Inliners International Forums General Discussion Hi Performance Siamesed Port

I didn't use a balance tube on the engine Ray used at Bonneville and it had no difference in plug readings. I would love to see the air/fuel ratio of each cylinder as it progressed upward in RPM. With twelve holes pointing into the sky, I doubt if your manifold would see a strong enough signal to make a difference. Besides, it could very well be a combination of things that give us this overall effect. I do believe harmonics plays a big part in all of it.

With the inline six firing order (1-5-3-6-2-4-1-5-etc.)cylinders 1 and 6 each follow 2 and 5, respectively, by only 240 degrees. Cylinders 3 and 4 are "evenly" spaced at 360 degrees. With a typical high-performance cam the intake valve on #1 (or #6) will start opening while #2 (or #5) is closing. This will certainly affect the flow into 1 and 6, both from a flow momentum and wave dynamics perspective. It is not surprising that dividing the ports or using asymmetrical valve timing would affect or help a six with siamesed ports.

Hoyt, This is exactly what my plot of timing cylinder to cylinder showed, and I think it only comes into play at higher HP numbers because the air can react quicker but the fuel can not.

Remember turbos do not speed up the air or force it into the engine but adds to the density therefore increases the amount of air in the engine and increases the HP.

What a good post!!!

Turbo-6: Guys here run siamese port heads with a lot of methanol going through the head! All guys here just run it super rich!!!
The most powerfull Chevy 6 engine here ran about 8.5 seconds on 1/4mile in a car with 3.000lbs and stock Body (No sub-frames, four-link and other chassis goods at all...)
The guy here Run a 950CFM Holley Dominator Carb with clifford manifold, 3 additional 160lbs/h injectors, running on methanol. About 40 PSI of boost (!!!!!!!!!), 100hp of nitrous to wake up the two .70 Master POwer turbos when lauching, and no main cap girdle on the bottom of the block. Only ARP bolts on main caps... A total amount of 1.300 horsepower on the engine!! (of course, the guy broke a lot of engines... but it run extremely fast)!!!

Sorry that I´m not posting too much! Lot´s of work here!!

Hank! Need to talk to you! I´ll e-mail you soon!

Thanks!

Douglas C.

About a year ago, before I left Brazil, a friend of mine(terrific engine builder) and me were working something really close Turbo-6 idea. We were discussing about changing time events to create more flow waves inside each whole port using the adjacent piston to helps sucks the air. We were never concerned about the mixture, as the main idea was enhance flow velocity using the big port volume, but after try two diferent custom made cams he realized that stoichiometry had change.
I wasn't there yet, but he told me he changed the center line in one cam and increase some .050 in the other keeping the total duration untouched. As I'm only being able to speak with him on the phone and he's a very busy guy, we don't have time enough to chat about it. Though he said the results was very interesting and we'll probably gonna get back to it when I return there. Hardly can wait!
He has some dyno figures, but i've never seen it. Still curious about results.

Congrats Turbo-6. It's been a long time I haven't seen such a good topic. Things became a bit superficial at this time here. Things change...