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Single carb manifold design.

P901 Single carb intake, FLAASH Cams, Super Charger, NOS.......
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Single carb manifold design.

PostAuthor: dazthebiker » Mon Feb 12, 2018 4:13 am

Building my 81 750 at the moment, and although i have standard carbs they are in crappy condition. I have got a mikuni HSR45 sat in my drawer from a previous project (supercharged bandit 1200) and thinking about using that, although it seems most opt for the 42 when using the HSR im not about to buy a new one...

Anyway, im just looking through manifold design and every single one i has seen so far has a huge imbalance in intake tract length, with a good run into one cylinder and a crappy side take off to other, which is going to result in horrible air shunting and mean one cylinder is likely to run lean.

Has anyone tried making a manifold with equal length tracts, and bringing both to a point where flow from the carb can be split equally? Seems like it should be possible, and stack the intakes on top of each other with a longer radius bend on the cylinder closer to the carb to increase its length.

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Re: Single carb manifold design.

PostAuthor: Flyingdog » Mon Feb 12, 2018 6:01 am

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Re: Single carb manifold design.

PostAuthor: Jake » Mon Feb 12, 2018 7:35 am

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Re: Single carb manifold design.

PostAuthor: dazthebiker » Mon Feb 12, 2018 7:51 am

KJS one is alright i suppose, hate the look of it but inlet path is reasonable.

Jake- the first one using a plenum style chamber looks like a pretty good solution, so surprised you changed the design back to one that means one inlet having to double back on itself. How did they run? Great fabrication skills by the way

Looks like i have set myself a challenge with the intake!

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Re: Single carb manifold design.

PostAuthor: dazthebiker » Mon Feb 12, 2018 8:00 am

PS, no idea why my last post now has a link in it, i didn't do that!

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Re: Single carb manifold design.

PostAuthor: Jake » Mon Feb 12, 2018 9:47 am

dazthebiker wrote:KJS one is alright i suppose, hate the look of it but inlet path is reasonable.

Jake- the first one using a plenum style chamber looks like a pretty good solution, so surprised you changed the design back to one that means one inlet having to double back on itself. How did they run? Great fabrication skills by the way

Looks like i have set myself a challenge with the intake!



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Re: Single carb manifold design.

PostAuthor: dazthebiker » Mon Feb 12, 2018 12:31 pm

oops, just spotted that, sorry smithtec!

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Re: Single carb manifold design.

PostAuthor: smithtec » Sun Jul 15, 2018 9:38 pm

I am aware that one leg jogs back pretty sharp, but I've sold about 100 of these all over the world, and they work just fine. Plugs generally look identical. I've still got to do some wideband O2 testing to confirm even burn, but I predict there will be a very small margin of difference.
:chop: :cl:
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Re: Single carb manifold design.

PostAuthor: mark75 » Mon Jul 16, 2018 4:28 pm

are you thinking "roll-yer-own" DIY? search P901
brother P901 did it 1st - so it's named for him.

there are some of these are old site phBB and will have to be 'converted' ---

http://www.viragotechforum.com/viewtopi ... =81&t=6842

http://viragotechforum.com/viewtopic.php?t=11693

http://www.viragotechforum.com/viewtopi ... =4&t=10624
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