You don't want the runners to come up to the TB bores. The concept behind a plenum is that you have air moving from a high pressure to a low pressure and it fills up a chamber to feed the runners. Hopefully you can raise the pressure of that chamber (plenum) to the point where it's higher than the outside air. This is the concept behind F1 and Pro Stock air intakes and boxes. The way you can tell this is if your MAP readings are around one inch of vacuum or closer to zero.

Bret


PS steve9899, ;-)

 

instead of the sides going up at an angle im gona run them straight up. the roof is probably gona be alittle bit taller too. i havent decided how much yet becouse im still using the stock ss airbox and i dont really want to cut the mounting points down too much.

the injectors are gona have to be tilted up straighter just a tad and new mounting points for the fuel rails are going to be made.

in my ppics you can also see how much the fuel rail crossover hangs down in the intake along with the mounting points for the rails. all that is gona and its going to be nice and smooth.

 

Cool, let me know how it turns out
What kind of gains do you plan on?

 

Brett I have a question that maybe hard to answer considering the variables. I was also thinking of taking a LT1 intake and cutting it like above and welding up the runners like I did with my welded/ported ported LT4 but actually reangling the injectors, raising them along with fuel rails/mounts and making the plenum larger.I can do all the porting/cutting myself and have a friend who tigs and also has a mill. I know not everybody can make this work but I do know quite a bit about how engines work. I do not know how to figure out how much I would need to enlarge the plenum or a length for the runners that would work well with this setup. I have more time then money so if I could afford a single plane conversion or sheetmetal intake I would go that route but would this be worth 25-35HP over nicely done LT4 piece with my hydraulic roller setup that only makes power to 6,500-6,600 rpms? I would also get a you to spec a cam for this that would work better then my old CC306. LMK Later Clint

 

Clint,

The key on the inside would be to weld up the runner entry and then have Lloyd match the intake up to the heads. If you enlarge the plenum then you pretty much have to reangle the injectors.

As for the cam stuff, e-mail or PM me about that. I still think we could bump you up in that area.

Bret