Vixen carb and engine level

[anonymous-user]

Something that has been puzzling:
With a standard Vixen (twin choke DGV carb) should the engine be broadly level or up at the front? The Kent was set tilting up at the front in the Escort hence the inlet manifold was formed the other way to make the float chamber level. If on the Vixen the engine is broadly level then the carb will be tilted forward. Unless the manifold face is machined flat and re studded like FF1600.
Most kit car applications are broadly level albeit a slight 'up' at the front to reduce air pockets.
So, on sight should the engine be 'flat' (very slight tilt) or at an angle to make the float chamber level (big tilt). If the former then are Vixen carbs on the piss?

[RCK974X]

As far as I know most RWD engines are set at a slight angle with front of engine up, around 2-5%.

(Most) Carbs can handle moderate angles as it really only affects where the float valve 'seals', and therefore the overall fuel level, and a few degrees makes pretty much zero difference.

Some angles and shapes were set simply to make sure everything fitted under the bonnet.....

[anonymous-user]

I think the escort manifold is about 3 degrees ish which doesnt sound a lot but quite noticeable on the air filter top. I would be very interested if any Vixen owners have level carbs with or without a visibly sloping engine. I think most Kent engines are installed 'flat' with a nominal tilt backwards only, but hopefully the PH Massive will have some feedback...

[Sonus]

Remember to set the diff angle the same so that the gearbox output and diff input is parallel.

[anonymous-user]

I think up to about 3 degrees difference is OK?

[RCK974X]

V6Pushfit said:

I think the escort manifold is about 3 degrees ish which doesnt sound a lot but quite noticeable on the air filter top. I would be very interested if any Vixen owners have level carbs with or without a visibly sloping engine. I think most Kent engines are installed 'flat' with a nominal tilt backwards only, but hopefully the PH Massive will have some feedback...

CAREFUL !! I can't remember for Kent engines, but on Cologne V6 Cortina Carb engines the air filter box is DEFINITELY not parallel (carb flange to top of box), so that the filter box top angles down to front to get it under the bonnet.....and it's not at all obvious to look at it when off the engine. (Carb flange is moulded in at an angle, but as it's indented you can't easily tell)

So just make sure you are measuring consistently on the carb/manifold itself.


Yes, I think default angle for propshaft/diff/gbox is 3 degrees. Don't know if Vixen sticks with that though.

Edited by RCK974X on Tuesday 28th June 01:25

[griff 200]

I have seen in a locust race car that needs to use the std inlet manifold carb set up to get a level float chamber the spacer plate made of phenolic was machined at an angle to get max power. Not in the rules but bending the rules. So this may be a mod worth doing but properly worth only a few hp. Richard

[anonymous-user]

griff 200 said:

I have seen in a locust race car that needs to use the std inlet manifold carb set up to get a level float chamber the spacer plate made of phenolic was machined at an angle to get max power. Not in the rules but bending the rules. So this may be a mod worth doing but properly worth only a few hp. Richard

That's a good idea, the studs will still be on an angle but that's minimal. It's surprising how just a few degrees is very visible I think the float level difference between the two is about 4mm so important to get right