Valve Seat Material

[Mr. Land Yacht]

I've seen some aftermarket heads have Ductile Iron as a valve seal material and others have Tungsten.
From what I read about the materials briefly on Wikipedia, I get the impression that Tungsten is a little better to the point that it is used on space shuttle nozzles or something like that due to its hi temperature tolerance.

What's a better material?

[88grandmarq]

I've seen some aftermarket heads have Ductile Iron as a valve seal material and others have Tungsten.
From what I read about the materials briefly on Wikipedia, I get the impression that Tungsten is a little better to the point that it is used on space shuttle nozzles or something like that due to its hi temperature tolerance.

What's a better material?

Say Wut ? !!

valve GUIDES are made of Metal... Valve SEALS are made of rubber or some premium synthetic material.

the valve GUIDES are pressed into the cylinder head and valve SEALS, seals the end of the valve to prevent excess oil running down the valve and into the combustion chamber.

[Mr. Land Yacht]

oh, I was off by 1 letter...Valve Seat.

[88grandmarq]

Oh.. I see.
Never mind then.

[Mr. Land Yacht]

I called up TrickFlow and they said the Tungsten is a little stronger for hi-temp than the ductile iron and they've been using it for a long time.
He also mentioned it doesnt wear as quick.

I also explained my oil burning issue and he mentioned that the valve guides could have gone bad and gave me a way of testing it.

[1987cp]

With zero practical experience, I'm sure tungsten should be an excellent valve seat material, especially for exhaust valves.

Your ported E7 head don't have separate valveguides unless Gerry drilled them out and installed bronze sleeves. My machinist in Indiana advised me that wear in the guide area on a stock iron head was typically not a concern, but then, his experience is mostly with stock stuff.

Do you know what style valve seals were installed on the heads before assembly? Common "umbrella" seals tend to lead much shorter lives than the fancy crimped-on variety, but either way yours should be nearly new ....

[Mr. Land Yacht]

no idea on these heads as to what's installed for seals.

[gadget73]

Fixed the thread title.

Most heads use iron seats. In fact, with a lot of production heads, they have no seperate seat, its just a machined area in the combustion chamber. Thats what the E7 has. Unless you have a crazy motor, you don't need tungsten valve seats.

Bronze guides are typical, and typically worn with a lot of miles. The heads on my car presently have new guides because the ones in the heads were shot when Gerry got them. He actually called me about it. Unless its real bad, usually it doesn't cause much oil burn. I'd expect a problem with the seals more than guides, but if the guides are really really bad for some reason (and I honestly doubt that), it could cause your problem. I kind of doubt thats the case though. Gerry checked mine and found they were worn, so I very much doubt he did not check yours for the same problem.

The seals that you should probably have look like this. Its what comes in most rebuild kits, and its what I have on my heads.




Just a side mention, if you haven't done a leakdown test on that motor, you might want to. It might be the oil burning is in the shortblock, not in the heads. I put a set of heads on mine trying to fix a problem that turned out to be out of round cylinder walls. I had 40% leakage, and it was all past the rings. I could have saved myself a lot of work if I'd diagnosed the problem correctly in the first place. Leakdown test will not pinpoint bad valve guides, but it will eliminate the rings. Since oil can only get into the combustion chamber through the rings or around the valves, that kind of narrows it down

[Mr. Land Yacht]

Thanx for fixing the title!

as far as the leakdown test, isnt that similar to a compression test?
cuz I did a compression test and saw 10% variance like normal so I figured the rings are still good.
Plus, I spent a bunch to have the block remachined and it had new pistons, rings, bearings, etc. so that such a thing wouldnt be an issue.
eh, even the best motors ever built aren't bulletproof.

[gadget73]

Leakdown test puts air in the cylinder while its at TDC. It has a guage that shows how much air is leaking, and if you listen around the motor you'll find where its going. If its hissing out the carb, the intake valves are leaking. Hissing in the exhaust is an exhaust valve problem. Air coming out the oil fill is a ring problem.

When I had problems with mine, a compression test didn't tell me much. I was showing about 140 psi on each cylinder and had no more than 5 psi variance. The leakdown test told me 40% leakage, pretty much uniform on every cylinder, and all the air was blowing out the oil fill cap. Under 10% is where you want to be, the less leakage the better.

Not saying the shortblock is for sure the problem, but I've come to appreciate the dollar value of an accurate diagnosis. It really sucks throwing money at a problem only to find you threw it in the wrong direction.

[Mr. Land Yacht]

I'm guessing my oil issue and my coolant issue are both due to the heads. Which I don't want to admit.
I'll do the leakdown test and see what happens.

When I do this leakdown test, should the engine be cold or warm?

[Lincolnmania]

do it cold so you dont burn yourself
here is the one thain keeps here for me to use http://www.harborfreight.com/cpi/cta...emnumber=94190