Sounds a bit like the route I want to take. Having read the Crossflow rebuild and tuning book it seems there is some mileage in making sure the ports aren't constricted too much by making sure gaskets don't impeed the gas flow. Means taking the manifolds off though. I can appreciate what you are/have done is non intrusive.
Yep, it's a good driveable engine as it is - any more significant mods will involve much more time (engine removal) and expense, so happy to leave alone from here!
"Y mae dafad ddu ym mhob praidd" 1972 4/4, 1981 MGBGT, 1984 FLHT1340, 1980 XLH1000, 1990 ZX10
Hello TMers i know the above dits, date back to 2020 but i have a couple of questions.
I have just had my twin Webers 40s rebuilt and my mate and myself have had fun and games. First one of the carbs kept flooding, this was caused by the smallest piece of rubber, from the fuel hose getting past the fuel filter and stopping the needle valve from lifting, which of course stopped the floats from lifting and shutting off the fuel and hence overflowing carb. But all that is sorted. When the carbs were rebuilt they were tested on a Ford Pinto engine and all was great. All the readings using a Synchometer (Balancer) were equal. (The guys who rebuilt then sent me a video proving this). Since putting the Webers on my engine, the forward Weber is showing higher reading than the back Webers. (Tested with my Synchometer) So i would like to check that the Advance and Retard is correct. I have found the notch in the front pulley and it seems a few degree out using my strobe light. Is this correct bearing in mind the car is now unleaded, it has been up-rated to 1700 or just under. The engine is a Ford Kent Crossflow with electronic ignition. When i rebuilt the engine, I Say rebuilt, I mean the head was removed, and de-coked, i did check the TDC position, that was about 2500 miles ago! Also i noticed above the mention of a Vacuum pipe (Arwyn Williams) , what is this? Basically we want to check everything on the engine is ok before we start tampering with the Carbs! Your help as normal is greatly appreciated.
I suspect the ignition timing will also depend on what cam type is fitted..? Seems like it is best to re balance the carbs to suit your own engine`s requirements. The vacuum pipe if fitted is usually a small diameter plastic pipe running from the inlet manifold to the distributor where it connects to a diaphragm and advances the ignition as determined by inlet manifold depression.. As best I can remember when unleaded appeared on the scene a few folk removed or blocked off the vacuum pipes..? If trying to use original settings on a modified engine would seem to risk less than ideal performance from it..?
Luddite You are correct, my MOG has a 'Kent' fast road fitted. Many thanks for your suggestions.
Regards
Originally Posted by DaveK
Luddite You are correct, my MOG has a 'Kent' fast road fitted. Many thanks for your suggestions.
Regards
It is also possible that with a non-standard cam that the valve clearances may also be different from standard. At least I think the Kent was a popular cam at the time, thus no doubt there will be info available on the www. Good luck.
The DCOE, IDF and IDA carbs are a marvel of engineering and quite simple but to operate correctly they rely on the basics being right.
If the carbs were sync'd on a Pinto and you then refit them on your Xflow manifold you will need to re-do them. It sounds like the front throttle plates are slightly more open than the rear, or, possibly but less likely, an air leak.
Ignition timing issues will not cause what you describe.
I have 'tinkered' with them with them for over 50 years on race and road cars both professionally and privately, I currently have a pair of IDF down draughts on my 1700 xflow 4/4. Let me know how you get on.
