LD28 conversion + Twin SU's?

[Xnke]

Ok, so I'm up late one night, after finding all six rods i need for my LD conversion, the block and crank are mostly lined up, and cylinder head choices are made. Here's my proposed setup, and the big question:

 

Will my '72 roundtop SU's have enough balls to run this bastard?

 

I already know i need richer needles, but if Rebello can run a 3.1 on SU's, surely I can run a 3.0. I'm looking to produce 200 N/A horsepower. Will probably run a Delta cams .480-282/282 cam, if not a little larger. Ported and Unshrouded P79 head. Compression about 9:1. Redline at 7000RPM. Home fabbed header, 2.25" exhaust. '72 E88 intake, port matched and "ported" as best can be done.

 

I don't know if that's enough information, but I figure it should be a good start. I like the look of the SU stockers, and to me, it just feels right to have that orange air cleaner and twin SU's on the driver's side. (gonna have to vent the crap out of the hood, I'll bet...)

[brokebolt]

I ran a 3.1L with bell top SU's for years with stock needles and nozzles. It can be done very successfully. I prefer my engine with triples however. I also used a 600 Holley 4 barrel on a Clifford manifold. The Holley carb was a bit much for that engine. If you ever decide to switch your induciton there are many options to consider...EFI is also a good choice. I am not a big fan of the DGV but it is also out their.

 

You didn't say what type of rods your using...stock L-24 or some aftermarket H-beam rod? Don't really understand the hood venting comment. If it is heat build up your commenting on, I would suggest a stock heat sheild on the induciton. I ran without one and it seems to keep the carbs cooler with one. I would highly suggest running one to prevent fuel bowl/carb. heating. My underhood temps were never bad but I did have to run a 280 Z radiator as the stock 240 Z unit was too small on hot days (90+) and in stop and go traffic too. I also used a 180 high flow thermostat. The 280 Z radiator was a direct drop in unit in my 1973 240 Z. Many a write up on aftermarket radiators here and other sites. Happy motoring.

[Xnke]

Since it's an LD28 block, I'm using 150mm 4G63 turbo rods. used, but spotchecked, no cracks or porosity. all weights are within 3 grams before matching.

[OlderThanMe]

So you are going to do a 4.5mm overbore on that thing?

I guess KA pistons?

[Xnke]

Yep, bored and sleeved. Might even go bigger on the bore, depends on what size the sleeves turn out to be. I've got all six sleeve blanks cast...