Will a HIF44 fit under the bonnet ?

[Daggers-xi]

My engine builder has recommended a single HIF44 carb for my XI, can anyone confirm if this fit under a standard bonnet?
Still waiting for my XI kit to arrive so can't measure.
If you have fitted a HIF to your car can you advise which manifold you used.

[Westfield 129]

Whether the carburetor fits or not really depends on the intake manifold. A Maniflow should work, provided it doesn't have much rise from the cylinder head to the carburetor mounting. Maniflow will make whatever you need to make sure that your HIF 44 clears. My guess is that a standard configuration Maniflow will work.

Most carburetor combinations, twin SUs, a single Weber 45 DCOE or a single SU will fit under the W11s bonnet, provided the manifold is not one of the "gooseneck" types that raises the carburetor above the cylinder head by a large amount (more than 1")

I have successfully fitted all of these combinations to a W11, both early and late types, without clearance problems, using stock or Maniflow intakes.

No more than a 3/8" rise from the cylinder head to the carburetor mounting center if you are using a 5~6" intake length. It is likely that the standard Maniflow will not have much rise, and will fit perfectly.

I have built a few engines myself, and recommend twin 1 1/2" SUs or a Weber for best power and response. That said... A single SU works well, too. You can get 10 hp with that setup, or more, if you carefully choose the cylinder head, cam and allow for a high enough compression ratio.

Also, the longer the intake, the more power available. I am currently using a 6" long manifold with my Weber.

[Westfield 129]

Sorry, should read 100 HP with a single large bore SU, on a 1380 with a good cylinder head and a proper cam.

[jonclancy]

I'll be able to answer that question very soon!!

I have a brand new Maniflow manifold to fit with my HIF44. I'll mock it up and take a pic of the relative height to the rocker cover.

I did ask Maniflow about the angle of the dangle when I ordered my maniold - answer was that the Midget item is almost flat.

Bear with me...

And yes, a single HIF 44 is a good, torquey compromise (and easier to set up!), according to Vizard and Teh Internetz.

[Daggers-xi]

Thank you all for the info.
Will be very interested to see the result of HIF44 with Maniflow tube inlet.

[jonclancy]

Bear with me, please readers...

Ran out of time yesterday, so will only be able to revisit this next week. I've stuck a reminder in my diary.

[erictharg]

From personal experience I didn't find an SU HIF44 could fit under the bonnet. Unless Maniflow do a design that angles down from the head (vs horizontal) it will not fit without mods. I ran an HIF44 at first on my car using the Titan manifold designed for the Midget, and still have the hole I needed for the dashpot in my bonnet. I don't think you will manage it without a custom or modified manifold.

[jonclancy]

Thanks for this info, Charles.

I'll mock mine up and if needs, give Maniflow a call next week. I think it would be helpful to identify a W11 spec. These manifolds appear to be made to order. Either maniflow will be able to alter mine, or I coud return it for exchange. Not even unpacked it from the delivery box yet!

The trick will be achieving the downward angle without interfering with the exhaust manifold, or vapourising the fuel in the float bowl!

[Westfield 129]

A "flat" manifold works, but there is also length to consider as well. Lots of areas to adjust when it comes to the intake manifold.

To our advantage, the longer the intake, the more power we can get. Sometimes, moving the carburetor farther from the engine can increase clearance. A 6" intake is not outrageous, and can make a significant increase in torque and HP, depending on the engine specification. And... the angle of the carburetor on the intake can be varied as well.

Also, angling the engine slightly on the mounts can help as well.

'Fact is, that big SU is expensive (even here in the US). Sometimes, a new Weber '45 is competitive in price, even with a 6" flat or 1/4" rise Maniflow. Of course a Sytec or other low profile linkage will have to be used. With all of the dyno information, a Weber is not hard to set up anymore, especially if your engine is a known combination.

Twin 1/5" SUs fit as well, but the cost is actually more than a Weber for a fresh set.

"Fact is, setting up single carbs and multiples really doesn't make any difference. I have driven plenty of single SU performance 1380s that were not spot on. There are a lot of needle combinations to play with... Just as many as there are jet and emulsion tube combinations for Webers.

What this all means is that there are more several combinations that will fit, and they are all about the same when it comes to precise tuning.

[jonclancy]

Here you go - sorry about the delay.

The Maniflow manifold is standard midget. It is angled where the carb meets the manifold, but pretty straight from the head.

Use exhaust wrap to stop vapourisation, and there is scope to angle the carb to at least level.

Charles' assessment was spot on. The dashpot cover is around 1/2" higher than the filler cap, so will, sadly, either require a hole, or a revised manifold.

HTH

Jon