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 :D 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 :eek: 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 :cool: there,s another cvh engine close by that would look great with the same treatment ;) :D & i saw a set of carbs on a bench yesterday ;)

andy

[mark]

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 :D

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 :eek: :D

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]

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 :rolleyes:

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]

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.

[RAYLEE29]

Hi, not sure what it is for your carbs but if you look at the float chambers where they split apart the gaskets should sit horizontal in normal use
heres a pic of mine at approx the right angle if it helps
Ray:)

[mark]

Well after a couple of modifications to my first manifold the carbs are now attached to my engine :)

Heres a couple of pics for you, my build is starting to see some light at the end of the tunnel now :D

[HandyAndy]

looking vey smart Mark, just wait till your bodywork is fitted :cool:

hope you,ve got some shades at the ready ;) :D it looks great

andy
ps ... what you doing on sunday? fancy helping moving a Roadster? :o

[AshG]

look good mate did you tap them to tale balancing tubes?

[mark]

No i didnt, i always thought you could balance them by shoving one of those carb balancer thingymjigs in the end of the trumpet? :D

If not its no big deal to add them in if i have to, as usual any advice on this subject greatly appreciated :o

[mark]

looking vey smart Mark, just wait till your bodywork is fitted :cool:

hope you,ve got some shades at the ready ;) :D it looks great

andy
ps ... what you doing on sunday? fancy helping moving a Roadster?

Only too happy to help mate, just let me know what time and i will be there impact gun in hand! we will reduce you car into a pile of parts in no time :eek: you have actually picked a good weekend for it as im not working and my van isnt crammed full of parts for a change.

[RAYLEE29]

Looking good mark and your bonnet should still miss the carbs (hopefully)
have you had it running yet?
if you can tap the runners to take vacuum gauges it will help setting up the carbs using gauges as opposed to those flow meter things (its a lot quicker and more accurate) thats if you have access to some.
Looks like youll be able to move under power soon thatll be a great feeling.
Ray:)

[mark]

Looking good mark and your bonnet should still miss the carbs (hopefully)
have you had it running yet?
if you can tap the runners to take vacuum gauges it will help setting up the carbs using gauges as opposed to those flow meter things (its a lot quicker and more accurate) thats if you have access to some.
Looks like youll be able to move under power soon thatll be a great feeling.
Ray:)

Not run yet but thats next on the never ending list of things to do! Megajolt and start sorting out the wiring. I will put some points in for vacuum hose if thats the best way to do it. In my work i take pressure readings in ductwork so have digital manometers so maybe i could use those for setting the carbs.

[RAYLEE29]

Yes im sure you could use digital manometers you might need to use some form of damper as on the anologue gauges i have with no damping they flutter around alot you can get a similar thing for adjusting air pumps on aquariums if you find you need some
Ray:)

[snapper]

check your hoses as i understand some silicon hoses are not fuel resistant