How hard to make your own intake?

[wyomingste]

I've been thinking about what everyone has been telling me so i'm going with a 3400 head swap on the motor i'm building. I've been told that the 3.1 (LHO) intake has different length runners, thus leading it to suck for performance... what about a 3400 intake? does the same apply?

 

If so how hard would it be to build your own intake (lower and upper)? I've been thinking more about this, I know that I can use a Plasma-cam (computer controlled plasma cutter) to cut the flat sides (against heads and bottom plate (what is this called?) but after that i'm lost on ideas, do I want exactly the same length runners on every cylinder, also what size runners should I run and what size will be to much (my guess would be match to gasket the entire way on the runner making the runner a rectangular shape).

 

Also what would have to be done? I know you would have to make a place for the fuel injectors and mounting for the fuel rails. I would also build a place to dirrectly tap nitrous oxide into the runners. Would you have to run vaccum lines with a custom intake like this? also which ones would you have to use if you were to reduce the amount of vaccum lines.

 

What throdle body would be a wise choice on an intake like this? One off a 3.1, 3100, 3400, possibly a LS1? I would think that the LS1 would make a nice adition but would it leave to much air (being for a 350 SBC? I think thats the size of a LS1?).

 

If you were to attemp this what type of metal would you use? 1/8 inch stainless? 1/16 inch stailess? or would it have to be thicher. If i chose to do this I'll be doing all of the welding (TIG), and I know you would have to have it pressure and leak tested.

 

Any suggestions or experience would be very helpful,

Thanks, Eric C.

[TeeJay3800]

I've been thinking about what everyone has been telling me so i'm going with a 3400 head swap on the motor i'm building. I've been told that the 3.1 (LHO) intake has different length runners, thus leading it to suck for performance... what about a 3400 intake? does the same apply ?

The 3.1 has long, narrow runners that give it it's strong low- and mid-range power, but that is what limits it's peak output, and kills its high-rpm performance. The 3400 flows much better due to the heads and both intakes. Other than the harder-to-come-by 3500, the 3400 is the ultimate intake swap from pushrod 60V6's. Might as well use that, rather than custom making one yourself.

 

I don't know about swapping it all onto a 3.1 though (I know for sure you'd have to use the heads as well, if it's even possible).