I had a post going a while back titled "bad rings with only 600 miles. I was describing in the posts about how I have a lot of blowby coming out of my breathers, which were installed due to my pcv system not being able to keep up with crankcase pressure. The responses I got didn't really answer my questions, but some said that visible blowby isn't anything to worry about and that I'm fine, others said that I should do a leakdown test which is obvious, and others said that I probably have ring problems, but I decided to test my car the easy way, running it down the ol'dragstrip. I'm not sure my car has major problems with relation to sealing compression (power). I'm guessing I'm losing between 15-20% of my incoming air past the rings. I will post the results of the teardown in a couple of months when I'm ready to rebuild, again. Anyway here's my results, promise not to laugh.....at least don't laugh hard anyways.

R/T .382
60' 1.942
330 5.530
1/8 8.557
mph 81.40
1000 11.176
1/4 13.384
mph 101.51

 

Wow no replies, I guess I didn't really ask any q's, all I really want are some opinions or advice. You can even tell me to go **** myself if you want, I'm just feeling bummed right now and hearing anyone speak up would be encouraging. So does anybody second the notion that it's my rings that are causing my lowww perf. #'s? Everything else has been modified or replaced. I just installed a new walbro pump a couple of weeks ago, my fuel pressure's fine, and I have brand new injectors, so I don't have a fuel problem. I also checked compression a while back and all my results hot and cold were 189 psi while cranking.

 

Your cranking pressure sounds fine... did you do a leak down test as well??? Otherwise I'd look elsewhere for any problems or a mismatch between parts.

You mention a custom chip in your sig... Just how "custom" is it?

 

My setup is matched perfectly except for the headers and my chip is dead on for this setup. The only thing I haven't tuned yet is WOT, but on MAF cars, if you get you part throttle dead on your WOT tuning usually isn't that far off. No I haven't performed a leakdown test, because 1. I can't seem to find a gauge to rent and I'm not going through the hassel of making one and I'm not going to pay 100+ on one and 2. There seems to be exponential amount of blowby coming from the breathers, which makes me suspect the rings. I guess what I want to hear is somebody say "your rings are the culprit", but nobody seems to have ever had problems with blowby out of the breathers.

 

when i bought my IROC I had stuff coming out of my pcv's and dipstick tube....thats some blowby

 

My experience w/ three MAF cars (one of which was mine) was the opposite...part-throttle tends to be very close due to the MAF itself measuring air quantity, assuming you set the injector constant to the actual flow rate of the injectors in use. WOT, on the other hand, was pig rich in all three cases...we had to pull out massive fueling from the PE versus RPM table just to get *up* to 13:1 air:fuel ratio.

For the crankcase pressurization issue...there is only one source of gaseous pressure in there: combustion gasses. They get there typically via rings not sealing, and the more pressure you have, the more the rings unseal...thereby causing even more pressure and more ring sealing problems. Go do a leakdown test and figure out what's happening.

 

There's only two ways to build that much pressure in the breathers, oil dipstick tube, etc and that is rings, or valve guide seals. Get a leak down test going. Usually, the compression tester will pop off of a 1/4" air line fitting (like most people run with their air compressor), then you just plug in an air source and run it about 80 psi or so.

If you take the valve covers off, you can spray soapy water around the valve seals as you test each cylinder. If you feel air or see bubble forming, you know it's the valve seals... If it's not the valve guide seals, the most air will be coming from the oil return holes in the head, which means rings are bad, stuck, broken, or just plan wrong for that size bore.

Good luck man.

 

Thanks for the suggestions guys. I just know when you're about 100hp off from where you should be no amount of tuning or tweaking or testing is going to magically make that power appear. So does anyone think I should pull the engine out and tear it down rather than wasting my time even doing a leakdown test? Think about my perf. here, I'm talking a stock L98 with minor mods could run my mph. This would also be a good time to port my heads and step up to a 236/236 custom comp cam, so maybe this is a blessing in disguise. The bad part is I'm going to have to eat machine work bills again and I'm going to have to put another $1000 in parts. Anybody ready to buy a 219 cam within a couple months?

 

Count me as one vote against it. I'd want to know which cylinder(s) was/were losing pressure and whether it was leaking downward (rings) or upward (valvestems). If it's the valves, that's just a head pull away from being fixed. If it's the rings, you'll know which cyls need attention before the teardown.

There's nothing more frustrating after pulling the engine, tearing it down, and everything looks wonderful...you'll have real trouble finding out what was wrong.

 

ditto

 

guys guys guys
some smoke from the breather with the pcv blocked off is normal!! the crank case pressure has to fo somewhere or you would blow all kind of seals on the engine that is what a breather does prevents excessive crank case pressure pcv positive crankcase vent if no smoke came from these it would find a way out elswhere

do not pull the motor it is unneccasary

the compression #'s are great there is NOT excessive blow by past the rings. if you are that unsure of how the car is running pay a reputable shop the hours worth of diag time you will probably see it to be worth your time and money

 

Hello, did you guys see my time and mph??? I'm missing about 150hp. I probably will go ahead and do a leakdown test to be sure like you said kevin. Then again to me taking the heads off is no harder than pulling the engine and then tearing it down, cause it least you have some room to work with while taking that bas$ard a$$ intake off. Also, there's no way that my valves should be the problem, these are brand new AFR heads assembled by AFR. There are no valve train problems that showed up after inspection underneath the v.covers, except my stamped steel rockers suck, but I'm getting RR's soon enough. I've talked to a hundred guys, about 20 of them at the track, they all said that white smoke puffing out of the breathers is a real bad sign for a brand new engine, regardless of anything else that needs to be considerded for suspecting the rings. I guess what I want is to hear from somebody on this site which is what seems to be common sense from everybody I've talked to in indy and that is "you're engine's screwed because there should be no smoke whatsoever". I just don't know why some people insist and say that "a little smoke coming out of the breathers isn't unusual" because it is on a new engine. Or else these guys with experience that I've talked to are full of horse dung.

 

Another thing, compression tests don't show a gawsh darn thing in terms of finding bad cylinders at least that's what I've found out after talking to Ski_dwn_it. All his cylinders showed up I think around 167psi both hot and cold tests. When he did a leakdown on his old 350 I think some holes showed up at around 50% leakage. What did the compression test show for him, not a freak'n thing. Mine all tested around 189psi during hot and cold tests.

 

I'd definitely do a leak down test.....beg or borrow the tools to do it.

I've seen problems like this when the wrong rings were put in the package, and I've also seen this happen when the hone job on the cylinders was screwed up by the machine shop......

In my experience, the newer rings are easier to seat, but again, those are the only two experiences I have with rings not seating / sealing correctly.


HTH

 

Do your leakdown test first. I think that you are correct in presuming the rings are the culprit, but you need to be sure. Sorry to hear about your troubles with your stroker. Did you assemble it yourself or did you have it done professionally?

 

I agree that a leakdown test sounds necessary, I dont know if this has been asked yet but is it both ways to where the white smoke is coming out of the exhaust also, I have heard stories of some moly rings not seating until up to 1000 miles.
Did you use any break in technique?

 

Whoa...his PCV is blocked off?? I guess I missed that...dude hook it up and be done w/ it. If you're worried about oil in the combustion chamber, fab up an exhaust scavenge setup. Either way, definitely give the crankcase a way to manage pressure.

 

You are exactly correct. EVERY top ring in my 350 was snapped in 1/2, yet the compression tests came back +/-2 psi.

NEVER, NEVER stop at a compression test if you suspect lower end problems. If there is an inconsistancy, then great, but if you find them all to be about the same, then move onto a leakdown for the real story.

I WISH someone would have given me that advise last year. It would have saved me a ton of checking other things. If you search the forums you can find how to build your own, or just take it to a reputatable shop and have them do it. Don't tell them you suspect problems, just tell them to give you the numbers.

Anything above 6% is not acceptabel on a performance engine. 1-2 is more like it!

 

There should be no smoke coming from anywhere under the hood, period, period, period. I've talked to guys with similar setups and they've ran breathers and they never saw any blowby coming out of their breathers and their cars ran like they should at the track. Some of you guys sound like my dad who just says hook up the pcv system and you'll be fine. BS, that's not going to give me 10mph in the 1/4! With the pcv funtioning I was blowing oil out of the valve covers, and out of the dipstick that's not how everone's tpi engine runs is it?!?

Me and my father built the bottom end, he's got quite a bit of experience, but he can be stubborn about some things, even though he does very good work. I'm really thinking if it isn't detonation that killed my engine it's the machine work that wasn't done properly. Remember from reading my old post that I'm filing a lawsuit against this crook at a local machine shop. I may have to drop it though, because it may not be worth all of the BS and $$. If anyone in Indy wants to know this shop, pm me. They've screwed me once for sure on the crank and know they might have sold me the wrong rings or bored the block improperly.

 

Well, one post said that your eng. might be pig rich. All that gas could be washing down the cyl. walls thus no seal ??

Auggie

 

Interesting thing is, above he said the chip is dead on for this combination. If it's "pig rich" as you say, then the chip is far from dead on...

How is the car running aside from the blow by? Does it have any problems idling? Bog when you punch it from certain RPMs?

 

No one ever said my car was running rich, it was just someone's experience with a different maf car that doesn't mean jackdiddly**** to what's going on with my car. I'm not a genius by any means, but I know how to read plugs and if anything I'm running a tad bit lean at WOT, but the plugs look pretty good and they are all burning the same. So yeah, their is nothing wrong with my chip. The engine's running like a beat old dog and it has to do with something in shortblock, nothing to do with the tune.

 

I hate to say it, but I think, based on my own experience and with what you describe, that your engine is fuct. Sounds like the short block needs to be very carefully measured and inspected. You said earlier that a machine shop had already screwed you on the crank, well, maybe they screwed you harder than that. I don't usually think so negatively, but that is just my thought. Sorry...

 

Do the leak down test and let's get past the guess-timating.

If it was me?
Knowing that the small block could be cheesed due to some sad machine-work?

I'd yank the SOB and drag it to a REPUTABLE shop to have it tore down.

But that's me.