New CMB 91 MOTORS

[ianfolkson]

New CMB 91 GPX 7 port M line replacment and RS.3 Evo replacment

 

[Joe Warren]

The Red head M91 is a Great Engine... Green Head GPX 91 Will only be Better.

 

[ianfolkson]

New Gpx Green has 7 PORT liner plus a special extra liner from aluminium fixed inside The crankcase to adjust fuel flow in transfer ports. The aluminium liner must not be removed it is fixed in and the new motors have smaller cooling jackets.

 

[RaceMechaniX]

Ian, is that information available somewhere to read or just your insider knowledge?

 

[ianfolkson]

I am afraid thats just my insider knowledge. I will be racing with CMB in 2 weeks I hope to get a few inside photos.

 

[RaceMechaniX]

Thanks Ian,
-Tyler

 

[Jeff Lutz]

New Gpx Green has 7 PORT liner plus a special extra liner from aluminium fixed inside The crankcase to adjust fuel flow in transfer ports. The aluminium liner must not be removed it is fixed in and the new motors have smaller cooling jackets.

“Choke your transfers down for your next heat you will love it” …..

 

[Timbo Whalen]

New CMB 91 GPX 7 port M line replacment and RS.3 Evo replacment
View attachment 316294

So, CMB's offering a standalone 91 GPX now, or just the GPX kit?....

I guess there is a limited run of 21 GPX engines available, too.

 

[ianfolkson]

There is no gpx kit as the 7 port liner does not fit the older cases. Only new complete motor.

The 3.5 7 port liner does fit the existing crankcase but you have been able to buy the gpx 3.5 for some time now.

 

[RaceMechaniX]

It's a little unclear as Tony Grinter is offering GPX tuning kits which I assume were for the current 91/101RS motors:
Hobby Supplies CMB Engines

 

[ianfolkson]

As far as I know the GPX TUNING KIT fits the M line case. The new GPX 91 Engine has a different diameter Brass liner. To fit the new case.
I will check with Mauro for a definitive answer

 

[ianfolkson]

The New Green GPX has a smaller diameter liner unique to the new motor.
The old GPX kit will fit the RS.3 case as well as the M line liners.

 

[Buckshot]

News release from CMB:

 

[FloridaScaleBoater]

Are these being offered/stocked by Stu?
Same with the M-Line 45 & GPX 45
Is Stu carrying them?

 

[Joe Warren]

It appears that the RS3-91 Does Away from the long M series Crank & needle bearing rear hsg? The GPX is the only New 91 engine that retains the long Crank shaft & the Needle bearing support rear hsg. Tony is saying 2/3 weeks before he has both new engines.

 

[Timbo Whalen]

There is no gpx kit as the 7 port liner does not fit the older cases. Only new complete motor.

The 3.5 7 port liner does fit the existing crankcase but you have been able to buy the gpx 3.5 for some time now.

Ok, so I'm confused-

 

[ianfolkson]

The GPX kit fits older Evo Motors and the new RS.3 cases.

The latest GPX liner in the green motor has a smaller diameter of to match the pressed in aluminium liner

 

[Timbo Whalen]

As far as I know the GPX TUNING KIT fits the M line case. The new GPX 91 Engine has a different diameter Brass liner. To fit the new case.
I will check with Mauro for a definitive answer

Ok, now it all makes sense...last looked at CMB's site a couple of weeks ago and didn't see anything about the M-Line/GPX connection.

So, as it stands now, the 91 GPX Tuning Kit exists only to retrofit the 91 M-Line customers have invested in?...

Thanks

 

[Timbo Whalen]

The GPX kit fits older Evo Motors and the new RS.3 cases.

The latest GPX liner in the green motor has a smaller diameter of to match the pressed in aluminium liner

Yes, thanks...older meaning 91 RS EVO (gold head).

Thanks for clarification.

 

[RaceMechaniX]

The GPX kit fits older Evo Motors and the new RS.3 cases.

The latest GPX liner in the green motor has a smaller diameter of to match the pressed in aluminium liner

I got excited for a second, but looking closely looks like there is a pretty bad mismatch between the case and the aluminum liner. Look at the transfer port below the exhaust side eyebrow. Do you know of the aluminum sleeve can be removed?