N882928

Rebuilding 77 2.7 and after bolting together the case halves I noticed that some of the blue o-rings for the through bolts are peeking out from behind the washers. They must have torn or stretched in the process. I know I positioned them in the washer recess... Anyway, I did use the black silicone sealant recommended in Wayne's book. Do you guys think this will be enough to prevent an oil leak? Can you take the through bolt back off to replace the o-rings without disturbing the case? Or can I just put some more silicone around the washers and bolts? Has this happened to anyone else? A little help...

Ed Hughes

Personally, I think you've got too much work yet to do to take a chance on o-rings that are known to be a beyotch to work with. Do yourself a favor and order a set of the GREEN Viton o-rings and sleep better when you start assembling. You can do the bolts one at a time without splitting the case. More silicone around the washers is NOT going to get you anywhere.

And yes, many have experienced tears and such with the blues...a search will show you that and will reinforce the fact that the Viton o's are the hot ticket.

Note: Spend some time on the rebuild forum here, you'll learn a lot on this sort of thing and get a few tips. Good luck!

Ed Hughes

Sorry, I should've said the rebuild forum on Pelican.....I forgot where I was for a second!! What can I say?

88911coupe

BTDT...as Ed says, just go ahead and switch to the Viton. I could not stand to see that blue crap oozing out and went ahead and bit the bullet and replaced them all with Viton. My "excuse" was that I'd ordered the parts some time ago and did not realize there were two "flavors" of through bolt o rings. In fact, I think the Vitons were actually a few cents cheaper, not that it's really relevant. I also did not use ANY of the sealant...due to many recommendations against it but you'll find highly competent engine builders on both sides of that issue.

Peter Zimmermann

Ed's right about the Viton. Here's how I do them...

1. All washers and case surfaces must be perfectly clean & dry. Q-Tips + lacquer thinner (or MEK).
2. Polish the o-ring contact surface (washer bevel) with fine Crocus Cloth.
3. Install a washer on a bolt, wrap the bolt threads with a layer of electrical tape, then "roll" an o-ring over the tape and then down the shaft.
4. Put a drop of oil on the o-ring, slide the bolt into position, and install a second o-ring on the nut side.
5. Put a drop of oil on the o-ring, install the washer, remove the tape, and install the nut.
6. Consider putting a thin smear of oil between the nut and washer - see #7...
7. Tighten in a way that will minimize the amount that each washer turns, which will eliminate any remaining chance that the washer will grab and pull the o-ring. I use a box-end wrench on the bolt head, and a deep socket and an extension just long enough to allow the torque wrench to clear the head studs.

Hope this helps!

N882928

Gentlemen, I thank you for your help. (Mr. Zimmermann has also bailed me out before and we all should thank him for his support as free advice and this forum are a priceless resource.) I was not aware there was a viton O-ring for this app. until now. I had simply purchased the gasket set and naturally it had the blue o-rings. If I would have know that ahead of time I would have ordered them separately. My machine shop introduced me to the wonders of viton with the valve seals. Now that I think about this app. it is a good improvement here. I will order a set from Pelican and replace them one by one. Again, danke!

theiceman

I am sure if Pete had not been a Porsche guy he would be a neurosurgeon . What attention to detail
:-D.

Oldtee

Where do you get these things the correct size. They don't come in the gasket sets and I haven't seen them on the shelf at my local auto parts store.

DWalker

You can get them from pretty much any Porsche parts supplier- EBS, Pelican, Paragon,Performance Products, etc.