Adding dog-ear reinforcement, Really going into details. Options

[michel richard]

On my /6 project, I have decided not to add the tub reinforcements on the inside rear wheel well, for a variety of reasons. I did decide that I wanted the dog-ear reinforcement, also for a variety of reasons.
I am building the whole thing from scratch and I will post a detailed picture sequence in the hope that some will find it interesting.

I first bought some cold-rolled flat stock, 1/4 inch by 1.5 inch. I will say that I did not try to calculate if this resulted in a tang of the right strength, but it's what I used.

There's 8 tangs required, 6 the same and 2 a little longer. To make the tangs, I began by drilling a 3/8 inch hole:

[michel richard]

Then I cut the outboard corners off:

[michel richard]

Back to the mill, I rounded the ends. I had a small pice of steel in which I inserted a 3/8 bolt, used to hold the tang material down. When the bolt is tightened, the plate can be rotated against the end mill and the end rounded.

[michel richard]

The picture is frozen, in the previous shot, but the mill was spinning !
Then I cut the tang to approximate length, and started over.

[michel richard]

To make sure all the tangs were the same length, I put a 3/8 pice of round stock in the holes, stacked the tangs, and cut them down to final length on the lathe. Once again, the lathe is spinning in this shot:

[michel richard]

The next step is to cut some more steel plate (or sheet, I'm not sure what the exact terminology is) from 1/8 inch stock. I made this 5 inches by 3.5 inches, simply based on measurements on the tub, and comparisons to Armando Serrano's site. This is what it'll look like:

[michel richard]

Okay, so the bolt I had was too long.

In the previous picture, you can see that I chamfered the tangs so that I would get better penetration when welded, which I did with my trusty Mig:

[michel richard]

And this is what it's going to look like with the rod-end (I'll post details on that part later)

[michel richard]

This part gets welded to the main bulkhead, as shown below.

What remains is to (1) put together the tangs that will be welded to the dog-ear itself, (2) and to make the rod that will go between the bulkhead and the dog-ear and (3) do the welding to the tub.

Picture below from Armando Serrano's site:

[okieflyr]

Watching with great interest ! (IMG:http://www.914world.com/bbs2/html/emoticons/welder.gif) KB

[Andyrew]

Seems like welding a tube in there would be much easyer..

But complexity is gud!!

Unless your going to be racing in a class that says no weld in reinforcements.. bolt in only.

[alpha434]

QUOTE (Andyrew @ Mar 13 2006, 09:43 AM)

Seems like welding a tube in there would be much easyer.. But complexity is gud!! Unless your going to be racing in a class that says no weld in reinforcements.. bolt in only.

Has to be removable so that the engine will come out.

[Andyrew]

Interesting..

guess I dont think about that unremovable engine tin now adays....

[Brad Roberts]

QUOTE

Has to be removable so that the engine will come out.

I have welded in 20+.. all the engines come out without issue.
I do agree that removable is more better (easier to adjust valves)

The issue is rust inside the ear. They are plenty strong up until a 12inch wide slick is used on a good ear (and a good driver)



B

[Andyrew]

Brad, real quick...

My left ear hole is ovaled out.. and I assume the right one is slightly ovaled as well. Both bolts come loose after driving them.

I have a lincoln mig now, and was going to replace the metal with 1/8in or something simular, then reinforce it a little on both sides. (with a welded in bar from the front firewall to the ear)

Does that sound right?

thanks..

[michel richard]

QUOTE (Andyrew @ Mar 13 2006, 09:43 AM)

Seems like welding a tube in there would be much easyer.. But complexity is gud!! Unless your going to be racing in a class that says no weld in reinforcements.. bolt in only.

Agreed.
Not going into any racing class. I just think that welding in a permanent tube is something that could come back to haunt me sometime down the road.
And the thing with the rod ends is that it's kinda fun to do.

[michel richard]

I got the Aurora CM-6 rod end, locally, it has a 3/8 inch hole, and a 3/8 inch fine thread shaft, but I think that's on the small side and I will probably get some CM-8 fittings. These are basic run-of-the-mill items. Here's the link to the manufacturer's site. I paid C$40 for the four ends that I got.

http://www.aurorabearing.com/

You can download their catalog free, it contains a lot of info.

[brant]

Nice..

but you can buy those mounts and ends pre-made too.
here are the ones we used:

[brant]

both sides are connected so they can be lighter weight and retain their strength. Close up:

[michel richard]

Brant, what size rod-ends do you use ?
In my case, part of the fun is making the things myself.