Freeing stuck valves.

[russcc]

I have 3 exhaust valves, cylinder #3, 6 & 8 that continue to not seat properly or stick in the guides. I had the manifold off, and was able to seat the hung ones. But after reassembly compression is way off in those 3 cylinders even after Kroil, MMO and driving it. Speaking of driving it, the engine pulls like gangbusters, but I hear an occasional back burp through the carb at steady throttle. It starts in a flash, but does not idle well. I hear an occasional pop through the exhaust, which goes away if you pull the # 8 plug wire. The engine has only about 7K miles on it, but has been sitting off an on for 10 years. Compression is an even 115 PSI on the other cylinders. So I plan to pull the heads and manifold, and remove the 3 valves and clean up the seats. What is the best method to free up the valve stem to guide clearance. I have a lathe, and access to a good old time automotive machine shop. I know Ron recommends knurling the stems, but I would probable do that if was a new re-build. Thank you Fordbarners

 

[WestCoast]

there is a couple of ways if the valve and guides are out of the engine, you can chuck the valve up in a drill press and polish it with emrey cloth, fine grit, and you can put the guide in a vise, not to tight you don't want to egg shape the valve hole, put valve grinding compound inside the valve guide hole for the valve, and some on the valve stem, insert valve in guide, put end of valve stem in a drill chuck. run the valve in and out of guide till the valve slides freely, don't over do the valve grinding thing, you don't want a lot of play between the valve and guide

 

[russcc]

Thank you "WestCoast". Couple of simple ideas. Great.

 

[Ross F-1]

If simply cleaning with solvents to remove varnish doesn't make the valves slide freely, I'd be inclined to simply replace those guides. They're cheap. Use NOS if you can. I'd assume there is rust if it isn't just varnish.

 

[va t]

Trickle some Shaler Rislone down the carb at idle. Let it soak overnight. You just might avoid a teardown.

 

[GOSFAST]

If you have the guides out of the unit simply have bronze liners installed.

We do these bronze lined Flathead guides all the time, they will never hang up as a result of "sitting"!

Thanks, Gary in N.Y.

P.S. Every Flathead build we've ever done got these guides, started doing them this way back in the '70's, have never had a single valve hang! My own '50 Ford pickup sat through winter months of storage with no issues.

 

[tubman]

Gary,

This all sounds very good! Are you a source for these bronze-lined guides or can you point us in the right direction? Do you need al 16 bronze-lined guides or only 8 for the exhausts? I have a couple of 8BA's ready to go and would really like to do everything right! Perhaps an estimate of what it would cost?

Tubman

 

[joe 1950]

i agree with va t I have used rislone oil supp. for 30 plus years this is one of the best additives on the market since about 1927 I think it was made for flat heads try this first if you don't have it apart

 

[Ronnie]

Stay away from valve grinding compound on the stem inside the guide that is a recipe for disaster. Determine what is making the valve hang up and repair said problem.You state you access to a good old machine shop they will give you the proper advice.Some 400 grit paper on the stem should be all you need and check for the valve being straight as the first thing and proceed from there.You also have to check the seat contact after the valve moves freely in the guide.This is the assumption you have an 8ba.A 59a is another can of worms.Ron talks of knurling in reference to the guide not the valve stem.Bronze guides are a good fix also but not cheap and you then need to attend to the seats as well another expense.

R

 

[Tinker]

Sounds like you have some burnt exhaust valves... Maybe.

You need to pull the heads. You might be able to clean up the carbon and run what you have. If so, Then you have to look at a rich running carb or maybe/possible a short engine running cycle.

 

[Ronnie]

Gary,

This all sounds very good! Are you a source for these bronze-lined guides or can you point us in the right direction? Do you need al 16 bronze-lined guides or only 8 for the exhausts? I have a couple of 8BA's ready to go and would really like to do everything right! Perhaps an estimate of what it would cost?

Tubman

Any good machine shop can install liners in removable guides if they do bronze liners as a standard repair.I have also done them for years but it is nice to have the valves for the engine to measure and get the correct clearance.Talk to one of your local shops and see what they want to do the job,but once again you now have to do the seats as everything has changed.It is a very acceptable repair indeed.

R

 

[Tinker]

If you have the guides out of the unit simply have bronze liners installed.

We do these bronze lined Flathead guides all the time, they will never hang up as a result of "sitting"!

Thanks, Gary in N.Y.

P.S. Every Flathead build we've ever done got these guides, started doing them this way back in the '70's, have never had a single valve hang! My own '50 Ford pickup sat through winter months of storage with no issues.

Guess I'm confused on this thread... Is this the same engine.

 

[russcc]

It's an 8RT. Thank you for all the good advice. I will take it down, and remove the 3 hanging exhaust valves and see if I can see why they are hanging. Probably reasonably obvious. Then go from there. Will check out the seats also, and maybe lap them to clean them up if needed. Prescription without diagnosis is malpractice. Thanks Fordbarners

 

[Old Ford Addict]

Id
Remove the valve assembly’s
Check spring pressure at installed height … (shim for more if needed )
Disassemble and clean
Spin the valves in the guides with a drill motor
Check that I’ve made them slide better
Lap and re assemble

 

[GOSFAST]

Gary,

This all sounds very good! Are you a source for these bronze-lined guides or can you point us in the right direction? Do you need al 16 bronze-lined guides or only 8 for the exhausts? I have a couple of 8BA's ready to go and would really like to do everything right! Perhaps an estimate of what it would cost?

Tubman

Hi "Tubman", we actually supply other builders with these finished pieces.

You need to do all 16 to make it worthwhile with respect to the valves "sticking", either intakes OR exhausts can "stick", we've seen both on occasion.

I would like to just add something pertaining to the overall cost, of course it will be more expensive to do the liners up front, but you need to just imagine the cost's of ripping into the unit later and repairing the problems. Labor aside, you are looking at a minimum of all the topside gaskets AND fixing the issues.

(Add) Knurling the guides is better than not, but is still NOT a 100% guarantee.

With respect to "sizing" the guides and not having the valves to work with, you would be looking at the very same issue if you merely purchase new guides. Almost ALL my customers have us supply the finished guides, (16) new "horseshoe" retainers, and 16 new stainless valves along with the "Viton" seals. It's pretty much a complete package.

If anyone needs to contact me, do it with an e-mail, I don't get to the forums sometimes for a week or so. My e-mail address is: Theengineshop@aol.com

Thanks, Gary in N.Y.

P.S. The only issue with doing these guides is you really need to get the existing pieces (guides) to us to save the cost of purchasing new guides and THEN doing the liners. These 16 pieces fit nicely into the smaller "Flat-Rate" USPS boxes. We normally cover the return shipping when finished. This means an outlay of about 6.00 to get the old guides to us. We will determine if they aren't useable, most times if they aren't broken we can salvage them. You can see in the photo's below, we keep a good supply of new guides as well as the lined pieces! Every piece shown here is "USA" made with the exception of the valves. Some valves are made here, some aren't! Ferrea has some of the best ones ever mfd, and they come from Argentina.

 

[supereal]

When we rebuild a flathead we install straight stem valves, new springs, new seats, and adjustable lifters, along with one piece guides and seals. To save cost, we usually put in Chevy valves. When laying out big money for a rebuild, anything less will result in problems and a dissatisfied customer.