I have an Olds 88 with the 307 V8. The hoodline is so low that there's no room to put in an aftermarket manifold. The stock manifold is aluminum. The inside looks and feels awfully rough like they used some coarse sand to cast it with. I think it would flow decently if it were smoothed out.

Are there any tubular wire brushes out there designed to fit on the end of a drill for material removal? I've looked everywhere and can't find any such tool. It would have to be small enough to fit in the manifold runner but large enough to be effective. Of course, I'm open to alternate suggestions, too!

 

Extrude Hone it! :0



------------------
85 Z28 - Daily Driver
60 Ranchero - Project ( Money Hole )

 

From what I've heard, since its a wet intake, i.e. gas and air flow in the intake, smoothing the passages will not allow the air and fuel to atomize properly. This is in contrast to a dry intake like the TPI system where you can smooth to your hearts content.
Just what I heard.

------------------
Rob P
89RSconvtZZ4TPI
92Z28convt5spd
71Impala convt 402BB
BETTER DRIVING THRU SUPERIOR HORSEPOWER!

 

True! The reason behind this is because the rough casting that you feel actually helps maintain turbulance at low rpm speeds. Without this the fuel droplets would start to gather together, due to sloooooow velocity (kinda like seeing a massively huge air plane before landing ). So the roughness causes turbulance that helps the droplets stay "airborn" (atomized, mist, vapor, etc ...). But that is only on low speed rpms (driving around town from a stop to the speed limit). On higher rpms (+4000 rpms IMHO) that roughness also hinders velocity to the ports (read as flow). Once the flow is fast the droplets of fuel don't have time to gather, so the un-atomization is not a factor anymore. If you smooth out the runners on a wet manifold design, you are promoting high speed rpms. For which a race engine would benefit, but a street car will feels sluggish on low-end. Clear?

------------------
George P. Lara
1994 Z28 LT1 T56
1984 Z28 High Output
Member: SCCA, SCFB, SC3GFB

[This message has been edited by MRZ28HO (edited November 10, 2000).]

 

Thanx for the advice! I enjoy the challenge of seeing just what I can do with "grocery getter" and "pack-mule" motors!

 

The finish on an intake is going to have very little effect on flow. The reason for this is that the air directly adjacent to the metal is moving very slowly if at all. Until you are approx. 1/32 of an inch away from the edge nothing really affects flow much.
This is not to say there is not room for improvement in the flow of your intake. If it is typical, there are tight spots, protrusions and misalignments at the heads. But simply polishing it isnt going to make any difference.
I would recomend you locate a long arbor and some coarse sanding rolls to allow you to reach up into the runners.
Roy

[This message has been edited by Roy (edited November 14, 2000).]