FMD dropped a valve

[Pepper Farms]

Last weekend I got my ‘59 FMD out to work up the garden a bit. When it was cranking over, it had kind of a funny sound like a valve was hanging up. It fired right up though and ran like a top like it always does. The tractor has never been over 1800 RPM and my Dad was just idling around with the scraper blade on. Next thing there was an awful sound and a bad miss in the engine. He thought for sure by the sound it had dropped a valve, so we got it pulled into the shop and took the valve cover off – sure enough the spring on #1 intake was broke and the valves long gone. We figure it was the spring that broke first and then finally the keepers and retainer just let go.

My question is, I have a spare head on the shelf from a Super Major, are the valves and springs the same as my FMD head? I haven’t looked any further into the engine, but I plan on robbing a valve and spring from that head if they will work and hopefully a sleeve and piston will fix the rest. Thanks for your help.

[Dandy Dave]

I do know that some of the Supers had a longer push rod. I'm not sure on the valves though. Best to pull a good one and compare them unless someone on here can tell you better than I. Dandy Dave!

[Timeee]

Dear Pepper Farms

There were a number of changes to valve gear, but mainly with the exhaust valve guides, rotator caps and collets, exhaust valve stem top profile, exhaust valve spring retainer and exhaust valve spring spacers (what the spring sits on) and so on. Stronger valve springs were fitted from Engine No1609839 and you can have 3 types of inlet valve spring retainers. The seals on the inlet valves were also changed from ring seals to cup seals. From what I can see in the Parts List, the actual inlet valve was the same.
Best course of action is to take a complete inlet valve assembly from your SM including retainers, collets, spacers etc. If one valve spring has failed, it is probably a good idea to treat your tractor to a new set of valve springs as well, whilst you have the whole thing apart. The damage caused by a dropped valve could be quite interesting too. Let us hope it is not too extensive.

Tim E

[Pepper Farms]

Thanks for the help guys. I finally got around to pulling the head off today expecting the worse and was pleasantly surprised at what I found.






The valve some how just fell straight down into the crater of the piston. The tractor probably ran for 15 seconds after it dropped the valve as we had to get the loader lifted and secured to pull it into the shop and work on it. Miraculously, it never hit the head, there isn't a single mark on the piston or the liner, and we haven't had it checked yet, but by eye the valve isn't even bent! I'm just thrilled that we don't have to pull the pan and get too far into this job to get it back up and running. I think I will treat it to a new set of springs, a gasket set and she should be good to go again.

[Pavel]

I would be inclined, PF, to check the head for warpage as there appears to have been water leaks into the cylinder, as well as slightly into the one next to it -- hence the pebble-dash appearance and shinier piston metal.

Pavel

[Timeee]

Dear Pepper Farms
What incredible luck, I think that would have made me smile in relief and possibly disbelief. You need to clear out the water galleries in your cylinder block, going by the sludge and debris you have there.

Regards Tim E

[AdrianNPMajor]

I agree with Tim's and Pavel's advice. Looks like your head gasket was blowing on no 1 cylinder too. If you have a machine shop nearby, it would be a good idea to have the head skimmed, new valve guides fitted, new valves and springs. You then know that the top end of the engine is back to tip-top condition.
As a matter of interest, what was the oil pressure like? Just wondering how the lower half of the engine is. Refurbishing the head alone is not always advisable.
Best
Adrian

[oehrick]

It looks to me as if the valve stem remained in its guide and was kept up by the piston (evidenced by the carbon which has been bashed off that bit of the of the piston crown), it probably dropped into the piston combustion / scavenge well after the engine stopped, or as you lifted the head, otherwise the stem would have punched through the head or caused even worse mechanical damage 'cos there ain't enough room at TDC.

Either way up whatever it is that looks after old Majors and their owners (known hereabouts as the Great Oily Rag) kept Mr Sod and his famous Law in check until you stopped it, award yourself a very large drink out of the money you've saved and get someone to make you drink it

Rick