My Bay

[rstucke]

Rick
Cam is a Scat C25
Steve spent a fair bit of time getting the cam gear right with “+2” or a “+3” gear

Compression was set at 8:0 - 1

Carburettors are Spanish Weber IDF’s

Jetting is
Vents 28
Airs.   Need to check but guessing 200’s
Mains 120
Idles.  47.5
Emulsion F7 (I think)
If F11 is the common one it’s F7. Could be the other way around. I’m checking. 

I was surprised that it wanted 28 vents. 
Steve started with 32’s, which is where I thought it should have been. 
That is where my 1916 was. 
Anyway - at the end of a lond day at the dyno it ended up with the above jetting. 

Steve reckons there is a tiny bit of lag in the idle/main transition but I can’t notice it.

So by the carby specs it's a 2 ltr?
The engine in Blitz at the moment was pretty much the same
c25 cam
40 idf's Spanish
115 mains
28 vents
120 airs
47.5 idles
can't remember the f number either (check it tomorrow)
Went to 44 with 32 vents and all the adjusting for jets, don't like them and putting the 40's back when I swap the engines. The 44's should be good for the 2.4 ltr that's going in (made a mistake calling it a 2.3 earlier)

A trick to work out if a flat spot is caused by the transition between idle and main jet flowing
disconnect acc pump
remove the jet tree
connect tacho
drive with slow throttle increase
note rpm which it dies (around 2100rpm)
replace tree
re drive, note when the power kicks in after the flat spot
you now need to determine if it's a lean out or the main is coming in to early and over fueling
going up or down by 20 on the air jet should show up which is which and fix
don't forget to reconnect the accelerator pumps
adjust screw in for less squirt, or out for more.