CMB

[Krusty 181]

Hi all , can someone tell me the difference between the CMB 45 hydro (purple head) and the CMB 45 RS (red Head) both are 2005 models , both made the same power and revs(claimed)

so whats the story???

And i have heard /read rumours that the hydro motor may be a bit average ?? true / false ? others experience with them?

Andrew

 

[Dan_Cousin]

purple head is a drum induction motor

rs Red head is a disc induction motor

I've seen the purple head Hydro (CAM) motors runs and they are far from average. Good torque and revs.

They are also a LOT easier to take apart becasue the rod can be taken off the crank easily. It goes together like a OPS/Picco engine.

The RS is like the EVO series and the rod is between two pressed together crank pieces and are essentially one unit. To take the engine apart, you have to remove the pistin pin retainer clip through the exhaust port with needle nose pliers. Even worse you have to reinstall them through the exhaust port o put it back together (YUK!) BUT the RS is a very robust engines.

My old gold head EVO of the same design is still kickin with a RS piston and sleeve in it.

There were problems in the past with both engines that appear to have been fixed on later versions. The pruple head was breaking cranks. The fix appears to be changing the stock bearings to WIBs. New cam motors will state that they have WIBs installed.

The RS had a small crank pin that was prone to breaking. CMB beefed it up to 7.3mm diameter and that fixed the problem. If you get a RS make sure it has the 7.3mm crank pin.

 

[Ken Retallick]

purple head is a drum induction motor

rs Red head is a disc induction motor

Other big difference is the purple head has a single piece crank

RS has a shorter 2 piece crank that is supported from both ends. Theory says better for high rpm.

Ken

 

[NAMBA860]

i can tell you that purple head cam engine is no slotch. one of the guys at our pond runs it in his .45 saw mono and it is a frikin rocket and he also holds the .21 mono record in namba. go thom hammer

 

[Krusty 181]

to all esp Dan thanks for your explanations

is one engine better than the other for a given application??

IE is the RS better in a mono for example?

 

[ALLAN YUEN]

to all esp Dan thanks for your explanations

is one engine better than the other for a given application??

IE is the RS better in a mono for example?

Oh Yeah Of course B) Did you see Jerry Crowther use 45 RS onto his Seaducer 45 mono and Really amaze fast excellent than CMB45 Hydro or CAM

 

[Krusty 181]

Allan , i assume the 45RS was not stock ?

i guess what im asking is in stock form in a hydro , will one engine out perform the other?

the purple head as some people have noticed is discounted at the moment ,and the hydro is about $100 less than the RS

and they are available , i need a motor now ... any help appreciated

Thanks

Andrew

 

[ALLAN YUEN]

Allan , i assume the 45RS was not stock ?

i guess what im asking is in stock form in a hydro , will one engine out perform the other?

the purple head as some people have noticed is discounted at the moment ,and the hydro is about $100 less than the RS

and they are available , i need a motor now ... any help appreciated

Thanks

Andrew

Will be clearance out (discounted) for 45 Hydro (2004 to 2005) still be unsolve problem. Will come new 45 CMB with Valvola soon 2006 but increase price$$$ :huh: Unknown Good or Bad???? h34r: When arrive????

If you can afford to buy? Good Luck!

 

[Stuart Barr]

Andrew,

The 45 RS is in stock now. I tried in stock form because the numbers were where we cut motors to. Great RPM. Don't know about the availablity of the "cam" motors. However, prices will be more when the next batch comes in.

 

[Krusty 181]

Then feel im getting is that the RS is a little bit better motor , if only because it will pull a few more revs , and after speaking to some others they have said the RS with the bigger crank pin is basically a bullet proof engine,

but that the hydro motor is still **** good

 

[Ronald van Essen]

Do the differences apply to the outboards with green and purple headcolours apply as well in the .21 series?

Ronald.

 

[Stein Tumert]

In Europe it is almost only the RS model that is used. With good results, often with no tuning.

Will not be surprised if it wins alot in this summers world champs (www.rcboat2006.com)

Stein

 

[user 115]

Do the differences apply to the outboards with green and purple headcolours apply as well in the .21 series?

Ronald.

The 21's are green and red with the latest motor being the red, RS.. Jim Irwin was taking the CMB 45 purplehead and converting it to an o/b..