CMB91vac pipe

[Rick Lamb]

I would like to know exactly what size pipe is everyone running on the CMB91vac.This motor will be in a rigger.Thanks for your info.

 

[Tom Foley]

Lots of different pipes at the last race at Brandon , AB67/80 pipes , new CMBpipes that looked like clones of the AB , Rossi 80 pipes . All were working although there were some carb issues , loosening up etc .

 

[Joe Warren]

Not if you loctite all of the carb parts & Dont run the Carb barrel valve against the Stop of WIDE OPEN........Limit the stroke of the carb & drop on the carb throttle linkage........ DO NOT OVER STROKE............

 

[Rick Lamb]

Thanks guys for your input and yes i have the pipe i need now.

 

[Joe Warren]

Rick the New VAC has a older type carb stop on the barrel valve like the older red head 90 engines. MAny of us take it out & put a screw into the side of the carb hsg to retain the barrel valve. Then put a Nylon spacer behind the barrel or just leave the spring in it to keep the barrel pushed to one side. Over stroking the throttle servos & holding presssure against it causes a lot of vvvvvibration in the carb the way it comes from the fac....jw

 

[Rick Lamb]

Thanks Joe

 

[Joe Warren]

The VAC pipe that stu sells for that engine is a Look a like A/B pipe tom is talking about & works well just the way it comes out of the box...... The engine does not need a Big pipe. it likes small volume pipes. Today the VAC 91 is a RACE ENGINE Nothing drill thru on the front of the case & extremely clean when you receive it.... Very Nice BIG BLOCK Engine Out of the BOX....... I cut the low needle out of the carb. loctite all carb screws... You can pull the front end off. Hold just the drum across the front of the rod while you rinse the engine out with WD or corrosion X to keep from spilling the needles out of the rod...... Reassemble & torque all of the engine screws & You are READY to ROCKKK. The engine I have torn down were extremely clean inside... Out of the box..... You let us know what you think after you look @ it.... B)

 

[Rick Lamb]

Will do Joe,thanks again