Jas,s 1200s

[Bartman]

Excellent!

[jas1200]

Had a good day on the Datsun today. Have been working away at the blower set up over thw last couple of weeks and sort of had it running today. I,ve had the blower belt on for the last couple of weeks (it makes a f------n cool hmming noice), I ducted it into the standard carb today, it keeped blowing fuel out of the accelerater pump, so I bleed out some of the boost and drove it.....It did, nt make any boost and no more power so back to the drawing board........but was fun anyway.....

[dirtyleppa]

why not do a draw through setup?

[jas1200]

Good question. After reading a thred on 1200.com I decided that blow through is a good start for intercooling and fuel injection..........Intercooling allows a cool charge into the engine and this is better for good h/p figures. However I,m not an expert so any ones opion is welcome....................

[classicdat]

I'm guessing the problem will be that the carb requires low pressure in the venturi to draw fuel into the air going into the engine, using atmospheric air pressure acting on the top of the float bowl fuel to push it through.
Maybe if you can exert boost pressure onto the fuel in the bowl it may work, and give you more power. Have you checked out Bart's system? I think it is draw through. I have a funny idea Lewis has a blow through set up on something he is working on.

[jas1200]

Yep I have seen Barts set up, it is draw through and a credit to Datsun development , very cool. So how do I do boost into the bowl, or do do I just go 350 holley????????Jas

[classicdat]

Sorry I haven't got a record of the link but there is one somewhere of 70's turbo charging of a 510, they built a box for the carb to sit in, essentially creating it's own atmosphere, so I guess you could just provide something like that, although I'm not sure if that is all that it would take. Mitsubishi cordias and tredias were factory turboed back in the day, blow through, some info there might help. I wonder if you had a spare carb (or didn't mind butchering yours) to add a boost line to the fuel bowl, seal up all air leaks and go from there, I'm guessing that would be pretty much what Mitsy did (again I'm not sure if that is all that it would take).
Surely the easiest way is EFI with a fuel pressure reg that responds to boost.

[jas1200]

Hey classic dat, i do have a spare carb. Do you think running a line to the fuel bowl will help, in saying that this is only a test as I plan to go 350 holley ...........

[classicdat]

Sorry I have no experience at all, just some basic mechanical knowledge, you would need to make sure there were no air leaks from the fuel bowl. I'd be interested in the results if you try it. Bear in mind there are very few Blow through setup, V8s use draw through, Manufacturers generally use EFI. A common set up back in the day was a draw through SU carb.

[jas1200]

Yeah I have no experience as well but have heaps of fun trying. The air leak at the mo is from the accerator pump, its pissing out big time......I had to buy a fire extisher (spelling) befor driving, there was that much fuel coming out the top of the carb that an under bonet fire was a big probabillity.