Pix added: Best way to clean up valve seats & a couple other questions

[700rpm]

I pulled the head on my coupe and there was a moderate amount of carbon, the worst on pistons #3 & #4 (see photos). When I removed the valves a couple of the seats were black, especially #5. What it is the best way to prepare them for grinding and seating new valves?

Also, looking at the photos, what do they tell you about what the engine was doing to create these conditions?

BTW, there was one Ford script valve, one marked EX, and one marked R.

[Tom Wesenberg]

Number 3 and 4 look like they may have overheated and scratched the cylinder walls. I think I'd remove the pistons and check the condition of them and the rings.

[pat in Santa Cruz]

3 and 4 look oily too, which leads me to suspect the scratched bores and possibly worn rings. I don't like home fixes for valve seats. If you're installing new valves, you should replace the guides. Then the seats should be cleaned up, centered to the guides and re faced by a machinist. If your rings are shot and the cylinders scored as much as they seem in the photo, new valves will increase the oil burning. A proper valve job means pulling the engine. If the cylinders are as scored as it appears in the photo, you might as well bite the bullet and consider a rebuild. Or button it up and drive it through this touring season as it is and have it rebuilt next winter.

[ford3]

in my opinion the engine needs to come out and be rebuilt, you have have several burnt exhaust valves, at least one burnt piston, and badly scratched cylinder walls, probably warped head and intake manifold, i think that would explain the damage to # 3 and 4 cylinders,cant put a mickey mouse fix on that engine

[Tom Wesenberg]

Be sure the coolant chambers are really clean. You might have a lot of rust flakes and scale built up around #3 and #4. Dig around with a screwdriver, coat hanger, and an old speedometer cable in an electric drill to knock the junk loose.

[James Rogers]

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Originally Posted by 700rpm

I pulled the head on my coupe and there was a moderate amount of carbon, the worst on pistons #3 & #4 (see photos). When I removed the valves a couple of the seats were black, especially #5. What it is the best way to prepare them for grinding and seating new valves?

Also, looking at the photos, what do they tell you about what the engine was doing to create these conditions?

BTW, there was one Ford script valve, one marked EX, and one marked R.

I will comment here because I see some problems not addressed yet. If you can wipe the up and down marks with a shop wrag it is oil. The #3 and #4 cylinders are burning a little oil. That is why the carbon was more there. I also see a score ring on 3 and 4. This is caused by water seeping into the cylinders and causing a ring of rust that is wiped off when the car is started. I see this most always in older motors and think it is the beginning of scoring that causes scratches that will make it burn oil.
Some close up pictures of the cylinders would be extremely helpful.

[Wick]

Head gasket leaking between 3 and 4? Does the head look just like just like it?
Could have a leaky intake valve or poor spark in #4.

[Gold Digger]

Cylinder #4 looks like a crack in the cylinder wall or water has stood on top of piston at sometime and etched the bore.

[Patrick L.]

I agree with #3 and #4 being a bit oily, especially #4. Clean up the bores in those holes with a rag and some gas and see what they look like then. I don't see any real issues with the valves,but... What was the compression ? Was a valve or two leaking ? Why do you want to do the valves, because of the excessive valve lash ? Anyway, a wire brush will clean up the valves and seats. Did you find a valve grinding machine ?

[Special Coupe Frank]

To answer you initial question about cleaning-up the valves & seats:


1 ) remove carbon deposits with a wire wheel (protect water passages, distributor drive hole, and cylinder bores from debris.

2 ) inspect valves and seats. any pitting or grooving in either face indicates the valve pair needs to be re-faced.

3 ) Inspect the edge of the valve head: it should have a flat edge perpendicular to the top of the valve head ( or parallel to the stem ): this is called the "margin". If there is no margin, and the valve is worn to a sharp edge, the valve needs to be replaced.

4 ) If the valve seats need to be refaced, best to either find a shop or knowledgeable enthusiast who has a machine to reface the seats with the engine in the car. Otherwise, you would have to pull the the engine, etc.

5) OR, you could take a page out of the "Grapes of Wrath", and "grind the valves" your self: get some valve grinding compound and one of those hand-drill type grinding gizmoes ( I believe Sears and Lisle still sell them ), and grind the valves by hand, until the seats clean-up. Technically, this is known as "lapping the valves" to a finish fit after machine facing. It's a slow way to go.


Now, the other responders have suggested that there are other issues that should be investigated, so I'm not saying you SHOULD try "grinding the valves" and driving on, but after thorough examination of the other factors, if it makes sense for you to clean-up the valves and drive on through this season, then tear-down for next winter, well, there you are.

Let us know how things progress. What's the known history of this engine ?

[700rpm]

Great answers and observations. Thank you all. I don't know the history of the engine. I have to be out all day today but tonight or tomorrow I will do some wipedowns and take closeups and keep you all informed.

[700rpm]

I wiped down the cylinders and here is what I found: minor vertical scratches on #3 (bare felt with a fingernail); some brown staining and what look like random scratches on #4, visible perhaps in the photos; a very slight carbon ridge on the top of #3, again just barely enough to catch with a fingernail. The worst of the valve seats is #5, though maybe even that is salvageable (I could try seating a valve there and seeing what happens). Overall the cylinders are not as bad as I first thought, but what are you all seeing now?

I plan to replace all valves with new, at least, but I don't know what else from there.

[MikeK]

This becomes a question of short term vs long term goals and how much money you want to throw at it. If it is just a bone-stock Henry 40 horse motor and you want to drive it this season just fix the valves, clean it up and drive. If you have long-term goals like a rebuild anything spent now is a loss.

[700rpm]

Originally Posted by MikeK

This becomes a question of short term vs long term goals and how much money you want to throw at it. If it is just a bone-stock Henry 40 horse motor and you want to drive it this season just fix the valves, clean it up and drive. If you have long-term goals like a rebuild anything spent now is a loss.

I figure I've got enough time left to drive this car maybe 8-10,000 miles before I'm too old. I guess that's a long-term goal.

[columbiA]

When I was 16,I hand lapped the valves with a suction cup on a stick,removed the cyl ridge with a brg scraper,replaced rings & adjusted rods & mains.I put 10,000 miles on the car in 2 years & it never leaked or burned oil.I think that there are many out there that spend big bucks on total rebuilds when an overhaul would do just fine.As long as babbitt is good & cyls are not badly worn,an overhaul will be fine.

[Tom Wesenberg]

What is the reason for the head being off?
Was the engine using oil, or making noise?

I agree with columbia that a simple overhaul might be good enough for several thousand miles. New rings and a light honing and valve lapping could be all you need for now. A putty knife, gasket scraper, or razor blade works well to remove the carbon from the flat surfaces.

[James Rogers]

Originally Posted by 700rpm

I wiped down the cylinders and here is what I found: minor vertical scratches on #3 (bare felt with a fingernail); some brown staining and what look like random scratches on #4, visible perhaps in the photos; a very slight carbon ridge on the top of #3, again just barely enough to catch with a fingernail. The worst of the valve seats is #5, though maybe even that is salvageable (I could try seating a valve there and seeing what happens). Overall the cylinders are not as bad as I first thought, but what are you all seeing now?

I plan to replace all valves with new, at least, but I don't know what else from there.

If you replace all the valves with new you will have to do the seats also. The new valves probably won't seat properly because the seats are ground by the guides. Just like machining a piece in a lathe, you can never take that piece out and put it back in EXACTLY the same way. If you just removed the existing valves and didn't mark them and the holes they came out of, you have this in front of you anyway. Now, if you marked them and can replace them in their respective holes, you can get a lapping tool and some lapping compound at the auto parts and lap the valves to get as good of a job as you can do with the new stuff. You might get lucky and be able to lap the new valves but you might not.

[Patrick L.]

Why do you want to replace the valves? The seats look pretty good from I can see from the pics, so maybe the valves are as good. If the valves have enough margin left when refaced then they should last for many years to come. I'm a believer in facing and grinding rather than lapping. You can set/put the seat contact area where you want/need it that way. I don't even lap anymore when finished like I used to. Again, previous questions weren't answered [ pretty normal]. Have you located a grinder ?

[700rpm]

Originally Posted by Patrick L.

Why do you want to replace the valves? The seats look pretty good from I can see from the pics, so maybe the valves are as good. If the valves have enough margin left when refaced then they should last for many years to come. I'm a believer in facing and grinding rather than lapping. You can set/put the seat contact area where you want/need it that way. I don't even lap anymore when finished like I used to. Again, previous questions weren't answered [ pretty normal]. Have you located a grinder ?

Five of the valves are pitted or slightly bent; only three look good enough to reuse. I have an ancient valve refacer, and it works pretty well, and a reciprocating tool with a suction cup for lapping the valves in, but I don't have a grinding machine, or even know what one of those is. I'm just a shade-tree mechanic.

I have kept the valves and guides in order and together. Three guides have carbon blacking on the inside journals.

The head came off because there was a ticking noise near #3 and my original hope was that it was just a valve that needed adjustment. When I opened up the valve chamber I realized I had non-adjustable tappets. I pulled the head to get the valves positioned properly for a valve clearance measurement. That revealed the situation shown in my first post, which raised all my questions.

The compression was good (about 55# on each cyl.) and the car was quite peppy. It just had that annoying ticking, which might have been tappet or maybe piston slap. There was a leak from the rear, probably the main, so I thought I might end up taking the engine out anyway, especially when I saw the non-adjustable tappets.

If I could find a hand grinder I might try adjusting the valves with the non-adjustable tappets, but those grinders are hard to find.

I'm not opposed to just pulling the engine and having new seats, guides, tappets and valves installed. It would also give me a chance, since I don't know the history of the engine, to take a look at the bearings and rings.

Given this information, any new thoughts? Patrick, did I answer your questions?

[woodypecker]

Thanks for all of the information. I learn a lot from this type of thread.