oil restrictor thread size?

[wrench87]

I have a set of precision oil pumps oil restrictors in my Edelbrock heads they are .090 I am seeing the tabs on the cork valve cover gaskets getting wet, I am wondering if the .090 is to large I am running a hydraulic roller cam on my 445 fe. does any one know the thread size that doug uses?

[blykins]

If the tabs are getting wet, I'd look to a gasket sealing issue. I've ran FE's without restrictors and they don't leak...they just put a little more oil to the top than necessary.

[Barry_R]

.090 is not much of a restrictor. We go .060 all the time and get plenty of oil. If you run a T&D without restrictors it looks like you're filling a swimming pool....

[wrench87]

I glued the gasket to the head with the yellow weatherstrip adhesive should I have glued the top also?. I am using the cast cobra lemans valve covers.

[blykins]

I don't glue at all.

The head/intake flanges need to be completely smooth at the joint. I will adjust that flange as necessary, use the Felpro rubber gasket, and bolt it down.

I use a #49 drill in the restrictors I use, which is a .070" hole. With T&D's I'm pretty satisfied with the oil flow up top.

[wrench87]

I am using the erson rockers, so am I better off using the rubber gaskets over the cork?.

[blykins]

I think that once cork gets saturated with oil it tends to leak easier...

[elmariachi]

Originally Posted by wrench87

I am using the erson rockers, so am I better off using the rubber gaskets over the cork?.

I've been down this same route with cast-ion heads, Ersons, both cast aluminum and pent roof valve covers, both cork and rubber and all the sealants. The mix that works for me is cork gaskets and Permatex Right Stuff. I clean everything up and use RS to glue the gaskets to the VCs. I have some little plastic clothes pin-type pinchers I bought at Home Depot to hold down the stubborn area of the gasket. I also lightly smear a coat on the inside edge of the cork with my finger so it won't soak oil in once its mounted. The RS dries in about 15 minutes so you don't have to babysit it long. I let them sit overnight and dry. I then run a 3/16-1/4" bead of RS around the sealing edge of the head, NOT THE VC. I use two pieces of 6" threaded rod in two of the holes as pilots and slide them on. Snug 'em up to about 10-15 lbs, run a couple of heat cycles and tighten them a tad again. No leaks ever.

I am running whichever Holley jets that are the equivalent of .070 restrictors in my cast heads with solid lifters. I have a set of the Kirkham clear Lexan valve covers I used when testing and I went from having 3" of pooled oil in the VC at idle to about an 1", basically just above the VC-to-head seal. You can see the oil pooling in the head towards the end of the clip:Head Oiling Video. At rpms above idle the level comes up about another 1/2" and douses the rockers and pushrods but its far less than it was unrestricted.

[Barry_R]

We use the cork valve cover gaskets in everything. Much more forgiving. Once we are satisfied that everything is OK we use a thin layer of Motorcraft TA-31 on the head side at the lower rail and the head to intake intersect to seal them up.

[blykins]

Well there you have it wrench....

Cork doesn't work for one builder but does for another. On the flip side, rubber doesn't work for one builder, but does for another.

[RICK LAKE]

wrench87 I had used 1 set of cork gaskets for 14 years. This is too long, 10 years is fine. My gaskets where glued to the valve covers and a small spot of sealer to the spot where the intake manifold and heads meet. Nothing else. IMO and racing with Erson rockers for 7 years, .080" oriface is a safe size. I have seen .060" and blueing of the pushrods and cups of the rockers them selves. How much oil in the heads is not just about the rockers. There is alot of heat produced from the valve springs going up and down at 200-400 cycles per minute and this is low rpms. I flood my heads to the bottom of the pushrod holes. I have had no failures or blueing. If you are using pushrod oiling than .060" would be ok for rockers.
The limit on the cork gaskets was push beyond normal and did cause a small oil fire at Hasteings race track. No damage to car, only 1 wire was repaired. I would still run cork over rubber because of the height differents at the intake to head location.
If you are getting leaks from valve covers or any gasket that is under a low pressure area of 2-4 psi like valve covers, I would take a pressure reading to findout what is going on inside the motor. Start with the PCV valve first and check breathers in valve covers. Too much blowby of the rings could cause leaks, have seen this with the new low tension rings and not using the power to help seal them and breakin on the cylinders. Any other questions, ask and blame Jim. Rick L.

[wrench87]

When I ran my small block I tried cork and then the cork with rubber over them so they both worked I just lke the thicker ones I am running studs so i get a good clamp. My engine is not leaking I just noticed the tabs were wet and i glued the gasket on the bottoms so i was wondering if i had to much oil in the valvecovers. Now per rick l i have poor ring seal and bad oil pressure? oil pressure and ring seal are fine. I remember when i was priming the engine with the drill there was a lot of oil up top and ran over the valve cover seal lip that is why I was asking.

[patrickt]

Originally Posted by wrench87

I am using the erson rockers, so am I better off using the rubber gaskets over the cork?.

It's been several years now, but I'm almost positive the instructions that came with my Ersons specified .060 restrictors, which is what I have. I can not, though, remember if they differentiated between hydraulic and solid lifters, of which I have the latter.

[blykins]

It doesn't take much for oil to run up over the valve cover rails....

If it an't broke, I wouldn't fix it. Although if you have screw in restrictors, it would just take a few minutes to change them.