45 VAC teardown.

[Terry Keeley]

Hi Terry thanks for the info, are the irwin s pipes still available ??? If not what would be the next best pipe.

Thanks Kevin.

They're around, you just gotta dig for them, then cut 1/2 the deadband out and have it re-welded.

OPS 6280, AA 45, CMB AB 45, NR 45 are all good from what I've seen.

 

[eekern]

Ok, what you hiding in the drum intake.

My drum has only one crankpin hole drilled clean thru, a mod buy you???? Very clean for 2 gallons.PS. stop biting your finger nails.

That is the old style drum. The new one has no ramp, one crank pin hole and adjusted timing. stu claimed he picked up 3mph when he switched from what you see in Terry's to the new drum in his VAC 45.

 

[Anders_Martinelle]

Terry, how old are you???

I lost count after 5 runs

..........

Easy fix for the rubbing is to just take a pice of paper and make a gasket.

Don`t need to be fancy gasket material.

Anders

 

[Tim Kish]

Thought I'd update this old thread with a quick teardown report 2 years later.

I've got 93 runs on the motor, about the equivalent of 7+ gal. of fuel.

All looks good, started to get some increased end play in the front bearing so I changed them both. Also had 66 runs on the rod needles and found they had worn about 0.0001" (a tenth) and were dark so replaced them too. Interesting the crank pin hasn't worn at all that I can measure.

Piston fit is still good, there was some slight deto on the exhaust side, also on the head, cleaned them up easily with some 400 grit.

There was minor galling on the crank where it seals just before the front bearing, cleaned it off with 400 grit paper.

It's completely stock, head set at 0.012", 60% nitro with 12% oil (1/3rd castor).

I thought you were new to this Nitro thang.

 

[Terry Keeley]

Terry, how old are you???

I lost count after 5 runs

..........

Easy fix for the rubbing is to just take a pice of paper and make a gasket.

Don`t need to be fancy gasket material.

Anders

Lol! Just started keeping track of all my motors a few years back. Did I change bearings in that one? Check the head on that one?

Ya, I'm not a big fan of the o-ring, using RTV to keep the parts from galling but a paper gasket would be easier.

 

[Terry Keeley]

I thought you were new to this Nitro thang.

After that DD dilemma I was starting to wonder!

 

[andre holster]

Terry, you probably already know about this but
There is a new crank in the later engines that will improve the balance. The left one is an older balanced crank and the right one i the newer one. The is also an newer balanced drum without the aluminium ramp.








//André

 

[Terry Keeley]

Terry, you probably already know about this but

There is a new crank in the later engines that will improve the balance. The left one is an older balanced crank and the right one i the newer one. The is also an newer balanced drum without the aluminium ramp.

//André

Nope, didn't know they had a new crank. I know Stu was slugging the original but I haven't noticed it shaking bad, breaking plugs etc.

Forgot they changed the drum, any idea what timing numbers are on it? Mine opens at 29 ABDC and closes at 66 AT for a total of 217*, pretty standard.

https://www.intlwaters.com/gallery/albums/userpics/10068/2012_CMB_VAC_45.xls

 

[shoboat]

Terry,

Pretty sure the first drums were 30/65

And the new ones I believe are 25/62

Stu should have the numbers for sure.

Thanks,

Mark Sholund

 

[David Bryant]

Terry, you probably already know about this but

There is a new crank in the later engines that will improve the balance. The left one is an older balanced crank and the right one i the newer one. The is also an newer balanced drum without the aluminium ramp.

I have two CMB 45VAC engines. Both brand-new never-run. One appears to be the original release (Ver1). The other was purchased more recently and appears to be more updated (Ver2):

Older (Ver1)- the blue anodized water jacket/head assy has no machined groove along the side. Has original crank disc counter-weight design configuration (with letter "L" symbol stamped). Rod lower-end has two machined oil slots.

Newer (Ver2)- the blue anodized water jacket/head assy has two machined groove's along the side perimeter. Has updated crank disc counter-weight design configuration (no letter "L" symbol stamp). Rod lower-end has three machined oil slots.

Terry- how has stock carburetor performed for you? Have you modded in any way?

 

[Terry Keeley]

Terry, you probably already know about this but

There is a new crank in the later engines that will improve the balance. The left one is an older balanced crank and the right one i the newer one. The is also an newer balanced drum without the aluminium ramp.

I have two CMB 45VAC engines. Both brand-new never-run. One appears to be the original release (Ver1). The other was purchased more recently and appears to be more updated (Ver2):

Older (Ver1)- the blue anodized water jacket/head assy has no machined groove along the side. Has original crank disc counter-weight design configuration (with letter "L" symbol stamped). Rod lower-end has two machined oil slots.

Newer (Ver2)- the blue anodized water jacket/head assy has two machined groove's along the side perimeter. Has updated crank disc counter-weight design configuration (no letter "L" symbol stamp). Rod lower-end has three machined oil slots.

Terry- how has stock carburetor performed for you? Have you modded in any way?

Thanks for adding to the info, looks like they put the grooves in the water jacket to show it's a 2nd gen motor.

Carb is working great completely stock, and at 11mm it's just the right size. The low end works well, you can come down to a crawl, punch it and go. CMB's got a winner with this one.

BTW, starting to see a couple of the new "Beta" 21's running, including one in my buddy Olly's Seaducer, looks like another stout piece!

 

[David Bryant]

Terry, you probably already know about this but

There is a new crank in the later engines that will improve the balance. The left one is an older balanced crank and the right one i the newer one. The is also an newer balanced drum without the aluminium ramp.

I have two CMB 45VAC engines. Both brand-new never-run. One appears to be the original release (Ver1). The other was purchased more recently and appears to be more updated (Ver2):

Older (Ver1)- the blue anodized water jacket/head assy has no machined groove along the side. Has original crank disc counter-weight design configuration (with letter "L" symbol stamped). Rod lower-end has two machined oil slots.

Newer (Ver2)- the blue anodized water jacket/head assy has two machined groove's along the side perimeter. Has updated crank disc counter-weight design configuration (no letter "L" symbol stamp). Rod lower-end has three machined oil slots.

Terry- how has stock carburetor performed for you? Have you modded in any way?

looks like they put the grooves in the water jacket to show it's a 2nd gen motor

Carb is working great completely stock, and at 11mm it's just the right size. The low end works great, you can come down to a crawl, punch it and go. CMB's got a winner with this one

great, thanks!