CMB 21VAC

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Stuart Barr

Well-Known Member
Supporting Member
Joined
Mar 24, 2005
Messages
1,231
Mr. Jim Wilson from California said I could quote him on this. He just ran the new 21VAC in stock form. This is in a SD3 mono hull set up in oval trim. Boat speed on the straight is 70mph and 66mph in the turns with 33,500 max rpm. Great clear through the entire throttle range. Head clearance is set at .006" and remove the shield on the front bearing. Shield did cause some binding. He believes this motor in a 4+ pound hydro will go 85+. Maybe I should start running 21 hydros if I could find a boat to handle this speed.
 
Ill be out this weekend with the speedmaster/vac... let's see how close I can get.

If you want to borrow my best 21 hydro to do some playing, it's your! Oh wait, thats right, It hasn't been built yet... get to it! :lol:
 
Last edited:
Maybe I should start running 21 hydros if I could find a boat to handle this speed.

just hold your pants on.. it is comming.. I HOPE..

i hope to get the motor going in a couple of weeks.

chris
 
Last edited by a moderator:
I thought Stu said he wouldn't run any motor that he couldn't stick his little finger down the bore of the carb, that 21VAC must have one hell of a carb on it. :lol: :lol: :lol: :lol:

Seriously, sounds it like a bad azz little 21. B)
 
70mph in a 21 mono in race trim,

i wanna see that... :huh: here we go...lol

come on lets get back down to earth.....

there are better ways to sell this motor.. :angry:

Luca
 
Stuart Barr said:
Mr. Jim Wilson from California said I could quote him on this. He just ran the new 21VAC in stock form. This is in a SD3 mono hull set up in oval trim. Boat speed on the straight is 70mph and 66mph in the turns with 33,500 max rpm. Great clear through the entire throttle range. Head clearance is set at .006" and remove the shield on the front bearing. Shield did cause some binding. He believes this motor in a 4+ pound hydro will go 85+. Maybe I should start running 21 hydros if I could find a boat to handle this speed.
Click to expand...
What pipe, and prop?
 
laedco58 said:
Stuart Barr said:
Mr. Jim Wilson from California said I could quote him on this. He just ran the new 21VAC in stock form. This is in a SD3 mono hull set up in oval trim. Boat speed on the straight is 70mph and 66mph in the turns with 33,500 max rpm. Great clear through the entire throttle range. Head clearance is set at .006" and remove the shield on the front bearing. Shield did cause some binding. He believes this motor in a 4+ pound hydro will go 85+. Maybe I should start running 21 hydros if I could find a boat to handle this speed.
Click to expand...
What pipe, and prop?
Click to expand...
What fuel, and plug?
 
What propeller where you running to get these speeds of 70mph in race trim and 66mph out of turns.
 
Luca Gray said:
70mph in a 21 mono in race trim,

i wanna see that... :huh: here we go...lol

come on lets get back down to earth.....

there are better ways to sell this motor.. :angry:

Luca
Click to expand...
Luca: you obviously haven't had the pleasure of seeing some of Jim Wilson's boats run, his are by far some of the fastest and best running boats on the west coast. If Jim ran that fast and Stu posted it you can believe it for sure. look up some of Jim's Namba records and decide for yourself. Rick
 
Luca Gray said:
70mph in a 21 mono in race trim,

i wanna see that... :huh: here we go...lol

come on lets get back down to earth.....

there are better ways to sell this motor.. :angry:

Luca
Click to expand...
Mr. Gray,

If you know Mr. Wilson, he does not stretch the truth. These words are from him. Answers to other questions: Price is $475.00, fuel was 65% nitro, plug was an OD9. He did not say what the prop was.
 
That is straight up smokin' for any size mono let alone a .21!

If Mr Wilson said it then it indeed happened!

I want to see/hear what it does in his already balistic Sport .21 boat!

:)
 
If Jim said it went 70mph you can take it to the bank! I have known Jim for 30+ yrs & talk often, no BS, just facts peroid!!!!

Don :)
 
DON MAHER said:
If Jim said it went 70mph you can take it to the bank! I have known Jim for 30+ yrs & talk often, no BS, just facts peroid!!!!

Don :)
Click to expand...
No offense to any of the performance claims of this motor. Similar statements from boat and engine manufacturers has been going on ever since i started running boats. (20 some years) There are always some that can extract maximum performance from a set-up. Is Mr. Wilson a average or slightly above average boater? Will the average guy obtain this performance? Stu, thanks for all the effort you put in to providing a great hydro, and CMB motors and parts. Richard D
 
Richard,

All I can give you is performance from people that I believe is credible. Mark Grim tested the proto-type over the winter and we already new what we had then. I will give anyone the facts and proper set up. It depends on what the "average boater" does with this information for their results. Nitro motor set up is not for the novice, but only a few principles are needed get a great performing out of the box motor. All timing #'s are stock and it is general clean up and setting the head clearance correctly. Then it is getting the right pipe and prop. Jim Wilson's info on his set up was using a Scott Bouchie's 33m. steel pipe and also using Mark Sholund's 1614 ABC chopper prop at 3.2" cup. Mr. Wilson current holds the NAMBA 6 lap record for A Mono (21) at 80 seconds that equates to just over 13 seconds per lap. He knows how to get there. However, Jim is a very low profile guy and will never blow his own horn. Sometimes we have to blow it for him for what he does. Jim has seen this new motor run than faster than his record engine. Wait until this fall when he takes it to a record trial for records to be broken again.
 
Richard Dahlheimer said:
DON MAHER said:
If Jim said it went 70mph you can take it to the bank! I have known Jim for 30+ yrs & talk often, no BS, just facts peroid!!!!

Don :)
Click to expand...
No offense to any of the performance claims of this motor. Similar statements from boat and engine manufacturers has been going on ever since i started running boats. (20 some years) There are always some that can extract maximum performance from a set-up. Is Mr. Wilson a average or slightly above average boater? Will the average guy obtain this performance? Stu, thanks for all the effort you put in to providing a great hydro, and CMB motors and parts. Richard D
Click to expand...
Jim will help the average guy if the average guy ask. Just make sure you have plenty of time to listen before you ask. I talk to Jim on the phone from time to time and have known him for many years. If he stated it as fact then it is fact. I cant wait to talk about this with him.

Robert Holland
 
70mph from 21 mono in race trim is awesome congrats on those speeds.

just wondering how Jim worked out the rpm of the motor at 33500rpm,

as i think he might have got that wrong,( i could be wrong on this)

but 1614 chopper propeller has a leading pitch of 1.875in

so to go 70mph with this propeller the least rpm he would have to be turning is just over 39000rpm

and from a stock motor that is awesome, i thought my 21 Nova in my rigger turning 35000+rpm was crazy i would love

to see this run,

Stu do you know if they got it on video,

regards Aaron
 

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