Steve
29-11-2008, 08:02 PM
Project bike carbs
http://i7.photobucket.com/albums/y253/swdonnelly/DSC_3920.jpg
As some of you may or may not know I have been working on the possible fitment of bike carbs to my engine. First of all I bought a bank of four Fireblade bike carbs.
We then took the bike carbs down to A&B’s who proceeded to split the carbs into a pair, redesign the choke, throttle and fuel rails on them and make a new alu inlet manifold.
So today was the day that we finally got around to fitting them.
When I got down to A&B’s today the first job was to do a power run on the rollers with the car set up with the weber on it.
During the first run we noticed a misfire so we ended up having to change the spark plugs and HT leads. Once we were happy that the misfire had gone we then did a second run on the rollers, again to find out the performance figures for the weber.
The weber was then removed and the bike carbs fitted. I have to say that once fitted the ease and of removal and refitting is great. To remove and refit the bike carbs takes about 30 sec. With the bike carb now fitted, we went for third power run.
The figures shown that top end performance was the same as the weber, but low to mid range power was up by appox 25% ie: at 4.5k we saw a power gain of 8 bhp and also saw gain of appox 25% on the torque in these areas also.
To conclude I then took the mini for a drive and was surprised how more drivable and general throttle response was over the weber. The top end power did not seem to have changed, but the general pickup from low revs to 5k was a lot smoother and quicker.
I generally think that if you were to fit this setup over a SU carb you would be highly impressed, my only downside is that I was starting off with a weber 45 that was already giving me a lot of grunt.
Was the conversion worth it well I think yes. Simply because it gives the same power as the weber 45 did at top end. The drivability at low to mid range as now great and the throttle reponse has been greatly improved. Also they should be a little more economical.
http://i7.photobucket.com/albums/y253/swdonnelly/DSC_3928.jpg
http://i7.photobucket.com/albums/y253/swdonnelly/DSC_3915.jpg
http://i7.photobucket.com/albums/y253/swdonnelly/DSC_3913.jpg
http://i7.photobucket.com/albums/y253/swdonnelly/DSC_3911.jpg
http://i7.photobucket.com/albums/y253/swdonnelly/DSC_3914.jpg
http://i7.photobucket.com/albums/y253/swdonnelly/DSC_3920.jpg
As some of you may or may not know I have been working on the possible fitment of bike carbs to my engine. First of all I bought a bank of four Fireblade bike carbs.
We then took the bike carbs down to A&B’s who proceeded to split the carbs into a pair, redesign the choke, throttle and fuel rails on them and make a new alu inlet manifold.
So today was the day that we finally got around to fitting them.
When I got down to A&B’s today the first job was to do a power run on the rollers with the car set up with the weber on it.
During the first run we noticed a misfire so we ended up having to change the spark plugs and HT leads. Once we were happy that the misfire had gone we then did a second run on the rollers, again to find out the performance figures for the weber.
The weber was then removed and the bike carbs fitted. I have to say that once fitted the ease and of removal and refitting is great. To remove and refit the bike carbs takes about 30 sec. With the bike carb now fitted, we went for third power run.
The figures shown that top end performance was the same as the weber, but low to mid range power was up by appox 25% ie: at 4.5k we saw a power gain of 8 bhp and also saw gain of appox 25% on the torque in these areas also.
To conclude I then took the mini for a drive and was surprised how more drivable and general throttle response was over the weber. The top end power did not seem to have changed, but the general pickup from low revs to 5k was a lot smoother and quicker.
I generally think that if you were to fit this setup over a SU carb you would be highly impressed, my only downside is that I was starting off with a weber 45 that was already giving me a lot of grunt.
Was the conversion worth it well I think yes. Simply because it gives the same power as the weber 45 did at top end. The drivability at low to mid range as now great and the throttle reponse has been greatly improved. Also they should be a little more economical.
http://i7.photobucket.com/albums/y253/swdonnelly/DSC_3928.jpg
http://i7.photobucket.com/albums/y253/swdonnelly/DSC_3915.jpg
http://i7.photobucket.com/albums/y253/swdonnelly/DSC_3913.jpg
http://i7.photobucket.com/albums/y253/swdonnelly/DSC_3911.jpg
http://i7.photobucket.com/albums/y253/swdonnelly/DSC_3914.jpg