I can't drive 55

[fjc-man]

Easy check, what is the cast in head number?

 

[mrboatman]

What am I testing with this work? (Or what am I ruling out?)

With no rear drive shaft you will know if it’s a rear end problem or a front end problem

 

[MatthewMcD]

Random one, but could someone have put one of the heads for domed pistons on? I'd think you see that in the compression numbers, though.

How would I know?

 

[MatthewMcD]

Easy check, what is the cast in head number?

Where is that on the head?

 

[fjc-man]

L/F side of the valve cover, just behind the third head bolt on that side. Five digit number starting with 6.

 

[Pighead]

Where is that on the head?

Here

 

[fyton2v]

I changed my poll selection to "Other".

 

[zerotreedelta]

If my math is right, the open chamber heads are 61030 and 61031. Definitely a long shot, but it's any easy check to rule out (and it's happened before).

2F Head? - https://forum.ih8mud.com/threads/2f-head.108475/post-1369855

 

[MatthewMcD]

If my math is right, the open chamber heads are 61030 and 61031. Definitely a long shot, but it's any easy check to rule out (and it's happened before).

2F Head? - https://forum.ih8mud.com/threads/2f-head.108475/post-1369855

61030 so what does that mean?

 

[zerotreedelta]

I think those are open chambered 2F heads...I thought you mentioned prior that it had the earlier .5F?

I'm currently on mobile...but I want to say those heads go with the dome top pistons. Do you have a boroscope to peek down a sparkplug hole to see if you have domed or flat piston tips?

If it's got the wrong combo, compression ratio would be lower than it should be, which definitely wouldn't help power.

My 76 2F had the domed - reference:

 

[island45]

I once bought an old Farmall A tractor for 300 bucks a couple miles from my place. Was lacking power on the hills. On the last hill almost home, a rats nest complete with glowing embers erupted from the stack and showered me with hot filth, rags and nut shells. Good power after that. I forget now if you ruled out such an obstruction. If not, that's my vote.

 

[77mustard40]

I haven't done the rear bearings, but spinning the rear wheels is easy. The front hubs do unlock and were cleaned and lubed when I did the knuckles.

Ok whats the

I think those are open chambered 2F heads...I thought you mentioned prior that it had the earlier .5F?

I'm currently on mobile...but I want to say those heads go with the dome top pistons. Do you have a boroscope to peek down a sparkplug hole to see if you have domed or flat piston tips?

If it's got the wrong combo, compression ratio would be lower than it should be, which definitely wouldn't help power.

My 76 2F had the domed - reference:
View attachment 3749838

Compression was posted in #98 130-150 across the board, not sure if that was we or dry

 

[zerotreedelta]

Background:
5/75 chassis with an estimated 68-70 F (PO said .5F but others have doubted that).
4 Speed transmission
32" tires

With that head, I wonder if it's just still got the original factory 2F from 5/75...doesn't seem like you'd have the 68-70 F. It seemed like compression was ok, so it may have the right pistons...not sure of a way to check besides visual/boroscope.

One other thing that *could* be amiss if someone's been in it could be cam timing...if it's off a tooth, things would also get wheezy/wonky. I'm not sure if there's an easy way to test in-situ, though (vs checking gear alignment behind timing cover). Could possibly tell by watching the rocker arms vs TDC, but would need to know at what point a correct setup starts engaging...

 

[Skreddy]

With that head, I wonder if it's just still got the original factory 2F from 5/75...doesn't seem like you'd have the 68-70 F. It seemed like compression was ok, so it may have the right pistons...not sure of a way to check besides visual/boroscope.

One other thing that *could* be amiss if someone's been in it could be cam timing...if it's off a tooth, things would also get wheezy/wonky. I'm not sure if there's an easy way to test in-situ, though (vs checking gear alignment behind timing cover). Could possibly tell by watching the rocker arms vs TDC, but would need to know at what point a correct setup starts engaging...

From pics earlier and in other threads, looks like he’s still got the oil fill tube in the block and no provision on the passenger side for oil filter, if I remember right. It very well could be the wrong head.

@MatthewMcD can you post a pic of the engine stamp pad? It’ll be on the passenger side of the block, pretty much right below the timing window. Should be a machined pad with numbers stamped in it.
Also, any pics when the valves were adjusted and the valve cover off?

 

[Skreddy]

More or less, the open chamber head on a flat top block won’t give “bad” compression numbers because it’s still creating compression just fine; crank it enough and it’ll build pressure. What would be happening is it’s lowering the compression ratio and impacting performance. (Maybe why it had that tiny carb on there!). Unfortunately, there’s no way to reliably measure compression ratio that I’m aware of without pulling the head.

 

[Grayscale]

I think that compression and compression ratio are a bit different. Compression ratio is the volume of the combustion chamber to volume of the cylinder.

If his combustion chamber is unusually big, due to the wrong head, then the engine's exhaust stroke is lacking, that means that there is an excessive amount of exhaust in the air/fuel charge at the point of ignition. We'll call it, 'Passive-EGR.'

Were on page 16, and I think this discussion might have taken a turn by me noting a color and some clean valve-train components, maybe? Pics are super valuable to Mudheads, in my opinion.

 

[Pighead]

The head casting number on my known 1.5F is 60051.

 

[MatthewMcD]

I once bought an old Farmall A tractor for 300 bucks a couple miles from my place. Was lacking power on the hills. On the last hill almost home, a rats nest complete with glowing embers erupted from the stack and showered me with hot filth, rags and nut shells. Good power after that. I forget now if you ruled out such an obstruction. If not, that's my vote.

Amazing, I have not really ruled it out. I cannot remove the muffler without cutting it off because of the way they welded it on to the mount. I could disconnect it at the manifold and wire it up temporarily, but without back pressure is it worth risking HOA complaints for the test?

 

[MatthewMcD]

Ok whats the

Compression was posted in #98 130-150 across the board, not sure if that was we or dry

Dry

 

[fjc-man]

Something is fishy, my 5/79 40’s head is a 61031.