Pipe for Vac 91

[dr gary turner]

What pipes are being used on a VAC 91?

 

[FloridaScaleBoater]

What pipes are being used on a VAC 91?

CMB AB.67 Silenced Marine Tuned Pipe (Works well on 67, 80 & 91 engines)​

 

[ALLAN YUEN]

Hey Gary Did you see Don Ferrette's Jagaur w/ CMB91 VAC at Hobart ?

No Excuse

 

[Scott Miller]

What pipes are being used on a VAC 91?

CMB AB.67 Silenced Marine Tuned Pipe (Works well on 67, 80 & 91 engines)​

+ 1...Very versatile pipe. I have used it with the VAC91 in both mono/rigger hulls. Great results.

 

[Greg Wannamaker]

Dido on the CMB pipe, good sweet spot and excellent rpm/torque, will pretty much pull any prop

I throw at it.

 

[dr gary turner]

Anyone try a Muck 13cc? How about MAC 13/15 cc?

 

[Elias Vazquez]

I've seen some run the Rossi 80-90 pipe with good results.

 

[dr gary turner]

Thanks

 

[Terry Keeley]

CMB Fat Belly with the stinger opened up to 0.430" or so.

 

[BigChuck]

Doc.. JW ran 13cc Leadin on a twin in Charleston a few years ago. If memory is correct he won the class.....The 80/90 pipes kick RPM. The MAC 13cc leads kick torque.

 

[Joe Wiebelhaus]

91vac 67/80 CMB pipe, what length center to weld ?

How are you joining them at the header, the header and pipe are same O.D., my coupler leaks/burns out after a couple of runs ??

 

[dr gary turner]

I ran the Bouchies pipe for a 90. It was awsome. Pulled hard out of the turns.

 

[LarryBeals]

Rossi 90 pipe muck 90

 

[mercguy]

91vac 67/80 CMB pipe, what length center to weld ?

How are you joining them at the header, the header and pipe are same O.D., my coupler leaks/burns out after a couple of runs ??

Joe

I am having the same problem with my .91 VAC and that pipe. Would be interested what others have done. I thought maybe cutting the header a little shorter and welding in a smaller diameter pipe and cutting a chamfer on the leading edge of the i.d. to help exhaust flow.

Bill Hoch

 

[FloridaScaleBoater]

91vac 67/80 CMB pipe, what length center to weld ?

How are you joining them at the header, the header and pipe are same O.D., my coupler leaks/burns out after a couple of runs ??

Joe

I am having the same problem with my .91 VAC and that pipe. Would be interested what others have done. I thought maybe cutting the header a little shorter and welding in a smaller diameter pipe and cutting a chamfer on the leading edge of the i.d. to help exhaust flow.

Bill Hoch

Bill,

Get with Tom Foley and have him weld a sleeve on your pipe to tele over your header.

I wouldn't reduce the header ID

 

[Ray Sametz]

91vac 67/80 CMB pipe, what length center to weld ?

How are you joining them at the header, the header and pipe are same O.D., my coupler leaks/burns out after a couple of runs ??

Joe

I am having the same problem with my .91 VAC and that pipe. Would be interested what others have done. I thought maybe cutting the header a little shorter and welding in a smaller diameter pipe and cutting a chamfer on the leading edge of the i.d. to help exhaust flow.

Bill Hoch

Bill,

Get with Tom Foley and have him weld a sleeve on your pipe to tele over your header.

I wouldn't reduce the header ID

Ditto on that, Fast Foley does great work.

 

[mercguy]

91vac 67/80 CMB pipe, what length center to weld ?

How are you joining them at the header, the header and pipe are same O.D., my coupler leaks/burns out after a couple of runs ??

Joe

I am having the same problem with my .91 VAC and that pipe. Would be interested what others have done. I thought maybe cutting the header a little shorter and welding in a smaller diameter pipe and cutting a chamfer on the leading edge of the i.d. to help exhaust flow.

Bill Hoch

Bill,

Get with Tom Foley and have him weld a sleeve on your pipe to tele over your header.

I wouldn't reduce the header ID

Rick

That is probably a better idea. Thanks for the idea. I have seen guys wrap a thin aluminum strip (like a soda can) around the joint and that worked except it is hard to put a coupler over that.

Bill

Bill

 

[Mike Hughes]

Yep Foley is my welder. Does awesome work. My welds just look horrible, except when I hit then with the grinder. LOL

 

[Greg Wannamaker]

Stu sent me a thick walled CMB header that I had a machinest friend machine out the inside of the header and so that the CMB pipe is a slip fit into it, no more coupler problems!

 

[dwilfong]

MACS 13cc 1" lead in pipe. will slip right over the thin CMB header. Open the stinger to .470

Octura 7/8 coupler tubing.