I have read a few bad things about the Combination Motorsports CM612 springs and retainers. I know these are the springs that Lloyd uses on his LE1 heads so I figure they cant really be that bad.

What is the truth on the CM612 springs and retainers.

 

I ran 'em for 15k miles, no problems with my cc503. I upgraded to 918's since they came w/ my LE2's.

 

JMHO---but when I am considering going with a particular part, I generally pick the one that has proven integrity. Tentively deciding on a particular part or brand and then trying to find supporters of the choice to counter a negative opinion is a waste of time.

For every part you can think of, there are going to be those for and against.
When it comes to springs, going with a brand name made of quality materials---one that has been used successsfully by the majority without problems AND one that meets the needs and requirements of the job and is installed correctly is the way to go.

 

I was going to ask a similar question. By the way, I can't even find the CM612 springs on cmotorsports webpage? Anyone know where to buy them? I'm looking to use them with the GM845 cam.

Dan

 

I never saw them either.

 

Ya could get titanium retainers and then there would be NO doubt.

 

I thought they took the 612's out thier line, because of the problems people had with them.

 

The CM612 or EX-612KCM valve springs are great springs, but like everthing else they have there limits. I would suggest using them for mild to medium camshafts. Beyond that you should machine the heads and install the "correct" springs for your application. I you do not want to machine the heads the 26918-16 Beehive springs will accomodate some of the larger cams. You can still purchase the 612 springs from NRP.


Sam

 

I ran them for @ 15k on my cc306. Spun the rod bearings. Rebuilt. Used them again on my gm847 for @ 5k.

Great springs. Set them up right and keep an eye on them. Although something beefier will be safer.

 

When set up properly within specs a spring might get tired and float but it should NOT break in halve.