Originally Posted by marlinspike

Here are some of the parts involved btw

Originally Posted by Fabrik8

The bigger throttle body would only be for greater flow.

If you want to polish something, polish the inside of the 8 outlet ports on the shoebox. If it's a multi-piece shoebox, you could internally polish the whole thing, but the gains will depend on what the surface finish already is, etc..

Arguably the best possible thing you could probably do is to make the shoebox deeper, so there is more space between the 8 outlets and the floor of the shoebox. Then you lose a little velocity (because of the greater volume) but gain a straighter flow path into the 8 outlets. Those outlets, and the runners they attach to, are really what sets most of the velocity into the head. The shoebox should affect the velocity a little, but mostly it's the geometry of the damn thing that will have the most effect on how well it works. It's the same reason that you see velocity stacks on race engines. A plenum box will be around them, but the best thing a plenum box can do is to not interfere with the velocity stacks. There are the obvious tradeoffs with plenum volume and throttle response too, but poor geometry is one of the worst things you can possibly have, because then you can't make the best of the other parts you're working with.

I'm starting to ramble, sorry.

Remember though, the biggest flow restriction is always a throttle plate that isn't open all the way.

Originally Posted by Fabrik8

Wow. I wonder what happens with the far cylinders at high flow. That's the intake equivalent of a log-style exhaust manifold, sort of...


Cool oil pan, is that a factory piece?


If you have time/money/ambition/underhood space, you should make a more traditional manifold setup and use a modern MAF or MAP. The valve covers look like they would set the hood clearance height, and you could probably stuff some long intake runners in the valley. Those intake ports make me drool by the way, it's really cool that they're perfectly circular. So easy to make runners...

I've left the realm of working with what you already have, and have now entered the land of "let's make a badass race setup".

Originally Posted by Fabrik8

No, I was saying that the throttle plate is obviously always restricting flow, unless you're at wide open throttle. That's how it works.

Originally Posted by marlinspike

Yep, that's a factory oil pan. 8.5qts at an oil/filter change baby.

As far as getting someone to make me custom stuff....nobody is interested in making custom stuff for an engine they have never seen before nor will see again. The few custom stuff I have gotten has required time, begging, and lots of money.

The air filter housing is actually what sets the hood clearance height, and as you can see it sits a good bit higher than the valve covers

(there have been changes made since then, like a third air intake line and reflect-a-gold all over the air intake housing.

Originally Posted by Fabrik8

Depends if they actually want to make money or not. Plenty of race fab shops would make you a manifold in a second. It really isn't any different than any other V8, the flanges and things are the only difference. An engine is an engine, so whether someone wants to make parts only depends on whether they want to make a production run of the same part. A one-off is the same no matter what though.

Originally Posted by marlinspike

Oh, btw, there is a guy in Estonia making a corvette-like manifold for these, but I really don't feel like dealing with megasquirt and that's what his setup requires. I'm able to get a perfect AFR map (when the digital component I bought for my mechanical injection works, right now I'm on the back-up full mechanical set up and it gets a decent curve but not perfect).

Originally Posted by Fabrik8

If it can use Megasquirt, it can use any other (read: better) aftermarket ECU on the market just as easily. There isn't anything magical about a manifold, and don't let that guy tell you any different.