Exhaust manifolds-Cast iron or aluminum?

[marada1]

Would like to get your thoughts on this. What are the pros and cons other than the obvious - weight and cost? Are the aluminums worth the extra cost?
Looking at the GLMs.
Thanks

 

[Bondo]

Re: Exhaust manifolds-Cast iron or aluminum?

Ayuh,.......

 

[dcg9381]

Re: Exhaust manifolds-Cast iron or aluminum?

The big plus with aluminum is that it has better corrosion resistance than cast.

If you're running in clean fresh water, not sure that I'd go to aluminum. Salt, maybe...

 

[sputnikv8]

Re: Exhaust manifolds-Cast iron or aluminum?

The big plus with aluminum is that it has better corrosion resistance than cast.

If you're running in clean fresh water, not sure that I'd go to aluminum. Salt, maybe...

Strike that...reverse it.

 

[HT32BSX115]

Re: Exhaust manifolds-Cast iron or aluminum?

The other plus is if you go to aluminum manifolds, risers/elbows and intake manifold, you get a pretty substantial weight savings. I thought about doing it next time with my 454. It would make it close in weight to a small block with big block power/torque. (of course the ultimate would be ALL aluminum engine everything!!)

Cheers,



Rick

 

[f_inscreenname]

Re: Exhaust manifolds-Cast iron or aluminum?

"Other than weight, there are no other reasons to use aluminum."
There is also this with the GLM's.
Performance manifolds individual exhaust runners inside the manifolds.These runners separate each cylinders exhaust gas pulses (the stock Mercruiser manifolds empty all of the exhaust pulses into a common chamber).

 

[Mkos1980]

Re: Exhaust manifolds-Cast iron or aluminum?

Weight and more power. We got a solid 10HP more out of my 350 mag on the dyno with the glm's vs stock sierras