M Head Question

[Bouncer]

I pulled the valve cover on the new to me M puller just to have a look around. First thing I noticed was what appeared to be new valves, springs, and retainers. That was a pleasant surprise in itself. Then I noticed the springs looked extra heavy and had another smaller set inside them, that would make good sense because when I checked the rpm yesterday it was turning a tick over 2800. The retainers were dished inward and looked somewhat custom, I am wondering if they are titanium. I then proceeded to pull the governor cover and found out how they were getting the rpm. The spring is gone a nicely made piece of round bar was in it's place and the stop screw was missing. Well, I will have to rob a junk governor of the stop screw and get a new spring from TSC and get my rpm back down to around 2000 where I am legal.

Anyways, back to my question. The head has no casting number on it. That was really the whole reason I even pulled the valve cover. Right there in the middle were the casting numbers should be, it is all flat. Does not appear to be ground flat, but cast that way. Would anyone have any ideas?

Thanks!

 

[red pullen]

is it a lemmons propane head

 

[north puller]

I believe a lemmons head uses 14mm plugs instead of 18mm plugs. That will tell you if you got one. If that tractor has a cam for 2800 RPM, you may want/need a new cam for your lower RPM range.

 

[north puller]

Possibly a smaller venturi too.

 

[Bouncer]

It is not a Lemmons head, I do know that. I went back out and cleaned the head off good and it does appear the casting number was ground off. Because there are a couple castings for the valve guides have the edges distorted on them from what looks like a grinder. I am attaching a couple pics and the only other markings I can find is a 5-20-L casting code on the outside. Also found what appears to be a hand stamped number on the back carb side of the #4 cylinder. I took a pic but it is hard to see. The hand stamped number is 3574. I guess since the casting codes are gone I will never know what head it is. I also included a pic of the way the governor was set up. I got new stop screws in it and a new spring. I will fire it up tomorrow and see what other adjustments needs to be made, because I think someone has messed with the linkage running inside the governor as well.

As for the cam, I have no idea what is in it and neither did the guy I bought it from. He took it on trade from a old guy who retired to Florida from pulling. The old guy told him it had head and block work done, with pistons, valves, cam, etc. I was going to build a ground up puller this Winter, but I am way money ahead starting with this tractor for what it cost and what is already done to it, as far as wheelie bars, weight brackets, lightened, etc. I am going to most likely go ahead and pull the head and see what is inside. Just trying to figure a few things out as I go. I do know it starts and seems to run awful well, and has a nice throaty note to the exhaust.

Also disregard the way the oil looks, the flash made it come out that way. You can see in the first pic that it is fine.

 

[north puller]

The only reason to grind off the numbers is because it's not original. Most likely a 450 gas or LP head. Doesn't matter if it works good. I would do a compression test. See where you are at and get an idea what fuel you need to run. After that, get it on a dyno. Record your HP and TQ numbers at 100 RPM increments from wide open high idle down to about 800. See where your peek power and peek torque are, and how it holds as you pull it down. If it works good, leave it. If it falls of fast in the bottom end, try carb work first as it is cheap and easy. I would only pull the cam if I felt it really needed it. I would only open the engine up if the compression test gives poor results. The dyno will give you a good idea of what you have for a pulling engine.

 

[MRGJNV]

In my uneducated opinion, it's not an LP or 400-450 head. My reasoning is if it was an LP head, it would have crater like holes on the top on the manifold side. You would be able to see them without taking the valve cover off. Second, 400-450 heads didn't have that breather pipe running horizontally under the valve cover. M-SM did which had a breather tube running from the back of the head to the oil bath. If it is a 40-450 head, the breather tube would have a fitting on the valve cover going to the oil bath.

Not the gospel but just some info I have found.

 

[blackih300]

Did that tractor come from new york/pennsylvania??

 

[Bouncer]

No, it came from Southern Kentucky/Northern Tennessee area.

 

[Anonymous-0]

what does the linkage do just give you more rpms, why didn't they just put a bigger spring?

 

[jd b puller]

Who put the chocolate milk in the bottom picture?

 

[Bouncer]

Like I said in the post, disregard the oil in the last pic. The flash caused it to look that way. You can see it looks fine in the top pic.

 

[colekicker]

I believe what you have is a head that was remaned from IH. I have one of these. The casting numbers were ground off. Mine has stamped numbers near where they old numbers were ground off.

Also, there may have been some integrity issues with this head at one time and it may have been welded or fixed in this area. Sounds crazy, but it have have happened.

I would look some more on the head with it cleaned up on top and see if you see any evidence of stamped numbers.

I think you have a gas or distillate head from a M or Super M.