|
When the butterflies are open there is a straight 40mm hole which is only obstructed by the needle and the slim butterfly.
But the butterfly & throttle shaft are bigger restrictions than you think, that why carburetor mofiyers spend an extreme amount of time on thinning the shafts & knife edging the throttle. The clue to power expectations form them is what the R1 makes: 130HP. No body uses carburettors larger than is required because it kills the engine output everywhere below peak torque.
The GOOD Mikunis are not CV, the are 'Flat Slide', eg, HSR 42 & 45. They have no throttle or throttle shaft, hence they flow much more air.
The HIF's won't work because the butterflies work the opposite way to the HS6's. I did not realise this until after I had bought them. It is not possible to get them sorted short of reconfiguring the accelerator mechanism to work in the opposite direction to what it does now.
They are that way on Volvo's too. I'd be only too happy to swap a pair of HS6 SU's for your useless HIF6's. :)
The head is now back on the car so I will persist with it for the moment. The valve sizes from memory are 43mm and 36mm. I suspect the work on the head was done many years ago. When I had new valve guides put in, the ridge leading to the spark plugs was rounded off from being sharp edged the rest left as it was. The head is defintiely not off a B20E.
It can't be a B20E head if it has 43mm inlets. What are you currently using for a bottom end, camshaft & exhaust?
--
Three 164's, Two 144's, One 142 & a partridge in a pear tree.
|
