Fins on back of Valve & Fins pre TB

[The1]

the one on this page is like yours delco, but has twin tubes.

http://www.sicsix.com.au/tech_specs.html

[vlad01]

lol I was about to post the same one.

[HQ355]

I might still go down the torque power single or dual plane 4 barrell manifold and throttle body route, it's going in my HQ so it won't matter if it looks old school and as the motor dosnt have to meet emissions that dosnt concern me either, has anyone got sny experience with these ?

[Holden202T]

yeah I have had experience with a torque power dual plane and CRD 750cfm 4 barrel TB .... it all worked really well in a 304 with 286 cam other than the owner never finished it off with the right converter and exhaust!

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[vlad01]

Do a search on Helmholtz Theory and intake manifolds, if you can get your head around he maths it's rather interesting. Below Is one I've found particularly good from a quick google search, there are heaps more:
http://www.stealth316.com/misc/grapeape ... ystems.pdf

There are some v8 Supercars that have the trumpet pointing perpendicular to the lid of the plenum, I think the idea is the wave coming out of the intake runner hits the plenum and bounces straight back down the intake.

The same basic principle is used for tuned length extractors.

thats a great bit of info there! its interesting how it says for more than 4 cyl dual plenum is needed, v8 don't like single big plenum it says. Same assumed for the 6 cyl as well.


I wonder if a stock like v6 plenum could be made with twin TB and divider separating the 2 halves. I wonder if that would benefit the engine?

Interesting how this documents is the complete opposite to the SAE paper I read in regards to plenum volume.

Also that the intake tube that goes into the plenum is equally important as the runners and volume. I always felt that on VN-VR the long ass intake pipe might have significant effects on torque, it came to me when fitting a pod in an enclosure due to the noise it makes at peak torque, I figured some wave action was going on in there.

[delcowizzid]

http://forums.justcommodores.com.au/hol ... d-how.html

[yoda69]

Biggest problem with V8 with split plenum is the uneven firing order bank to bank, it doesn't go LRLRLRLR but RLRRLRLL, the v6 however should be good as it does fire LRLRLR so can be easy split up as shown in the earlier manifolds in this post.
Like with all engine design the package of parts needs to work together, no point having an intake manifold with short runners designed for high rpm work and then fitting a tow cam.
This is the reason for variable intake manifold design so the engine can swap from long runners at low rpm to short runners at high rpm. If you could come up with a robust design that sealed well, reacted quickly and could infinitely vary the length of the runners could improve the torque spread across the engine range. The same applies for exhaust, was tried by Yamaha on there motorcycles with the EXUP system.
http://www.yamaha-motor.com.au/service- ... nology/EXU
Have never seen this system fitted to a car, but is no reason I can see that it wouldn't work if tuned to work with the engine rpm, capacity and header length, could even drive it using a 12p flex table

[Gareth]

This is the reason for variable intake manifold design so the engine can swap from long runners at low rpm to short runners at high rpm. If you could come up with a robust design that sealed well, reacted quickly and could infinitely vary the length of the runners could improve the torque spread across the engine range.

Dammit, beat me to it , was dreaming inlet manifolds last night (yes, I have no life...) and remembered the Falcon EF manifold hanging from the wall down the back of the shed, long-ass runners with a butterfly valve for short runners (long runners for low down and switches to short runners for high speed) those engines always seemed to make great torque compared to a V6 of the same era, cubic cap., rod ratio, valve size not really THAT different, manifold design is...

The1, this is what I think we should be looking at, what are your thoughts?

[The1]

well most likely, though comes down to my drawing ability and lack there of.

[HQ355]

Thanks for the pics holden 202t, how many killer wasps did the motor make ?