I don't know if this matters, so I'll ask. I'm going to make a couple of new blocks. Which of these is "correct"? The only significant difference between them is the bevel.
This might be of some help.
This has some good info.
Don't use either one, leave them out.
They do more harm then good.
Neither one of those are made correctly. Up until the early '20s, they were the early design. By 1923 they got smart and made a rectangular square block.
Steve, I have only seen originals with reliefs on the long sides. All have had the 45 degree chamfer, some have had a square rebate opposite the chamfer on the bigger face.
Allan from down under.
The chamfer is to clear the fuel line.
The diagram Jim posted shows why neither block is exactly right. While most of the dimensions are accurate, they both have a rectangular notch for the fuel line instead of a chamfer. I have no idea why the chamfer on the left one is there. It's vertical (!) and useless for the fuel line.
Steve: It wouldn't be useless if you had the correct block. As I mentioned above, neither of your blocks are correct! I wish I didn't hate taking photos so much. I have a whole bag of original genuine Ford blocks out in the garage.
I assume the diagram Jim posted is correct. I'll use that.
What type of wood would you use? Do you need it to be strong or a soft wood?
If strong--- Could you make them out of Black Locust? This wood is rot resistant and can withstand being in the ground for a long time.
I bought a bunch of it for a project of mine last spring from a guy named "Blue-Sky", in western Massachusetts.
Since no one has posted a picture of the correct blocks, I'll try to remember to do it tomorrow!
The block is there to help keep the frame rails from twisting, putting stress on the arms. But the cross bolts should not be tight or will cause the problems Herm is referring to. They are needed.
I just took a picture of three different designs of ORIGINAL used CC arm blocks. The one on the right was definitely used from 23-27, maybe earlier, the one on the left is early, definitely used through '13 and probably later, the middle one is in between somewhere. I'm going to the archives in a few weeks, and will definitely check on them while I'm there.
The wood was hard maple. Never deviated from that. I have the drawings for these blocks and they did change a bit but only to make them simpler as you can see that for the purposes that the notches and grooves were added they can be simplified and still do the same job. That is the nature and reason why the blocks changed IMHO.
John, I looked in the "documents" section of your website and didn't see the blocks drawing. Is there a reason (licensing, etc.) why you can't post the drawings?
What harm could these blocks possibly do?
The harm that the blocks do is they hold the Crankcase arm to rigid.
With the block in the frame, and it makes no difference if the block bolt is tight, loose, or anywhere in between, it hinders the crankcase Arm from moving to its full potential.
With the block out, when the motor twists, when the engine is revved, the crankcase arms will relieve the twisting from the top of the arm bolt, to the pan rail, or a little below.
Most of the crankcase arms, crack right at the pan rail, because at that point, it has to take all the stress, with a block.
In all these years, we have never used the blocks, and the same recommendation to all the engines we built, with out any cracked, or broken arms.
As far as the blocks holding the frame from twisting, it does nothing except throw stress on the pan arms.
Watching the old FORD videos, they show how the frame twists on uneven ground, Ford built them that way.
What you say Herm may be so but my only experience with a broken arm was in one of my own T's. I know for a fact that it was without the blocks since 2002 and some 13 years later, the engine arm let go with a big bang while just cruising down the road.
Many USA T'ers know and have meet Warwick Landy, he was passenger the day it happened if one needs to verify my post.
I run the blocks in all after that.
If someone feels the need to leave them out, at least fit the side bolts so if and I say 'IF' they let go, then the engine doesn't end up 1/2 way to the road.
It is in fact a violation of the Ford Museum copyrights to post their drawings in any public place without their permission. I know many do that anyway but I signed an agreement to NOT copy or provide copies of their drawings. I love to research there so I don't want to lose my invite to go there. Museums are always hurting for $$ so they rightfully charge for copies of things. They own those drawings. Being a design engineer I am sensitive to that issue. It hurts when I have spent a goodly amount of time making up a product and instruction sheets for it that are copyrighted then only to have my instruction sheets furnished with a "copycat" product and to see a competitors name exactly in the place on my instruction sheet where my copyright notice was. It is illegal but some people sell their integrity pretty cheap.
The TT trucks didn't have any blocks in the last years - and after the diagonal straps from the hogshead bolts to the rear motor mounts were introduced in november 1925, I don't think the car needs them either. Thus I drive without blocks and think it'll work fine since the sideway flex is very limited with the straps. With an older pre 26 engine I'd worry and probably use the blocks.
Just returned from the archives. The early style block was used from 09-20, the mid style was used in 21-22, and the late style was used from 22-27.
Thanks for researching that Larry!