Who knows what the maximum practical mounting angle for an HIF44 is?
1. I have been told they should be horizontal,
2. I have measured a Minispares manifold, it is about 10 or 11°,
3. I'm sure somebody here has a pair on a Maniflow twin SU inlet- I suspect they are sitting at 30°, but I'm not 100% sure...

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

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My Montego has it mounted on an angle but I am not going to venture outside to measure it tonight.

Kev, i think you would be looking more at what the motor is used for. if it is a little bore or std to mild big bore, you wouldn't be sucking enough fuel out of the bowl. bigger motor's could suck a bowl dry quickly, so increasing the bowl angle would be limiting the practical float level which in turn would mean when you are cornering or powering up hill you would be decreasing the float level of the bowl even more. thats when you will run out of fuel and that will be your drama.
Thats what would cause the issues of increasing the angle the HIF sits at.

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I can't actually think of a car with a stock HIF44 that sits at 0°

Volvo 260

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Stop Licking the Dog...I Don't Care Who Started It

they are all kinked up to a point, but the more you do, the more issues. not an issue if you can run the car on LPG

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Kev-I'm running on the inlet Manilfow setup.
Is this pic of any help to you?.

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Thanks for the pic- those are HS6 though, I thought you had HIF44s.
Yep, looks like that manifold is 30°.....

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Here's a Maniflow intake overseas with 2x HIFs on so apparently they do work at ~30°

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Kev, twins may be ok of a larger angle as there less fuel being drawn fromt he bowl's of each carb. A single carb would be a different matter i would think

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Aaron,
The rate of fuel going in must equal the fuel flowing out. This is regardless of what angle it is mounted at, it will run lean after a few seconds at full throttle otherwise. Even if it is mounted dead level. So, the needle valve & seat must be big enough already.
The real question is, to what extent does the carby angle affect the float level? As the jet is concentric with the float bowl, I doubt the level at the jet will change much.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Hi Doc,

I have a maniflow mild steel manifold, they are all at an identicle angle for all A series twin SU applications. (according to Maniflow when i bought mine from them)

From memory it is 12.5 degrees. Here are some pics that might be a bit clearer:







Hope that helps

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68 Deluxe.... it's shiny..... I like shiny!!

That's an awful lot more than 12.5° included angle.. anybody got a protractor??
You wouldn't fit twin HS2s even in there at 12.5, the 1098 Sprite HS2 manifold is 20° and the carb jets used to hit if used in a Mini.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

I'll measure the angle this evening (it's off the car at the moment so easy to do) and post up what it measures. My memory is rusty, 12.5 degrees sounds right but that could always be for something completely different!


Matt

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68 Deluxe.... it's shiny..... I like shiny!!

I think my point is kev, that because the HIF's have such a small float bowl, by increasing the angle it is sitting at, will reduce the amount of fuel in the bowl, in your case 17.5% less fuel. Which means that when at full throttle on a corner or the likes you will emptying the fuel bowl alot quicker than if you had a full fuel bowl at 0%, so you are relying on the fuel pump getting fuel to the carb much more. Bigger PSI will help, BUT then you run into fuel pressure V float. Too much pressure and the fuel will just push the float open and fuel will run out. Too little, and we are back to were we started.
In the case of twins, your pulling less fuel from each carb as the needles wont be needing to allow as much fuel down the carb to the motor As you have two. PLUS your doubling the amount of space fuel is stored in the carb, plus allowing the fuel bowls to be filled faster.
IF you can adjust the float angle in some way to sit at a more neutral angle i think that may help. But i don't know if that is possible.
At this point in time, it is all theory, but until it's on a car we won't know. We will soon find out i guess.

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