Hi all. Have built this motor and car up for collector plates here in Canada. Have already built one car with twins and it was more expensive than I would like to admit. Looking for some better options for a single carb set up or maybe twin SU's2 if I can find a complete set.

Cheers in advance for any advice!

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By far the most popular single-carb upgrade is a Weber 32/36.

Only $400 brand new ex-USA.

Already used the new 32/36 for the cam break in. Engine isn't getting enough fuel for this engine build DD. Was thinking of trying a Webber 40 IDF. Nor sure about adaptability with the single carb intake for the H89.

I was thinking the same, obvious choice for not going twins is the 32/36.

How about a single sidedraught carb (i.e Dellorto DHLA 40 or Weber DCOE 40)?

Doesn't Datsa73 run twin 32/36 carbs? I've never seen that set up in person but it would be cheaper than a twin sidedraught setup if you could source manifolds for them.

I own new 40mm Dellorto carbs and port matched intake. But moving booster and master for brakes and getting a Wilwood pedal box is time consuming and hard on the wallet.

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Yeah that problem has been reported before. If you're making 120hp, the fuel lines need to be upsized to 5/16" and a high volume fuel pump fitted. That will allow the 32/36 to make full power.; plus a fuel regulator to get down to the 3.5 psi that Weber specifies.

If you are revving more than 8000 RPM moving up to IDF 40 is a good idea. Maybe get a big Rowland A14 manifold for the 32/36 and adapt it for the IDF.

Well it seems I am going to try the single side draft option first and see how we go from there. Have new electric fuel pump, lines and pressure regulator. Now all I need is the intake and linkage. Rev limiter is set to 8500 rpm for now with a 6AL from MSD. Waiting on my crank fire ignition to get here.

If you're not getting enough fuel for a 32/36, you'll have the same fuel shortage with a side draft.

If you are making maximum power at 8500 rpm, I would jump up to a Weber 45 tuned with 40mm chokes. The maximum a 40 can go is 36mm.

A14 engine
Weber 32/36 max HP at ~7000 rpm
Weber 40: max HP at ~7600 rpm

This is an A15 with 80 thou over bore. Forged Pistons,Con Rods and Push Rods. Maximum Power is projected with this cam and head design at being in 9500 RPM. However I will not be pulling this off on the streets vary often. CAM break in was done with all stock parameter on the car. Lines, cam driven fuel pump, filter, 98 octane fuel. I'll put on the electric pump, regulator and lines/filter aND see how the 32/36 handles it all. I have a 6 up and 6 down jet kit with air correctors for the 32/36. See what happens on the dyno next month.

That's wild!

40s are too small for that engine. But the 32/36 should pull strong up to 7000 rpm or so when tuned correctly. Make sure the power valve is big enough.