Looking for input. Here is the basics: On my early rigid frame project (The one with the Super flash style dogleg) I am going to run a late model alloy head on it and after many years of study of factory and modified dual carb heads will be doing one myself.
First order of business- Which head to use? I have several alloy late model heads and checking casting numbers i have 2 types to choose from. 57-1126 or 67-1549 The 1126 heads I have appear to be late 50s Super rocket heads and the 1549 heads were of the early 60s version, SR & RGS,
I have not flowed them or done any port modeling to see if there is significant differences but soliciting opinions on which one would be best suited to a dual carb modification.
(Not interested in a dual carb vs single carb discussion, that is not what this is about and well versed in that topic)
This is for a mild performance hot rod BSA built as a tribute to the BSA Daytona racers but street legal. So the topic is, which head would be the BEST candidate for this modification.
Bigger is not always better, velocity wins on the street but these 1950s castings could probably be improved on so,,,,,,,,,,,,
#2) I have access to a few guys who are well versed in vintage cyl head mods and considering having it reworked somewhat for improvements as well. Any insights or topics I should look at for alloy BSA head mods? Not looking to reinvent the wheel here but if someone documented stupendous improvements I would be very interested in hearing about it and analyze what was done.
(One source might be Baisley performance, Back in the day their cyl head work was transformative on even a basic rework,, I rode Sportsters, Triumphs, BSAs and Nortons they did the heads on and it was night & day difference. And,,,, trivia tidbit. Baisley had a lot of input on the design of the modern Norton cyl heads. See:
http://www.baisley.com/services.htm )
#3) I will be looking at several options for the carb intakes and type, and will be happy to update with pictures and what I end up with. Machined flanges with bolt on intakes or welded on stubs and race style spigot and hose coupling.
#4) carb type,, There is a lot of options for carbs and this is likely to come up but while I am huge fan of some of the modern Mikuni and Keihin flat slide and round slide carbs I want it to look period correct so at this point will likely run some reworked Amal Monoblocs as I have some Handed (L&R) sets I have stashed. Not the best carb in the world but that could still change.
Will update with pictures and details over time but again, first order of business is WHICH head to start with?? (I would like to narrow down what I am keeping and sell off the excess to help fund the project)
The motor at this point is not revolutionary. Early 50s A10 with late model crank, upgraded rods, higher compression pistons, 356/357 cam and a few other tweaks but nothing earth shattering. Basic 50s hot rod is the goal