I am starting to look at stuff for a possible engine build/buy.

I like the idea of a 1 piece rear main seal. I heard that they are easier to install and leak less.

1 piece cranks are also pretty cheap relative to 2 piece cranks.

I am kind of leaning towards either getting a cheap crate engine and upgrade it over time or get an assembled short block and build up the top end because I don't have the time or space for a total buildup. This makes my options with a 1-piece kind of limited (GM crate or hit the junkyard for a 1-piece block and build my own short block).

What I am asking is if the 1-piece rear is THAT much better and worth the hassle or should I just go for a 2-piece engine.

Any opinions?

Thanks,

------------------
Charles Perrell
cperrell@yahoo.com
65 malibu SS Convertible
283 4bbl & 2004r

FYI-1 piece takes a different flywheel/pressure plate than the pre=86 engines.

------------------
Sid Coleman, 71 Ragtop
TC (Gold) #174, MCC #347,
Aces #5457, N3JHV@bellatlantic.net

It depends on what you mean by easier. To replace one with the engine in your car, you have to remove the transmission. Of course, in a Chevelle, you have to remove the engine from the car in order to remove the oil pan to replace a two piece, so it really doesn't make any difference when we're dealing with our older cars. To replace a one piece seal, you have to remove either the transmission or engine. But if we're talking about a pickup or Blazer or Surburban, then the two piece seal is much easier to replace since you don't have to remove the transmission or engine to yank the pan.

Thanks for the replys.

I know that the flexplates on the 1-piece is different than the one in my 283. That is another negative toward going with the 1-piece, but not a big one since I will probably go with a 383 if I get a 2-piece engine which would require a new one also.

The big question I have is the better design of the 1-piece versus the greater availability of 2-piece engines.

The main advantage I see in the 1-piece is that it is more reliable than the 2-piece. I always hear stories of 2-piece seals leaking, even new, and how hard it is to put the seal in so it doesn't leak.

The only reason I am considering a 2-piece is because there are few (if any) builders offering crate engines/short blocks with 1-piece seals. I would basically have to buy a new GM engine/short block (which limits my selection) or build my own short block (which adds to the expense, time, and potential problems).

I would like to get some opinions as to whether the 1-piece really is a big improvement in design (and leakproof-ness) over the old 2-piece.

This will be a daily driver and I don't want to have to worry about leaving oil stains everywhere and having to top off my oil every time I fill up with gas.

------------------
Charles Perrell
cperrell@yahoo.com
65 malibu SS Convertible
283 4bbl & 2004r

hey guys, i have been working at a GM dealership for the past 8 years now and have yet to see a 1 piece seal leak.i see trucks, and old B-bodys with 150, to 200,000 dry as a bone. now granted im a young guy. i was in elementary school when they quit putin carbs on cars, so i have no experience with them, or 2 piece seals. just throwin my $00.02 in.

I figured the 1-piece seal was pretty leakproof, but it is good to hear that it can go that many miles.

Since this is daily driver, I am kind of leaning towards using a 1-piece seal right now, it just kind of limits my options.

Now that I think of it, the engine forum might have been a better place to post this. I might try posting this over there, as I would like to get some more input.

I'd go for the one piece seal. If you had a two piece you know how nasty those leaks can be. By the way, I bought the 350 deluxe crate motor and so far, I think it was a great deal.

A properly installed 2-piece seal doesn't leak! I've done dozens of them. The key is patience and the correct amount of "offset" in the block/cap and a dab of sealer on the ends.

The choice is yours.