25 replies to this topic

[bmcecosse]

That pancake filter is hopeless - far too thin - it's costing you power! But sort out the float bowl first.......

[IainNeon91]

That pancake filter is hopeless - far too thin - it's costing you power! But sort out the float bowl first.......

I have been looking into a cone filter today, so should get one soon.

I would have kept my K&N element box filter but it wouldn't fit on from the angle the carb sits

[The_Doc]

This is going to be a 10 year thread revival, not sure why it's not been discussed more though.

I've seen it written in lots of places that all minis with HS carbs need a 30° angle to get the float bowl horizontal given the angle of the inlet manifold and carb assembly. But I can't be the only one to notice that the angle on a single hs4 is nowhere near as steep as on twin HS2 carbs, or even I think on some single hs2s on very old 850s. Just by eye they look different, so are we sure they are all 30?

My single HS4 looks like a 10 degree angle but can't measure it to be sure. Would welcome a list of carbs and float angles if such a thing could exist?

[nicklouse]

The angle is different due to the need to clear the bulkhead. When fitting single carbs to a twin manifold you need to change the angle of the float chamber. You did not on the Inline engine as there was no bulkhead in the way.

[The_Doc]

But what about single carbs to a single manifold?

[Ethel]

Can't be that critical or we'd never be able to drive up 'n down hills. The level in the jet is what really matters, so if tipping the float chamber keeps the juice level with that it should be good enough.

[Lplus]

This is going to be a 10 year thread revival, not sure why it's not been discussed more though.

I've seen it written in lots of places that all minis with HS carbs need a 30° angle to get the float bowl horizontal given the angle of the inlet manifold and carb assembly. But I can't be the only one to notice that the angle on a single hs4 is nowhere near as steep as on twin HS2 carbs, or even I think on some single hs2s on very old 850s. Just by eye they look different, so are we sure they are all 30?

My single HS4 looks like a 10 degree angle but can't measure it to be sure. Would welcome a list of carbs and float angles if such a thing could exist?

You would need to measure the angle.  Burlen produce 4 different grommets to provide 0, 10, 20 and 30 degree angle depending on which hand the carb is.

[The_Doc]

So in conclusion the mantra that all minis are 30 degrees is incorrect?

[Lplus]

So in conclusion the mantra that all minis are 30 degrees is incorrect?

Yes.  Twin carbs on minis are 30 degree whilst twin carbs on sprites are 20 degree.  The single 1 1/2 " off my 1100 clubman estate is 10 degrees.  I don't know what 11/4 su's sit at.   To add to the fun the grommets can be solid or flexible.

[Spider]

This is going to be a 10 year thread revival, not sure why it's not been discussed more though.

 

The angle isn't that critical. The level of the fuel in it much more so.
 

[Ethel]

I suppose if you were to extend an axis from the fuel level in the jet, you'd want it to run through the float chamber so the  volume below it remains constant regardless of angle. Though the float ought to compensate too as it's attached to the float chamber (maintaining the same tilt as it) and will displace a constant volume.

 

The nearer to horizontal the float pivot is, the freer it's likely to move - so maybe that's why less incline is best???