Originally Posted by racroom
The motor is a 468 cubic in. the injector nozzles are 35, the by pass pill in it now is a 125, the pump is a hilborn 1-6898.
Are you saying that the nozzles are 35AS as in hilborn size or they rons nozzles. If they are hilborn 35AS then they are for nitro, for straight alcohol, the biggest you need is 20as nozzles. Yes the high speed leanout is a necessary evil for good top end performance. On all the injections that i've hany thing to do with we use 18AS nozzles with the PG150-1 pump, which puts out about 6GPM.
You can plumb the high speed lean out into the feed line to the injection and back to the tank or loop it back into the intake on the pump.
The high speed leanout should be set between 55 and 65%/LBS. you can use a secondary bypass body if you can shim it to the approx. 60%/LBS.
the starting point on the barrel valve should be at 23% and work down from there. The .125 pill is a good starting point with the correct size nozzles, also an EGT setup will tell you if you're too rich or lean, usually around 1050/1100 degrees for 1/4 mile runs.
It also helps if you leakdown tester to come close on the original starting point setup.
Hilborn suggest starting at 25% on the barrel valve, in fact i just an email from Don Enriquiz,(Hilborns resident expert) on a setup i'm working on to run 20% nitro on a 434" motor.
JMO,
Zip.