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Hello guys -
I pulled the unit in the barn to start cleaning and disassembly and noticed that both valve covers are surprisingly loose - 1/4" movement up and down.
Is this an indicator of anything more than the lower gaskets are missing?
Just thought I would ask so I can prepare myself for potential disappointment.

Thanks
 

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:wwp:

If your engine was manufactured as a 6.6 hp, the valve covers should be single-piece assemblies bolted to the top of the case. It's hard to see how they'd be moving at all. If it was circa 57-58, was manufactured as a 5 HP then updated, it probably has the aluminum add-on valve covers. Those do come loose, though again it's hard to see how they'd be flopping around that much.

More details please.
 

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Oops. Misred; it's a '60. Still would like more detail on the valve covers. It's possible that it was a leftover 5 hp model which was later upgraded.
 

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Interesting; I have two 6.6 hp tractors and they both have the two piece valve tappet/adjuster covers. My understanding (and it could be wrong) is that the old spring loaded covers were used on the 5 hp tractors, the two piece covers (aluminum and CI) were used on the 6.6 hp tractors and the single piece all cast iron tappet and adjustment housings were used on the 7.6 tractors. IMO the single piece CI units are the best as you eliminate a potential leak point where the two piece covers go together. Also they have a slot in the tappet bore that lets oil vapor up into the spring area with would help with lubrication of the valve stems and help solve the dreaded exhaust valve stem seizing problem.
 

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Heres what they look like on my 1960 L , or used to. And I have a parts tractor that is supposed to be a 58 model but I dont know but it has the valve covers or "towers" as I call them the same as the 60. Oh BTW the 58 or so model is supposed to have a 7.6 motor but the jug fit right on my 6.6.
But this is the extent of my knowledge about them.
 

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Interesting; I have two 6.6 hp tractors and they both have the two piece valve tappet/adjuster covers. My understanding (and it could be wrong) is that the old spring loaded covers were used on the 5 hp tractors, the two piece covers (aluminum and CI) were used on the 6.6 hp tractors and the single piece all cast iron tappet and adjustment housings were used on the 7.6 tractors.
Sort of. But the thing about these machines is that everybody, from the owners to the dealers to the factory, fiddled with them, so there's no hard rules about what you'll find on what years.

The factory was always willing to indulge in parts-bin engineering, so it's not uncommon to find things that are a little bit of a mish mash. Also, there were retrofit kits sent out to the dealer network, to do field mods on tractors being serviced or returned. The original 6.6 engine is an example. About mid-'57, IIRC, they started making the parts for the 6.6 hp upgrade, and changing the assembly line over. But they still had 5hp parts, so they kept using those too. The change included the two-piece aluminum valve covers, so that they could use the original cases from the 5 hp engine. My '58 has (well, had, I changed the engine on it, but aim to change it back) an engine which clearly started life as a 5hp unit, then was upgraded with the aluminum covers, either at the factory or at a dealer. Others of my 6.6 hp machines came stock with the CI covers.

It's misleading, to the point of being wrong, to think of 3 different engines, of 5, 6.6, and 7.6 hp. It's the gravely T-head engine, which was in use from 1935 up to the '70s, and along the way, assorted tweaks were done to it to increase power. But the configuration never changed, and most of the parts are usable on any engine anywhere in the history.
 
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