Steel Crossflow

**TimGR** · 11-12-2006, 08:53

Here's the plot from mine (taken a couple of years ago, but the engine has hardly been used). Not far off 140 lb/ft torque which is not bad for a crossflow

However, according to some comments I've read, the engine should be capable of 170+ bhp

**Pushrod King** · 11-12-2006, 21:05

658:Race, POWER RANGE:4500/10800,PEAK TORQUE:7200 PEAK POWER RPM:8300,ACHIEVABLE BHP PER LITRE:102 TIMING FIGURES:66/88 88/66.VALVE LIFT: .421.DURATION:334 degrees.
If your engines 1600 cc then the maximum power would be 163.2bhp according to these figures so it's not far off

NB:If it's a 1700 it should be 173.4 (virtually the same as mine)

**TimGR** · 12-12-2006, 08:48

Originally Posted by PUSHROD KING

658:Race, POWER RANGE:4500/10800,PEAK TORQUE:7200 PEAK POWER RPM:8300,ACHIEVABLE BHP PER LITRE:102 TIMING FIGURES:66/88 88/66.VALVE LIFT: .421.DURATION:334 degrees.
If your engines 1600 cc then the maximum power would be 163.2bhp according to these figures so it's not far off

NB:If it's a 1700 it should be 173.4 (virtually the same as mine)

Cheers.

Er, it's quite a bit bigger - looks like it should be around 180 bhp - so why am I losing around 20 bhp

I posted on the ultimate crossflow thread - you have a very impressive engine there!

**dangerousdave** · 18-12-2006, 16:29

Tim is this for flywheel or at the wheels??? That could be where your 20hp is

**TimGR** · 19-12-2006, 09:08

Originally Posted by dangerousdave

Tim is this for flywheel or at the wheels??? That could be where your 20hp is

Dave, I presumed it was at the flywheel. I need to try and get more spec from the original builder, but it sounds like it should be capable of around 180. Perhaps it would need bigger carbs (running on 45s) and the peak power seems to be down on the cam profile mentioned below by Pushrod King.

Cheers

**dangerousdave** · 19-12-2006, 13:27

Looking at it i would guess its from when the engine was on an engine dyno?? As there is only one power and one torque curve

Looks like a stonking engine though

makes standard power at 3700 and then nearly double at 7000

and you have more torque at the start of the graph than mine has got peak

If you look at the afr its all over the shop, and particularly at the end past 7000 you see it drops off to run quite rich, the power drop off is almost the same shape as this so that might have some effect as you should be able to rev higher than 7800 with a steel bottom end??

I would think looking at the afr that it needs setting up a bit better as its very wild....but i only have a basic knowledge of tuning from what i have learnt from my rr graph

What ignition has it got?

**TimGR** · 25-01-2007, 09:52

I spoke to the guy who built the engine - it hasn't got a particularly big valve head (I'll have to whip if off some time to check) and neither. so he recalls, was it properly gas flowed. Also the dyno test was done with the engine only with the wrong exhaust and he recons with a big bore exhaust (now fitted) in present spec the engine should be close to 170 bhp.

With a decent head, and perhaps 48s the engine should be good for 180 bhp. So who to go to: Connaught, Wilcox, Puma