aluminum heads?
 

hey guys, i am planning to build my chevy 350 once my dad finally signs the title of my truck over to me. It is a 84 chevy 3/4 ton 4x4. The engine in the truck is the first engine that i ever worked on and so far has had no problems. It only has a mild camshaft, polished stock heads, edelbrock rpm series intake manifold and 750 cfm carb. It also has a cheap set of headers and dual exhaust. I am planning on rebuilding the complete drivetrain and further modifying the engine. I am seriously thinking about putting a small roots blower on it but i am unsure about whether or not it is safe to use aluminum heads with the supercharger. I was looking at a blower made by edelbrock(with matching 850 cfm carb) and using edelbrock rpm series heads(aluminum) since i have had good luck with them in another N/A engine i built. I just dont know if it is safe to use the aluminum heads with a blower. Also, is it safe to run the stock compression rating of 8.5 with about 6 psi boost? I thought it would be ok but a friend of mine thinks it is a bad idea and i should just use vortec heads. Please let me know what you other gearheads think about this situation. thanks in advance.

Chris

:confused: :confused: :confused: :confused: :confused: :confused: :confused: :confused: :confused:

Dozer has answered your questions....


Dude, seriously speak with wherever you are getting the blower from. Like the RX-8, you can't just assemble stuff together and expect it to be the best. You've gotta talk to experts to assemble your motor with the right compression ratio, valve/cam train, boost, ignition and fuel.

Perhaps a Chevy forum (if there is such a thing, lol)?

(see I got some RX-8 content in here).

Dude. I'm thinking the first thing you need to do is rip out that old iron block clunker V8 and drop in an LS1 or LS2 from a wrecked GTO or Vette.

Start with something that has tons of aftermarket support, and proven set ups for making reliable power. Just a thought...

To be honest, I've never been a fan of the Chevy motors or vortec heads. What with the whole reciprocation issues they suffer from. What I'd recommend is swapping a 20B into it. You should get about the same horsepower and drop a ton of weight. You could completely rebuild the suspension with an articulated 4 link, 6 inch lift kit, some fat knobby beadlock tires, and a low range 420 transfer case. It could be a real off-road trail monster. :)

i appreciate everyones answers, but it seems i should have mentioned that i am planning on restoring the truck and giving it back to my dad. He bought it brand new and it was his first brand new vehicle. Not to mention it was my first vehicle. The idea of swapping in a 20B is pretty funny to me. It would be unique but its a heavy 4x4 so i think i will keep with the V8. I had considered a big block but want it to remain close to original(displacement). I didnt even think to look for a forum of some kind, but the idea of a LS1 swap is way out of my budget. If i was building a drag toy for myself then i would consider it. This is just an old farm truck that i am restoring and making more powerful. I have no intention of taking the engine to an engine builder, though i may consult a real engine builder. The whole reason i made this thread was to see if anybody remembered the general rule for boosting a piston engine. This will be the first engine i build with forced induction. My next will be my 8 but i plan to use the BHR kit. Thanks for the replies. Any other thoughts are welcome.
P.S. why do you think that the chevy small block doesnt have much aftermarket available? They are some of the most used engines for racing(please dont flame for that).

Aluminum Heads with a blower should be fine; just get some ARP STUDS; don't use bolts.

Stock Compression should also be ok depending on intake temps - but 6 PSI is not too big of a deal. Premium fuel to be safe.

Biggest Change would be the cam; your gonna need one built for an FI engine. And of course roller rockers; lifters; hardened pushrods; water pump; convert from the mechanical to an electric fuel pump, etc. Better Distributor would be a good idea too.

I mean if you are going to rebuild the top end of this thing anyway; all this stuff is not too hard to add to the part bin.

This is exactly what i had in mind. I wasnt really sure if my cam would be ok to use with the blower. Its a comp cams Xtreme 4x4, but i dont remember the specs on it, just that the operating range is 1500-5500 rpm. When i install the blower, if i decide to do so, i am definetely going to rebuild the top end. Thanks kane for all the info.
Chris

You need a cam with lower overlap - I think higher lift and less duration maybe.... I can't remember but an NA cam will not work well in an FI push-rod.

Blower cam...

Link referenced http://www.aa1car.com/library/supercharge.htm

thanks i will look into that. Im going to be spending quite a bit on this truck either way so i am going to do it right. thanks again
chris

f-that roots crap- get a nice twin screw in there if you're going SC

http://forums.superchevy.com/70/7161...ger/index.html

http://www.carcraft.com/featuredvehi...evy/index.html

that last one is a good article its like a blueprint for you if you go with the Roots

good twin screw article

http://www.hotrod.com/techarticles/w...est/index.html

ooh i also see people talking about nixing the SC and making it into a 383 stroker. that sounds like fun


http://cgi.ebay.com/ebaymotors/Chevy...QQcmdZViewItem



http://www.rpmmachine.com/350-chevy-...roker-sb.shtml


http://www.rpmmachine.com/scat-strok...0hp-2pcrs.html

zoom, those are some really good links. I especially like the article from car craft. I remember i have that particular magazine somewhere. I also like the 383 idea but i really dont want to pull the engine out again and have it machined. I could get a really good deal on the machining at the shop i work for, but still not sure i want to bother with it. Its just an old farm truck that i wanted to make a sleeper. Before i add this kind of power i absolutely have to rebuild my TH350. I put on a few too many smokeshows when i was in high school and that tranny needs to be rebuilt. I am going to have one of my old instructors rebuild it. I have a lot of ideas now. thanks zoom and kane for all the info and links. they are very informative.

Anytime - I like 350 builds.... there is a lot more room in there than the rotary - which is nice.

PS - Don't overtighten the valves....

that is one thing i am pretty good at. I set valves almost everyday. Im really excited for this build now that i looked at those links. Ill keep you guys updated as i get the work done. thanks again
chris

I was joking cause that was what I fugged up on mine; I followed the Haynes instead of the directions from the manufacturer.