weird crankshaft

L

larry harding

Senior Member
here are some photos of the crank that was in the engine i purchased at portland ind. last week. notice that 3 and 4 throws are at 90 degrees from 1 and 2, not 180 degrees as most 4 cylinder cranks. what is this crank out of?
i think i have a good crank in an engine with a busted block i can use. this engine had been worked on (looks like new valves etc.) but never could have run properly with two pistona out of time.
 

Attachments

  • DSCN5306.jpg
    DSCN5306.jpg
    76.2 KB · Views: 412
  • DSCN5307.jpg
    DSCN5307.jpg
    121 KB · Views: 411
Have you removed the center main cap yet?Never mind,For some reason only one picture showed up until my second look.
 
As d.j. said. With a matching cam to time the valves correctly it could run. Not sure how you would get proper ignition timing tho. :rolleyes:

Very Interesting... :p:p
 
Before you took it apart did you see if the valves were opening and closing in relation to the piston positions?

Bob
 
Yes, that really is an odd one.
Does anyone know anything about who or why such a crank was built?

As mentioned, you'll have to check the camshaft and distributor cam to see if they are correct for this crankshaft or correct for the stock crankshaft. Now is also a good time to check the cam gear condition.
 
larry harding said:
here are some photos of the crank that was in the engine i purchased at portland ind. last week. notice that 3 and 4 throws are at 90 degrees from 1 and 2, not 180 degrees as most 4 cylinder cranks. what is this crank out of?
i think i have a good crank in an engine with a busted block i can use. this engine had been worked on (looks like new valves etc.) but never could have run properly with two pistona out of time.
Click to expand...

Hey Larry,
Hm, very interesting, as it looks like the crank was custom made that way, i.e.- not 'farmer' fixed. Yeah, cam would have to be special also. Let us know what you learn.
Maybe a variation on the Winfield idea...two up/two down :)
Someone spent a lot of energy (time/$) on this. Have you tried to trace history back ? Ooops , that's right you bought it from a guy who didn't reveal (or maybe didn't know)build specs.

We do have an innovative builder as a member here, who may could help explain what we see ;)
 
Just my guess but I'll bet Money you have a Ford Prototype.
Especially if the cam timing matches.
A very Unique piece of Priceless Henry Ford History.
It would cost a lot of money to make that.
Unless it was broken and repaired, I Doubt that tho.
 
Maybe an air compressor type motor. Run on two cyl. & pump air on the other two?? Gordon Smith made these but I thought they used stock cranks.
 
Didn't Winfeild build a 2 up 2 down T motor in the 20's? Ran like hell, but shook like hell too if I remember correctly. Never heard of an A motor like this though
 
Look at the wear of the pistons.

If it is compressing the wear will be on the opposite side of the piston then combustion pushing down. At least I am pretty sure that was what I was told once.
 
i went to see the local "a" guru who is in his 80's, he had no ides, but another guy came up looked at the crank. that is when we noticed a couple of small divots around the middle of the center main. either the crank broke or someone cut it into and welded it back together with 3 and 4 off by 90 degrees and probably not very strong either. you would have to run an 8 cylinder distributor to get timing right. i'm pretty sure the cam is stock with openings corresponding with a regular crank. right now i think i have a $500.00 boat anchor unless someone has a better idea. the extra crank i have has different size mains so that is out.
 
forever4 said:
That is what I am thinking also.
It would be a better compressor with such crank having the running and pumping throws offset.
Also note Larry's crank had the slinger cut off.
Here is a Model B version that runs on 1 & 2, and pumps on 3 & 4.
It likely has a similar crankshaft.

www.fordgarage.com/pages/germancompressor.htm
Model A Ford Garage ~ 1944 German G28T Model B Air Compressor
Click to expand...

That is what I was thinking also. I did have a Gordon Smith but I never had the engine apart.
 
Tiny said:
Didn't Winfeild build a 2 up 2 down T motor in the 20's? Ran like hell, but shook like hell too if I remember correctly. Never heard of an A motor like this though
Click to expand...

The standard Model A motor is 2 up, 2 down. That's just what you get with a flat crankshaft.Having 2 pistons at the top and 2 at the bottom (all stationary) at the same time is what causes such motors to be difficult to balance well.
 
Perhaps one of our Gordon-Smith compressor guys will chime-in...

I think the compressor theory sound most likely.


Looks like a stock Ford crank, aside from the two wonky throws...
 
George Miller said:
That is what I was thinking also. I did have a Gordon Smith but I never had the engine apart.
Click to expand...

Hey George,
Was at a car/machinery museum with a fordbarn buddy just Monday...in Simi Valley. Wished I'd taken pics and paid more attn., as they were restoring a Gordon Smith air compressor and one of the volunteers was showing me the torn down / dismantled engine. Never had seen such, so was very unusual to see. Crank looked like normal A crank to me. I think that he said that the center two compressed and that the outer two ran on gas. The top of block (head) was in three major pieces. The center head piece had 'valves' that looked like 'feeler guage' blades.
We were invited back and I'm going back. These guys are also Simi Valley Model A Club members..great bunch ! Restoring and restored great variety of antique tractors, engines, cars and train stuff.

Yup, Larry's crank was either a great find one off, or a busted crank :eek:!
 
My first thought was someone cut and welded the crank, but that would be a good bit of work and highly unlikely. Still people have tried some amazing things with engines.

If the block and babbit are both good, then it would be worth your while to find a good crank.
 
Piston to wall wear.

The combustion is creating pressure with the crank pin on the down rotation.

The compressing stroke is working during the up stroke.

So the piston is being pushed against the opposite walls. If I have it right.
 
hardtimes said:
Hey George,
Was at a car/machinery museum with a fordbarn buddy just Monday...in Simi Valley. Wished I'd taken pics and paid more attn., as they were restoring a Gordon Smith air compressor and one of the volunteers was showing me the torn down / dismantled engine. Never had seen such, so was very unusual to see. Crank looked like normal A crank to me. I think that he said that the center two compressed and that the outer two ran on gas. The top of block (head) was in three major pieces. The center head piece had 'valves' that looked like 'feeler guage' blades.
We were invited back and I'm going back. These guys are also Simi Valley Model A Club members..great bunch ! Restoring and restored great variety of antique tractors, engines, cars and train stuff.

Yup, Larry's crank was either a great find one off, or a busted crank :eek:!
Click to expand...

IT has been a few years ago that I had it. But it does seem like it ran on 1,4 and compressed on 2,3. It seems like it had reed valves and compressed air on every stroke.
 
You must log in or register to reply here.
Back
Top