressure may erase details on the plugs.

B18C1CYA

yes you can run the car hard right to the rev limiter and shut it off , but shut it off while your at the limiter, and make shure right after you push the clutch in or you will burn the plugs clean again when you coast to a stop , what year is your car btw ???

evosol

i'm sure it won't hurt to gap your plugs to .028-.030". most turbo guys gap them to that... although i don't have any experience with SC i would think that all FI is real similar... i personally gap mine to .028".

lenn

well theres a really good chance i'll be hitting the dyno tomorrow (at DRT), hopefully I'll have time to grab a set of new plugs. I'm a 97 SH BTW. I'll probably gap at .32, other JRSC Ludes on PO.com seem to favor it.

I'll figure out how the plugs look after a pull on the dyno... thats assuming i make it tomorrow.