Bike carbs manifold

[mark]

Just thought i would share some pics of what i got up to today. I chopped the original inlet manifold flange off the cvh manifold. Rolled some flat bar into tubes and made myself an inlet manifold for my bike carbs.

Well at least i did after i farted around with my mig for an hour until it would weld aluminium properly Hope santa brings me a tig set, i miss having the use of one for jobs like this. The mig did it ok in the end but you have to weld at warp speed when doing ali with a mig so its hard to be neat.

[RAYLEE29]

Thats a nice job Mark.
Just a few concerns dont the runners need to be the same length?
Also most of the manifolds ive seen have been about 5" long it helps lowdown torque apparently (short runners are better for top end)
what carbs are you using because my gsxr ones need to be set at 45degrees?
Ray

[spud69]

Very nice job Mark, i did mine in a similar way and they worked out fine, did similar to the exhaust manifold and just made to suit with a focus st170 high flow exhaust. Worked a treat and goes like stink, and there's plenty of torque, the good thing with the cvh is that they both will just fit straight onto the zetec. Also saves hundreds of pounds having bought in.

Very Good....>AndyH

[HandyAndy]

nice work Mark there,s another cvh engine close by that would look great with the same treatment & i saw a set of carbs on a bench yesterday

andy

[mark]

Originally Posted by RAYLEE29

Thats a nice job Mark.
Just a few concerns dont the runners need to be the same length?
Also most of the manifolds ive seen have been about 5" long it helps lowdown torque apparently (short runners are better for top end)
what carbs are you using because my gsxr ones need to be set at 45degrees?
Ray

Yes they will all be the same length from the engine once i connect them with silicon hoses and in an ideal world they would be at 45 degrees but they would hit the bonnet if they were set like that, also if the runners were much longer plus the dimensions of the filter i would have to chop the bonnet and have them poking out the side! which looks cool but i dont want to be chopping big holes in a nice new bonnet. They are set at an angle on the bike but they still work when the bikes doing a wheelie

As spud says his are the same carbs as mine (ZX6R) and his are close to his engine and his car goes some probs on parr with the m3 i recently sold and thats enough for anyone when you are a few inches off the floor with no windscreen

Thanks for the comments though

[AshG]

mark if you want a bit of silicone hose give me a shout. i had to buy 1m of the stuff to do my bike carbs. i have over half a m left the internal diameter is 38mm but it stretches fine over the bike carbs which are 42mm on the outer flange.

[mark]

Originally Posted by AshG

mark if you want a bit of silicone hose give me a shout. i had to buy 1m of the stuff to do my bike carbs. i have over half a m left the internal diameter is 38mm but it stretches fine over the bike carbs which are 42mm on the outer flange.

Thanks for the offer ash but i have already ordered some

Done the same as you and ordered a metre of the stuff!

Wish i had seen this post first.

[RAYLEE29]

Ok.
But I do think you will have probs with the float height if you run at the wrong angle.
If you make the hose too long the carbs try to pop off when idling as it gets sucked in by vacuum also by having a long length of tube you create bad flow at the carb mouth you should aim to only have a couple of mm between the carb and runner
Might be a good idea to add some tube to the middle runners so they end up the same length
and bare in mind the float height if you cant get it to idle properly
Ray

[mark]

Originally Posted by RAYLEE29

Ok.
But I do think you will have probs with the float height if you run at the wrong angle.
If you make the hose too long the carbs try to pop off when idling as it gets sucked in by vacuum also by having a long length of tube you create bad flow at the carb mouth you should aim to only have a couple of mm between the carb and runner
Might be a good idea to add some tube to the middle runners so they end up the same length
and bare in mind the float height if you cant get it to idle properly
Ray

Thanks for the advice i will try and modify it to suit, as you may of guessed bike carbs are not my strong subject and only know what i have read on the internet. Are all bike carbs set at a similar angle or is it specific to make and model? I will try and angle them as much as poss within the clearance i have. Do you know what the optimum angle is?

Thanks

[AshG]

just put them on and see if they work. thats all i did. i just made sure the bottom bowls looked level and not the intake openings.