Speedmaster intake porting. Hopefully I can make something out of this
I’m thinking my Indy SR heads may be the choke point at this time. So then will it be beneficial to port the intake at this point? Thanks. Kim
YES!!!!! You’d have a choke point at the heads and the intake. I’m not sure that your heads are much of a choke either. But that intake needs serious work.
About 3 months ago I was looking at a manifold that was bolted to the flow bench. It was a dominator top but something just bothered me. I was talking and looking the intake over at the same time, and then it hit me.
Whoever made the intake (I can’t remember whose intake it was) just took a 4150 top and converted it to a 4500 top. It looked a lot like what your intake does, in that the outer edges of the throttle blades are opening right on top of the runners. On that intake, the opening from the flange to the top of the runner was a little more that a 120 degree bend!!!!!!
There were two options to fix it. One was put a 2 inch spacer on it and try and blend some of that out. That IMO was the best option.
The other option was to bring it home and weld up all for corners of the manifold where the flange met the runner. My rough guess was 4 hours of welding minimum. Then you have to machine and grind the plenum to get it right. I took a hard pass on that.
The guy ended up selling that intake and starting with a better piece. I’ll see if they actually did any flow tests on it, or if they just said screw it and took it off the bench.
I’d bet everything guy was having distribution issues like crazy, because he complained the car was sucky in the gear changes and off the foot brake. Plus other issues.
I don’t know who can produce and sell an intake like that. My guess was it was a very old intake that was made 20 plus years ago when everyone started switching to dominators and they reengineered an existing 4150 intake to take the 4500. It was straight garbage.