cNw Specialized Machining Services

Turn Crank Journals

Service description:  Turn and polish crank journals


  • Precision turned with state of the art equipment to proper Commando specs.
  • Polish journal
  • – .010, – .020 and – .030 available
  • We can also supply new rod shells to fit.

cNw part # 1205-10

Price $ 170.00

Note: The above price assumes that the crank is separated. If it needs to be taken apart and reassembled see additional charges below.

Additional services:

  • Remove rods $ 21.50
  • Disassemble crank $ 43.00
  • Clean & prep before turn $ 21.50
  • New, complete crank hardware $ TBD
  • Assemble crank $ 43.00
  • New rod shells 79.00 set (quality US made)

We do not offer rod re-assembly at this time


Barrel & Lifter Service

Service description:  Precision bore, hone and finish barrel


  • Barrel is pressure washed
  • Barrel is put through a heat cycle to stabilize
  • Bores are checked for parallel and corrected if necessary
  • Precision bore to size
  • Final hone to finish
  • Barrel top surface is decked
  • Ceramic coating applied. High gloss Black
  • All top mounting threads are cleaned and chased

cNw part # 1205-03

Price $ 385.00

Notes:  850 cc barrel can be bored to + 20, + 40 and + 60 over. 750 cc barrel can be bored to + 20 and + 40 over. We do not recommend to bore a 750 barrel to + 60 over since there isn’t enough material for the base nuts to hold the barrel securely to the cases

Additional Parts and Services:

  • Remove lifters from barrel $ 21.50 set
  • Clean & prep barrel $ 21.50
  • Re-assemble lifters in barrel when done $ 43.00 set
  • Std, quality aftermarket pistons $ 134.50 set
  • Total Seal, gap less 2nd, ring set 114.95 set
  • Custom made, Forged pistons $ contact us
  • Custom made Total Seal for Forged Pistons $ 134.95 set
  • Surface lifters Flat $ 85.00 set
  • Surface lifters, Radius $ 160.00 set
  • Install sleeve in 850 cc barrel $ contact us  (We can not install a sleeve in a 750 cc barrel)

Custom Camshaft

Service description: Build a new cam based on your cam core


  • Grind down lobes and re-hardweld new material then cut to specification
  • This service is done by Web Cam. One of the leaders in the industry specializing in cam grinds
  • We offer a couple of different grinds to suit your requirements
  • We do the work on a customer supplied cam, so you get your cam back. No exchanges
  • The bushing journals do not get redone, so it's important that they are undamaged and in spec on the core cam
  • Turnaround is 4-6 weeks

cNw part #

Price $ 447.00

Surface Lifters

Service description: Surface your lifters


  • In house service done on our Brown & Sharpe surface grinder
  • Perfect stone ground finish
  • We do the work on customer supplied lifters, so you get your lifters back. No exchanges
  • We do not clean or machine any damage or wear on the lifter bodies, only the top
  • We can only cut to a certain depth in order for the top plate to retain adhesion to the lifter body. So if there is deeper damage, this may not clean up
  • Turnaround time is 2 days

cNw part #

Price $ 85.00 per set of 4

cNw Breather Modification

Development:  Comstock Engineering

Manufacturer: cNw

Description:  We are very excited about offering the most efficient breather modification for Commandos on the market. This kit is developed and designed for maximum performance. We have operated this through a variety of circumstances and rpm ranges and how found it to actually pull a vacuum in the crankcases up to about 4000 rpm. From there to red line it’s virtually running at 0 pressure. The benefits are many and the idea of reducing the excessive pressure in the crankcases that, due to the parallel twin design, will free up the engine and actually create some horse power. It will also virtually eliminate any and all leaks associated with the pressure in the cases. You will notice this where there is a gasket, seal or a material joint. Because of additional modifications that we do in the timing side case to further increase the performance of the breather we are also lowering the operating temperature of the engine oil.

In order to install this kit the engine needs to be completely stripped down as we mill a mounting surface on the lower backside of the drive side case half. We also modify the timing case half.

The above mentioned results are of course directly related to how the engine is built as piston clearance, cylinder bore, piston ring quality, head work, gasket quality and much more will all play a part in how well the engine breather will operate and what kind of results you will experience.

  • Experience an increase in engine performance
  • Eliminate persistent leaks at gaskets, seals, tach drives, head, crank case joints and more
  • Lower the operating temperature of the engine oil
  • The valve can operate consistently during a far higher rpm range than the Commando engine can ever reach
  • The valve is not affected by oil contamination and can perform even if submerged
  • The valve will actually aid in returning the crankcase oil back to the oil tank in case the engine has wet sumped
  • The valve housing is CNC machined out of high quality billet aluminum
  • The valve has an indefinite service life and will not have to be replaced
  • Turnaround on this service is 7 days
cNw part #0500-08

Price $ 265.00

This includes:

  • Milling the drive side case half
  • Modifying the timing side case half
  • Breather components
  • All parts necessary to install the breather valve

Special order – Please contact us for information  (not available through online ordering)

Note:  If you have a 1972 engine case, you do not need the machining done. You can install our bolt up version of the valve available for puschase in the parts catalog in the Engine category


Copyright © 2013-2020 Colorado Norton Works. All Rights Reserved.