XD standard dynoed at 72 kw to rear

[Anonymous]

Looking in library agian recently and Aussie Motor mag 1979 did a dynoe comparison with the 253 V8 in a Commodore against the XD Falcon with the carb 250 Alloy Crossflow.
The Cross flow peak power came in at 3500rpm at 72 kw to rear. 253 was about 73 but at 4000rpm and considerbly less torque.

Question (Execute?). If this was the kw of Crossflow to rear in standard form with the emission control ect Im wanting a "rough estimate" of what it would be with it off and cam (mild) carb and extraction upgrade. If I do this I would like to get at least 95kw to rear and maintain efficiency of engine.
I am fairly certain from other comparisons Ive done that my 250 2V with the cam and carb and dizzy changes is about 95kw to rear and it has good economy on open road.
Over time I want to prep another engine just trying to work out if it its worth going to crossflow. I am guessing that with similar or same changes might end up with same power maybe bit more and better economy as well.
This is what Ive worked out emission off 15%. Minimum 25% with cam, carb and extraction changes. Equals 40% increase. I presume this would not be difficult and would give more than 95 kw to rear. Am I off the mark or is this about right.

 

[xctasy]

1. With no EGR, and good tube header exhast, your 72 Rear wheel kW would end up at about 89 kW.

2. With a good road cam, you could have any amount of improvement. The head breathes so well in stock form, that a good Crow cam in the 270-280 duration area could yield lots of extra power. The limiter would be the stock Bendix carb. HQ racers can't break over the 165 flywheel hp level, so I'd say 97 kw at the rear wheels with a 280 cam.

3. With a 500 Holley, up to the 146 flywheel kW ol' Dick Johnston claimed. Thats about 115 kw at the bags

Scources:I know exactly because NZ Falcons came without ADR 27a EGR valves. A 98 kW Falcon got 103 kw without it. So a gain of 5% for a start. scource was Don Anderson from the Kiwiland column in a mid 80's Wheels mag.

Secondly, Perry headers were dyno tested by Wheels on a stock XC Falcon in 1979, and this gained about 11.4 kw at the wheels, and a good 4.1 Falcon XC did only 62.6kw at 3500 rpm with the nasty BW35 draining off the ponies...was supposed to be 92 Kw at the flywheel. And the headers gave a 12.6% fuel economy boost. If that car did 62.6 kw+11.4kw, then thats an 18.2% boost.

The 146 kw came from a January 1987 Wheels article on the ill-fated SVO XF Falcon

 

[xt falcon]

tim i just dynoed my crossflow. it has extractors with no pollution, cam (mild i think still a fairly smooth idle) and a 600 holley a littel too big (runs rich bellow 3000 and above 5000 other wise right on 12:1 air fuel) and i have 130kw at rear wheels which isn't too bad and i get good econamy compared to the log head that was in it before.

 

[Anonymous]

Thanks youve just given me a big incentive. I cant imagine what 115 kw to rear would be like in the Cortina. I think Ill fit those bigger brakes first. And Ill try and get one of those sprint manifolds if someone could tell me of an Aussie supplier.

 

[addo]

I think the place is called ultraflow manifolds. If you can't find them, ring the Matilda foundry (who cast them) and ask who markets the Sprint.