Valve stem oil seal for TFS street heads

[Jack21]

Previous engine builds (lotsa Pontiacs, coupla Olds's, few 289's & 302's), used teflon or teflon insert valve stem oil seals. This was SOP. The rubber seals with the gasket set were trashed. The rubber ones harden after awhile, then the engine starts drawing oil down the valve stem. Not a good idea for a warm street motor.

TFS recomends using the stock type neoprene rubber valve stem seals stating the valves need more oil. Machinist doing heads dutifully removed the teflon seals and put the rubber ones on. Has iron, not bronze guides.

Some of you have more miles on your TFS's than I do. Teflon, or rubber valve stem seals?

[Jack21]

C'mon guys. Somebody has had to have addressed this. Use teflon and forget it? Use neoprene and replace them every coupla years?

[Leo]

I had an early production set. In less than 1,000 miles the guides were worn so much you could wobble the valve and spring assembly by hand. At that time, (I know) they had teflon seals and (I'm not as sure but think that they had) guides made of a black material.

TFS rebuilt the heads, converted the bolt-down to stud mounts, put in bronze guides and black rubber seals.

They have never been installed since; they're actually for sale.

I too have heard that the teflon seals seal too good and would rather change valve seals than removing the heads for new valve guides.

Hope this helps!!!

[Jack21]

Thank you. That's what I was looking for. The TFS smallblock Ford heads were taken off the market for awhile ('97 - '98) because of accelerated valve guide wear as you describe. I got one of the first sets of newer production heads that were supposed to have solved the guide wear problems. They use hardened iron valve guides with neoprene rubber seals to allow more oil on the guides.

As a precaution, I had the pistons flycut for both TFS heads, and standard heads, so if the TFS's gave me any problems, I could swap for another brand.

The seals I'm accustomed to using are the Perfect Circle teflon insert, not the full teflon with the wire spring on the valve. They seemed to provide just enough sealing for stem lubrication and long life. They worked well on my Pontiacs, Olds's, and 289 stock head Fords.

I suppose with the TFS's, I could leave well enough alone. They work, although for how long remains to be seen. The engine used one quart of oil during break in, and has used one additional quart to its 6 month oil change.

Was wondering what others experience had been.

You might inquire with TFS on those early production heads. Make enough of a fuss, and TFS should replace them under warantee for a pair of later production heads. Performance wise, they work great.

You do have to play games with the pushrod guide plates, making sure the rocker arm tip is centered on the valve tip before tightening everything down. No easy to adjust, and TFS tech support is no help.

Again, thanks

[Leo]

TFS did rework the heads under warranty. I was impressed as they had sat in my garage about a year before I installed them...they even gave me a decent price on rocker arms as I had to buy a new set.

I did the same thing on the flycutting. It paid off when I replaced the TFS with stock heads when I sold the car.