CMB .21 Green vs. Red Head

[waterbug]

Can someone fill me in on these two "Inboard" engines...?? Have a chance at one of each... Please !!!! Any help will be helpfull and appreciated......... :unsure:

 

[Scott Schneider]

Have HAD 2 of each version.

Basicly the same engine with a few minor differances.

The Green head has a slightly smalled bore and longer stroke, Both use same rod.

The red heads used a 14 mm crank and a $$ bearing because of the odd size.

The green heads use a 13mm crank and the same bearing most of the other 13mm italian engines use.

Basic crankcase layout on the Red heads had a full lenth divider to seperate the transfer ports on either side, The Green head case is opened up and only has the divider on the top 1/4 of the transfer passage.

In a nutshell ** The Red heads will rev like hell !! but are pretty weak in the torque department, The Green heads have more torque but down on RPM a tad.

** But the Green Heads do make more power and are the better engine.

Lastly, ALL the Red Heads came with Con rods only bushed on the big end and will not last very long. Early production Green heads were the same, Latter and current Green heads have better rod bushed on both ends.

Hope this helps. Scott

BTW. I sold ALL of them and now run MAC 21's ~~ A Far Far quicker engine !!

If I were you ? The Green head It's current and you can get P/L sets, The reds are obsolete and parts avaliblity ???

The green heads are a really good engine and run really well with the right pipe combo.

 

[Terry Flynn]

Are you looking at the engines on eBay with a seller buy the name of NAMBA 1203

if so you might want to go to page 5 and look and my posting

(unfair trading SG 21) just thought that I'd let you know about this person.

 

[waterbug]

Thanks Scott

I agree on the Mac........and thanks for the advise......!!!

Terry

Thank You Very Very Much !!!!!!!!!! Because I sure was !!........ looking for two .21's to go on a Micro Burst and SpeedMaster for me and the [Wife/Daghter = {SAMETHING}.]......#$%^%^$ :lol: :lol: