The Stovebolt Site Forums The Shop Area Engine Shop Grinding Fentons

I am ready to begin my apprenticeship as a Fenton sculpturer but before I ruin something I wanted to poll the experienced. I read the recent thread on Fenton/Offy misfits and that is exactly what I have. In my case the Fentons' tabs are all too high compared to the Offy. All 6 of the tabs are mismatched, and they range from 1/16" up to almost 1/4" that would need to be removed.

Another alternative would be to grind one side of the "buttons" that the manifold bolts pull up against the Fenton/Offy combo.

What do you recommend? Thanks in advance.

Get ta grindin' Those are rough casts & always have to be "trimmed" for the final fit.

shoeless- It sounds like you are on the right track. Those fenton ears need a good amount of grinding. I also did some work on the "buttons" as you call them. It's kind of a long process, grind some trial fit, grind some trial fit ........ You get the idea.

Good LUck
George

Hey Shoeless, be careful when you grind on the Fentons anywhere except the tabs or "bottons" as you call them. These castings are pretty thin in places. I finally got mine right after taking a lot of metal off the bottom of the intake. Now I need to remove some more from the aluminum heat plate to make it clear the rear exhaust header. If I had it to do over I would send it to that guy in KS who reworks the original exhaust manifold. Good Luck. :p

Thanks for all the tips guys. I don't think I need to touch the intake at all, just all 6 of the tabs on the Fentons. I'll certainly take my time, as I want to do it right, not quick. I would also prefer to not change the tabs (buttons) so I'll just grind, fit ... grind, fit,
etc. I'll try to take a couple of before and after pics and post them.

Instead of grinding my fenton/clifford manifolds, I got an extra set of manifold clamps. I ground some material off some clamps, and MIG welded 1/8" to 1/4" spacers to other clamps to get the fit correct. Then I shaped the spacers with a grinder to look nice. No problems so far. Just requires patience, some small pieces of plate steel, a MIG welder and a grinder.

chip

Well, I had a free afternoon today so I tackled the Fenton sculpture challenge. I decided to make a jig out of a 2X4 and long clamp bolts and mount the intake/exhaust on the jig, then work one tab at a time. This made the project go pretty easy and I finished in about 3 hours. I probably did the 2-step of grind/fit about 25 times, as I had to work on all 6 tabs. It was really pretty easy since I had time and it was sunny and 75 degrees. Thanks for all the tips.

I took a before photo but I screwed it up ....
sorry.

There is another choice.
Take the Fentons to your favorite machine shop and have them grind the entire amount off of the mounting surface that bolts up to the head. Both headers , the entire surface the entire amount you need to grind off. In other words , you resurface the ports of the headers.
With this procedure, two things happen; the tabs are then thinner as you need them and the headers clear the Offenhauser intake because both headers are about 1/4" closer to the block.