Yeah, that other thread is the longest thread I have ever seen on the BB, and definitely hard to follow.

John, you were mentioning some of the early alloy SU manifold flowing noticeably better than others? How can one differentiate between the two?

So yeah, I'm planning on getting some TWM air horns and some spacers for my HIF6s.
Spacers such as these(of which I actually used to have some, and decided to run without, maybe I can find some thicker ones or something...):

And air horns such as these:

Last time I was at the dyno, I was running with retarded timing, I don't even know what it was at, and this is what I got:


Next time I make it to the dyno, I'll be running advanced timing, starting somewhere in the neighborhood of 17 degrees advanced to start with, and then experimenting with mixture a little bit, and then going on to play with the air horns and spacers. Or, I might just instal the spacers and air horns first and then tune to decent running on the street and then get it on the dyno to reduce my time spent on the dyno. I'd love to spend more time on the dyno, but that costs money, and big bucks for tuning little bits on a measly stock b20b with minor external mods doesn't seem too worth it... Thoughts? Procedure advice? What manifolds flow better?

Oh, and then on top of those air horns, I was planning on sticking with the stock airbox that I have now, with 2" air horns it won't be too bad, but worse than going without an airbox. I really want to stick with cold air, so I might go with a TWM specific box that is a little "deeper" you could say, with more room above the air horns, or make a custom box that is even larger. OR, just go without cold air and rig up something along the lines of this:

Which I'm assuming is fitting over the air horns?

The images that aren't mine I am pulling from Grassroots Motorsports 122 buildup where they say they ended up with 103hp at the wheels from a b20b with SU HS6s and a KG Trimning header.

So yeah, thoughts, experiences, ideas, and what not. I know I need a different cam if I want to make power up higher like I want to, but I can still work on maximizing what I have in the meantime before this engine dies. Then the next motor will get to benefit from what I learn and gain with this motor.

Oh, also, in the dyno runs, the car was getting cooler and cooler with each successive run. My car currently has the little 4 blade direct water pump drive fan on it. I'm planning on taking it off and getting a nice electric fan on there beforehand as well. Or maybe sticking on a big flex-a-lite fan, but I don't really want to listen to the noise it will create, and then the engine will still have to spin it as well, which I don't want it to have to do either.
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Kyle E.
VP of Membership and Website Administrator
Oregon Volvo Tuners
Portland/Corvallis, OR - 1968 142 - 71b20b SUs, m40, ask me for more info...