marky mark

I have heard a couple of reports that the 502 GM crate motor uses some oil, even when new.

Possible explanations were valve seals installed wrong at the factory and perhaps the rings were not seating properly. Other reasons mentioned intake gasket and also pcv as possible culprits.

Anyone heard about this ?

Regards. Mark

GDaina

yup, that's true..small leaks here and there, valve cover, pcv valve if you use stock covers, and the normal use.

bigvette1

That's sick - spend $5-7k on a new engine that has leaks or uses extra oil and you have to start fixing!

69ttop502

Mark, my GEN V 502 used a ton of oil. One day I was flipping through the Scoggin-Dickey catalogue and they mention the problem with the 502's as being too low a tension oil ring and they have a different ring package recommendation for the 502's.

GDaina

Thanks for the heads up...I may end up pulling the 533...

marky mark

Thanks for all the replies.

69ttop, did you get your problem resolved? Also, was the indication or wording from the Scoggin-Dickey catalog that they have since fixed the problem and the new ring in the catalog was for older motors? I can ask them Monday for the answer but since they are selling those motors, not sure how "complete" the answer will be, ha, ha.

Wow, let's see. 502's may use oil. 454's may not have the mechanical fuel pump machined properly to fit the rod in there (Orvette).

Perhaps re-building my old 427 a second time (as opposed to a new crate motor) is not that bad an idea!!!

Man, when you have to pay the big $ to do something like this again it makes you nervous. I was only thinking crate motor as I sure as heck can't do this a third time!!!!!

I guess there are now real certainties. You pays your money and takes yer chances!

I'm off to work now to help pay for more parts/work on the "vette. At least I don't own a boat too!!! Man, how expensive this hobby can be!!


Regards, Mark :flag :chevy

69ttop502

Mark, when I get home today I will copy the words from the catalogue but as I remember they are still selling the crate motors as is. I am rebuilding and beefing up my motor now but when I pulled it there were only 7500 or so miles on it and it used a quart every 250 to 300 miles. When I tore it down everything looked perfect inside. I believe the ring set they mention is to retrofit into older motors though. I will post it later for you. Bill.

RJR99SS

i know there was a gm bullitin about new gm big blocks using oil, the problem was related to the pcv.

That dosnt pertain to the new 502s in gm vehicles because they dont have pcvs.

WA 2 FST

Mark,

I know Orvette had issues with his fuel pump rod, but mine in my Gen VI 454 HO gave me no issues. And it burns no measureable amount of oil.

It's disappointing to hear of the potential problem with the late-model 502 burning oil (assuming its a ring-packaging issue).

That's the reason I waited a year to buy a new Z06. The '01 Z06s burn a LOT of oil straight from the factory, and GM has acknowledged a oil ring problem. :(

Rebuilding your 427 is not a bad idea, either. I'm sure you can find a reputable local shop who can do the bottom end with no problems. Get yourself a good set of heads and you're good to go! :D

69ttop502

Mark, here it is from page 12 in the 2002 Scoggin-Dickey catalogue.
502 Necessities
Things you should know about 502's
All 502's built since the inception during the mid-80's have used a unique ring combination of 2.0mm/1.5mm/4.0mm. The factory installed 4.0mm oil ring is a low tension oil ring. It is used to reduce frictional horsepower losses. Oil consumption is a natural characteristic of this type oil ring. When it is time for a freshen up on your 502, we recommend and sell the Speed-Pro high performance file-fit ring set which includes a standard tension oil ring for improved ring sealing and oil control. The part # for the ring package is
r-10575-005.

Tominator

Don't remember where I read that info to, seemed like it was on a web page with GM notices.

marky mark

Wow, that's incredible info!!!

Hard to believe they would put that ring in there to be able to claim a higher hp rating, if that was the intention.

Thanks for all the input on this subject. It's things like this that make this the best Forum.

I still think the 454 might be the best crate choice for me anyway. I'll be using the Hooker 1 & 7/8" headers into 2 & 1/2" duals with X-pipe and Dynomax Super-Turbos. I know everyone says 2 & 1/4" headers but I'm not going there (everything mentioned is virtually in perfect shape). Also, Chevy Hi Perf Mag's article on The Frankenrat" specifically conducted their dyno runs with the 1& 7/8" headers (Hedman) and a 2 & 1/2" pipe into a street type muffler. So, I will sacrifice less power I think with the 454 than with that exhaust on a 502.

I still need to think over everything on the re-build. If I stay pretty much stock it's much cheaper than a crate motor. But if I start adding in better heads, roller cam, forged internals it gets up there pretty quick. Then I think the crate makes more sense.

Thanks again fo rall the great info on this subject. I owe you all a beer or two!!!

Regards, Mark :flag :chevy