SeaBass
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| posted on 12/3/07 at 02:39 PM |
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Bike TB Manifold Manufacture
I'm about to source some materials to build a manifold for my ZX12R TB's. They are going on to the Zetec E that I'm in the process
of installing.
The outside neck of the TB's is 57-8mm but the size of the aperture is a bit less. I'm thinking that if I get tube with an OD of 57mm
& maybe 2-3mm wall the flow throught the tube maybe a bit slow down to the head. The next logical size down is 50mm (metal stock still seems to be
tied to imperial!). With 50mm tube I could turn up some adapter to slip over the end of the tube to use 57mm connecting samco etc.
Anyone else making up manifold care shed some light on what they have used?
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chrisg
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| posted on 12/3/07 at 03:30 PM |
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Neat solution!
Not thought of that!
cheers
Chris
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andyharding
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| posted on 12/3/07 at 05:37 PM |
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quote:
Originally posted by CaLviNx
why not just place some suitably sized "O" rings as seals over the bodies and bore some ali tubes that are slightly larger than the
throttle bodies and use a mechanical restraint at either end to stop the bodies from popping out of the manifold tubes.
Because the carbs would then be solid mounted which is incorrect. The carbs must be rubber mounted.
Are you a Mac user or a retard?
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Project7
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| posted on 12/3/07 at 05:50 PM |
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they are throttle bodies though not carbs - that is how i have mounted mine.
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thomas4age
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| posted on 12/3/07 at 11:32 PM |
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these guys have all sorts of alloy tube's in other sizes that metric.
I don't know who gave me the link over here nut THANX.
http://www.aircraftspruce.com
I have just ordered some stuff.
grtz Thomas
If Lucas made guns, Wars wouldn't start either.
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chriscook
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| posted on 12/3/07 at 11:57 PM |
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What is the spec of your engine and the diameter at the engine end of the TBs? Those TBs sound a little on the large side for a zetec....
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TangoMan
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| posted on 13/3/07 at 08:25 AM |
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quote:
Originally posted by SeaBass
The outside neck of the TB's is 57-8mm but the size of the aperture is a bit less.
Are you sure that they are that size on the manifold side and not just the airbox side (as my GSXRTB's are tapered!!)
I think that mine are too big as small throttle openings give 100KPa MAP and the are smaller than that at 48mm ID head side. They are 54mm ID at the
airbox side though.
Summer's here!!!!
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SeaBass
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| posted on 13/3/07 at 09:35 PM |
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As I attempted to explain. 58mm in NOT the internal and much quoted diameter of the TB's. It is the external mounting flange
diameter. They will be fine for the application.
My question relates to intake manifold runner internal diameters and there effect on charge speed. Is this even important??
Cheers
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flak monkey
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| posted on 13/3/07 at 09:37 PM |
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If you go from a 58mm bore in the manifold to a smaller bore on the cylinder head the flow will speed up as it enters the head.
David
Sera
http://www.motosera.com
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SeaBass
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| posted on 13/3/07 at 10:36 PM |
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OD of the tube will be 58mm - 2xwall. I'm thinking quite a thick wall so prolly down at about 52mm ID. This will be squashed to an oval shape at
the face of the head to suit the Zetec's ports.
TBH I haven't really learnt anything from this thread guys sorry!
Cheers
[Edited on 15/3/07 by SeaBass]
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chriscook
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| posted on 13/3/07 at 11:48 PM |
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Well what is the ID of the TBs at the engine end. The same diameter would probably be a good start point.
Without knowing the ID at the TB how can anyone know what the effect on the charge speed will be?
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02GF74
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| posted on 14/3/07 at 08:53 AM |
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quote:
Originally posted by andyharding
Because the carbs would then be solid mounted which is incorrect. The carbs must be rubber mounted.
.... the reason being?
and if they are not, what would happen?
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flak monkey
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| posted on 14/3/07 at 08:54 AM |
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Carbs need to be flexibly mounted otherwise the fuel in the float chambers froths up. Doesnt matter with ITBs though.
David
Sera
http://www.motosera.com
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02GF74
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| posted on 14/3/07 at 08:59 AM |
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aha, I thought so - but does it really make that much difference?
on a bike, the engine has hardly any movement but a car on its usual rubbers does so I am disbeleieving that it is gonna make a difference. 
be interesting to see if anyone has tried both methods of mounting (ooh err!) 
[Edited on 14/3/07 by 02GF74]
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SeaBass
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| posted on 14/3/07 at 04:22 PM |
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quote:
Originally posted by CaLviNx
OK I'M NOT HAVING A PERSONAL POP AT YOU.. BUT
If you had initially asked the questions you asked LATER in the thread people might have managed to help you, the old adage works here
"crap question = crap answer"
Actually Mark - If you re-read the initial question carefully rather than skimming and reading what you think it says, it is still exactly the
same..
I state I'm worried about flow in a given ID tube size and ask what others think! I did give an explanation of how I could overcome a reduction
in tube size.
Anyway to update I've ordered the aluminium in 2 1/4"/ 57mm OD and I'm set to go.
Cheers
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SeaBass
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| posted on 14/3/07 at 04:25 PM |
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quote:
Originally posted by chriscook
Without knowing the ID at the TB how can anyone know what the effect on the charge speed will be?
Easily - because there will be established theory on the subject. I'm not looking for an exact flow in m/s because that would be useless...
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TangoMan
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| posted on 14/3/07 at 07:43 PM |
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quote:
Originally posted by SeaBass
quote:
Originally posted by chriscook
Without knowing the ID at the TB how can anyone know what the effect on the charge speed will be?
Easily - because there will be established theory on the subject. I'm not looking for an exact flow in m/s because that would be useless...
Erm.... Did I miss something.
Not trying to be pedantic but....
A+B=C
A = Outer Diameter
B = Wall thickness
c = Inner Diameter.
We know that C = 57 - 58mm
If you give us A or B we can work out the rest.
Everyone wants to help but you do need to give the full info.
For what it is worth, I used tube slightly smaller than my TB's as I figure the throttle butterfly will have a greater impact on flow than a
slight reduction in diameter and any impact will only be a full throttle anyhow.
I did chamfer the edges though so the air doesn't hit a step on its way through..
Summer's here!!!!
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paulf
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| posted on 14/3/07 at 09:06 PM |
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Im using throttle bodys with an outside diameter of 44mm and bore of 38mm.I found some 50mm od alloy scaffold pipe and am going to bore the ends out
to allow the Tbs to be pushed in against an O ring and then arrange a clamp to hold them in place.I have tried a few ways of fitting to the manbifold
plate but have decided that the best and easiest way is to just squash the tube oval to match as well as possible and then am going to match the
manifold to the ports when fitted.
Paul
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SeaBass
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| posted on 15/3/07 at 12:47 PM |
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Sounds like a neat solution Paul.
Cheers
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