CMB RS91H ENGINE

[Ian Inverarity]

Does anyone know if the RS91HR will have the same piston and liner as the RS91 engine? :blink: Is there any likelyhood that there will be a 101HR engine further down the track? B)

Ian.

 

[carlnoki]

the piston and liner are not the same. it is a new one for the engine

carl

 

[Anders_Martinelle]

Ian, bore 27mm and stroke 26mm and ABC.

3 port config (1 boost 2 transfer) and 1 exhaust.

Anders

 

[ALLAN YUEN]

Ian, bore 27mm and stroke 26mm and ABC.

3 post config (1 boost 2 transfer) and 1 exhaust.

Anders

Is CMB91HR more powerful than CMB91(EVO) RS or CMB101RS? :huh:

 

[Ian Inverarity]

Thanks Carl and Anders.

Ian.

 

[Wild Bill]

So for those of us waiting for some performance feedback on these new motors - did any of the 'samples' run at the Internats and, if so, how did they go?

Or does anyone have any info on their heat racing performance? I am especially interested in any 'Twin' results - if any.

Still trying to work out how to fit them under my old Eagle cowl with the carby's stuck up like that.

Many thanks.

Bill Annabel.

 

[carlnoki]

just shots some pics of the new 91HR motor.

it is under carlnoki on the gallery, hope they turn out.

carb opening: 14 mm

head clearance: .015"

didn't have time to check timing on all the ports yet.

ramp installation in the back plate is completely different from teh 45 hydro. mounts from the rear of the back plate assembly.

transfer ports are "T" type.

port matching is pretty good.

no bits found lurking inside the motor when taken apart.

you even get the parts breakdown for ordering spares in PROPER Italian.

carl

 

[Piston1]

Can you tell us the head volume.

 

[Chris Wood]

We had one of the motors apart.. nothing fancy.. basic ports.. the only cool thing i liked is they did a nice job on the bell mouth on the carb.. comes with a .550 bore..

and the fixed ramp?? will have to see how it works.. now everyone will have to redisign a cowl so it will fit in there boat.

chris

 

[Ian Folkson]

New Motor wins its first race in Sweden

https://www.intlwaters.com/gallery/displayimage...lbum=563&pos=44

Ian

 

[Buckshot]

So these are now available to purchase?

If so, who has them in the USA (Tidewater?) and how much are they?

-Buck-

 

[Don Ferrette]

New Motor wins its first race in Sweden

https://www.intlwaters.com/gallery/displayimage...lbum=563&pos=44

Ian

There are alot of nice shots of that race, thanks Ian. Also what kind of heat speeds are you guys running & what are being used for muffled tuned pipes? There are alot of boats there running the same engines as US boats & finding some info out on what muffled pipes you all are having good results with would be greatly beneficial to those of us here in the States who'd rather find a way to get under the new noise limits than just ***** about it......

 

[Anders_Martinelle]

CMB 91H-Racing helped me to win the 2:nd race in sweden also.

Anders

 

[Ian Folkson]

The Photos are from Sweden Maybe some of those guys will let us have the pipe info.

I am off to the world champs in a few weeks so I will see first hand what the Hydros are using . Then I can give more answers.

Many of the top guys from Norway and Sweden seem to use the standard CMB silenced pipes we use for our endurance racers.

http://www.iansboats.co.uk/cmb.htm

Ian

CMB 91H-Racing helped me to win the 2:nd race in sweden also.

Anders

Sorry Anders I did not find all the results.

Ian

 

[carlnoki]

Ian;

Shouldn't you be holding a little green 20 hydro in your profiles picture?

:lol:

carl cisneros

 

[Preston_Hall]

I suppose that if a MAC 21 had the intake through the crank next year then you guys would be saying that it was a copy of a CMB or NR. I doubt you would.

And so what if mounting holes are the same. As far as I am concerned, that would be smart marketing by making a motor that is a direct replacement.

And if CMD was the first to squeak "small block 90" I guess CMB should be at fault for copying the idea. Wow, I must have smoked a big one for thinking that. That is like crapping on every car manufacturer in the word that came after Ford. They must all be copies by this rediculous line of thinking. Look at the car motors for heaven's sake! IT'S CALLED FREE ENTERPRISE!

This is the kind of BS that is running me out of the sport.

 

[Ian Folkson]

Hi Carl

No Hydros at the moment just developing the business for endurance may move into other things if time allows.

nice to hear from you

Ian

 

[Ian Inverarity]

A few technical questions for Anders or those who have had the new engines apart:

-Do they have 6mm wrist pins like CMB/MAC 67/80/84's, Rossi 90's etc or 7mm wristpins like the CMB EVO/RS 90/91/100/101's?

-Is the rod centre distance 45mm?

-What is crank pin size? Does it have a rod bottom end like the CMB/MAC 67/80/84's or like the the CMB EVO/RS 90/91/100/101's? :huh:

Ian.

 

[Bob Finn]

A few technical questions for Anders or those who have had the new engines apart:

-Do they have 6mm wrist pins like CMB/MAC 67/80/84's, Rossi 90's etc or 7mm wristpins like the CMB EVO/RS 90/91/100/101's?

-Is the rod centre distance 45mm?

-What is crank pin size? Does it have a rod bottom end like the CMB/MAC 67/80/84's or like the the CMB EVO/RS 90/91/100/101's? :huh:

Ian.

Haven't measured mine yet, but it appears to be the same size rod as the 67/80 , but longer. Small wrist pin and crankpin. 27/25mm = 1.08 bore/stroke ratio

 

[Ian Inverarity]

Bob,

Thanks, that's good info!

Ian.