As I've said in a previous post I personally don't like studs for this type of application. It's a personal dislike not an absolute mechanical issue other than the fact I have less clearance for moving the pan around when I don't have access to a lift. I have nothing against Roger's stuff. To the contrary I am a faithful client:-)

Also I like the idea of self-sealing hardware for other uses and factors and want to see how they hold up under these conditions. To be truthful I got the idea from Porsche and CAT. The 928 uses similar self-sealing washers on the oil pump. CAT uses them in the injection system and several other applications.

In a prior life I was an early Harley Davidson (1915-1936) hardware geek so I have a special liking for nuts, bolts and screws

As to the red-line-of-silicone I can sort of relate only in the sense that 90% of the time I see the "red line" I am usually disappointed by what I find on the other side. While form-a-gasket products have been around for as long as automobiles in various forms; I don't think anything epitomizes the proverbial "hack job" more than red RTV:-/ Its the hackers panacea along with JB Weld. Both are great products when used and applied for the _right_ reason. I personally like Yamabond / Hondabond products better in known-to-be-leaky situations like H-D engine cases, etc.

Anyway the experiment will commence when and if the hardware arrives. Since these pan bolts are non-standard length they are a custom order. I may send APM Hexaseal an original set of Porsche hardware for them to retrofit the Viton seals and nylon locking bars. Still waiting on a call from them.

Cheers,

Fronkensteen

 

Oh and one note to Greg. I am just like you an absolute retentive perfectionist But what I have learned after doing many restorations is this. Almost no one, other than another type A personality enthusiast who will geek out with you over all the nitty gritty details of your perfectionism expressed in an over restored product will ever, ever appreciate what they have purchased from you when you sell your beloved.

My suggestion is to restore rare "keepers" when you find one and buy great street cars that someone else has dumped a prodigious amount of cash into only to give up the fight in search of another vice to waste one's money. Street vehicles are so much more fun. You can beat them relentlessly and not feel bad and for some unknown reason they stay together. Case in point is my 1996 Volvo 850R with 275,000 miles. I run this car at 20 pounds of boost as soon as the tires hit an appropriate road and it rarely sees less than 12 pounds. Average RPM when I am driving is between 3500-4000 and this is an automatic. I beat this car and hard and she has never let me down.

Anyway I am wayyyyy off topic in my own thread. If you care about this experiment stay tuned otherwise have a great morning!

Cheers,

Fronkensteen

 

I believe Carl / 928 Motorsports makes a neoprene oil pan gasket which is more rigid than the soft silicone one so it seals better and doesn't allow the bolts to work loose. It would also be much better than the cork one.

 

Yep and I am using that gasket

 

We have both the silicone and the neoprene gaskets. Both are upgrades to the stock cork gasket.

I found that, on supercharged cars running high boost - it was possible to push the soft silicone gasket out between the oil pan and the block. No problem on NA cars where it works very well.

Thats why I had some neoprene-cork gaskets made. Thinner, and more ridgid. Eleminates a potential problem on boosted cars.

The studs work better than the bolts because the torque setting is so low on the OEM bolts they aren't likely to stay in place, especially as the stock gasket shrinks. The stud, however, has a bulb in the center(like the collar on a nightcrawler) that seats against the block and you get better resistance to backing out. That and a bit of loctite red on the threads of the studs as you put them in seems to keep them in place.

Then we provide an interference nut (or a nylock nut) and the torque you apply on the nuts stays put.

So its a combination of the right gasket (not shrinking) and the ability to maintain the torque you set after the installation is long past done.

 

Carl,

Yes, thank you. That is precisely why I chose your gasket even though I have all the flavors. Oh did I mention - NO STUDS B-)

Fronkensteen

 

Bummer. So the oil pan hardware is non standard, or should I say "commonly stocked". That means that I have to supply my own hardware. Oh well...

 

The other option, of course, is no steenking gasket at all, just a little goop. Oil pan bolt torque is very uniform, this way:

:

 

This ^^^^.

Or this. ^^^^

 

I installed a combo cork/neoprene gasket over ten years ago now, with the original fasteners. Spacing on the bolts more important than torque. The silicone gasket wasn't commonly avaialable at that time. Looks stock, no seepage at all.

Since then we've done a number of silicone gaskets on clinic cars. In my tool collection is a pretty cool inch/lb torque screwdriver that has a 1/4" square-drive available. The silicone gaskets with 20 inch/lbs on Nylok nuts and studs seems to work best without risking squeeze-out. This is an allowance of 11 inch/lbs for the breakaway friction on a new Nylok on a clean new stud, by the way (discovered empirically). All would need to be adjusted if used nuts were used. New ar cheap enough to replace anyway IMHO.


Rob's example: Many moons ago I was working on a notoriosly-seepy British engine, and I decided to surface-polish the girdle and the sump on a granite surface table with lapping compound swimming in a light oil film. Tedious work that took a couple days. But the mating surfaces were really flat and really smooth. Then assembled with just non-hardening Permatex. There was no Hylomar, Hondabond, Dreibond or 574 Anaerobic sealant at the time. Worked extremely well, with NO leaks at all. It was just a LOT of work on the surface plate.

Fast-forward: Many OEM American engines are assembled at the factory with 574 instead of some gaskets these days. It works great --IF-- the parts are scrupulously clean. 574 has a very limited shelf life, something like 90 days from date of manufacture and only a few days after opening the first time, even if immediately resealed. It must be refrigerated to reach that shelf life. So don't waste time buying shelf stock from the local parts place unless you can see the manufacturing date is OK. Older stuff may still work OK, but new is mandatory at least for me.

 

Yeah I like [Honda|Yama|...]bond #4 and the other line product. 574 is a great option, use it a lot on diesel applications. Would have been nice if Porsche went with o-ring and overlapping silicone gaskets on more applications. Large face mating surfaces like the cam towers without enough torque capacity and high warpage prone items like oil pans make things difficult. Any...way....

Fronkensteen

 

Porsche uses Loctite 5900 for almost all engine and transmission sealing applications (at least they did two years ago). It's used for flange sealing (metal to metal) and metal to plastic and non-rigid materials.

The spec sheat doesn't mention it but the tube says it's safe for oxygen sensors and for catalytic convertors.

 

Could the silicone gasket be modified by punching larger holes to accomodate a spacer?
For example http://www.mcmaster.com/#unthreaded-spacers/=t722b2

If the length of the spacer was thinner than the gasket, you could torque the fastener to any reasonable value while limiting the squeeze on the gasket.

Just sayin'

 

That would work great, ASSuming the correct length spacers and the same length spacer on every bolt. I'd be hunting down some existing screw-machined part so I didn't have to pay some exhorbitant setup charge. The sleeve would need to be steel, with a thick enough wall to prevent collapse under bolt compression at nominal 6 lbs/ft (72 lbs/inch) on the 6mm 1.0 bolts or studs.

It's a lot of work and worry for a gasket that rewards correct installation without using sleeves. Using reasonable care and keeping the mating faces really clean, with even light torque and just enough squeeze to have things touching, they don't leak.

All that said, the factory cork gasket, installed correctly, will give decades of leak-free service. I suspect we devote a huge amount of time and concern to things that are not real problems with the product itself, but just require good installation technique. Hearing some of the horror stories and seeing silicone gaskets squeezed out after installation with the "pull on it 'til it's snug and another turn to be sure" method, I really like the cork and cork composite gaskets. Just sayin'.

 

Rob, what is that hose you have plumbed in up there? Also, never even thought of no gasket... great idea! Obviously, no clearance issues?