mxt_77

Nope, I was using the Toda valve springs.

allenheathdj

I wonder if the SPEC A, now version 3's are better.

mxt_77

I didn't realize that there was a v3 of the Spec A's available. Where did you hear that, and do you have any additional details?

allenheathdj

I'm joking.... third times a charm for toda.

allenheathdj

they re-did the spec A cam 3 times....spec A v1, spec A v.2 and now they have the spec A V.2 with different material

mxt_77

I see. Yeah, the mfg process may be different, but AFAIK the spec itself didn't change. From the v1 to the v2, they actually changed the spec of the high cam to produce more power.

allenheathdj

Well MXT_77 congrads on the new cams....I'm jealous because I have the old V2's.

BenR

What were your running in procedures?
Sorry if you mentioned it before but there is ALOT to read through.

The failure on the nose leads to simple fact that an inccorect running in procedure where no enough rpm was used for long enough and the material wasnt allowed to work harden. The highest loadings on teh cam at idle are on the nose.

With a roller follower setup its even more important since work hardening takes more time and no hydrodynamic wedge is able to form to protect the nose of the cam.

The VTEC lobe probably wasnt damaged since the loadings at idle are very small in comparison, and when its activated at high rpm the majority of the forces are on the BCD.

marcucci

Only unhardened cams need to be "work hardened" which is not the kind of cam you want in any engine you want to last. Even Delta who specializes in regrinds induction hardens their cams. I am quite certain based on the hardness test results that the Todas were hardened at their factory.

The engine was run at idle until the engine started to warm, then run at 2000-3000 RPM for about 20 minutes.

mxt_77

Not sure what the run-in procedures were. In fact, I wasn't aware that billet cams like these required any special run-in procedure. When I picked the car up (after the initial install), I drove it straight from marcucci's shop to my house (about 50-60 miles) at freeway speeds, so if there was any break-in necessary, that should've done it. The cams didn't fail until 2000 miles later.

Can you explain what a "hydrodynamic wedge" is? I'm not a physics major, so I've never heard that term before.

Edit: I've got to start typing my replies faster.