NEWS engine " SHOCK"

[Bob Finn]

I just received a new CMB 45 from Tidewater. After all the discussion here, I was hoping they had not copied the MAC. I tore it down immediately and heres what I found. The bore/stroke/ and rod length are the std CMB numbers. The piston and cylinder appears to be the same as the 45 RS, as does the head button. The crankcase is CMB design(CAM) with a slight change at the rear to allow for additional flow to the side transfers. This model has a cutaway style crank. The carb and flywheel are std CMB, but this new one does have a low speed needle. It does appear that they may have used the casting on the MAC drum housing, but they machined it differently and added a unique feature. The ramp for the drum is added to the housing instead of in the drum. Thats why it has a screw in the back, to retain the ramp piece in place. The earlier model drum and housing does fit for those that don't like the angled up style carb housing. I will try to attach some pics of the inside

Anybody know how to post the pics. My files will not load. It keeps telling me the file size is too large for even 1 picture???? Be glad to e-mail pics to anyone interested.

 

[CMBrunner]

I just received a new CMB 45 from Tidewater. After all the discussion here, I was hoping they had not copied the MAC. I tore it down immediately and heres what I found. The bore/stroke/ and rod length are the std CMB numbers. The piston and cylinder appears to be the same as the 45 RS, as does the head button. The crankcase is CMB design(CAM) with a slight change at the rear to allow for additional flow to the side transfers. This model has a cutaway style crank. The carb and flywheel are std CMB, but this new one does have a low speed needle. It does appear that they may have used the casting on the MAC drum housing, but they machined it differently and added a unique feature. The ramp for the drum is added to the housing instead of in the drum. Thats why it has a screw in the back, to retain the ramp piece in place. The earlier model drum and housing does fit for those that don't like the angled up style carb housing. I will try to attach some pics of the inside

Anybody know how to post the pics. My files will not load. It keeps telling me the file size is too large for even 1 picture???? Be glad to e-mail pics to anyone interested.

NO-NO-NO.....don't do it Bob....

"somebody" might try and copy it !!!!

 

[oldlugs]

I just received a new CMB 45 from Tidewater....Anybody know how to post the pics....It keeps telling me the file size is too large for even 1 picture???? Be glad to e-mail pics to anyone interested.

I'd be happy to shrink the file size & post 'em up. email 'em to: [email protected]

Duane

 

[Dan_Cousin]

I just received a new CMB 45 from Tidewater....Anybody know how to post the pics....It keeps telling me the file size is too large for even 1 picture???? Be glad to e-mail pics to anyone interested.

I'd be happy to shrink the file size & post 'em up. email 'em to: [email protected]

Duane

Bob,

thanks for the informtive post.

What is the carb bore on the new engine? Did you measure the timings and head volume?

For shrinking pictures it is very easy once you install the free dowload from this site.

http://www.irfanview.com/

It lets you resize the pictures to something more manageable. i usually convert them to 800 x 600 resolution JPG file. Make copies of the pictures you want to resize or you may lose your originals.

if you go to the photo gallary and register there, you can dump the files there and the limit is much larger than trying to post pictures in messages.

Some pictures can be found at the top of this page.

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

 

[Anders_Martinelle]

Dan, the bore is going to be 11 and 12mm.

Anders

 

[Bob Finn]

Carb on this one measures .462. Way bigger than I would like to see it.

 

[Dan_Cousin]

Well that sounds MACish with the big dump valve carbs. Didn't the MAC 45 come with a .500" carb at one time?

I have known some folks that have run a 9B on the purple head cam with success. 9B is 0.470" I believe.

My old EVO45 had a 10mm (.393"). I changed that to a .433" and the engine seemed to like it.

 

[brandonclan]

hobby suppy has them for $377. RS is still $400.

the purple head hydro 2005 is $285!!!! Anyone looking for a good deal on a older but good 45 might take a look.

Where is this $285 hydro engine?? That's a good price for that engine!

Dan

 

[Don Ferrette]

hobby suppy has them for $377. RS is still $400.

the purple head hydro 2005 is $285!!!! Anyone looking for a good deal on a older but good 45 might take a look.

Where is this $285 hydro engine?? That's a good price for that engine!

Dan

http://www.hobbysupplies.com.au/CMB%20Engines.HTM

 

[brandonclan]

hobby suppy has them for $377. RS is still $400.

the purple head hydro 2005 is $285!!!! Anyone looking for a good deal on a older but good 45 might take a look.

Where is this $285 hydro engine?? That's a good price for that engine!

Dan

http://www.hobbysupplies.com.au/CMB%20Engines.HTM

Shipping across the pond will be high I bet!! Any idea how much and how long it would take to get one shipped to the states??

Dan

 

[Don Ferrette]

hobby suppy has them for $377. RS is still $400.

the purple head hydro 2005 is $285!!!! Anyone looking for a good deal on a older but good 45 might take a look.

Where is this $285 hydro engine?? That's a good price for that engine!

Dan

http://www.hobbysupplies.com.au/CMB%20Engines.HTM

Shipping across the pond will be high I bet!! Any idea how much and how long it would take to get one shipped to the states??

Dan

It's not as bad as you might think. Going out of Aussie land is alot better than going into as far as shipping. The last CMB's I ran came from there & I think shipping on 2 67's was under 40?

 

[Dan_Cousin]

there is a price list from a domestic dealer in the for sale group.

http://www.intlwaters.com/index.php?showtopic=14191

Not as good of a deal as the $285 cam45 but the $200 99 hydro 67 is a steal.

 

[jeff baham]

hey, then steal it and give it to me.

 

[Dan_Cousin]

hey, then steal it and give it to me.

Your dreams aren't even that good!!! :lol: :lol:

 

[Don Ferrette]

It does appear that they may have used the casting on the MAC drum housing, but they machined it differently and added a unique feature. The ramp for the drum is added to the housing instead of in the drum. Thats why it has a screw in the back, to retain the ramp piece in place.

Well I wouldn't really call it unique, that was one of the new parts I got to play "touchy feely" with when I stopped by Andy's place back in December that will be on the A/A Pro & the A cubed motors. Hmmm, interesting though how that suddenly appeared on the CMB's .... oh well no matter. Difference with Andy's set up is that his is part of a radically designed new drum housing, not an add on. I'd be scared to see what would be left of the motor if that screw comes loose sending the ramp or parts of it into the motor's internals. For all you guys who choose that CMB motor you might want to throw some red Locktite on that little bugger before you run it. Just a thought, I don't want to see anyone lose a motor like that. B)

 

[Piston1]

Don,

Which one gives you a better balanced rotor mass. The old style solid metal heavy slugged rotor or this new CMB style. With these ones here, the AA proto that you handled with your fingers and the new CMB it seems to me that you are trading balance for friction. Maybe we should slug them with ligther delrin and get rid of the stationary screwed on slug or etc. etc. This sounds like going back to the begining. Stationary slug whats that going to do to the flow, it will be interesting to see. What you think.

JOSE

 

[Don Ferrette]

Don,

Which one gives you a better balanced rotor mass. The old style solid metal heavy slugged rotor or this new CMB style. With these ones here, the AA proto that you handled with your fingers and the new CMB it seems to me that you are trading balance for friction. Maybe we should slug them with ligther delrin and get rid of the stationary screwed on slug or etc. etc. This sounds like going back to the begining. Stationary slug whats that going to do to the flow, it will be interesting to see. What you think.

JOSE

Well Jose' keep in mind that on the MAC's with the ramped drum the center bore of the drum was offset to aid in the balance, it is/was not a centered hole or bore. This new style (and since I saw this a while ago & well before CMB added it on I'm going to call it the A/A stationary ramp design ) alot will depend on the accuracy of the fixed or stationary ramp. If the ramp is perfectly centered in the bore how would it induce more drag if it's not touching the drum? Now that is something I would wonder about with the CMB add on as you & I both know to allow a screw or bolt to pass through a hole, that hole has to be a few thousandths larger than the bolt or screw itself. With that in mind you cannot have the tolerance as far as drum clearance goes you would get with a machined fit so that ramp will have to be made smaller to allow for the extra play in the required clearance for the bolt/screw. Now one would have to assume on a drum designed from the start (such as the A/A Pro and A3) to feature the stationary ramp it will allow for a more precise machined fit. I would have to believe you want that stationary ramp as close as absolutely possible to the drum walls for best results. Another thing I would have to wonder about & can only theorize is that does the induction angles coming from the carb need to be changed for maximum benefit of the stationary A/A style ramp? If it is an add on you cannot change the angle or maybe length of the passage since you're using an existing casting. I think if I had to choose I would prefer a housing designed from the start for the stationary ramp but that's just my thoughts. Will it make a difference? I guess I'll find out how well it works when my A/A Pro's arrive. B)

 

[dave roach]

I heard thur the grape vine that it's going to be some time before we see the new MAC's, problem in machining is what I heard. Any commeants on this Andy.

My .002 cents

 

[Duck899]

I heard thur the grape vine that it's going to be some time before we see the new MAC's, problem in machining is what I heard. Any commeants on this Andy.

My .002 cents

Finding a decent machine shop is always a problem.....then you have to find a good one that won't want your first born....material issues as well.....set-up fees for every part they touch, etc.....it all adds up to a pricy engine.

Good luck.....

 

[DaveMarles]

Don,

Which one gives you a better balanced rotor mass. The old style solid metal heavy slugged rotor or this new CMB style. With these ones here, the AA proto that you handled with your fingers and the new CMB it seems to me that you are trading balance for friction. Maybe we should slug them with ligther delrin and get rid of the stationary screwed on slug or etc. etc. This sounds like going back to the begining. Stationary slug whats that going to do to the flow, it will be interesting to see. What you think.

JOSE

Don, Jose has hit it on the button. With a Moki/Cyclon/CMB/AA type stationary ramp the gasflow through the drum is going to be disturbed except for a few degrees of induction opening. Also, unless the drum is balanced in some way that I can't see, he is right in pointing out that there may be extra friction because of the unbalanced drum. I never liked the metal slugged drum that was used recently in the Valvola/Mac 21 because I hated to hang all that weight on the end of the crankpin. I prefer to use the old drums with the offset induction hole and run them plain or with a delrin insert.

At the end of the day I'm sure Andy will have some good ideas which we can all copy if we feel like it because he is an ideas man, thats for sure. (not the only one though).

Dave