I was wondering if it's at all possible to find a set of 5.7L HEMI heads somewhere that would fit on a Chevy 350. Would any fabrication be necessary, or would most heads fit on that block? I think it would be cool to pop the hood and say that that's a HEMI. Not to mention the horsepower.

 

I'll make it easy: no.

 

try it and find out

 

there's nothing stopping you from popping the hood and saying "that's a hemi". i've seen it happen on several occasions.

 

... i'm speechless ..

OK heres a quick lesson in cars..

HEMI = MOPAR = Dodge/Chrysler

so to anwser your question.. most people would not open the hood of a 3rd gen.. let alone a CHEVY and go... is that a HEMI?!... now if you want to modify and drop a MOPAR engiine like a 440 or a "HEMI" in to our cars then sure go ahead..

350 does equal 5.7 liters... but 5.7 doesn;t always equal HEMI.

 

I have a 429 Ford Hemi-head.
I would suggest making molds and casting them yourself, or you could design them and have a shop machine them out of billet.
If you find/make some, let us know.

 

 

I didn't exactly intend on that to be funny (well...maybe a little!!), but if someone is motivated and sufficiently challenged and willing to take the time, then anythings possible.

 

Sorry, thought you were being sarcastic. Seems to me that anyone asking if fabrication would be required to bolt a Chrysler head on a Chevy engine probably isnt serious enough to design the head or cast it themself.

 

Actually, there is a Hemi head that will bolt onto your 350... GM made a few experimental Hemi heads for Trans Am racing use on the 302 in the late 1960s.

There are 8 heads (4 sets) known to exist, so I hope you have a real Constanza wallet.

 

i forget the name of it, but that 4 valve head setup for the SBC also has a hemi chamber.



short lesson on what the hell a "hemi" is.



hemi is short for hemispherical. a hemi engine has a hemispherical combustion chamber, usually with the plug in the center and the intake and exhaust valve(s) on opposite sides

thats it.

to be a hemi motor, it just needs to have a hemispherical chamber. meaning if you were to make some heads to fit on the SBC that had the proper chamber shape, it would be a hemi.

almost every 4cyl made today is a hemi... so next time you see a honda, yea..... its got a hemi in it.




now Hemi was also a nickname given to mopars motor since it was one of the first to have a hemispherical chamber.

the new hemi motor that dodge is selling has nothing to do with that motor. its all marketing... its just a POS dodge motor that isnt all that great. i'd take the turbo cummings before id take that.

 

if you do some serious resurch you would find that way back when like i believe the early 50s or 40s ...it was chevrolet that designed and built the first hemispherical head and found it was too expensive for the amount of power they could make and they sold the copywrite to dodge way back when and dodge made it out to be a huge deal ...lol...but your probably not gonna find a "hemi" head to bolt onto your thirdgen engine..or any chevy for that matter ...so just go and build a nice set of heads and be done with it ..

 

if im not mistaken....a long time ago i watched the t.v show "trucks" on spike tv the host found an aftermarket company that made "hemi" heads that were designed for sbc's.

 

Duntov built a 377ci hemi sbc back in the 60's for r&d on the Corvette which made something like 532 horse, but the engine never went into production.

 

one of my car crafts thats like 2 months old lists companies that make SBC "hemi" style heads.

 

Yeah....

Whenever people start to want something, someone will step up and sell it to them, whether it does anything or not; whether it's the best way to accomplish something or not; and so on. Wave enough money around long enough and someone will figure out a way to separate you from it.

Isn't capitalism wonderful?!? Even idiots (like me even!) can participate.

 

A far better question is if anybody makes 4 valve heads for the SBC? I know that it would have the potential to require a lot of modification to the block. Research has proven that a 4 valve head will out flow a large valve 2 valve head.

 

32v Chevy Cyliner Heads: http://www.araoengineering.com/

 

I've always heard the opposite, that two large valves outflow four small ones, because of restriction around the 4 valves. Never really thought about it though, cause Im not gonna put a 4 valve setup on my car anyway.

 

I believe it has more to do with the valve position. I could be wrong, but most modern DOHC engines still use a pent-roof design. The intake valves are on one side, the exhausts are on the other and the spark plug is in the middle. You dont have to cram a big intake valve next to an exhaust valve, so you dont have to worry as much about bore/chamber shrouding. But I think the real virtue of an OHC design is the approach of the intake/exhaust ports.

 

Thats one reason the Hemi head (Chryslers, I mean) worked so well... almost every OHV pushrod V8 made has valves that are pushed straight down into the bore, which creates a big restriction.

Chrysler's Hemi though (the 392 and 426 anyway) had the valves at an angle, so when they were opened by the rockers, they were pushed in towards the middle of the bore!!! Thats part of the reason the Hemi can breathe so well.

 

are the heads you are referring to by chance the porcupine heads that GM worked with Smokey Yunick on?

*Eric*

 

The first "hemi" (in an automotive application at least) was a conversion cylinder head package for the flathead ford V8, to boost power in truck applications. Called the ARDUN, after the designer Zora ARkus-DUNtov, who later worked for Chevrolet and is better known for his contributions to the small block Chevy program and of course the Corvette, they're pretty rare today.

 

If he is, they aren't hemi heads...they were porcupines, like a BBC, and showed very little gain for the trouble. Oldsmobile did experiment with hemi heads in the late 60s/early 70s, but they never made production.

 

If you read back, I already stated that Duntov built a 377 Hemi for the vette that made around 532 horse, but the engine never went into production.

Best idea I have is to have an engineering firm fab some up for the original poster, but I sure hope he has the $$$$!!

 

Yes, I read that, and agree with you . The ARDUN was much earlier than that, though...mid-late 40's I believe, and was Duntov's first dealing with hemispherical combustion chambers. Completely different setup. Ive only seen a few of them, but the Garlits Museum in Ocala Fl has at least one in their engine room.

 

Any make of car can have hemi heads. its not ONLY a dodge thing. i know for a fact chevy and ford make them. and i wouldnt be surprised to hear any other company that makes them. the only reason you dotn hear about them, is they cannot call them "Hemi". becasue it is a registered trademark, by dodge. alls it really means is hemispherical combustion chamber. and any manufacturer can and some have, made them. So for those who are saying no its imposiible ect.. your wrong...

 

no one is saying its impossible to do from a technical standpoint...just bloody expensive, and probably not worth the effort anyway. For all its hype, the Chrysler hemi was a great race motor but a lousy street motor. They were a pain to keep in tune, and a well prepped 440 6 pack would often beat them in a street race. Great for higher RPMs, though.

 

i was refering to these guys...
does anyone have the price on the 4 valve aluminum heads? did you guys see the HP and Torque gains they got? over stock and an aftermarket brand?

and does anyone have more insight about which is better, 4 small or 2 big? (valves)
im assuming 4 small, because thats the way the industry is going, the new mustangs and imports have more valves.

 

Nope, they were basically scaled-down versions of Chrysler's Hemi head. It was a real Hemi... true hemi chambers, spark plug in the center, valves on either side of the plug.