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skep419

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I've been battling an oil leak for a long time. Stubborn and cheap as I am put new pistons and rings in with just a monkey ball hone. After multiple oil pan gasket and rear main seal replacements. The conclusion is the rings aren't sealing and its blowing oil out the rear main.

I have another 360 block that I'm going to bring to the machinist to have bored,decked,etc.
.030 h116 speed pro pistons, scat I beams, .010 stock crank, ede rpm heads, ede air gap, 60403 voodoo cam, 750 holley street hp.

Going to need different rings (what would you recommend)
anything I should test before taking the engine apart/while taking the engine apart?
didn't have problems (leak oil) with the old 405cp pistons/stock rods. If I find another crank I could throw the bottom end back together with the old rods/pistons.

thanks


Super tuning car runs good shooting for great
 
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Good that you are starting with fresh bores; excess bore taper will kill rings in a hurry. More than a few thousandths of taper is getting enough to start that problem; .005" taper is a service limit and is too darned high in my book. You just have to bore and start fresh if you have too much taper. Excess bore out-of round: same story.

Is this for mostly street use ? If so, just go with a good set of moly top rings and standard rings the rest of the way. I've hammered on my rally and street engines with this type or of rings and never had issues even at 1.75 Hp per ci turbo'd. Piston ring seal all seems to work consistently and reliably if you start with good bore quality: straight and the right finish and proper piston-to-bore clearance. Make sure your machinist knows the rings so he can put in the right hone finish.

BTW, chrome top rings are known to be hard to seat. Total Seals are not worth the hassle in my 1 experience; I am sure they have a place in some racing discipline, but not for 1 to 1.2 HP per ci engines for general street and occasional race use.
 
I have used many sets of gapless top Total Seal rings.

They work. Worth every penny.
Understood; IMHO, it is in the application.... as usual. My use was in a rally engine; I ended up with a lot of ring drag and, for my use, rapid bore wear (1970's Opel block castings). Now keep in mind, a typically rally is 200-300 miles total, and roughly 80-100 miles of that will be full hammer-down on the engine. 3 such events is like running a full 1/2 mile circle track season in terms of engine use . I seriously doubt that anyone competitive would run a full circle track season on the same rings and pistons.....so I would expect a different view there. And getting that last HP out for rally is not always the best use of time and money; the old truism is that putting 100HP per wheel to the ground is on gravel limits the value of raw HP.

So for rally use, the bore wear was not much of a surprise but it was silly for me to put up with that for little or no benefit, when I don't have to with different rings. Ditto for the street, IMHO. So it gets back, as always, to what the OP is doing with his engine.
 
Street car. 3.91's at the moment. But I have a 742 3.23 ready to roll and tow a boat!

1469928447_zps2nzd1gic.jpg
 
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Compression loss is blowing out the rear main seal? That's a theory I haven't heard before. With so many other places for crank case pressure to escape... Good luck though.
 
Compression loss is blowing out the rear main seal? That's a theory I haven't heard before. With so many other places for crank case pressure to escape... Good luck though.

I'm open to try any suggestions.
I can clean up all the oil. run it on jack stands with no leaks. once its driven it leaks like a sieve.
 
I'm open to try any suggestions.
I can clean up all the oil. run it on jack stands with no leaks. once its driven it leaks like a sieve.
I don't know. It don't make less compression on jack stands. Have you done the compression tests?
 
I've had this happen. Bought a used 340 out of a wrecking yard in the summer of 1981. Was working a butt,lad of hours and wanted my car back. Knew the owner. Said it was running when it came in.

It leaked oil from everywhere. I'd stop it in one place, it would move to another. Especially bad after mashing on it and stopping at a light.

Almost all the top rings were broken. The bores had .015 taper and I don't remember how much out of round. Someone killed it with a ridge reamer. Dumbest tool ever.

And yes, when everything was sealed, it leaked out the rear main seal.
 
I've had this happen. Bought a used 340 out of a wrecking yard in the summer of 1981. Was working a butt,lad of hours and wanted my car back. Knew the owner. Said it was running when it came in.

It leaked oil from everywhere. I'd stop it in one place, it would move to another. Especially bad after mashing on it and stopping at a light.

Almost all the top rings were broken. The bores had .015 taper and I don't remember how much out of round. Someone killed it with a ridge reamer. Dumbest tool ever.

And yes, when everything was sealed, it leaked out the rear main seal.

Also with the pcv valve disconnected it puffs smoke out the breathers
 
I do believe the E215K rings are a standard moly faced ring. They come with the H116CP and H405CP Speed Pro pistons.

The R9903 rings look have a moly insert in the face and a rounded (barrel) shaped face for lower ring drag.
Speed-Pro Premium Piston Ring Set
 
Understood; IMHO, it is in the application.... as usual. My use was in a rally engine; I ended up with a lot of ring drag and, for my use, rapid bore wear (1970's Opel block castings). Now keep in mind, a typically rally is 200-300 miles total, and roughly 80-100 miles of that will be full hammer-down on the engine. 3 such events is like running a full 1/2 mile circle track season in terms of engine use . I seriously doubt that anyone competitive would run a full circle track season on the same rings and pistons.....so I would expect a different view there. And getting that last HP out for rally is not always the best use of time and money; the old truism is that putting 100HP per wheel to the ground is on gravel limits the value of raw HP.

So for rally use, the bore wear was not much of a surprise but it was silly for me to put up with that for little or no benefit, when I don't have to with different rings. Ditto for the street, IMHO. So it gets back, as always, to what the OP is doing with his engine.
 
Most guys figure to run 1000 laps between engine freshens... Some run the same pistons until the second rebuild. Depends on how well the air filters worked and how well the engine was maintained.
 
Most guys figure to run 1000 laps between engine freshens... Some run the same pistons until the second rebuild. Depends on how well the air filters worked and how well the engine was maintained.


Big time on the air filter. A bit of dirt does a bunch of damage.
 
I have used many sets of gapless top Total Seal rings.

They work. Worth every penny.
agree w/ this. any problems I`ve had w/ ring sealing on chevies, have been fixed by gapless rings. All tho my 2 closest mech. dragracing buddies don`t care for them .
 
I like Total Seals... they make a bunch of different styles in all price ranges. They came with the Venolia pistons on my last Hemi build. Used 'em again in my kids dirt track engine on Wiseco slugs. There are others that also are good... depends on your application.
 
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