I am putting new pistons in. Presently it has flat tops. I want to put in a small dome piston from Sporstman Racing (JE Pistons). I am running a Voodoo 60203 & thought a little compression increase might help.

Also don't know what rings to use: Moly, cast iron or whatever. I wondered if any of the experts here had any suggestions.

I am not racing this car, just a street cruiser.

Thanks for any help.

Sorry Brian you have to go through this.

Look at the KB forged line, excellent product for a good price. Alot of reputable builders like them better than the JE/SRP's.

Hi Vince,

Why not the hypuretic ones?

Brian, the hyp's will probably be fine for what your looking to do. If you plan of kicking its butt hard, you should go forged.

Any other suggestions pelase?

Do the pistons need replacing? Simply zero decking the block and perhaps a flat mill of .030" off the heads will get you into the "over 9:1" range, saving you the cost of the pistons and a balance job.

If you're replacing rings, so long as the block is honed and there is minimal "untouched" area in the cylinder walls, no reason to buy a ring type other than moly.

It's an oil consumption issue related to the low tension oil rings. That's why I was replacing them. I just thought while I was at it, I would put a little dome in it.

No interest in just replacing the rings with a standard tension set? I believe Hastings makes stock replacement rings for the 502's.

Of course if you choose to overbore to 4.5", there are a pile of different manufacturers that make pistons for that application, and would use a normal 1/16 1/16 3/16 ring set, no oiling issues whatsoever. Pro Tru sells a PT077H04 (4.47 bore) and PT077H3 (4.5 bore) to work with your current combo, 9:1 compression, 3.8 cc dome.

60203 in a 502 is the problem!!!!!
Cam too small to feed the beast! A 60203 is barely enough cam for a mild 454.
A 60203 cam in a 502 makes a tow truck stump-puller!!!!!
Go large!

It's an oil consumption issue related to the low tension oil rings. That's why I was replacing them. I just thought while I was at it, I would put a little dome in it.

If you have this engine torn down, I would check into having it plate honed while it is apart. That has just as much, if not more to do with your oil usage than the low tension rings.

As to your pistons, if it were me, I would go ahead and go forged pistons. You never know what future upgrades you may want. If you go forged, you can throw anything at it and won't have to worry. The SRP's I got from Wolfplace were nice pieces for the price.

If you have this engine torn down, I would check into having it plate honed while it is apart. That has just as much, if not more to do with your oil usage than the low tension rings.

As to your pistons, if it were me, I would go ahead and go forged pistons. You never know what future upgrades you may want. If you go forged, you can throw anything at it and won't have to worry. The SRP's I got from Wolfplace were nice pieces for the price.

^ what he said. All of it.

Just what Gary & Kyle said.

Scott

I plan on plate honing and i would like to avoid the expense of new pistons as there really is very little wear on this engine. If I can get a set of standard tension rings along with that I hope to solve the problem but I suspect I am throwing good money after bad by not changing pistons.

Do you guys really believe those scrawny oil rings could ever work?

This motor also brings oil in through a properly baffled pcv system and seems to direct it to the 1,3 & 7 & 8 cylinders. I don't see any evidence of combustion getting past the first ring either.

I am pulling my hair out.

The thickness of the rings isn't the issue, it's the tension they push against the cylinder wall with that's probably causing your problems. I think your pistons should be fine, it usually doesn't take more than a couple of thousandths to clean it up. You might send 'em off for a skirt coating, that'll help with scuffing and help to make up a bit of the clearance.

Brian, I know I mentioned to you, I'm using a new set of rings again with the "shallow" oil ring, and not buring oil. I lied, I'm buring very little as opposed to before, maybe a qt. to every 1000miles, probably not even. I run her super hard though, which seems to make oil dissapear. Either way, not enough oil consumption to buy pistons over (which I was thinking of doing).

here's the rinsg from a 454HO, notice the oil rings, how flimsy they are:

http://i134.photobucket.com/albums/q116/VGIORDANO_2007/oil.jpg?t=1230497483 (javascript:void(0);)

I plan on plate honing and i would like to avoid the expense of new pistons as there really is very little wear on this engine. If I can get a set of standard tension rings along with that I hope to solve the problem but I suspect I am throwing good money after bad by not changing pistons.

Do you guys really believe those scrawny oil rings could ever work?

This motor also brings oil in through a properly baffled pcv system and seems to direct it to the 1,3 & 7 & 8 cylinders. I don't see any evidence of combustion getting past the first ring either.

I am pulling my hair out.

While I was attending my father's funeral when my 454ho was being gone thru--I did not actually see, but the builder mentioned that rings were in upside down (and that there was a lake of oil on top of the pistons when he took it apart). 2600 miles----15qts----oil dripping from tailpipes.

Plate hone--new rings--machine heads for perfect circle seals is what the engine guy did.

I trimmed the center tab from the valley baffle as it was keeping the intake from seating correctly.

2000 more miles------not a drop has vanished from the dipstick

BRYAN,thats VERY impressive for a bbc,2000 miles and not any oil use at all,very good in deed.

What rings (MFG & TYPE) along with what oil mfg & grade oil was in the motor for the 2k miles?

Thanks...Scott

While I was attending my father's funeral when my 454ho was being gone thru--I did not actually see, but the builder mentioned that rings were in upside down (and that there was a lake of oil on top of the pistons when he took it apart). 2600 miles----15qts----oil dripping from tailpipes.



I forgot to mention that. A lake of oil on top of the pistons. I had that both times I disassembled. Where the heck does that come from? The oil return is at the top of the heads which was long drained off by the time I pulled it. I saw from Vince's Franencrate pictures that he had the same lake on his pistons and mine looked exactly the same.

I guess mine should be called the Bride of Frankencrate?

Joe,

Here are some new photos of the pistons & block.

Thanks for your help!

You can see how the lack of a plate hone did you in Brian. You can easily see how the cylinders are a different color by each bolt hole - that's b/c when the bolt is torqued, the cylinder is distorted a bit. The dark spots, rings werent even touching.

I forgot to mention that. A lake of oil on top of the pistons. I had that both times I disassembled. Where the heck does that come from? The oil return is at the top of the heads which was long drained off by the time I pulled it. I saw from Vince's Franencrate pictures that he had the same lake on his pistons and mine looked exactly the same.

I guess mine should be called the Bride of Frankencrate?


A "lake" of oil on top of the pistons is probably caused by the second ring being installed upside down. The second ring is designed to be 80% effective in oil control and 20% effective in combustion pressure control. If the ring is installed upside down it will actually pump oil into the topside of the ring and this oil will get by the top ring and into the combustion chamber. The second ring used in just about all performance applications are "reverse twist" design. The face of these rings is tapered and the leading edge of the taper must be pointed toward the oil pan when the piston is installed.

A typical three piece oil ring assembly does appear to be "flimsy" but this design works very well when assembled and installed properly. The width of the oil ring assembly 3/16"; 1/8"; 3.0mm, etc. has no bearing on the rings ability to seal, nor the reduction of friction. Oil ring friction is reduced when low tension rings are used, but these should only be used in conjunction with a pan evacuation system or a vacuum pump. Low tension oil rings should be avoided in any engine that is driven on the street.