Twin HS4 / air box

Post any technical questions or queries here.
swifty
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Twin HS4 / air box

Post by swifty »

Just fitted a pair of HS4 and used the oval air box . I used 1 1/4 carb elbows with a spacer . As you can see they fit well … Shirley
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1963 austin Cooper s mk1 1071
1966 Austin Cooper s mk1 1275
1968 Austin Cooper mk2 998
1962 Morris mini super 850
Porsche 997 turbo S
Ford transit van 280s.

I am from Essex
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Re: Twin HS4 / air box

Post by Exminiman »

Nice engine bay, looks very “Factory” , is that a bellmouth pointing down ?

Nother question, didnyou make the spacers or are they a standard item ? ……….Shirley
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Re: Twin HS4 / air box

Post by Peter Laidler »

What is that bell-end hanging out of the bottom? Is that part of it?
swifty
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Re: Twin HS4 / air box

Post by swifty »

The spacers are similar to the image , couldn’t find another pair for the photo . It’s not as straightforward as bolting carb elbows and spacers to the back of the carbs . The spacers need drilling and the carb elbows need the air holes modified with a small die grinder to match the gasket. If this is not done correctly the dashpot plunger will not operate correctly or evenly . The carbs are from a 63 to 69 MGB . The elbows are 11/4 su . The mini is my modified mk2 cooper . I’ve modified the air box with a 45 dcoe trumpet and a 11/2 su bellmouth. The intention to draw a lot more air into the carbs . As we all know it’s not ideal drawing in hot air but you’ve got to reach a compromise somewhere . Did think about the MED air filter but that’s still surrounded by hot air anyway . Oh nearly forgot the inlet is a Minispares manifold slightly ported and no spacer between the manifold and carb body … I am pretty critical when it comes to performance on my own cars and will readily admit when one doesn’t perform to well but every now and again you hit that sweet spot , this mini absolutely lights up , it’s very quick and doesn’t miss a beat … . I get in it and feel in my 20s again ! …. Shirley
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1963 austin Cooper s mk1 1071
1966 Austin Cooper s mk1 1275
1968 Austin Cooper mk2 998
1962 Morris mini super 850
Porsche 997 turbo S
Ford transit van 280s.

I am from Essex
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Re: Twin HS4 / air box

Post by Polarsilver »

Ken, re your vertical air intakes,that is a good idea " Nice One".. hope there is not your patent on this as i am fed up with the K&N intake noise on my 1071 & already have a spare OE Filter Housing & also have the 1.25 SU intake bends.. now i just need to find those carb to elbo Spacers .. can you tell us that Spacer thickness ?
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Re: Twin HS4 / air box

Post by Exminiman »

Peter Laidler wrote: Sat Sep 28, 2024 9:41 am What is that bell-end hanging out of the bottom? Is that part of it?
I wondered what you meant Peter……” Bell-end hanging out of a bottom” , maybe posted on the wrong forum :lol: :lol:
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Re: Twin HS4 / air box

Post by Classic1 »

It did cross my mind but I was to scared to ask :lol: :lol:
Times money and I'm always short of both
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Re: Twin HS4 / air box

Post by swifty »

Hi Norman , the bottom end / short block of this engine is the one I purchased from you at bingley mini show . With this set up the induction noise is low . Mind you it may be that I can’t hear it because of the straight cut drop gears ! . I have coopers air filters in the air box but if you use the slightly higher air box you can fit K+N filters inside . Will measure the spacer’s tomorrow…
1963 austin Cooper s mk1 1071
1966 Austin Cooper s mk1 1275
1968 Austin Cooper mk2 998
1962 Morris mini super 850
Porsche 997 turbo S
Ford transit van 280s.

I am from Essex
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Re: Twin HS4 / air box

Post by Polarsilver »

Ken, can i ask what exhaust Manifold you have fitted .. my reason to ask is i have a Maniflow LCB supplied from MS fitted & when fitting up the HS2,s had center downpipe on exhaust manifold to carb linkage contact.. therefore i needed to fit spacers between the carbs & the inlet manifold to get that clearance.. whatever think your solutions to the Filter Housing are great so will try to get your system onto my 1071.

Good the Fresh Engine is doing the job .. what Cam did you Fit?
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Re: Twin HS4 / air box

Post by swifty »

Norman the exhaust manifold is a maniflow medium bore supplied by minispares. The spacers measure just over 13 mm thick . Camshaft is SW10 .
1963 austin Cooper s mk1 1071
1966 Austin Cooper s mk1 1275
1968 Austin Cooper mk2 998
1962 Morris mini super 850
Porsche 997 turbo S
Ford transit van 280s.

I am from Essex
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Re: Twin HS4 / air box

Post by mini_surfari »

More great work from you Ken.

You should do some build threads, and show off these cars and your work!
swifty
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Re: Twin HS4 / air box

Post by swifty »

Thanks mini surfari, yes I been asked many times . I am just finishing building up my mini super , once that’s done I will start a build thread on either my 1071 or another modified mini .
1963 austin Cooper s mk1 1071
1966 Austin Cooper s mk1 1275
1968 Austin Cooper mk2 998
1962 Morris mini super 850
Porsche 997 turbo S
Ford transit van 280s.

I am from Essex
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Re: Twin HS4 / air box

Post by panda911 »

Hi.
It looks a very very elegant solution to fitting my hs4s to a 1071.
The H4 carbs are difficult.
Thank you
Paul
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Re: Twin HS4 / air box

Post by swifty »

So I went for a spirited ride with my old mum in the car and thought I would have a look at the plugs on return . Any plug experts among us ? . To my mind there ok but would like some other opinions … Shirley
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1963 austin Cooper s mk1 1071
1966 Austin Cooper s mk1 1275
1968 Austin Cooper mk2 998
1962 Morris mini super 850
Porsche 997 turbo S
Ford transit van 280s.

I am from Essex
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Re: Twin HS4 / air box

Post by Peter Laidler »

I'm going to stick my neck out and say that, to use a highly technical term, that it is running as rich as buggery judging from the unburned black soot around the central ceramic part. Maybe a change of bell-end is needed!!!!!

Always game to be corrected of course
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Re: Twin HS4 / air box

Post by almond cooper »

You can check on the online NGK spark plug colour chart and that will give you a good indication.

Maybe slightly rich? Might need a longer road test?
swifty
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Re: Twin HS4 / air box

Post by swifty »

Maybe Pete . I was just judging it on this image of plugs from the internet and adjusting my mixture with the good old colourtune… but I’m no expert . Let’s see if anyone else has an idea …. Shirley
1963 austin Cooper s mk1 1071
1966 Austin Cooper s mk1 1275
1968 Austin Cooper mk2 998
1962 Morris mini super 850
Porsche 997 turbo S
Ford transit van 280s.

I am from Essex
swifty
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Re: Twin HS4 / air box

Post by swifty »

swifty wrote: Sun Sep 29, 2024 6:50 pm Maybe Pete . I was just judging it on this image of plugs from the internet and adjusting my mixture with the good old colourtune… but I’m no expert . Let’s see if anyone else has an idea …. Shirley
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1963 austin Cooper s mk1 1071
1966 Austin Cooper s mk1 1275
1968 Austin Cooper mk2 998
1962 Morris mini super 850
Porsche 997 turbo S
Ford transit van 280s.

I am from Essex
abs
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Re: Twin HS4 / air box

Post by abs »

I`m lead believe the black around the threaded part of the plug is due to unleaded fuels these days and the insulator and electrode are the things to look at and in this case they look good but the black is rather black I must say.

Hopefully one of the very knowledgeable members will be along shortly to clear this up and give me more work to do on my own mixture no doubt :D
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Re: Twin HS4 / air box

Post by rnp68 »

Can I ask for reference what needles and springs are you using?
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