Part mounting questions

[B Mann]

I have a Burke mill and self teaching myself. Home shop. Mostly from hands on and internet searching. I have an older Ford 460 truck. I rebuilt the engine several years ago and never could get the exhaust manifolds to seal well. Was told the cast iron exhaust manifolds on the 460 warp and after removing they won't be flat. I was thinking of giving it a try myself. Thinking of using a fly cutter and truing them up.

For the new guy to machining, how do you mount something that is practically round and not flat? I do have a hold down set, but what kind of shims? Most of what I have machined so far has been ether clamped flat or held in a vise.

 

[RJSakowski]

There was a recent thread which dealt with exactly what you want to do. https://www.hobby-machinist.com/threads/cast-iron-manifold.111060/

I believe there also was another. Run a search for exhaust manifold.

 

[Downunder Bob]

Without knowing what that manifold actually looks like, a photo would help, but perhaps you could set it on a couple of "V" blocks, maybe have to shim one of them to get it level. Clamp it down with regular hold down clamps, be careful to not induce any distortion in the manifold. then mill it flat.

 

[RandyM]

Here is a video that may help.

 

[markba633csi]

One could do that 1/2 at a time with two setups- but the method above works too

 

[B Mann]

This a 460 manifold, But I don't think mine is even this flat on the back. Just wanting to add a picture and seen the replies.

 

[B Mann]

This is a picture of the back side. Sure are a lot of styles. (btw just internet pictures, they are still on the truck) With the rust belt here I looked into stainless headers to save a hassle, but they are well over $1000.

 

[benmychree]

I'd take it to an automotive machine shop; its what they do.

 

[B Mann]

I'd take it to an automotive machine shop; its what they do.

Kinda funny coming from a machinist forum. I am pretty much a DIY guy. Every time I take something in, I am disappointed. I could do a better job a lot cheaper. I just finished working on a friends car. The shop that did the last alignment left one of the lock nuts loose. Last time I took my truck in for an alignment (decade ago) they left the connecting sleeves loose. By the time I caught it, they backed out quite a ways and ate up the threads and destroyed the tires. Shop manager had the attitude I loosened them.

 

[piper184]

I would try to fab up some kind of mounting block where the manifold could be bolted through all the mounting holes at the same time.

Then as you mill down the length you can remove one hold down bolt at a time. Mill over that spot and replace the bolt before removing the next one. Leap frog style progression.

Using studs instead of bolts would let you put a double nutted support under each mounting ear, even if they are different heights.