I started cleaning up my exhaust manifolds with my new blasting cabinet and saw that one had been beaten up with a hammer. What would be the best way to fix this without smoothing out the finish? (if any)



The right side manifold doesn't seem right to me...

 

The marks you have on that manifold is not from abuse but rather normal rust over the years. This is common to see. While I have never used it, there is a product called Pyro Putty this is designed for repairing exhaust manifolds and it seems it would work well for your repair. Google it to get more info on it. You would need to do a little experimenting with it to duplicate the cast look but one way may be to let it cure, final sand it and then use a small punch and hammer to dimple the surface.

You would need to post your application to get input on the other manifold being correct or not.

Brian

 

Thanks for your reply... I will look into Pyro Putty. My car is a 1970 Cutlass Convertible with a 350 engine.

69442C, I love the 442 you're doing. World class work that I will be working to duplicate.


http://www.aremco.com/product/a15/

 

Thanks.

I'm not sure about the pass side manifold so if you still have doubts, post another thread with that question or maybe someone else will see this and respond.

Good luck with your car.
Brian

 

yeah my pass side exhaust manifold looks very similar to that. 72 350 sbo

They sell a block off plate for the cross over tube FYI

 

Really?

That's what we call "negligible rust pitting" in MI. no HOLES THRU? it's good to go. Maybe you can get the NOS ones available recently from the Vendor Who Must Not be Named. Or Thornton's repro true-duals SB manifolds. New and pretty.

You guys down south....

 

Really. Olds never ever made a 350 'true' dual exhaust manifold for the 68-72 Cutlass. It's a shame too since it's a great engine. All the 350 powered Cutlass models with the N10 exhaust had the p.s. manifold blocked off with a filler plate. Same as you can do at any muffler shop.

Just a heads up on the Thornton product. I've corresponded with people who bought those when they first came out because I was thinking about them too. The word to describe what you call "Thornton true duals" would be underwhelmed. They are new and pretty indeed. They also do not have any GM markings or casting numbers. They do however have castings that Identify them as Thornton manifolds.

Thornton says they have corrected the flaws in the original casting on the center web area.

 

Here is a picture of a factory small block dual exhaust block off plate on pass side manifold

 

Thanks for the picture, is this for your 1971? What would be the purpose of the 'dual' outlet on the passenger side?

 

The manifold was removed from a 72 442. 71 442 came with 455 and the W and Z "bigblock" exhaust manifolds.

The "dual outlet" is where the cross-over pipe from drivers side attaches in a single exhaust application.

 

That was the only exhaust Olds made for the 350. So it had to serve 'dual purpose' no pun intended. The majority of Cutlass produced were single exhaust so it was probably easier to just produce one ex manifold for mass production.