Ford Crossflow on twin 40s. Help needed!

[SkodaMart]

Hi, I have recently purchased a Westfield SEi with a Ford crossflow (Kent) engine. It supposedly has a Piper 285 cam shaft, although upto now I have seen no evidence of this, it drives and idles like it has a standard road cam.
It is fitted with twin Weber 40 DCOEs.
When I bought it, it was running extremely rich, this was cured by changing the choke size from 30mm to 32mm. The original (rich) settings are as follows: Choke 30mm, Main jet 115, Air 180, Emulsion tubes F11, Idle jet 45 F8.
I have changed to: Choke 32mm, Main jet 125, Air 180, Emulsion tubes F16, Idle jet 45 F9.
The car drives much better and is far more willing to rev than it was, however it still seems to be running lean at 4000-4500 rpm. I feel a surge of power at 5500 rpm so I suspect that the airs are correct and the mains may need to go to 130s. Can anyone offer any help or advice as I am new to this twin, twin choke carb game.
I suspect I am getting around 110 Bhp. The car should be able to produce around 125Bhp.

 

[gjz30075]

I think you're on the right track with upping the mains to 130. I would also drop the air to 170. If you can get on a rolling road, or otherwise known as a chassis dyno, with an AFR meter, this will tell you for sure where you're at.

Problem is, with twin DCOEs, is the expense of experimentation. Any jet change is $$, times four, and the same goes for any other brass item change in the carb.

Good luck.

 

[eschneider]

I refer to this article when diagnosing Weber jet selection:

https://www.teglerizer.com/dcoe/dcoe_a_letter_from_an_end_user.htm

The rest of the teglerizer site is interesting reading, too.

A couple more links:

https://7faq.com/owbase/ow.asp?HowDoI/TuneWeberCarburettors
https://www.aircooled.net/gnrlsite/resource/articles/jetting.htm

And this is my preferred parts source.

https://www.webercarbsdirect.com/

Hope this helps!

 

[SkodaMart]

Thanks for your help, I have used this site:

https://www.geocities.com/motorcity/9526/carbs.html?200929

Using there formula I think I have got it right. Plugs look ok at all rpms and it is running pretty good.
Two things I would do first next time is adjust valve clearances (tappets) and balance the carbs ( I used a piece of tubing to listen to the hiss, which works far better than you would imagine!)
I have settled on 32mm chokes, 45 F8 idles, F16 emulsion tubes, 130 mains and 180 airs.
My engine (to the best of my knowledge) is a Ford Kent (Crossflow) 1700cc with twin DCOEs, Piper 285 cam and ported head.
I hope this helps someone else in future.
I would be interested in anyone elses jet selection for a similar setup.

Mart.