Replacing a loose valve seat

alexiskai said:
I have managed to locate a machinist who says he can do it. Thanks everyone for the advice.

Brent, I want to be clear that I think your perspective is really valuable and probably correct in the long run. I certainly see myself in part as a caretaker of this car.

But in practice there will often be times when, for budget reasons, a decision has to be made between doing a partial repair that kicks costs down the road or putting an engine, or an entire car, in mothballs for years.
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Thank you for the complement. It sux when $$ get in the way of our 'toys'.
 
alexiskai said:
It was hack jobs by backyard mechanics that kept most of these cars on the road long enough for "hobbyists" with thousands of dollars to spend to come sneer at their work.
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Years ago they were hacked due to the value of the car. The cost of pulling the engine and having a valve seat correctly installed is minimal provided you do the labor.a few gaskets a valve seat and machinist time is all you are out of pocket,given the block damage its under 300 bucks..whats your engine worth ? How about your car? When you could buy one for 10 bucks they got hacked...only a fool hacks a 15k car
 
Jack Shaft said:
The cost of pulling the engine and having a valve seat correctly installed is minimal provided you do the labor.
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You're making some interesting assumptions about my prior investments in hoists, jacks, crates to put the engine in, a truck to haul it around... oh wait, I forgot, the magical "guy from the local club" is supposed to provide these for me.
 
Model A club 'goodwill'? meh..the good lord helps those who help themselves,once they found out I've been a mechanic for 40 years they were on me like flies on ****..you're tooled up? quit posting and get to work,it always goes faster than you dread..the satisfaction from a quality repair performed at minimum cost far outweighs the risk..
 
From Brent....

As far as the India-made cutter, there is a portable valve seat machine manufactured by Neway that will dress valve seats. The two or three issues I have personally seen with these is they are not really robust enough to cut the new angle on a new seat that is vertical in shape where the 45° angle usually is. The next issue is these hand-operated cutters are very easy to apply pressure on the pilot in a direction that pushes the cutter outside of perfect alignment with the guide bore. When this happens, the concentricity of the seat is not in alignment with valve face. The third thing is many times you will see start & stopping places from the carbide cutters when being twisted by hand that left tiny gouges in the seat. Generally speaking, compression pressure leaks across the seat and this can cause poor performance or even cause a burned valve.

I can vouch for the accuracy of all the above. The human element of controlling the allignment during the process is very difficult to achieve. I have done three jobs with the Neway device, it is very difficult to get excellent results.
 
I'm hoping to get it done next week; I'll be sure to report back on how it goes and what tools were used.
 
OK, I just had the new seat inserted and ground in, plus he reground the other 7 seats. Unfortunately I had to take a call and I missed the actual doing of the thing, so I don't know what he used except that he said he uses stones rather than carbide cutters.

However, he did recommend a product called Seal-Lock Fluid Weld for anyone doing valve seat inserts, valve guides, and minor crack repair. I had brought some with me to ask about, and it turned out he had his own supply and used it all the time. You spread it underneath the insert, and between the guide and the bore. When the engine is run, the polymer flows into any gaps between the steel parts and the block, and then the heat sets it permanently. This helps keep the parts in place and improves heat transfer. Formula is proprietary but is suspected to use hexagonal boron nitride as the "active ingredient."

Next step is to put some Prussian blue on my new valves from Snyder's and see how accurate the grind is.
 
If the guide was treated with the magic juice I hope your new valves are straight stems. This is a fascinating discussion, I'm old enough to remember the local automotive machinist coming to the shop with his hand held tools and doing a flathead valve seat replacement neat and clean. Small upcharge for the house call. :)
 
Flathead said:
If the guide was treated with the magic juice I hope your new valves are straight stems. This is a fascinating discussion, I'm old enough to remember the local automotive machinist coming to the shop with his hand held tools and doing a flathead valve seat replacement neat and clean. Small upcharge for the house call. :)
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Yep, I got the Snyder's kit with the straight valves and the one-piece guides with shoulder.

Guy did the whole repair on the driveway in front of the shop. New insert, ground all the seats, charged $60. I said I had $56 in cash, he said that'd be fine. :)
 
Hello
I had this problem on the number number 4 cylinder .
I went to the auto parts store with the old seat and got the next size up
then i took a piece of strut material and drilled two holes to match the head bolts next to the seat and used a socket just a little smaller than the seat and used
the head nuts to press it into the block ,worked good . you do have to grind the new seat after and hand lap the valve.
Dennis
 
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