Aluminum vs. Iron intake

[Dave Kay]

Searched for something on this topic but didn't find much.... any pros and cons here?

[Pyrotechnic]

Most aluminum intakes you find will have runner designs geared towards enhancing performance vs. the stock iron intake. Aluminum is lighter. The stock iron intakes are HEAVY.

[Dave Kay]

Originally Posted by Pyrotechnic

Most aluminum intakes you find will have runner designs geared towards enhancing performance vs. the stock iron intake. Aluminum is lighter. The stock iron intakes are HEAVY.

Thanks for that and no doubt the iron is way heavy and in fact, I'm in the middle of a minor teardown to fix an intake leak and get the carb redone, so I guess I need to be more specific here... ok, so when we look at the performance side, what I want to know is do aftermarket replacement alu's make a dramatic difference in mpg and/or drive-ability? Positive or negative impacts?

When I say after-market replacement I'm talking about something for a daily-use work truck, stock 350, no need for overwhelming power here, something like the Weiand 8000 w/egr, spreadbore for Q-jet. By the way, this will also be my tow-vehicle too for boat, car-hauler, etc., and I'm looking for longevity, dependability, and not getting killed too badly on the gas mileage--- compared to the stock iron that is.

[f.monroe]

My opinion is the aftermarket intake can only help in all aspects . If you keep the same carb , camshaft , etc and the intake picks up 10-15 horsepower , it will help with the towing and mpg . Frank

[Yankeelights]

I remember an article in one of the mags a while back where not one of the aftermarket aluminum intakes greatly out-performed the stock iron SBC intake; in fact, the iron intake outperformed some of the others for street applications.

My personal preference is however, the Chevy aluminum intakes.

~ Dave

[old Rusty C10]

i have had both on my trucks as i get my trucks well used and beat them to death and frankly i see no significant increase in power or economy with an aluminum intake over the factory one
to me the best thing you can do for your motor to keep it running efficiently is to do the plugs every 12K on a gas non EFI motor and keep up with filters and oil changes

[Dave Kay]

Thanks to all for your input and it seems to me I've heard something like what Yankee metioned too, in that for stock/street apps it's a toss-up on the performance curve between iron and alu and the only real significant differences are when you're going racing, then it's aluminum hands down. But then I've heard of other guys saying the samething as Monroe; better power and milage... hmmmm... but I've also heard that that could be due to other factors not related to the intake change.

So Yankee, what is it you like about those Chevy alu intakes? I note that they're a bit pricier than Weiands and Edelbroks for the same applications... and of course they are made in The Good Old USA.... Boy, I'd sure hate to buy something out there and find out it's Made in China!

So is it a toss-up really?

[chev74]

Im an Edelbrock user myself... i snagged mine from my neighbor for $50! he is a big Corvette restorer and he had it powder coated a silver color, but it didnt match the EXACT color of the other components he was using- so he was going to scrap it since it didnt match (those Vette guys can be pretty picky!).

On the real subject- the lighter the better. Less weight= less power it takes to move it. Its not significant, but its about 50 pounds lighter probably. The only real increase i think is when you have it ported and polished, otherwise there is no significant positive or negative aspect to the aluminum.

[crm318]

i have swaped both on different engines. the iron one was 45 lbs, the aluminum one was 17 lbs. however, i hear that the edelbrock intakes lose a good bit of torque over a factory iron one.look at the goodwrench engine build up on chevy high performance magazines site. it gained 10+ hp and lost the same in tq. if your only swaping an intake, i would go with a non-egr factory iron or aluminum one.

[shadetree]

IMO, aluminum heats up faster (needs less "choke time" in cold weather), are lighter, and are usually improved in the breathing department over the cast iron units. On the minus side, aluminum can be harder to seal (aluminum expands much more than cast iron, making gaskets harder to get to seal). Aluminum manifolds usually cost more.
For your build, either material should be OK, with aluminum getting the nod if you can find a good one, cheap, and you remember to use the reccomended gaskets for it.

[Ivan D.]

I have some weird Offenhauser intake in my 350, tis a split-port runner design (about 1:2 ratio) and the primaries feed the smaller part whic theoretically keeps the airspeed high. This intake design is good for low-rpm torque and supposedly dies up high, but hey, my usual operating range is 1000-2000rpms so I really couldn't care less how it flows at 5-6k. Now I don't have actual sheets with the old and the new intake data, but the butt dyno tells me the split port design works well for what I want from it - honestly, at 2k rpms the truck feels like it can climb vertical walls! I've been told that this whole split-port deal is an outdated concept, but Summit still carries several models of these intakes, if anyone is interested here they are:

http://store.summitracing.com/egnsea...rdSearch#rstop

[Zoomad75]

Look at it this way, with a stock cam, an aftermarket performance aluminum intake is just able to get more air into the engine right? But if you don't have a cam to match it, the total performance gains if the intake will be limited by the stock cam.

On the mild 350 in my Nova I noticed good seat of the pants difference between the stock iron intake with a qjet to a Edelbrock performer with a holley. But in my case I'm running a factory L-79 cam (from the 350hp/327) so it's a little more aggressive than the stock cams that came in most of them. The 350 ran well with the iron intake and q-jet, but it woke UP with the performer and the holley.


I'd say if the cam is stock, swapping to a performance aluminum intake isn't going to gain you all that much.

[gchemist]

I'll take aluminum for looks!

[Yankeelights]

Originally Posted by Dave Kay

So Yankee, what is it you like about those Chevy alu intakes? I note that they're a bit pricier than Weiands and Edelbroks for the same applications... and of course they are made in The Good Old USA.... Boy, I'd sure hate to buy something out there and find out it's Made in China!

Since I read the article about the intake shootout and the iron manifold performed so well, I figure that I can't go wrong if it's a Chevy product; the aluminum makes for an easier install.

~ Dave

[lurch115]

i'll have to agree that on a stock motor the stock intakes are usually best...but the one intake that i have usedon stock and built small blocks is the Weind "Stealth" intake with a power range from idle up to 7,000 rpms...and i tell ya it doesn't matter if the motor is stock or built i've always seen a difference in power...never really paid attention to milage cause i figure since i am driving a truck it isn't gonna be the best anyways

[crossy]

[QUOTE=Ivan D.;2413879]I have some weird Offenhauser intake in my 350, tis a split-port runner design (about 1:2 ratio) and the primaries feed the smaller part whic theoretically keeps the airspeed high. This intake design is good for low-rpm torque and supposedly dies up high, but hey, my usual operating range is 1000-2000rpms so I really couldn't care less how it flows at 5-6k. Now I don't have actual sheets with the old and the new intake data, but the butt dyno tells me the split port design works well for what I want from it - honestly, at 2k rpms the truck feels like it can climb vertical walls! I've been told that this whole split-port deal is an outdated concept.

Nah. that Offy 360 was a GREAT intake, ugly though and cheap if you find a used one because of that.
It was just too expensive when new. they were great intakes. did some testing on 1/4 mile way back when on a 351W in a heavy truck and it was the winner hands down. ALL full-size trucks are heavy. BTW, the Offy 360 weighs nearly as much as a cast iron intake because of the internal design.
just so you know a normal performer will NOT out perform an early cast iron, non- EGR intake. I find them cheap at swap meets but i would never pull a cast iron to install a regular performer unless it needed it or I was re-doing the engine. The performer has port design to fit a variety of head designs and is a money making compromise for edelbrock.
crossy