Latest pics (April 2011)

Thursday, November 30, 2006

Bobby Hart racing - G50: shifter, linkage, pump and cooler..

Spoke to Bobby Hart in California re the G50 trans and side shifter kit he supplies -iirc I used to watch Bobby race in Champ/IRl years ago..

"Jon, 600 hp is a lot for G50 You should be looking at a 50/50 or 50/52 they have better Gear ratios and stronger Ring and pinion I assume you have about 550 lbs of torque, yes we can do a oil system, pump,cooler, oil filter, A 50/52 rebuilt With side shifter 80% or 40% LSD is $11000.00 us Hope this helps Bobby Hart"

This is the thing with Barry's engine - most V8s create huge low ened torque which is a massive problem for traction, hard to drive out of turns and threatens trans longevity - this is also usually coupled with a lazy hammer of a delivery: Barry's engine doesn't have so much torque - maybe about 470.lbft at the full 650bhp (4-bore); and 410.lbft currently with 575bhp (2-bore). But it's a seasoned wincaton/sportsman spec Dart block and heads (348 crank with slight bore to 358) and the torque curve has deliberately been moved up the rev band for traction; but revs outs nicely and spools up quickly with minimal inertia.

It also have a wide power band and redline at 9000rpm engine; but we're limiting to 7400-8300rpm for road circuit use. Only runs off a custom 700CFM Da Vinci 2-bore and doesn't have much porting over the standard Dart.. but all internals are very strong and light. We could run more torque but on road circuits the advantages may be outweighed by the disadvantages; not to mention the extra stresses etc. Aim is to gradually port the engine to give +50bhp each time and see how the set-up feels. Roller cams also pegged for next rebuild.

Some good news - Mike Sekinger is going to sell me the shifter and linkage from John Hazzard's G50 and Hazzard is also going to sell me a pump and cooler kit he had made up for one of his UN1s.

Cheers
Jon

No comments: