Flathead valves

[Joe Harrill]

Are the early mushroom valves the preferred valves for a flathead rebuild? Thanks Joe

[fordwife]

One problem I've had is they won't fit in my old Thor valve refacer. They might work in others.

[rotorwrench]

They are fine for originality on the early motors. The single piece guide and straight stem valves are easier to work with in my opinion. Apples & oranges, they both get the job done.

[GOSFAST]

You also cannot use bronze-lined guides with any 2-piece guide setup.

Anyone building their Flathead today is very foolish not to use bronze guides!

Thanks, Gary in N.Y.

P.S. As of today we probably have supplied "thousands" of the bronze guides AND stainless valves literally over 45 years of doing Flatheads. Not a single "hung" valve no matter what type driving conditions.

[Ol' Ron]

Another reason to use the solid guide is: they seal the intake valve better from hi vacuum oil filling the combustion chamber. THis was a major problem with the split guides. Now I just put a small amount of RTV on the guide when I install it

[rotorwrench]

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Originally Posted by GOSFAST

You also cannot use bronze-lined guides with any 2-piece guide setup..

It seems most replacement valves are all stainless now days, an even better reason to use the phosphor bronze lined guides.

[Talkwrench]

Originally Posted by Ol' Ron

Another reason to use the solid guide is: they seal the intake valve better from hi vacuum oil filling the combustion chamber. THis was a major problem with the split guides. Now I just put a small amount of RTV on the guide when I install it

I think Lawrie would agree with this, hey Lawrie..

[Ol' Ron]

When I was building engines, I always knelled my guides. Then reamed then for a tight fit. A knelled guide holds oil and prevents seizing. Never had any trouble with the, Bronze guides are a better way to go, just a few more $$$$.
Another thought is the length of the valve stem. That depends on the base circle of the cam.

[Brian]

Anyone building their Flathead today is very foolish not to use bronze guides!

I must be foolish then.....

[flatjack9]

Me, too.

[tubman]

Should we start a club?

[Seth Swoboda]

I guess I just don't understand the bronze guide idea in a stock flathead build. I've never had this done and so far my engines are still running.

[rotorwrench]

It would be advisable to run a soft metal guide insert if using an all stainless steel valve. Stainless valve stems tend to gall against the guide if they are hard cast iron or steel. I've noticed that a lot of the new replacement valves are all stainless these days.

Back in the day, they had steel stems fusion welded to a stainless valve head at least for exhaust valves and many times for both valves depending on the manufacturer and the time frame. Charles Thompson of TRW is the man that developed that process. Valves were cheaper to manufacture this way and there were no galling problems with the cast iron guides.

[GOSFAST]

Originally Posted by Seth Swoboda

I guess I just don't understand the bronze guide idea in a stock flathead build. I've never had this done and so far my engines are still running.

Hi "Seth", the first time you experience any "hung" valves you will be wishing you had the bronze in there.

There are a couple more advantages than first meets the eye, one being you can run "tighter" valve-to-guide clearances with the bronze. This helps extend the life of the valves/seats AND cuts down on the amt of oil into the chambers through the guides. We've further eliminated any added oil consumption with the use of the newer "Viton" stem seals on the intake valves!

(Add) There are still mfr's using the 2-piece welded stem procedure, Federal-Mogul for one! Part #V-1041, made in S. Africa (photo below)!

Thanks, Gary in N.Y.

P.S. You may want to start a club for anyone that experienced the "hung-valve-syndrome", I would be the first member. My own '49 F-1 was the first set of bronze-lined guides I installed long ago!

[Seth Swoboda]

Thanks for the info GOFAST. I'm not running any stainless valves. Would that make any difference in using bronze lined guides?

[freddie]

I am in the process of rebuilding my V8 flathead. A lot to do: new sleeves, solid valve guides. new valves etc. Where do you purchase these "bronze sleeved guides?

[tubman]

Originally Posted by freddie

I am in the process of rebuilding my V8 flathead. A lot to do: new sleeves, solid valve guides. new valves etc. Where do you purchase these "bronze sleeved guides?

PM Gary "GOSFAST" (two posts above). He manufactures them. Plus, he's a good guy to know if you're doing anything major with one of these engines.

[Frank Miller]

Got a friend who has an airplane with a Lycoming opposed 6 cylinder. Had to make an emergency landing due to a cold cylinder. In the end it was a stuck valve. You can google this and learn more than you expected. They have a procedure for servicing them without removing the cylinder which includes reaming the carbon buildup from the guide. He said his mechanic suggested he run some MMO in the fuel.

[rotorwrench]

Originally Posted by Frank Miller

Got a friend who has an airplane with a Lycoming opposed 6 cylinder. Had to make an emergency landing due to a cold cylinder. In the end it was a stuck valve. You can google this and learn more than you expected. They have a procedure for servicing them without removing the cylinder which includes reaming the carbon buildup from the guide. He said his mechanic suggested he run some MMO in the fuel.

I've been dealing with stuck valves for many years. Lycoming SI-1425 covers the procedure. The valve can be pushed back into the cylinder when reaming the carbon and polishing the guide. It can be a b!tch to get the valve back in the guide sometimes if it gets away from the magic fingers holding the stem. I've fished a few back in like that. Luckily it is not as common now as it used to be. The modern high chrome guides do very well as long as the clearance is correct to begin with.

[drolston]

Consider Power Flo stainless valves from Flathead Jack, while he is still open for business. Those valves have the lock groove moved up .190" so spacers are not needed. I had a little vacuum flutter at idle and compression a little low on two cylinders until I started adding 4 oz of MMO to each tank of gas. Now compression is within 5 lb on all cylinders and vacuum is steady at idle. I am using solid guides of the non-bronze variety. Not sure whether it was the MMO or just a matter of breaking in the new rebuild.