I know a few people were following along on this- been a while since I last posted here- but finally all came together!
Mounted up and running strong! Still a few details to work out; but runs good, sounds good, feels good on the initial pulls. Super happy it worked out!
Went with 42's and a TWM manifold. Still lots to sort out, but Ill start another thread on it somewhere and link it back here. Rought calculations hopefully put it in between an OER setup and a Mikuni PHH setup $wise.
Part of running a single shared throttle shaft was for a super clean look- like how datsun_tokyo linked above has it.
I also still haven’t decided on the manifold- but was planning on the TWM one- seems to be the cleanest and allows me to run without all the linkages.
I have common under mount bar mount I could sell you, with either teflon or brass bushings. You would need arms, but it would be the best for actually balancing them. Just a thought.
That car is one of the main reasons I’ve even considered this. I have been in touch with him- unfortunately the language barrier is tough. Might need to recruit an old autox friend who is in Tokyo now to translate. The owner of that car did express that he much preferred the HSRs over OERs and that he was never able to find the right tune with OERs. Looking back through his thread he had PHH 50s on there at some point - but that is a very built engine - 3.1 I think with custom head etc.
Did a little more digging and thinking on this last night - I think mechanically the hardest part will be the common throttle shaft - it looks like each carb has 3-5 holes on the shaft. 2 for pins for to hold the throttle stop and accelerator pump levers; at least 1 maybe 2 for the return springs; and the main threaded one for the slide lift. With some patience and precise measurements it’s shouldn’t be to terrible, but not a cheap if you mess one up and have to start over on a new stainless shaft.
For the sake of keeping this in the same thread. I found a little more info on the car in the photo- unfortunately it seems the owner passed away last year.
But this post on hybridz says he replaced his Weber 45s and actually saw better gas mileage and great throttle response
https://forums.hybridz.org/topic/64666-mikuni-hsr45/?do=findComment&comment=1229737
“I decided to try my own setup with 6 HSR45 Mikunis. I had previously run Weber 45's. I used the original linkage so that I could return to the Webers if I wasn't happy with Mikunis. Because of the shape of my extracters I had to add some extensions as The bowl of carb 4 was hitting the exhaust. Apart from that it was pretty straight forward with the carbs being quite straight forward to tune. The throttle response is very good and although I wasn't looking for it the mpg ismuch improved over the Webers.”
This of course does not help my decision process… on one hand it says to me it works! But on the other hand it makes me wonder if I should do 45s? I do believe it was a “built” engine but to what extent I don’t know.