Originally Posted by ThisIsLivin (Post 4842305)

It was season 3 episode 39. I think their analysis was that the jets shoot down under pressure and the fuel can't make the turn. Get a subscription to Motor Trend it's worth the money. Over the seasons they have tested everything I've done and I'm feeling pretty good about my choices. They do a lot of testing on BBC so we can learn a lot.

Originally Posted by articfriends (Post 4842246)

weiand stealth and regular performer intake. % or so years ago a friend brought a 502 to dyno, small cam, vic jr intake. motor was a zz502 he had got cheap and fixed up. motor made a embarrassingly low tq number for a 502. We bolted a ported performer on, picked up tremendous torque AND top end hp (only hgad power to 5400/5500). #3 was burn down lean, #2 was pig rich, talking 4+ afr points apart. we monkeyed with carb spacers, still sucked. He bought a perfomer rpm, picked up even more tq and hp, 2 was like 11.5, 3 was like 13.5 give or take, half as bad.
Fast forward, guys building a similar engine, asked what he should get, I told him a perf rpm, he couldn't get one, so he bought a weiand dual plane. Same deal, 2 in low 10s, 3 in almost the 15s. tried a couple spacers, made no difference. Compared a stock carbed 502 intake I had to his weiand, they were a mirror image of each other BUT the factory intake had little ridges/troughs turning the sharp corner to 3, I assume to help fuel distribution. We looked at a beat up, nasty perf rpm I had, the turn to 3 was much more radiused and port to 2 much smaller than the other 2 , as if they actually put some thought in the design. We found a new perf rpm online, ordered it, swapped it on, picked up tq/hp over the weiand (like around 15/20 at peaks) and again, distribution was half as bad as the weiand. If anyone calls and wants to dyno a marine engine with regular dual plane in future, Im pretty convinced theres no real good way to fix the fuel issues, Smiitty

Originally Posted by SB (Post 4842325)

Looks like the BBC RPM rect port's are back in stock. Note, the air gap's don't seem to be yet.
https://www.summitracing.com/search/...take-manifolds