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56-210Sedan
05-10-2013, 03:48 PM
http://spokane.craigslist.org/pts/3772160183.html

Well i screwed this one up posting it in this forum :eek: Sorry
(http://spokane.craigslist.org/pts/3772160183.html)

Maddog
05-10-2013, 04:23 PM
why?..................

chevynut
05-10-2013, 05:47 PM
What do you mean you "screwed it up"? I wonder why he pulled it.

Rick_L
05-10-2013, 06:35 PM
What do those suckers go for at a dealer now? $8200 seems rather high for even a new one, unless I'm behind the times.

Maddog
05-10-2013, 06:38 PM
$10,400 with computer. I'd pay for new with warranty. But then he may come down some.

Rick_L
05-10-2013, 07:02 PM
Usually a good used one would go for 60-70% of new. But with only 1000 miles, maybe a bit more, if the circumstances of pulling it at 1000 miles were "explainable".

If an EFI BBC was in my sights, I'd be looking at alternatives. Like building my own, or buying a carb'd one and doing a different EFI conversion.

Maddog
05-10-2013, 08:36 PM
Usually a good used one would go for 60-70% of new. But with only 1000 miles, maybe a bit more, if the circumstances of pulling it at 1000 miles were "explainable".

If an EFI BBC was in my sights, I'd be looking at alternatives. Like building my own, or buying a carb'd one and doing a different EFI conversion.

I'd start my own website, bullshit about having 28000 members and collect all the easy money from bone head advertisers then buy a 572!

chevynut
05-10-2013, 10:19 PM
What do those suckers go for at a dealer now?


$11,289.97 at Summit



$8200 seems rather high for even a new one, unless I'm behind the times.

How much do you think you could build a BBC with forged internals, roller cam, and aluminum heads for? Add $3000 for just about any EFI setup. I thought about building my own engine but decided it didn't make sense. I bought the ZZ502 longblock (same as RJ502) with an aluminum intake and distributor new for $4400, and pieced together my Ramjet EFI with better parts for around $2000.

chevynut
05-10-2013, 10:22 PM
I'd pay for new with warranty.

IMO a warranty on these engines doesn't mean much unless your car is finished when you buy the engine. I'll bet most guys go through their warranty period of 2 years before their car ever hits the road.

55mike
05-11-2013, 08:47 AM
I understand the early ZZ502's had an issue with ring sealing and excessive oil use. As a matter of fact, I have a close friend who put a ZZ502, FI in his high-end 55 and he is pulling it out and going through the short block due to the fact it uses so much oil. Interestingly, no leaks, and no smoke... but.. it uses waaay too much oil

Rick_L
05-11-2013, 08:55 AM
cnut, your engine proves my point - although you probably couldn't duplicate that today as prices have increased.

A "build" doesn't have to be piece by piece from the bottom up in the sense I was thinking of.

Another way to go might be to spend the $11000-12000 and use better components, especially some Brodix or Dart heads.

chevynut
05-11-2013, 10:49 AM
I understand the early ZZ502's had an issue with ring sealing and excessive oil use. As a matter of fact, I have a close friend who put a ZZ502, FI in his high-end 55 and he is pulling it out and going through the short block due to the fact it uses so much oil. Interestingly, no leaks, and no smoke... but.. it uses waaay too much oil

Yes, the early engines were "marine" engines that had "low tension" oil rings in them. They did burn oil. I am not sure what mine has in it, but since it's been sitting so long I have decided to go through it, clean it up, and check everything out. I may bump the cam up a bit, maybe add roller rockers, and will probably change the rings out. So much for a "crate engine" eh? :)

55mike
05-11-2013, 02:25 PM
Yes, the early engines were "marine" engines that had "low tension" oil rings in them. They did burn oil. I am not sure what mine has in it, but since it's been sitting so long I have decided to go through it, clean it up, and check everything out. I may bump the cam up a bit, maybe add roller rockers, and will probably change the rings out. So much for a "crate engine" eh? :)

I'm amazed Chevrolet would put something like that out in this day and age... folks buy crate engines to keep from having to deal with the internals with a certain trust factor (especially from the dealer)

Rick_L
05-11-2013, 03:42 PM
I fail to see the reasoning that a marine engine needs a different oil ring than an automotive engines. They just blew it and they were pretty lazy about fixing it, as it was a well known problem for a while before they changed it.

GM has had other oil consumption problems on OEM engines. Crate engines are just part of the bigger picture. And at the bottom of the list on getting some attention to fixing problems.

Maddog
05-11-2013, 04:09 PM
Crate engines are good for those that can't do any assembly or leg work themselves for those that can one can build a better engine for less. Also good for those that live in rural areas without a competent machinist/engine builder avail. Many of those folks have to "order" something and have it shipped to them. Ordering from a reputable GM dealer is probably safer then some of these fly by night so called engine building companies.

56-210Sedan
05-11-2013, 07:12 PM
Sorry for not posting sooner, but i was just now able to get back on at the site, i kept getting a message that the server was down? anyway when i mentioned i screwed up posting i meant i should of put it under craigslist,ebay,auctions, etc...

chevynut
05-11-2013, 08:39 PM
I'm amazed Chevrolet would put something like that out in this day and age...

Well, I don't think it's a problem anymore. As you said, it was the early ones. I have read a lot of posts on other forums about people not having oil consumption issues with the newer engines. I actually looked at building my own 540, but by the time you get the machine work done, buy the good parts, and finish it off, the crate engine is a pretty good deal. I think there are some better engines on the market than the GMPP crate engine nowadays. Seems everyone's into it.

55mike
05-12-2013, 07:50 AM
Well, I don't think it's a problem anymore. As you said, it was the early ones. I have read a lot of posts on other forums about people not having oil consumption issues with the newer engines. I actually looked at building my own 540, but by the time you get the machine work done, buy the good parts, and finish it off, the crate engine is a pretty good deal. I think there are some better engines on the market than the GMPP crate engine nowadays. Seems everyone's into it.

Yes, I understand the problem has been solved. My issue is the attention to detail missing from the git-go. The General has produced millions of engines, and thousands of crate engines.. but yet they let the (early) 502 go out the door with a fundamental issue of poor ring sealing. Sad.

chevynut
05-12-2013, 08:26 AM
55mike, it seems you keep missing the point. The 502 was originally designed to be used as a marine engine. Marine engines need special considerations for rings, because the cylinders run a lot colder than in a car, so the don't expand as much. Also, marine engines run at high RPM a lot of the time. Hence, the desire for low-tension rings in them. In the early days, guys started buying these marine engines for use in their cars, and they used more oil than people expected from a car engine. Once these engines hit the streets, GMPP got a lot of feedback from guys running them, and they changed the specs. If you notice now the 502s say "not intended for marine use". They have made some adjustments to make them suitable for use in cars. So it wasn't like GM screwed up....the engines weren't originally intended for street use.

I don't know what serial numbers are affected. If I can find that out I could determine if mine had low tension rings or not.

55mike
05-12-2013, 08:59 AM
55mike, it seems you keep missing the point. The 502 was originally designed to be used as a marine engine. Marine engines need special considerations for rings, because the cylinders run a lot colder than in a car, so the don't expand as much. Also, marine engines run at high RPM a lot of the time. Hence, the desire for low-tension rings in them. In the early days, guys started buying these marine engines for use in their cars, and they used more oil than people expected from a car engine. Once these engines hit the streets, GMPP got a lot of feedback from guys running them, and they changed the specs. If you notice now the 502s say "not intended for marine use". They have made some adjustments to make them suitable for use in cars. So it wasn't like GM screwed up....the engines weren't originally intended for street use.

I don't know what serial numbers are affected. If I can find that out I could determine if mine had low tension rings or not.

Point taken. In other words you are saying GM didn't make a mistake per se, it was the design of a "marine engine..." 'spose I can buy that... but in a way makes the issue even worse in my noggin! They KNEW the dang thing wouldn't do well on the street by (their) design.. just as they know the (newer) engine is not for marine use. Amazing.

Rick_L
05-12-2013, 09:37 AM
Chevynut, I don't buy your explanation for low tension oil rings in a marine engine. Oil rings depend on the fit and shape of the expander/spacer between the rings for their tension, and that's going to be unaffected by thermal expansion.

If that was true, the Ram Jet 350s would have had the same problem, and they didn't. (Of course they had their own.)

chevynut
05-12-2013, 09:35 PM
Rick, first of all, I don't think the RJ350 was ever intended to be a marine engine....was it? Low tension rings produce more horsepower and are often used in marine and racing applications. Marine engines need more clearances, so are build "looser" due to the cold water running through them. Read this:

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.

chevynut
05-12-2013, 09:40 PM
More stuff...

http://racingarticles.com/article_racing-10.html

Engine Building
by SPEED-O-MOTIVE ©1998

There isn't a universal set of rules that govern all engine building. The following is information that has worked successfully and should be considered when building a performance engine.



Marine Applications require an extra .001"-.003" clearance because of the possible combination of high load operation and cold water to the block. A cold block with hot pistons is what dictates the need for extra marine clearance.


The goal of most performance engine designs is to utilize the highest possible compression pressure without causing detonation or a detonation related failure. A full understanding of the interrelationship between compression ratio, compression pressure, and detonation is essential if engine performance is to be optimized. Understanding compression pressure is especially important to the engine builder that builds to a rule book that specifies a fixed compression ratio. The rule book engine may be restricted to a 9:1 ratio but is usually not restricted to a specific compression pressure. Optimized air flow and cam timing can make a 9:1 ratio but is usually not restricted to a specific compression pressure. Optimized air flow and cam timing can make a 9:1 engine act like a 10:1 engine. Restrictor plate or limited size carburetor engines can often run compression ratios impractical for unlimited engines. A 15:1 engine breathing through a restrictor plate may see less compression pressure than an 11:1 unrestricted engine. The restrictor plate reduces the air to the cylinder and limits the compression pressure and lowers the octane requirements of the engine significantly.




RING TENSION

Piston ring sets are available with either standard or low tension oil rings. The standard tension rings are recommended for street driven applications, and for race vehicles which may see frequent open to closed throttle transitions in use - such as road racing. They are also useful in engines that may experience cylinder bore distortion during operation.

Low tension oil rings deliver increased performance due to their reduction in cylinder wall drag. These are highly recommended for many racing applications. Engines using low tension rings should be built with particular attention to cylinder concentricity, and often benefit from the use of a crankcase vacuum system.

RING END GAP CLEARANCE

The piston ring's end gap can have a significant effect on an engine's horsepower output. Rings are available both in standard gap sets, and in special "file fit" sets. The file fit sets allows the engine builder to tailor the ring end gaps to each individual cylinder. Ring gaps should be set differently dependent upon the vehicles use, within the range of .003" (for the 2nd. ring) to .004" (for the top ring) per inch of cylinder diameter. The more severe the use, the greater the required end gap (assuming the use of similar fuels and induction systems). Engines having low operating temperatures, such as those in marine applications is too small. The chart below is a general guideline for cylinders with a 4.00" bore, adjust the figures to match your engine's cylinder diameter:

Top Rings (ductile iron, 4" bore)

Supercharged

Nitromethane .022 - .024"

Alcohol .018 - .020"

Gasoline .022 - .024"

Normally Aspirated - Gasoline

Street, Moderate Performance .016 - .018"

Drag Racing, Oval Track .018 - .020"

Nitrous Oxide - Street .024 - .026"

Nitrous Oxide - Drag .032 - .034"

2nd Rings (plain iron, 4" bore)

Supercharged

Nitromethane .014 - .016"

Alcohol .012 - .014"

Gasoline .012 - .014"

Normally Aspirated - Gasoline

Street, Moderate Performance .010 - .012"

Oval Track .012 - .014"

Pro Stock, Comp. .012 - .014"

Nitrous Oxide - Street .018 - .020"

Nitrous Oxide - Drag .024 - .026"

INSTALLATION NOTES -

CYLINDER WALL FINISH

When installing new rings, the single greatest concern is the cylinder wall condition and finish. If the cylinders are not properly prepared, the rings will not be able to perform as designed. The use of a torque plate, head gasket, and corresponding bolts are necessary to simulate the stress that the cylinder head will put on the block. Main bearing caps should also be torqued in place. The correct procedure has three steps. First the cylinder is bored to approximately .003" less than the desired final size. Next it is rough honed within .0005" of the final diameter. Then a finer finish hone is used to produced the desired "plateau" wall texture. Use a 280 - 400 grit stone to finish cylinder walls for Plasma Moly rings.

Note - the "grit" number we are referring to is a measurement of roughness, it is not the manufacturers stone part number (a Sunnen CK-10 automatic hone stone set #JHU-820 is 400 grit). The cylinder bores should be thoroughly scrubbed with soap and hot water and then oiled before piston and ring installation.

Piston ring grooves are also sealing surfaces, and must be clean, smooth and free of defects. Ring side clearance, measured between the ring and the top of the groove, should be between, .001" and .004".

by SPEED-O-MOTIVE ©1998
http://www.speedomotive.com (http://www.speedomotive.com/)

http://www.trifivechevys.com/images/friends.gif Send this article to a Friend (http://racingfriends.com/cgi-bin/tell.cgi)

Rick_L
05-13-2013, 10:51 AM
[QUOTE]I don't think the RJ350 was ever intended to be a marine engine....was it?
UOTE]

Indeed the Ram Jet 350 it was a marine engine. Just like the oil rings, GM used to blame the rich fueling and black smoke by saying "it was a marine engine".

As far as low tension oil rings, there's "low" and then there's "too low". Apparently the 502 falls in the "too low" category, at least for most.

When I was building/maintaining competitive drag race engines, we used "low tension" rings. I once got a set of them that caused the engine to smoke. I replaced them because I didn't like the look of the combustion chambers and spark plugs. Too much oil in there, oil in the chamber can cause detonation.

We used to use 2nd rings that were back cut to reduce friction (about 30% of the depth of the ring was removed by machining.) We also used thin top rings (.043" wide rather than 1/16") for the same purpose. The rings were aided in their sealing by combustion pressure applied to the back side. So they had extra friction on the power stroke, but not so much the rest of time.

Thing is, there's a practical limit to all this.

chevynut
05-13-2013, 03:00 PM
Thanks for the explanation Rick. I guess the point is that marine engines are built with different considerations than street engines, and both the Ramjet engines were marine engines at the beginning. I know the RJ502 intake was built in collaboration with Arizona Speed and Marine.

I wish there was a way to tell which rings were put in my engine, but I'm thinking I'm just going to replace them anyhow. Any experience with Total Seal rings? They seem like a great idea.

Rick_L
05-13-2013, 05:08 PM
I don't like Total Seal rings, at least what they sold years back. But my opinion is based on trying them and not liking them 30 years ago, and frankly I have not kept up with their current offerings. In those days they didn't have their own oil ring design, just top and 2nd rings.

One deal was that I thought the elimination of the ring gap by using 2 rings in one groove was misleading. It gave you great readings with a leak down tester because of no gap, but you couldn't tell they were wearing out with any degree of precision.

I've usually used Sealed Power or Speed Pro rings, or the same rings repackaged with another brand name.