RS45 CMB

[Marty Davis]

Rod Hendricks, Norm Doerr and I are building a new 45 boat and have a question about the CMB RS Engine.

Rod has been running that engine with Great Success and I would like to take one of his engines and build it up to turn very high RPM's (30K).

Has anyone used the 45 RS in this manner to run high RPM's? If so, have you seen any breakage. My main concern is whether the crank/rod assy will hold up to very high rpm.

Interested in any feedback.

 

[TonyK]

I am running the 45RS in my 45 rigger, 60% nitro and 15% coolpower blue, at about 29,000 to 30,000 and have had no problems to date. That is about 18 months now.

Tony

quote name='MartyDavis' date='04 August 2009 - 12:05 PM' timestamp='1249340719' post='309567']

Rod Hendricks, Norm Doerr and I are building a new 45 boat and have a question about the CMB RS Engine.

Rod has been running that engine with Great Success and I would like to take one of his engines and build it up to turn very high RPM's (30K).

Has anyone used the 45 RS in this manner to run high RPM's? If so, have you seen any breakage. My main concern is whether the crank/rod assy will hold up to very high rpm.

Interested in any feedback.

 

[Ron Jefferson]

Rod Hendricks, Norm Doerr and I are building a new 45 boat and have a question about the CMB RS Engine.

Rod has been running that engine with Great Success and I would like to take one of his engines and build it up to turn very high RPM's (30K).

Has anyone used the 45 RS in this manner to run high RPM's? If so, have you seen any breakage. My main concern is whether the crank/rod assy will hold up to very high rpm.

Interested in any feedback.

Marty,

Almost everyone I know that has run the RS motor has had problems with the bushing at the top end of the rod. This can be a huge pain in the butt because not just anyone can split the crank and replace the rod. I found these engines to be way too high maintainance for me. I actually had to send mine to England for repair. They definately spin up well but lack torque in my opinion. And, the wrist pin out the exhaust is definately a challenge. Installing without a fixture is even more fun. If you are replacing a higher torque engine like the Picco. Toss out all your props and start again.

Ron

 

[Chris Wood]

marty,

i don't think you can hardly blow up that motor.. the 2pc crank is superstrong.. and dads boat can pull a 1650. so i don't get all the talk of know torque.

i think you will be happy with it.

chris

 

[Norm Doerr]

Time to fire up the dyno

 

[Norm Doerr]

I am running the 45RS in my 45 rigger, 60% nitro and 15% coolpower blue, at about 29,000 to 30,000 and have had no problems to date. That is about 18 months now.

Tony

quote name='MartyDavis' date='04 August 2009 - 12:05 PM' timestamp='1249340719' post='309567']

Rod Hendricks, Norm Doerr and I are building a new 45 boat and have a question about the CMB RS Engine.

Rod has been running that engine with Great Success and I would like to take one of his engines and build it up to turn very high RPM's (30K).

Has anyone used the 45 RS in this manner to run high RPM's? If so, have you seen any breakage. My main concern is whether the crank/rod assy will hold up to very high rpm.

Interested in any feedback.

Tony

Can you share what pipe, prop, and how much does the boat weigh?

Thanks

Norm Doerr

 

[Stuart Barr]

Marty,

Just broke in a new motor (45RS) with a new style CMB nitro pipe. They timed this break in at the nats thru the traps and was running 82 mph. Still rich and I expect it to heat race at 86+. Call me and I will give any other details.

Stu

 

[Marty Davis]

Marty,

Just broke in a new motor (45RS) with a new style CMB nitro pipe. They timed this break in at the nats thru the traps and was running 82 mph. Still rich and I expect it to heat race at 86+. Call me and I will give any other details.

Stu

Somebody told me that your new 40 boat hit something really hard.....

 

[Stuart Barr]

Yup. Switch turned off and boat came right back to the pits at full throttle. Glad nobody was hurt.

 

[Marty Davis]

Yup. Switch turned off and boat came right back to the pits at full throttle. Glad nobody was hurt.

How about the boat?

 

[Kim J]

In Europe many drivers especially in the FSR-V class had problems - flexing and breakage of crank - with this engine.

The V class often uses gearing combined with high rpm`s and long heat times.

It was cured when the crankpin was increased to 7,3 mm.

Actually NAVIGA runs the European Championship in Hungary now - 1 to 9 of August.

 

[Stuart Barr]

Marty,

Boat received little damage. Amazing. It will be ready for Hobart.

Kim,

I have run the RS hard for five years and finally worn out the crank rod assembly. I consider this a good testimate to the quality.

 

[ACTION JACKSON]

with all this being true i cant see any reason to have to change the crank assembly at all, or for at least 8 to 10 years.

i still like the old picco black heads that are very bullet proof & your replacement on parts can be done yourself without sending off a crank there are some trad offs both motors run great it just depends on your preference. just my thought

not to mention you still have almost 10 year old black head picco motors still at the top in some classes. have a great day

 

[Marty Davis]

with all this being true i cant see any reason to have to change the crank assembly at all, or for at least 8 to 10 years.

i still like the old picco black heads that are very bullet proof & your replacement on parts can be done yourself without sending off a crank there are some trad offs both motors run great it just depends on your preference. just my thought

not to mention you still have almost 10 year old black head picco motors still at the top in some classes. have a great day

Steve:

I want a 40 engine that I can turn 30,000 RPM and I KNOW that the Picco Black heads will blow up at about 27,500. I am looking for something more bullet proof.

 

[Kim J]

Marty have you seen this :

DEAR CUSTOMERS,

THE LATEST 45 RS ENGINE AS IT IS NOW SUPPLIED, HAS BEEN TESTED OVER A VERY LONG PERIOD OF TIME. IT CAN GIVE A HIGH PERFORMANCE FOR MANY HOURS IF USED PROPERLY.

WHEN USED IN FSR-V BOATS WITH A GEAR BOX THE BEST SETTINGS WE FOUND DURING OUR TESTS WERE:

FUEL: 25% NITROMETHANE

13% OIL JET JP4 EXPERT OR 14% ELKALUB VP 846

GLOW PLUG: CMB C7C

PIPE: CMB 45 EVO2 (LENGTH GLOW PLUG/ WELDING POINT 260 mm)

GEAR RATIO/ PROPELLER: 1/1.5 2026 (MOCOM) 2028/5070 (POLISH)

1/1.38 2027 (POLISH) 2025/2026 (MOCOM)

RPM : 29/30.000 RPM MAX

AS WITH ALL COMPETITION ENGINES THE 45 RS REQUIRES REGULAR SERVICING.

WE ADVISE YOU TO CHANGE EVERY 8-10 HOURS THE MAIN BEARING, THE CRANKPIN AND THE ROD NEEDLES.

WHEN IT IS USED ON HYDRO BOATS, WE ADVISE NOT TO PUSH DIRECTLY ON THE ENGINE WITH THE PROPELLER.

IT IS VERY IMPORTANT NOT TO COOL THE ENGINE TO MUCH AND CAREFULLY FOLLOW THE INSTRUCTION SHEET FOR THE COOLING DIRECTION.

IF THE ENGINE IS USED WITH NON ORIGINAL ACCESSORIES OR TUNED YOU WILL DO SO AT YOUR OWN RISK.

THE MANUFACTURER.

C.M.B. MOTORI ITALIA SNC

 

[aaron alberico]

Marty

i'm running the new blue head picco 45 modded at more rpm's then that,

and hav'nt blown up yet(touch wood)

regards Aaron

 

[DaveMarles]

Marty, I'm running geared 45 RS's and run 29,700 to 30,000 rpm (measured with onboard tacho) with no problem except I change wrist pins every 3 hours because they will break. Changing the wrist pin is a simple and quick job to do. Other than that the motor is almost bullet proof. Crankpin can fail occasionally even on a new engine but its one in 20 that will do that and if it does it generally will not damage anything else. For example I broke only one crankpin in 3 years and a race meeting for me is 1 hour 15 minutes of racing plus some open water testing so I run the motors a lot. Bearings last forever, disc doesnt wear in the centre, for me its a reliable motor.

Dave

 

[Marty Davis]

Marty, I'm running geared 45 RS's and run 29,700 to 30,000 rpm (measured with onboard tacho) with no problem except I change wrist pins every 3 hours because they will break. Changing the wrist pin is a simple and quick job to do. Other than that the motor is almost bullet proof. Crankpin can fail occasionally even on a new engine but its one in 20 that will do that and if it does it generally will not damage anything else. For example I broke only one crankpin in 3 years and a race meeting for me is 1 hour 15 minutes of racing plus some open water testing so I run the motors a lot. Bearings last forever, disc doesnt wear in the centre, for me its a reliable motor.

Dave

Thanks Dave, that is what I was looking for....