very odd problem
 

just fitting up a 1915 type 1 motor with 041 heads, 110 cam and a pair of kadrons. all brand new.
will only run on the front 2 pots.
have changed dizzy (trehaft 010, 2x 009), cap, leads, plugs also tryed a pair of 40 dells with no differance. valve clerance is all good and valve lift looks good and even between all pots. have chacked to see if the heads are for long reach plugs. retimed the engine from scratch at least 4 times.
this was a turn key motor and ment to have been bench run so all should be ok.
getting to the piont of pulling the motor out and pulling it apart, but customer is reluctent to have this done as has spent a lot of money on a built engine.
i did not build this motor and will not give out detials on who did, unless it proves to be somthing they have done.
thanks in advance for any ideas

Might be the cam was not broken in correctly? Pop the valve covers and watch each rocker arm as you hand turn the engine. Maybe this helps out. Good luck!

have tryed that and had a dial guage on the valves and measured the lift, all are about the same.
all i can think of is the cam timing is out?

Distributor out 180 degrees?
Definitely something to do with timing for it to have spark on 2 cyl.
I would check to see if the valves were opening in time with the rotor postion on the distributor.

The cam could be bolted to the gear out of index (180 out). If they ran the engine before you got it there should be carbon in ALL the exhaust ports (did you check this when you got the engine). This is a strange problem you have :confused: . Something will "rear it's ugly head" sooner or later.

i got the car after engine had been installed and run, owner could not get it running right so brought it to me to sort out.
spoke to the engine builder last night in the states, who insisted that it was a leaking header that was the problem, then told me to put bigger jets in the carbs and it would be ok. went quite when i told him i had fitted a pair of 40 dells of another engine and had the same problems.
cheers rob

I hate to say it, but teardown time (at least the top end). Then you can see the cam through the cylinder spigots, might find other problems along the way. :(