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C20XE Bike Carbs & Tuning
Benzo - 13/8/18 at 12:19 PM

Recently Purchased an XE engined Car running on Boggs Brothers Manifold & Reportedly Kawasaki ZX6R Bike Carbs.

These are not the traditional route to go when tuning an XE, usually twin 45's/48's or Injected Throttle bodies are the norm.

I'm considering wanting to extract some more power from the engine, are the bike carbs adequate? reliable?

Or should my 1st step be ditching them for 45's etc?


Charlie_Zetec - 13/8/18 at 12:34 PM

I could be wrong, but are ZX6 carbs man enough for the job? I was recommended ZX9R carbs for my 1800 Zetec install (bearing in mind these engines had 115-130bhp as standard, and the XE had 150 to start with).

In answer to your question though, the XE will run nicely on 45’s or 48’s (I’ve had previous Cavaliers & Calibras running on them before now). You’ll probably squeeze more power out using TB’s, but with the cost of these, a manifold, new ECU/loom etc. is it really worth the change? I would suspect not.

No doubt someone on here will tell you what they’ve used on their XE-powered 7, but a good RR session will soon give you feedback on the current setup and capabilities.


Mash - 13/8/18 at 12:35 PM

I'm sure a lot of experts will be coming along to give you advice, but I went for ZX6R carbs as 40/45/48s are way more expensive, and reputedly much more difficult to get running properly. I have a 32/36 on at the moment so I will get more power anyway.

both Bogg Bros and Dan ST are big promoters of bike carbs.

Injection requires a significant increase of cost over the 40/45/48, both for the bodies and for the control unit.


Benzo - 13/8/18 at 12:42 PM

ZX6R is what i've been told! I must try and ID a Part number off them or something this evening to be sure.

If it was beneficial I would move over to Webbers & Mapable ignition such as MBE but I don't think I would be bothered shifting to ITBs, engine loom and full management, injection tank, pumps etc etc

[Edited on 13/8/18 by Benzo]


rm0rgan - 14/8/18 at 07:30 AM

ZX6 carbs are the preference for 1.8 to 2.0 engines in no or low state of tune - bigger does not always mean better, plus Bike Carbs are a more efficient and modern design over webers etc - the other thing is they use a sliding choke so maintain a larger port size the whole way down the body of the
carb, unlike a Weber which has chokes in the way.

I've just changed from Webers to ZX6 carbs and although outright power was about the same, the throttle response and torque is massively better.


Have a read of this - https://www.classicfordmag.co.uk/wp-content/uploads/2017/12/classic-ford-ultimate-guide-to-bike-carbs.pdf

:-)


SJ - 14/8/18 at 02:59 PM

Zx6 carbs are about 38mm so not small.


Benzo - 14/8/18 at 03:09 PM

Has anyone made any substantial power on Bike Carbs?

I've some Omega Pistons, steel Rods & National Hotrod Cams under my bench, wondering if the Bike carbs will be man enough to support these mods.

Similar Spec makes ~240hp on 45's with mapped Ign.


bill132hotrod - 26/8/18 at 01:10 PM

Hi there
I have a kit with a c20xe engine in it currently been off road now for over a year. I used to race this engine on grass back in the day but when I packed up racing I could not bare to get rid of it. I was running twin 48 webbers but it used to drink fuel.
When I built the kit I used this engine but went motorbike carbs and loved it.
My engine also has Comcast head ,omega Pistons, steel rods and reprofiled cams solid lifters, I made my own manifold and used 1100 zzz carbs that were cleaned and jetted by bogg brothers good setup better throttle response and good economy producing over 220bhp.
But now its on std cams and hydraulic lifters but still produced 190bhp on last rolling road. Hope this helps


Benzo - 2/9/18 at 06:27 PM

Rather than start a new thread,

Can anyone here with Vauxhall experience suggest a good set of ignition leads and what plugs to run on an early XE still equipped with the distributor?

Current lead do not give a positive connection onto the top of the plugs, I’ve developed a misfire and trying to diagnose!