CMB .90 or 1.0

[jaso]

Can anyone tell me the advantge of a 1.0 cmb over a .90 in a otrigger hydro or dissadvantage. This will be the first boat I've built for over ten years, just got back into the boats, currently running a .21 rigger of my own design which was very competitive then and still seems pretty fast. Very keen on putting together my new boat.

Any insight greatly appreciated.

 

[Ian Inverarity]

I asked the same question a while ago on another forum. I was told that for a light boat, 9-10lbs or less, then a 90 was better. A heavier boat can work better with the hgher torque of the 100.

Ian.

 

[jaso]

thanks for that info . I was just told that the .90 was the safer bet because a lot more testing and modifing has been done to the .90. I was also told that I should ensure I get the revised engine with the larger crank and crankcase, and try to find the reason for this mod. Any one who has any ideas please let me know ???

 

[Mick J]

Jaso, I was told some time ago on this board by Dale Heilier (please forgive me if I'm mistaken ?????) that the you can put a CMB 1.0 piston and sleeve into a CMB 90, straight swap, personally never tried it. I own two CMB 90's and absolutely love them to bits, a great motor in my opinion ;D

Johno

 

[Chris Wood]

not to get in a big pi$$ing match but i really like the green head cmb 80 motor.. anyone that has seen it runs says it runs great.. i love it, very very conisistant. and hard running in a hydro..

runs 80-85 all day and has run a best of 89.5...

can't go wrong with them..

chris

 

[nitrotoys]

YES you can put a 1.0 P/S in the .90, there the same block and crank. I have a gold head .80 and its a great runner, I have had good luck with the CMB .80, after several dunkings and mishaps on the water ;D ;D ;D knock on wood, been holding up. Now i seen the A.90 run, and thats a screamer. I would like to see more people have them and try them and give input.

NT

 

[jaso]

I heard the a90 was a fairly heavy engine but thats all of them I've heard other than I think spares may be a bit hard to get down here in Austraila?

 

[Ian Inverarity]

Jaso,

The A-90's are not unduly heavy, they are certainly about the same weight as CMB 90's or K-90's, altho all are bigger and heavier than the 80 type engines.

I get my A-90 engines from Craig Chenco (Eat My Shorts) in Victoria. I have not needed a lot of spares but Craig has always been able to supply me.

Ian.

 

[Mark Anderson]

Iput the 100 in my eagle thinking bigger was better. the motor ran good but not great. After about a gallon of fuel I had a misshap and needed to replace the piston and sleeve. I replaced it with the 90 piston and sleeve based on advise I got from several racers and the motor ran much better. The 90 would rev higher.

When CWI started carrying the A90 I put one in the boat to try it out. The CMB was sold very shortly after that!

Either motor will run good and be reliable.

Mark

 

[Ian Inverarity]

Mark,

I used to run an modified A100 in a 46" mono. I wasn't too impressed at first because it just wouldn't rev like the A-90HP. But I eventually worked out what it needed was big props. I went from a 6516/3 or X467 with the A-90HP to a 7016/3 or X470/3 with the A100! With the larger props it was faster than the 90! I had to give up on it tho, the torque was too much for that hull. However I dont know if the A100 would work well in a hydro because of the very mimited selection of large rigger props.

When you say you put a 90 P&L in the 100, was it the LS or HP P&L? The A100 is based on a bored out A90LS, which has a longer stroke than the HP. The HP P&L in the 100 would be larger than a 90.

Ian.

 

[Mark Anderson]

I'm sorry I was not clear in my post the 100 that I converted to a 90 was the CMB. I am now running the A90. The A motor was much faster for me than either CMB.

Mark

 

[Ian Inverarity]

Ah! Now I understand! 8)

Nitrocrazed racing:Easily confused.

 

[EatMyShortsRacing]

Folks,

A90, 100 and 45 Parts and engines are readily available here in Australia... from me..

[email protected]

EMS Racing Woohoo, a free plug for me!!!

 

[Ian Inverarity]

Craig, I think Tom accepts donations!

Nitrocrazed racing: Kickbacks required....

 

[jaso]

Thanks everyone for your input on these motors it's been very helpful

Jaso.