I haven't had my '51 F-1 running since I bought it in 2002. The 'ole flathead V8 ran then, but I didn't really run or drive it much and frankly can't remember how well it ran. I've been putzing around with it lately and got her running again without too much trouble, but it was missing badly. I figured it had a couple valves stuck open as these crazy flatties tend to do when they've sat. My compression tester isolated #6 pretty quickly as being one of the dead holes. A quick exam through the spark plug hole revealed that the valves were working, but the intake seat has popped out and is rattling around and preventing the valve from closing.
Question #1 - I didn't think that the flatheads originally had removable seats. Is this correct?
Question #2 - If a removable seat had been installed to repair a bad seat, what would cause it to come back out? I've never seen this before. The flattie crack specter is haunting me here. I'm concerned that it may have a crack between the cylinder and that valve that opened up and released the seat. I don't have the head off, so it's purely speculation. A new seat and a valve job is one thing. A bad crack = boat anchor
All in all, I'm pretty disgusted with the situation. This old engine otherwise seems to be in good shape. Good oil pressure and the other cylinders were holding around 100 PSI cold. I've been toying with selling this truck to focus on my '52, but I don't want to sell it with a hobbled engine. Attempting to fix it is opening a can of worms and I don't have time for any more surprises right now. I've got other good engines I could put in it, but I don't have time for a swap right now, either. It's always something.
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Let's agree to respect each others views, no matter how wrong yours may be.
1 -- yes, they had hardened replaceable seats through '50 or so, then they went to a different spring assembly that was supposed to make the valves rotate and eliminated the replaceable seats
2 -- the seats do pop out from time to time, not "common" but it happens. Probably due to a replacement that wasn't staked in place well enough, seat and valve rusting together, something like that.
If it hasn't been run a long time with the seat flopping around, it's usually just a matter of removing the valve, cleaning up the block as needed, putting in a new seat (maybe oversize OD), and dressing the new seat.
You do want to check carefully for cracks, but cracks don't usually cause loose seats. Replacement seats are cooled with dry ice and simply dropped into the hole. Old one can be split with a chisel (cracked), I'd read up on how to do it first.
the earlier 8BA's 8RT flatheads had hardened valve seat inserts on the intake valves only I think up to or through 51, then 52 53 didn't have them. it could have been rebuilt at some point and had them installed as well. or engine swap?
I don't know if having the seat come loose is necessarily a sure sign there might be a crack in that valve pocket? chances are that if it's running and your not getting antifreeze in the oil you might be ok??
now having said that I purchased a running flathead a while back, (sounded just fine) and after getting it home found number 6 and 7 had cylinder to valve pocket cracks...
pull the head and replace the seat and valve, re-install head and run it. let us know what you find.
Josh
I think they do, or can. I had a repair shop from 1970 to 1974 and customer had a 48 pickup that he inherited from his father in law and it needed a new engine. I ordered a new rebuilt fatty from the local ford rebuilders and after installing and starting there was this noticeable tapping noise.
I pulled the head on the noise side and I don’t know if the blocks a fly cut (?) for new seats at the rebuilders or they come that way from Ford but one valve seat was lose in the block, no damage, and no time running. Now what? Warranty claim and paper work would take forever and this was a working shop, not a hobby, time was money.
The block is relativity soft compared to the hardened seat, four medium taps with a center punch (staked) next to the seat and viola (spelling), ………..fixed!
To the best of my knowledge the truck is still running today?
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It's always something.
