I have had a great response to my last post. So here is my latest question. My car is an 82 4/4 with a Kent crossflow and a 28/36 weber. I have the standard rather beautiful cast "Morgan" air filter and all the gubbins it is attached to. However, I think it is probably a bit restrictive in that the hole it eventually sucks its air through is very small. And the whole set up must weigh near to twenty pounds or more. Will I get a better 'breath' through a K&N or similar? If so, what do I do with the small breather that plugs into the bottom of the cast thing that sits on top of the carb? Also has anybody who has done this had to re-jet?
Matt 1982 Morgan 1600 4/4 1980s Reynolds 531 Touring bike, 30 gears!!! The bus.
I agree it looks elegant, but I suspect you are right.
I base this on the fact that the fuel consumption at high throttle use is awful.
When I fitted DCOE40's the fuel economy improved a lot.
The small thing in the top I think was to do with diverting air from the hot spot on the exhaust on a cold day, are you in the habit of Morgan driving with frost on the ground?
The best conversion you can do for your money on your car is to fit 5 speed box, that will way improve fuel con.
1972 4/4s came with no air filter and a lid for the carburettor. So the fitment of a K&N didn't cause jetting problems. A car that came with a paper filter, may need leaner jets if you put a K&N on it.
4/4s if you keep it slow, won't open the second choke and can do fantastic MPG. I got 45 mpg out of Woodstock on a long and slow trip.
Not what a Morgan is for though, and the engine I sold the car with did 25mpg if you utterly behaved, and about 8 competitively. Yes, 8!
Don't ask me to explain as I can't but some carburettor are fussy, and others aren't.
The Webers in common usage on older Ford engines seem to be fine with more airflow, but SUs are quite different story. I had to change the needle on a SU equipped Maxi - thing was undrivable with standard needle.
Gosh, this all takes me back to tuning the early 2000 Bonnevilles with twin CV Carbs!!
If you do anything to increase air in you have to be certain that air gets out and the right amount of fuel is mixed at all throttle openings. It isn't simple.....
It is easy to get it wrong, too much fuel just wastes it, to little can result in damaged exhaust valves.
I wrote a guide on the subject. It applies to all CV "Stromburg" type CV Carbs, but is good background anyway.
When I replaced the Ford air filter on our CVH engined car with a K&N filter it did cause problems with pick-up at times. Re-jetting solved the problems completely and transformed the drive.
Paul Costock, UK Plus Four 75th - Furka Rouge - Pip Disco 5 Teddy - 17h1 Irish Draught cross
