Oil leak-free small block, is it possible?

[CobraV8]

I need a little help on this one. Since I built this engine 7 years ago I could never stop it completely from leaking oil.

The problem seems to be (cheap) valve covers/breathers, oil pan gasket and/or front/rear main seal.

In order to adress the topside of the engine I ordered new fabricated aluminum valve covers with extra thick flanges, Fel Pro #1684 molded silicone gaskets and a breather tank that will connect to the valve covers with braided ss lines and AN fittings. That should do the trick, or at least I hope so.

About 4 years ago I already installed a new Kevko oil pan using a molded, one piece Fel Pro #OS 34508 R silicone gasket, but to no avail as it seems. While the side rails of the oil pan look rather dry the leakage seems to come from the front and rear part of the gasket, below the timing cover seal and rear main seal.

The timing cover also received a new seal 4 years ago (Fel Pro), as recommended I installed the cover loose and torqued it up after the balancer was in place to make sure it is centered.

I used the Fel Pro Viton rear main seal #Z2901 for this engine from the beginning. Installed it with the parting lines not lining up with the rear main cap parting lines, with a dab of sealer between the main cap and engine block. Everything was cleaned meticulously before assembly.

It's hard to tell if the leakage is coming from the main seals or the oil pan seal.



What gaskets are recommended for the oil pan as well as the rear main seal and the timing cover seal?

I finally want to find a solution for this problem as I'm really tired of having to clean the garage floor from oil droplets from a freshly rebuild engine after every drive.

-Simon

[Bean]

I call mine "My four-wheeled Norton".

Bean

[DAVID GAGNARD]

I have had terrible luck with 1-piece oil pan gaskets over the years and have tried all brands,maybe it's just me, but all have leaked and some have poured..........I switched back to the standard cork gasket/rubber seals and have had great success in the "no leaks" department......same for valve cover gaskets.......

One thing I do that I think helps is with the block upside down on the engine stand,I clean the oil pan rail very good with brake cleaner on a shop rag and let it dry, them smear a thin coat of blue RTV on the rail and put the cork gasket on and press it down in place and let it dry completely before installing the oil pan.....that way I'm pretty sure it will not move/shift when I tighten the oil pan bolts.............same for valve covers,cept I RTV them to the valve cover itself.......
hope this helps....

David

[CompClassics]

Here's the way I do it, I've never had an oil leak complaint.
Start with your engine upside down on the engine stand with clean oil pan rails and saddle gasket areas as David has suggested. Then I apply "Hondabond" in the corners where the saddle seal and oil pan rails meet (4 corners) then install the saddle seals making sure that they fully engage the creavases where the sealer has been applied. Then apply another thin layer after the saddle seal is in place and install the pan rail gaskets. Then I apply another thin coat of sealer on top of the oil pan rail gasket and then install the pan. The sealer is only applied in the area where the saddle gasket meets the pan rail gasket, in effect making both gaskets one. If you use a one piece gasket you still need to apply sealer in the same areas and on both the engine block side and the oil pan side. Torque the oil pan down evenly and allow the sealer to squeeze out and dry, then trim the sealer with a razor blade when dry.

[scottj]

I use the blue silicone rubber VC gaskets on solid roller motors (for re-usability). I haven't used a pan gasket in 15 yrs., only clear silicone. Never had a leak.

[CobraV8]

Well thanks for the hints so far. I installed the Fel Pro 1- piece gasket for the oil pan with a thin coat of RTV one time - didn't seem to help a lot.

Maybe I'll do as recommended and move back to the cheap cork and rubber gaskets for the oil pan.

I'm still thinking it might have been more of a timing cover seal problem than the oil pan gasket. Guess I'll find out with the new balancer and a fresh seal.

[CobraV8]

Originally Posted by scottj

I haven't used a pan gasket in 15 yrs., only clear silicone. Never had a leak.

Did you use any special kind of silicone? Does this also apply to sheet metal pans, or welded aluminum pans with thicker flanges only?

[blykins]

Gotta watch your pickup to pan clearance when you do that, as you lose an amount of gasket thickness as clearance.

To echo some of the others' thoughts, I too only use cork or nitrile rubber multi-piece gaskets on my small blocks. I've had way too many issues with 1-piece gaskets. I smear a layer of Right Stuff down on the block, put the gasket down, use Right Stuff in the corners where the end gaskets meet the sides, smear another layer on the gasket, then lay the pan down.

It's also very helpful when you can do it on a stand without the harmonic balancer or flywheel on, as you can see how the end gaskets move/remain in their spots. I've had some of them move when the pan gets bolted down and had to redo them.

[twobjshelbys]

My Roush 427 which is a bored/stroked Windsor, never leaked oil and didn't use nearly as much as others have indicated.

There's a funny statement about the 427FE:

Q: How do you know if a sideoiler is out of oil?
A: It stops leaking

[twobjshelbys]

duplicate

[scottj]

Originally Posted by CobraV8

Did you use any special kind of silicone? Does this also apply to sheet metal pans, or welded aluminum pans with thicker flanges only?

In the past my builder used clear 100% silicone. Lately, on my own builds I've been using Right Stuff. Pans and VC were fabbed aluminum with billet flanges. We also used clear silicone in place of header gaskets and as a thread locker on header bolts. I now use MLS header gaskets... much easier to work with and last forever.

Blykins makes a good point below regarding pick up clearance... never thought of that as I've always run drysumps.

Originally Posted by blykins

Gotta watch your pickup to pan clearance when you do that, as you lose an amount of gasket thickness as clearance.

To echo some of the others' thoughts, I too only use cork or nitrile rubber multi-piece gaskets on my small blocks. I've had way too many issues with 1-piece gaskets. I smear a layer of Right Stuff down on the block, put the gasket down, use Right Stuff in the corners where the end gaskets meet the sides, smear another layer on the gasket, then lay the pan down.

It's also very helpful when you can do it on a stand without the harmonic balancer or flywheel on, as you can see how the end gaskets move/remain in their spots. I've had some of them move when the pan gets bolted down and had to redo them.

[CobraV8]

Thanks for all the replies. I'll give the Right Stuff in combination with cork gaskets a try.

[Rick 427 Cobra]

Might I suggest that you add some fluorescent dye to the oil and drive it before you tear anything apart. Knowledge is king. Right now you are just guessing where the leak is. Drive short distances and inspect with a black light and pin down the leak. Right now your just hoping to get lucky, and you know how that goes!

[zrayr]

Do you have a PCV system ? If not, they can help a lot with pesky oil leaks on a SBF.

even with a PCV system that is working good, and with no blow by issues as you state, SBF are well known for crankcase pressure issues. I can go for weeks without any oil ooze. But a few minutes of redline activity almost always shows up as a slight, and temporary, rear seal leak.

Z

[midnightrider]

Originally Posted by twobjshelbys

My Roush 427 which is a bored/stroked Windsor, never leaked oil and didn't use nearly as much as others have indicated.

There's a funny statement about the 427FE:

Q: How do you know if a sideoiler is out of oil?
A: It stops leaking

Make sure when the flywheel is reinstalled that U use sealer(Red Loctite preferred) on the bolts. The crank holes communicate into the oil pan & if threads aren't sealed U can get a leak that way. Then most folks think they have a rear seal leak. Have seen it numerous times in my shop...

[CobraV8]

The first 70 mile test drive today revealed that the valve cover leaks seem be gone, thanks to the fabricated valve covers with thick flanges, Fel Pro silicone gaskets, screw-on oil filler cap and breather tank connected to the v/c with AN lines.

Also I discovered what most probably caused the worst leakage in the past. A lot of oil seems to be coming from where the dipstick tube enters the timing cover. I always wondered how this design was ever intended not to leak, as the tube sits relatively loose in the hole and RTV generally works very poor for such applications. However I didn't suspect it to be the main culprit.

What have others done to solve this problem? Compression fitting would be the best solution in my opinion, however cleaning everything with acetone and JB welding it to the cover might work better if disassembly is not an option.

As far as the flywheel bolts go, I always used sealer on these thanks to Tom Monroes small block Ford book...

[DAVID GAGNARD]

JB welding it to the cover might work better if disassembly is not an option.

I've done this in the past when I could not stop the leak other ways,works well,doesn't take but a "smear" of JB Weld around the tube,then push it down in the timing chain cover and leave it over night to cure......

[ScratchBuilder]

I had a fair amount of oil come out of my GT350 when I switched to synthetic and synthetic blend. Went back to dino oil and problem went away other than grime around the sandcast parts which are porous?
Finally replaced timing cover crank seal, it was shot but did not leak that much. Point being Ive had more issues with oil over seal quality. ymmv
SB

[Ron61]

I have had 4 small block Fords, two of them strokers and never had any oil drips at all. Now I have most likely jinxed myself. But my big block FE engines are another story. Every one of them has always had oil drips and I have never been able to completely stop them or even find where they are coming from.

Ron