Insert

I am looking for one Mitsubishi CCMH060204MD220 insert I have searched the internet and not found one. It is for machining high silicon content aluminium Pistons for my 2.5cc tether car engines. I have machined up 8 blanks ready for final machining to size to fit the liners.

Try just searching for CCMT 060204

Bob

Doesn't the H signify the holder uses a different screw to CCMT and CCGT? might get away with it, might crack the insert.

Its probably a bit of a special insert or at least coating to deal with the high silicon content maybe crystaline diamond coated as I have read of another high performance model engine builder who uses that coating to machine his 30% silicon alloy pistons

Edited By JasonB on 01/01/2016 20:34:05

"Doesn't the H signify the holder uses a different screw to CCMT and CCGT? might get away with it, might crack the insert."

yes, looks like a different countersink, not that I really know much about inserts but I use this guide to de-code the codes: **LINK**

PCD insert

Emgee

It is a PCD insert these have a diamond coating on them that allows you to take very small cuts less than a thou, standard inserts for cutting aluminium won't take the small cuts you end up putting on two or three cuts and it finally cuts and the piston is undersize and scrap. If I cannot find an insert I will end up lapping them which will do the job but you loose some performance. Just a bit of background the engines are 2.5cc and typically run around 40,000rpm the Pistons don't last long before they loose the nip. The liners are brass hard chrome plated and tapered so at the top of the stroke the piston is an interference fit the nip.

What about buying another make of PCD insert that you can get and a holder to suit. You could ask the guy that I mentioned he builds similar performance engines for hydros.

7.2HP from 0.90cu.in (15cc)

Jason I have read about his engine I will contact him to see what he uses, I don't really understand inserts and was given the part number of the one he uses, they are not cheap around £100 each. I don't have an engineering background my father was a clockmaker and always had access to machinery my passion is fast models currently tether cars I hold the British records for the 3.5cc class and the 10cc class this car has done just over 200mph actual speed. Working on the 2.5cc record now got within 1 mph building a new car for this season three engines to rebuild hence the piston project.

Go to APT site, they sell them £20

KWIL thanks one on its way a useful supplier will be using them again