CMB 67 Engine Analysis Measurements

[Marty Davis]

I am interested in getting the Engine Analysis Measurements for a stock 67 CMB Engine. I am designing a pipe for that engine and don't have the specs. I want to design the pipe for the stock specs so I don't want modified engine measurements.

I would also be interested in the 45 CMB and Nova Rossi DD measurements as I will be designing pipes for those also.

 

[Joe Wiebelhaus]

Hold on, I'll send them to you asap.

 

[Ray Sametz]

I have them for the CMB 45 vac if you don't get them from Joe.

 

[Terry Keeley]

https://www.intlwaters.com/gallery/albums/userpics/10068/2006_CMB_RS_21.xls

https://www.intlwaters.com/gallery/albums/userpics/10068/2005_CMB_67_HR.xls

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

https://www.intlwaters.com/gallery/albums/userpics/10068/2012_CMB_VAC_91.xls

 

[Marty Davis]

I also need the diameter of the case exhaust stub on those engines if you have them.

Thanks to all who provided info, but the case stub ID is very important. Anyone have them or can measure?

Not sure if we will make the pipes to attach directly to the stub or have the pipe slip over the header, SO I need the OD & ID of the CMB Headers for these pipes (21, 45, 67, 91, 101)

Thanks in advance.....

 

[John Beardslee]

Hi Marty,

I've got the NR.46DD specs, I'll e-mail them to you.

John

 

[Joe Wiebelhaus]

Marty,

ID is .70 OD is .870

piston face to end of stub is 1.12

 

[Marty Davis]

Marty,

ID is .70 OD is .870

piston face to end of stub is 1.12

Joe:

What engine is this for? Do you have the other items that I asked about?

Not sure if we will make the pipes to attach directly to the stub or have the pipe slip over the header, SO I need the OD & ID of the CMB Headers for these pipes (21, 45, 67, 91, 101) as well as the stub id measurement.

 

[Joe Wiebelhaus]

Marty,

ID is .70 OD is .870

piston face to end of stub is 1.12

Joe:

What engine is this for? Do you have the other items that I asked about?

Not sure if we will make the pipes to attach directly to the stub or have the pipe slip over the header, SO I need the OD & ID of the CMB Headers for these pipes (21, 45, 67, 91, 101) as well as the stub id measurement.

CMB 67 Greenhead exhaust stub on the engine, Header ID is .695 - OD is .780

CMB 91 VAC Header ID is .790 OD .875

Your original post Subject is CMB 67 , I assumed Greenhead.

 

[Marty Davis]

OK, I have the timing numbers for the 21VAC, 45VAC, 67VAC, 91VAC. Would like the timing numbers for the 101VAC

What I need for each of the above is:

Stub ID & OD

Header ID & OD

Length from Piston to End of Crankcase Exhaust Stub

I am not sure if we will make the pipes so that they attach directly to the Exhaust Stub or make them Slip Over the Stock Header. It depends on the temps and whether the Carbon has a problem with the temps coupled directly to the stub.

Thanks for all the help with this, I hope that it makes available some new pipes for our engines that perform well. My idea is to design the pipes for stock timing to apply to more people. Most people are running their engines in stock form so this makes more sense for someone selling pipes rather than design pipes for various MODIFIED timing.

This will be a fairly long process to get in production but the above info is critical to the design.

 

[Stephan Peterson]

Marty over the past I have seen a lot of variation on the .67 cmb green head, stock piston and sleeve from 180,184,186,190 exhaust and 124,128,130 on transfer and boost. These measurements are taken with a digital depth gauge and are very accurate.