351W rear main seal

ORFIA · #1 (**permalink**) 02-07-2005, 02:53 PM

I'm in the process of replacing my wasted rear main seal (stroker 351W)... I did a search and didn't find an answer-
It looks as though Ford switched over the one-piece seals in 1985 or so...
If my block is newer than that- but is there any reason I can't use the older two-piece style??
Is the groove itself different?
(Block is still in car, I'd rather leave it there...)

thanks for any help,
Russ R

NMattison · #2 (**permalink**) 02-07-2005, 03:53 PM

Hi Russ i have a 351w also mine had the 2 piece seal, which right now my machine shop is changing that. i had the rear main bored out to accept and circle seal. im not sure what year your block is but if its newer it may be a circle seal also. on mine it is a d4 block made in 74.if you need a two piece seal i can get you the part# of felpro racing gaskets. just email me if you need it. Neil

ORFIA · #3 (**permalink**) 02-07-2005, 05:51 PM

Thanks Neil... What does the new "seal bore" look like??
I'm really just trying to see if my newer Windsor block *has* to have the circle (1-pc) seal or if it's alright to use the 2-pc, since this engine is still in the car...

Hmmm...
Russ R.

tpiini · #4 (**permalink**) 02-07-2005, 06:08 PM

You really need to see the rear of the engine to tell. The one-piece will be obvious, as it's fully visible and can be changed from outside the engine. The two-piece can't be seen at all from the back of the engine. The rear main cap has to be removed to change it.

Is that what you were asking, or am I out to lunch?

ORFIA · #5 (**permalink**) 02-07-2005, 06:26 PM

tpiini- no, I already have the pan and rear main cap off, ready to install the seal...

We took out the existing 2-pc rear main oil seal, but aren't sure that was correct, since while looking for seal part #'s on Fel-Pro's site, I see that the 2-pc are technically only applicable for 1969-1984 Windsors.
My block is newer than that- do I have to use a 1-pc, or is either one fine?

thanks all,
Russ R

tpiini · #6 (**permalink**) 02-07-2005, 06:33 PM

Quote:

Originally posted by ORFIA

tpiini- no, I already have the pan and rear main cap off, ready to install the seal...

We took out the existing 2-pc rear main oil seal, but aren't sure that was correct, since while looking for seal part #'s on Fel-Pro's site, I see that the 2-pc are technically only applicable for 1969-1984 Windsors.
My block is newer than that- do I have to use a 1-pc, or is either one fine?

thanks all,
Russ R

Boy, The year-model thing has me stumped. The only small blocks I have screwed with have been 289's & 302's, but I don't think that the seal issue is different on 351's. My thinking is that unless you're ready to do some serious machining, you're needing to stick with the two-piece. The one-piece is driven in from the back, totally different than the way the two-piece goes in. Sorry if I'm just further clouding the issue.

Tom

dlowe01 · #7 (**permalink**) 02-07-2005, 09:20 PM

I have two blocks, a 74 and a 84. The 74 uses the two piece seal that goes in by taking out the rear main cap. The 84 uses the one piece that slides in from the back. The one piece is much easier to change. I have not seen any way to convert the two peace to the one piece or visa versa.

ORFIA · #8 (**permalink**) 02-08-2005, 08:28 AM

Hmmm- so there shouldn't be any way to switch from one to the other?
That's good! Since this had a 2-pc (rightly or wrongly, we dunno) to start with, and it looks like the 2-pc fits "correctly", I'm gonna say this must be a considerably older block than I thought... (it's not handy or I'd dbl-chk it).

Cool!

Thanks for the replies, sorry if wasn't communicating my confusion earlier. Mainly I was unsure if the seal *groove* was different,

i.e. was the 1-pc just an improvement and you could use either one, or if the groove IS different then you must use whichever it's designed for...

Russ R