Hey guys, I'm still new here. I be been looking all over about if I should polish/ smooth out my old new weiand Intake on my 400. I don t know a lot about performance and racing. It s all stock 400 any info would help Thanks

 

polish what? to make it smooth and shinny? Or intake runners for performance? For looks thats up to you, for performance NO, it will do nothing for you and you can hurt your hp if you dont know what your doing. Really need more infor here.

 

Sorry smoothing out the runners( inside) of the intake

 

If its a stock engine leave it alone, smoothing the intake runners are for full competition engines only. If you were to do anything just port match them and ONLY take it up into the runners about an inch or so, you want the ruff texture you feel with your finger, thats to help mix up the gas and air for better atomization.

 

Don't polish. That can be bad for street performance, and the "as cast" Weiand is good to 400HP or better anyway.

 

I ve read all over the place to polish not to I could n t find a real answer

 

For a carbied, or "wet gas flow" manifold you can port, smooth casting dags, match port etc. But you need to leave the surface finish rough to keep the fuel-air mix in suspension. Same for the inlet ports. Exhaust ports can be polished smooth.

On an injected manifold, it can all be smooth.

 

Brad, what would you use to smooth every thing out with?

 

If you have the coin to spend there are options like extrude honing or power polishing (a pnuematic abrasive process). Otherwise its a die grinder and flap wheels, drum sanding tips and rotary burr files.

 

At the level indicated by your questions, don't bother. There's not a single horsepower to be gained.

There's real power to be gained by g3tting your camshaft degreed properly, even a stock cam.

Anyone wanting to "port and polish" his heads should be beaten with a "3/4 race" camshaft. Both are holdovers from 50 years ago that have very little meaning in today's world.

Adding the intake and a nice four barrel carb will help the truck quite a bit, and that's what you're doing. Your next step after making sure the cam is in the right place would be exhaust, IMHO.

R.

 

Well let me ask about a carb and headers. I d like to go with an e Brock carb. I ve read a lot of places a 600 650 is good, but a few local dent side guys here say 750. And if I did headers what s out there for cheap one s

 

An Eddy 600 CFM carb on an Eddy 400 intake will help quite a bit. But, a stock cam and timing set sorta defeats the purpose of a 4bbl. However, put a new aftermarket timing set on a stock cam, and the engine can wind and use the intake and carb.

I have a buddy that just did exactly that - new timing set and an Eddy 600 and intake - and he says it made a huge difference.