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X FLOW BHP GAINS
Stevestriker750 - 4/1/22 at 10:11 AM

Hi all,

Is it worth trying to squeeze more bhp out of a x flow?

My car currently has a 1700cc with fast road cams and twin Webers


Mike Wood - 4/1/22 at 12:54 PM

Depends what your objectives and budget are as well as if the car is trying to fit in with any race or speed event series.

1700cc on twin 40 sidedraft Weber carbs is a classic recipe for Seven type cars, probably up to about 135bhp. Beyond that can get expensive to get more power from a Crossflow as well as maybe a different kind of fun and driving car. You might want to investigate Ford Zetec, Rover K Series or more modern car engine swaps or the bike engine route.

What gearbox are you running? Back axle? Brakes?

Cheers
Mike

PS could be interested in the engine, gearbox, carbs, manifolds etc for my Locost project . Is it under 1700cc, e.g. 1690cc?

[Edited on 4/1/22 by Mike Wood]


MikeR - 4/1/22 at 08:37 PM

Define fast road cam - it's possible more power from a better cam, or improved running/setup. Better drivability would be from electronic ignition or ignition and fuel injection.

(I'm working very slowly on a bolt on manifold to use the Weber as throttle body and position the injectors under the Weber's)


snapper - 5/1/22 at 07:14 AM

quote:
Originally posted by MikeR
Define fast road cam - it's possible more power from a better cam, or improved running/setup. Better drivability would be from electronic ignition or ignition and fuel injection.

(I'm working very slowly on a bolt on manifold to use the Weber as throttle body and position the injectors under the Weber's)


There are injection converted Weber’s available where the injectors are in the carb body, they look just like carbs, very retro.


snapper - 5/1/22 at 07:23 AM

Depends on a lot of factors, if you have high compression pistons (1300) you may need cutouts in the pistons if running standard oversized pistons then you could push to a 223 or even a 224 camshaft


MikeR - 5/1/22 at 08:58 AM

I'm aware of these and like them very much, but they're not cheap (although I don't think that expensive) and I wanted to try and do my approach for much less.

quote:
Originally posted by snapper
quote:
Originally posted by MikeR
Define fast road cam - it's possible more power from a better cam, or improved running/setup. Better drivability would be from electronic ignition or ignition and fuel injection.

(I'm working very slowly on a bolt on manifold to use the Weber as throttle body and position the injectors under the Weber's)


There are injection converted Weber’s available where the injectors are in the carb body, they look just like carbs, very retro.


Mike Wood - 5/1/22 at 10:23 PM

If you search for info on ‘Ford Crossflow all steel engines’ you will get a flavour of the next big jump up level of Crossflow builds used in some competition cars, such as hillclimb and circuit racers sports racers (such as Mallocks including in historic Clubman’s races) as well as short circuit cars:

http://www.turbosport.co.uk/showthread.php?t=988232
https://racecarsdirect.com/Advert/Details/98210/ford-crossflow-all-steel-engine-209-bhp-ax-bl

‘All steel’ refers to using specially made racing components for the crankshaft (such as by Farndon) and the connecting rods as well as aftermarket pistons. IIRC engine builders for such power plants include companies such as Auriga, MASS, Philspeed, Connaught etc.

Guess you have seen: https://www.burtonpower.com/tuning-guides/tuning-guide-pages/ford-kent-crossflow-tuning-guide.html#

You may want to optimise what you have and then do a swap to a different engine type to get a bigger increase in power on a sensible budget; i.e. reached the end of sensible Crossflow mods and can then get easier power gains and also something with a tractable power curve.

Cheers
Mike

[Edited on 6/1/22 by Mike Wood]

[Edited on 6/1/22 by Mike Wood]

[Edited on 6/1/22 by Mike Wood]

[Edited on 6/1/22 by Mike Wood]

[Edited on 6/1/22 by Mike Wood]

[Edited on 6/1/22 by Mike Wood]

[Edited on 6/1/22 by Mike Wood]

[Edited on 6/1/22 by Mike Wood]