Batass

Just found out my top ring is gapped to .022, I know N/A is around .016-.018 and it seems like most guys are running around a .026 forced induction. I only plan on running around 9 psi max. Vortech S-trim.

Non-intercooled, no cold air-pulling right off the headers. Alky inj not installed either. I plan on running E85 after I get a few good runs to compare.

How safe will I be until I run the alky inj OR E85?

Apeiron

Considering how catastrophic butting together the ring ends can be, it's better to err on the side of caution.

Batass

You think I should keep the air as cool as possible then? A lot of stock vehicles say they will take around 6 psi and thats with stock specs, is 9 much more?

I was really hoping to start at the bottom to compare mph....I'm running cold plugs r42t...

Screw caution, im looking for optimism here!

Apeiron

As an optimist I think you should open the ring gap. ;-)

Batass

Dangit, the motor's in the car, I'm not tearing into it to change it until something blows up.

Ok that question aside, how much timing should I pull to help remove as much heat as reasonable?

whiteghost7

iTrader: (1)

Are you locking your timing or retarding based on boost?

I'd stay in the low 20s total timing with 93 oct gas and 9psi to be safe.

Batass

Timing is locked at 32, and I've been pulling another * per psi at 6 psi per BTM.

Well, I'm going to make just one pass, then swap over to ethanol. That should give me all the octane/cooling I will need for 9 psi.

anesthes

iTrader: (12)

.022 is fine. Some guys just love blowby.

-- Joe

Sonix

iTrader: (1)

I would be very nervous only running .022" on that motor. I gapped mine to .026" or so, just in case I ever decide to run nitrous. I'm using hyper pistons.

You didn't mention what pistons you're running? I would assume forged?
Why would you build the engine, put it in the car, THEN notice what your ring gap is, and start to worry????

If you're now trying to keep the combustion chamber overly cool, to avoid butting the rings together, then you're kinda shooting yourself in the foot. Heat =power (up to a magic point), but if you're limiting power to save yourself some work that you should have done before....

Here's my bible about ring gaps;
http://kb-silvolite.com/article.php?action=read&A_id=56

Apeiron

I don't really love it, but I'll put up with some to make sure the ring lands stay attached to the piston.

Batass

Well when I had the guy put together the shortblock, I told him I was going to run some around 8 lbs. He's not much of a forced induction guy but he knows N/A stuff really well. Then later when I mentioned the blower, he gave me kind of a funny look. Not sure what it was for but it worried me a little, so I let a little time pass and then popped the ring question. I really respect the guy and don't want any hard feelings. He looked back in his log and found it.

I'm running SRP forged. From what I've read before opening up the ring gap a couple thousands only drops compression by a small percentage of a point. I would absolutely be happier to have a .026 gap. But I REALLY dont want to tear this motor apart until the winter, when it gets hardblocked/dart block, prepped for nitrous and more boost, cam change, lalallalala.

I'm not sure how much value this holds, but I kind of modeled my engine off of two motors that Super Chevy did. Both were using vortechs, one was a HT383 (vortec) and a ZZ383 (fastburn). Straight off the crate they ran 8 psi on the HT and 11 on the ZZ. 93 octane on the first and 100 on the second. Didnt mention anything about opening up the ring gaps. ??

junkcltr

iTrader: (1)

I did the ignorance is bliss method with my first turbo engine that had new rings in it. I never measured them and just eye-balled them.....yup, those look "loose enough". I have been running 9PSI non-intercooled with 8.6:1 compression. It seems fine so far. No messed up plugs or head gaskets, etc. I wouldn't worry about the difference between .022" and .026". I would worry about how long you run the engine under 8PSI of boost. I wouldn't worry about 1/4 mile runs, but 10's of miles at 8PSI might start to make me wonder.

The area of a larger end gap is still small and contributes very little to blowby. Worn rings and out of round cyls cause noticable blowby.

anesthes

iTrader: (12)

I have had an explosion from exactly what your talking about, and honestly I do agree to a point but I've seen some pretty crazy suggestions on here with regards to ring gaps. On the motor in question, I was running like .015 or something tight like that, and 15psi boost. Motor lasted like 4 years like that until I got stupid and wanted to go faster. Ripped the top of the piston right off.

I think .022" is fine. thats damn close to what I run on my low-expansion SRP/JE pistons. I wouldn't run 30psi like that, but for most 'street' cars running less than 14psi with SRP pistons it's fine.

Also, SRP blower pistons have the rings located pretty far down in the hole and out of the fire. If the kid is running hyper pistons I might be a little more concerned.

-- Joe