TR4/4A Manifold clamps on TR4A when installing Webers

[Darrell_Walker]

I'm getting closer to being ready for the final mounting of my DCOE Webers on my TR4A. One thing I still need to solve is what to do about the manifold clamps. The flange on the intake manifold is about 1/8" thicker than the exhaust header. I've come up with a few ideas, but was wondering if anyone had better ones:

-Grind out half of each clamp by 1/8"

-Grind down the intake where the clamps press. But I don't have any way to do this and still look nice, and the top ones are quite visible.

-Have the entire intake mounting surface ground down by 1/8". Not sure if this can be done while maintaining alignment, but this would probably be the best looking solution. I also don't know if removal of 1/8" of the flange would weaken the intake enough to be an issue (could be a problem with the solution above).

-Build up something on one have of the clamps. I don't have any way to weld, though I could perhaps drill and tape a hole to insert a screw/bolt, and use the head as the additional space.

Any other ideas, or comments on the ones I have?

Thanks,
Darrell

 

[DougF]

Take both pieces to a machine shop to have the header surface checked and resurfaced if necessary and the intake surface matched to the exhaust.

 

[PeterK]

Possibly the clamps have enough play on the stud that they will simply angle in against the header at an angle to the intake and tighten OK. Have you tried?

Good question, I have a set of headers for my 4A to install and never thought about the different flange thicknesses.

Another option would be to weld a patch on the outside of the header flange for the clamp to ride on to make up the difference.

 

[DougF]

I don't believe you could ever get a good clamping seal with this set up without alterations. I had the opposite problem, the intake was lower than the exhaust. I even tried a heavy gasket, but it wouldn't seal. The nut works to level the clamp so it can't make good contact with the low side.
It is the safe road to go to the machine shop. You will have confidence in good seals.

 

[TRMark]

I had the same problem years ago when I put a header on the TR4. The flange on the header was thinner than the intake. I added a little weld to the tip on the clamp to make up the difference so it fit parallel to the bolt. Never had a problem with it.

 

[Bugeye58]

Have pads welded to the header flange to bring the clamping surface level with the intake flange. Don't cut the intake. With the Webers cantilevered off there, you need all the meat you can get on the intake.
Jeff

 

[Darrell_Walker]

Just thought I'd update this and let you all know how I solved it. I ended up drilling out one end and tapping it for a hex head cap screw. I initially used a sheet metal screw, but the head wasn't quite thick enough. If I had the equipment and skill to weld, building up the bump would certainly have been a bit faster, but my method wasn't too hard either. Not any more time that driving them down to the welding shop, and $60 cheaper (their min charge).

 

[prb51]

Darrell,
That looks like it'll work just fine, the mother of invention.

 

[PeterK]

Looking good Darrell. BTW, thinking about this problem yesterday, I had to dig out my header to examine if it had a patch already on the flange to add thickness for sealing clamps.

What I found is that the TT split header from Moss has a flange that is the same thickness as the original cast manifold. So I guess it depends on whose header you use to determine whether you need your mod or not.

btw, Uncle Jack also makes a special thick gasket fo sealing tough header problems which is 1/8" thick, compresses to 1/16".

 

[Guest]

The only thing that bothers me about this setup is you will be using a tremendous amount of crush when tightening down your manifolds. Those cast parts can take the pressure and heat. Not too sure about a threaded bolt. I think this is headed for long term problems. IMHO.

 

[Darrell_Walker]

Hi Bill,

All of the pressure should be between the clamp and the head of the screw, the threads are really there just to hold them in place. Now it could be that I've weakened the clamps (enough to fail) by drilling a hole in them, I'll need to keep an eye on that.

 

[Guest]

Good point. Thanks for clearing that up. I doubt you weakened it. I had to grind mine to adjust to the GoodParts manifold and Falcon headers. That is some tough bracket material!