Aluminum exhaust manifolds...

So ive just started a 1964 chevy and its got some strange older hot rod parts with it. Including a pair of N.O.S. aluminium exhaust manifolds. The customer has left it up to me what to use and what not to. He wants to drive it a bit but not all the time.

Would these manifolds be a bad idea?

And has anyone else ever heard of them or used them before? Unsure of who made them since no brand name only a foot imprint on them...

 

i think a foot imprint would mean they were made by eelco could be wrong , ive never heard of aluminum exhaust manifolds but they sound cool

 

Those would be Eelco, only ever seen them for Corvair. Hard to believe the would have held up to the heat.

 

Probably a few aluminum flathead exhaust manifolds (Fenton) still around after 60 yrs

 

I believe those are for a boat?

 

Because it's aluminum? Aren't a lot of heads made from aluminum?

 

Yeah, but they're water cooled.

 

Ahh.... with water jackets....

 

Pontiac in those years offered aluminum exhaust manifolds on their racers. If it looks like a car exhaust maybe Chevy did too? If they are automotive a restorer will pay big money. I saw some Z-11 cast iron headers selling for $1500.

 

Are they shaped like regular manifolds? I'd guess (withoug seening them) that they're a marine manifold. If so, there'll be pipe thread fittings at the front for water to be pumped in. Marine manifolds for SBC, vary, but some look much like Lakes style headers, while others, like my Chris Craft, are a simple square "log" style. Be interesting to see, post a picture?

Brian

 

That is correct - Pontiac did offer them on their lightweight Super Duty drag cars. But the caveat was that they were OK for drag racing applications where high heat loading was very brief, but they would not hold up to sustained operation.

I've never seen a Chevy set. I would be tempted to put them aside and use factory cast iron pieces.

 

I just checked and yup. 18 billion Porsche, VW, Corvair and a few billion motorcycle aluminum air cooled heads, not to mention a trillion lawnmowers, go carts, minibikes and a few million airplane cylinder heads are alumninum too.
Seems they'll work!

 

Heads don't see the same heat loading as headers. Heads are cooled a little by the incoming intake charge and a lot by either the water jacket or, in an air-cooled motor, lots of fins. Headers just see FLAMES! They could work on a drag-only application - or, if they are water-cooled in a marine application - but that's about it.

 

badshifter--Ok, then put your hand on a alum head, then on the exhaust manifold-each after the car has been driven. See which one gives third degree burns faster. I can tell you...

 

aluminum exhausts are usually a bad idea IF you have high rpms people that ran the pontiac catalina SD with original aluminum manifolds quickly changed them out because the hear from rpms would after a short while actually make the manifold start to warp BUT a low rpm and if there is a water cooling then i wouldn't see an isssue with it BUT id recommend an an inclosed cooling system because sal****er eats aluminum like nobodys business

 

Oh yeah.

 

My bad, I thought we were talking about traditional powerplants, not weedeaters.

 

Here's some Corvairs.http://corvaircenter.com/phorum/read.php?1,375771

 

Cutless,you got any pictures of the manifolds ?

 

Most likely, as mentioned, those are marine headers and were water cooled. If the water stopped flowing through them all kinds of bad things happened to them. Aluminum heads get nowhere as hot as headers. I have shot my aluminum heads after a long drive and they are under 180, and my headers are at 400-500 degrees.

But to be sure, post a picture and we can tell you for sure what they are.

Don

 

Aluminum melts at around 1200 degrees. Some high heat paints claim to be able to withstand temperatures up to 1500 degrees and they still burn off of manifolds so it doesn't bode well for an aluminum exhaust manifold.

 

You could get the insides ceramic coated. That would protect them a good bit.

 

SS pontiacs had aluminum exhaust manifolds, they also came with a warning that they couldnt be ran for over 15 or 20 mins or they'd burn up the manifolds.....

 

It should be noted too that there are OTHER aluminum exhaust manifolds too, ive seen an aftermarket flathead manifold for running a heater off of too....

 

At the Des Moines Goodguys show I saw an A sedan with aluminum boat manifolds on a hemi. He didn't have any water lines running into them, but there were plugs where they might have been in a boat application.

 

Well hell that would be easy, it's the heads because the manifolds would be a puddle on the ground .

 

I have an image in mind of an engine on a dyno with red glowing exhaust headers.

Yeah, I think aluminum is a mistake.

 

Normally aluminum exhaust manifolds are as well. heads are normally thicker than most exhaust manifolds.

I have seen boat manifolds that wee not water cooled for sale on hear a few years back. But I think that normally they are water cooled. You can plumb them just like a heater with waterlines and they work just fine and won't burn you as bad when you go to change the plugs.

 

ok porky, if you insist it wont hurt as bad when I do the plug changes!

 

The aluminum Pontiac super duty exhaust manifolds are reproduced today. If they're coated with Jet Hot or similar, they'll hold up to regular driving - I know a guy here who has had a set on his street driven Catalina for several years now.