whats the diff between a 1 piece and 2 piece rear seal? if i have an engine with a 1 piece rear seal can i put in a 2 pc rear seal rotating assembly? what is a rear seal?

 

The rear seal holds the engine oil inside the engine around the rotating crankshaft. It's located right behind the rear main bearing.

You can put a 2-piece rear main rotating assembly in a 1-piece block by use of an adapter. Costs $100, last time I looked.

 

Can you put a 1pc seal crank into a 2pc seal block?

 

No. It won't happen.

 

Just my opinion, but who cares??? Yes- a 1 piece seal is an improvement over a 2 piece, but remember - they ran 2 piece seals since.....well for a long time.

 

Only those who don't like leaks care.

I've had many, many 2-piece seal engines. Most were used (only one new), some rebuilt, but they all leaked to some extent. The "new" one is a Goodwrench 350 I have in my van now. It's the best I've had, have 60k on it now, but even it weeps more than my 160k LG4 seal.

 

It's really not hard at all to get a 2-piece to seal. I never noticed it being a problem with factory motors, until they hit about 10,000 miles, and all of the gaskets and seals started turning to dust just from age and heat and all.

The main reason the factory changed the design was not because the old kind leaked; it was to reduce assembly time. Anybody who builds motors can tell you that it takes a while to put in a 2-piece one; probably 5 or 6 times as long as it takes to bonk a 1-piece one into the carrier and bolt it up.

 

RB - I bet you meant 100,000 miles!

It's not difficult if you're doing the install yourself to get a good seal with a 2-piece. I never knew they changed over due to assembly time.

5-7 : Yes, I'm also one of those guys that don't like leaks.

In the 6 or so engines I've rebuilt, only had a problem with one weeping.

Oh - and I actually use the rubber china wall gaskets on my intake too.....without leaks!!

But - no argument....a one piece seal is less likely to leak over time. On the other hand, I'm not going to ditch an engine because it has a 2 piece crank seal...

 

Actually, I meant 1,000,000 miles!

 

so which would be best 1 pc or 2 pc? this is for a performance engine. are zz4 crate motors 1 pc or 2??

 

Yes. A 1-piece or a 2-piece would be best.

The seal by itself doesn't really matter.

2-piece stuff (flywheels, etc.) is easier to find. But, no 2-piece blocks are equipped with the factory roller setup, so if you get a factory roller block which is cheaper to roller-ize, it will be 1-piece. However not all 1-piece blocks are roller-ready.

Other than that, it makes little difference.

 

ZZ4 1 piece seal.
PM