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Anyone ever deal with heads designed for a blower or is there a companythat sells heads that work better then what ya see in the jegs catalog and stuff for a blower .
I have a blown SBC in a datsun 280z and need more power so the heads are about the only place left for me to go at the moment .
Jason
As far as I know, AFR *Air Flow Research* makes heads for blowers and n20 systems. Some of their competition packages are pretty serious.
Usually good blower heads are the same as good normally asperated heads. Big ports, and big valves, preferably in aluminum because of their slight advantage in reducing detonation. If you have a choice in the valves, go slightly larger on the exhaust since that event does not have "boost" to aid it.
porschehacker
There's nothing wrong with the heads. Change the pulley.
What does changing the pulley have to do with it yes maybe more boost but if ya cant get the air out of the engine what good is more boost . Im lloking for the easy way to buy heads already built even the supercharger company said to increase exhaust flow but dont bother with the intake as the blower will force it past the intake valve
What are the cam specs.?Quote:
Originally Posted by SBC DATSUN
stock flat tappet cam 114 lobe seperaition not sure on lift or duraition nothing big im sure but im in the process of ordering a blower cam in the next month or so it has a intake lift of .500 and a exhaust lift of .540
If you are really serious I would think about a moderate. mech. roller cam.Quote:
Originally Posted by SBC DATSUN
The blower guys I've talked to don't seem to have a whole lot of concern on head flow on blower engines.... mostly their emphasis was on reasonably sized chambers and free flowing exhaust. With all the pressure created by a blower, it will force the air into the cylinders. Not to say a set of junk smogger heads will work fine but would a big chamber enhance the performance on a blower engine? Most of the engine guru's will say that the compression ratio and cam are the most important considerations when building a blower engine.....
Well weiand said and i quote bigger combustion chamber shows less boost but adds more power im not sure i just heard from lots of people that i need to get the exhaust out which i have 3 inch duals all the way out with block hugger headers due to space i assume ill need to get a head custom ground at least the exhaust valve anyways
Thanks everyone for the responses more then what i knew about this stuff as this is my first V8 ever and heck im 30 years old
jason
Block huggers huh, a long way from the preferred forced induction zoomie exhaust, I doubt heads or cam or pulley change, etc will help much till ya get the exhaust flowing (spell that NO back pressure) IMHO :cool:
....I read something in Hot Rod Magazine awhile back where they used Brodix aluminum -8 Heads on a blown motor {Chev. small block}. They said that these heads had 1.80 exhaust valves and that this was the major contributor to the high HP readings that this motor produced.... so you might check out these heads. But then, as someone mentioned eariler, your lack of large free flowing exhaust headers arn't helping things at all...... Bill
WHat diameter are the pipes in your exhaust pipes ? because with a blower you need at least a dual 2 1/2 inch exhaust, if you really are pumping the air you may have to go to 3 inch all the way back to the tail pipes.
The pipes are 2 1/2 mandrel bent all the way out with a free flow magna flow muffler i cant go 3 inch as i have no room for a bigger pipe .
As for the headers all i can use is block huggers nothing else as the engine bay is so tight that is all that will fit this is a rice burner powered by a chevy
A 1978 datsun 280z the block huggers left me 1/8 th of a inch clearance between the header and the steering shaft there are some full length headers i can buy for 700$ but the diameter is the same size oh and with 2 1/2 inch pipe the pipes are only 3 inches off the ground