hi jules 
nothing wrong with fitting a holbay [^] at 100+ bhp its the engine they should have fitted in the first place [:0]
the twin 40,s probably would need some cutting out of the body to fit and even then they would end up "updraught" as the holbay sits at an angle originally.personally i dont like them as they cost a fortune to jet up and never stay in tune. the hif s.u is a great carb, easy to get,cheap, and jetting is done by changing the needle, they will give much more low end torque than webers for less fuel as well . obviously a one off manifold is needed (i can do this).
after a good study of the holbay head i have decided to do chris,s with Amal mk2 30mm bike carbs ,these are period as well(70,s). i have a bank of four ,so its carb per cylinder which gives the best throttle response and economy [^] as you can tune each pot individually. they are easy to tune and jet cheaply, can be modded to improve flow,will run 20 degrees of downdraught and because they are slide carbs have no butterfly/throttle shaft restricting the airflow,so they will flow more than webers.
my plan is to bore into the head at an angle and weld in tubes to give downdraught and a straighter port and get them up away from the exhaust and bodywork.
option 2 is a cut down single zenith manifold with the tubes welded to it so they are side draught,easier to do but not as efficient.
the biggest headache will be the throttle linkage,but where theres a will..........
minispares did a kit in the 60,s to mount the earlier mk1,s on a mini.
the drawback is the cost, about £140 each new, but i got these of ebay for £60 2nd hand [^].if you sold the webers you should get a good price for them.
hope this is of help to you,if you need a manifold adapting/making i can help with that.
"you were only supposed to blow the bloody doors off no.3"
nothing wrong with fitting a holbay [^] at 100+ bhp its the engine they should have fitted in the first place [:0]the twin 40,s probably would need some cutting out of the body to fit and even then they would end up "updraught" as the holbay sits at an angle originally.personally i dont like them as they cost a fortune to jet up and never stay in tune
. the hif s.u is a great carb, easy to get,cheap, and jetting is done by changing the needle, they will give much more low end torque than webers for less fuel as well . obviously a one off manifold is needed (i can do this).after a good study of the holbay head i have decided to do chris,s with Amal mk2 30mm bike carbs ,these are period as well(70,s). i have a bank of four ,so its carb per cylinder which gives the best throttle response and economy [^] as you can tune each pot individually. they are easy to tune and jet cheaply, can be modded to improve flow,will run 20 degrees of downdraught and because they are slide carbs have no butterfly/throttle shaft restricting the airflow,so they will flow more than webers.
my plan is to bore into the head at an angle and weld in tubes to give downdraught and a straighter port and get them up away from the exhaust and bodywork.
option 2 is a cut down single zenith manifold with the tubes welded to it so they are side draught,easier to do but not as efficient.
the biggest headache will be the throttle linkage,but where theres a will..........
minispares did a kit in the 60,s to mount the earlier mk1,s on a mini.
the drawback is the cost, about £140 each new, but i got these of ebay for £60 2nd hand [^].if you sold the webers you should get a good price for them.
hope this is of help to you,if you need a manifold adapting/making i can help with that.
"you were only supposed to blow the bloody doors off no.3"
