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Posted by: thomasotten Aug 15 2004, 06:44 PM

I was replacing a motor mount on my engine as I prepare to stab it back into the car. I got my hands full of oily grease crap. It just got me wondering about the possibility of a "leak free" motor. I started to look for leaks, and you know my engine didn't have any dripping leaks, it just gets coated with oil nevertheless. I know the real gushers are the pushrod tubes seals, and the oil cooler seals. But mine are fine, and my car doesn't drip any large amounts of oil. Obviously I have a small leak (or several leaks) that cause the engine, and engine compartment to get coated with gunk. Why the heck are these engines so dirty?

As I start to consider rebuilding, I want to know if it is possible to build the engine so it doens't leak. Period. Any tips?

Posted by: newdeal2 Aug 15 2004, 07:00 PM

I beleive it can be done with very careful assembly, proper tourques, good pushrod seals and the right use of sealers, etc. Jake's video covers some of this and I am sure others will chime in with the best techniques...I know I look forward to them since I am close to assembly.

One thing Iam certain will be helpful is the elimination of the copper gaskets and lapping the cylinders. This apears to be the most common place next to the pushrod seals. If I am correct the green seals are the best [but my Pelican gasket set came with 2 colors, green and black...not sure why].

Peter

Posted by: seanery Aug 15 2004, 07:25 PM

Brad's assembly of my 2.0 was dry.

Posted by: silver2.0 Aug 15 2004, 07:47 PM

Mine's dry. Use these ingredients:


-casehalves: Loctite 518 (new technology) or Permatex 3H Aviation Form-a-gasket (old tech)
-sumpplate(s): Hylomar 71285, now avail from Valco. Awesome stuff - a must have!
http://www.valco-cp.com/Hylomar.htm
-sumpnuts/washers: Permatex Ultra-grey, Loctite 5699, 3-bond silver or grey (Cummins p/n 3823494 - cause I like the small tapered metal nozzle). All these, essentially the same product, readily available, and are much more oil-resistant than other RTV's.
-headstuds in case: Blue loctite 242 (w/ case-savers, which are essentially inserts with enclosed bottoms). You only need this as a convenience to keep the studs in place.
-headstuds/nuts/washers in head: Ultra-grey/5699/3-bond silver. Small bead under washer only.
-case studs/nuts/washers: Ultra-grey/5699/3-bond silver. Small bead under washer only.
-rockerstand studs: 242
-valve covers: 3H, gasket to cover only. Let cure overnight before starting engine.
-push rod tubes: good quality seals only.
-fuel pump: hylomar
-gen/alt stand: hylomar
-oilcooler/adapter: good quality seals only
-oilpump to case: hylomar
-oilpump to cover: hylomar - thin coat. Do not use RTV which, unlike Hylomar, will squeeze into (and plug) the return groove.
-full flow fittings: Loctite 567PST high-temp thread sealant (green 292/sleeve retainer is overkill, but thank you for sharing Gene).
-oil filler type 3 and 4 (+universal case): hylomar
-oil pressure switch: Loctite 567PST high-temp thread sealant.
-gallery plugs: Loctite 567PST high-temp thread sealant and lock per B. Hoovers detailed instructions.
-pulley sand seal holder to case: 3H. It seals, doesn't harden, and still allows easy removal to change the seal.
-cam plug (metal): Permatex high-temp form-a-gasket #1572. Awesome sh*t! Messy, stains fingers!
And lets not forget,
-jugs to case: Ultra-grey/5699/3-bond silver

Posted by: ArtechnikA Aug 15 2004, 07:53 PM

do you still have the thermostat ?

Posted by: thomasotten Aug 15 2004, 08:06 PM

I am almost certain I don't have it... are there oil issues there? From what I remember that is just a flap cutting off air to the cylinders when it is cold.

Posted by: Tom Perso Aug 15 2004, 08:13 PM

The more detailed question is - do you still have the wheel for the thermostat wire?

If it's gone, that's a direct hole into the case....

A leak-free T4 IS a pipedream, IMHO...

The leak to mark their spot. Deal with it. Steal some cardboard out of your neighbor's trash (they hate you for owning a Porsche anyways) and stick it under the car.

Better yet, park in their yard and kill their grass...

Later,

Tom

Posted by: thomasotten Aug 15 2004, 08:16 PM

The thermostat wheel is still there. No leak there.

Posted by: ThinAir914 Aug 15 2004, 09:51 PM

I've forgotten how many times I've asked this same question on this list, only to get half answers or evasive replies. This kind of list is truly helpful! I'm about to start assembling my 2.0L so I really appreciate this.

Are there any special sources on any of this stuff or should I expect to be able to find it at my local NAPA?

Posted by: brp914 Aug 15 2004, 11:31 PM

Silver2.0 may be right but, it seems too complicated. My 2.0 /4 with 10k on a rebuild doesn't leave spots on the ground or smell of oil after driving it, and the engine bottom is still fairly clean.


after enduring years of oil spots and smells, I found 2 things:

1. use silicone pushrod seals. They are the brown ones. Get them from Performance Products or other places. The green ones that come with rebuild kits are junk.

2 rebuild kits dont come with the o-ring seal that goes behind the impeller drive. This is easily overlooked and will cause endless annoyance. The impeller drive is the thing that bolts onto the front of the crankshaft with a single bolt and large washer. 3 bolts go into it through the impeller (fan)

Posted by: DNHunt Aug 16 2004, 08:02 AM

I just assembled case halves with Curil K2. It's like fancy contact cement so I let it bench cure for 20 minutes then put it together. I used Locktite 518 under the case hardware. One thing I did was checked the case mating surfaces really well for any barbs. The dips won't hurt as much as the upturned lips on the marks that are on these old cases. I very carefully used very fine wet dry paper to take these off (final grit 1500).

The engine in the car doesn't leak a drop. the only oil it uses is what gets through the valve guides.

Dave

Posted by: rhodyguy Aug 16 2004, 08:05 AM

check the condition of the cork gasket beneath the oil fill tower. if it's compromised it can let quite a bit of oil vapor get pumped into the engine compartment.

kevin

Posted by: Racer Chris Aug 16 2004, 09:10 AM

That doesn't sound right Dave. If the stuff cures before mating the two halves there will be some residual thickness after torquing the bolts, which will affect the bearing clearance.
Locktite 518 is the shizzle for the case seam IMO.
I use Hylomar at the barrel/case interfaces and the oil pump seal surfaces.

Posted by: Jake Raby Aug 16 2004, 10:32 AM

we build leak free engines everyday.... It takes 10+ sealants to do it, and alot of assembly experience.

One key is KILLING CRANKCASE PRESURE! Crankcase pressure MAKES oil leak from any orfice.

I will be selling all my selants in a kit soon that goes over in depth where we use them and how to prepare the surfaces.

BTW, I don't use 518 for cases, it does not have a thin enough compression factor. I use 515 for those flanges.

Posted by: ThinAir914 Aug 16 2004, 10:43 AM

How soon? I want to build this engine ONCE and never have to do anything but regular maintenance to it after that! (Which is why I'm also anxiously waiting for the results of your next round of lifter tests!)

Posted by: Jake Raby Aug 16 2004, 11:00 AM

It will be happening along with a few other big developments around the first of the year..

The lifter testing is taking a while, so don't expect to see anything for a product on that till about then either. I don't believe in just throwing parts out and letting people be guinea pigs.

Posted by: DNHunt Aug 16 2004, 11:15 AM

Chris

Jake sent the Curil so I think it must be OK.

From the time I applied it until we got it together was about 20 minutes since we had to reposition a clamshell bearing. The Curil was just starting to loose it's sheen but was still plenty soft. I had a nise little bead all the way around the case seam. The bearings were certainly compressed as the crank was slightly less free.

Dave