Greenlight

I just disassembled my head and found 6 of 16 valve spring retainers cracked/split. Has anyone else experienced this problem? Some were on intake valves and some were on exhaust valves. Is there a fix? I'll likely replace them with titanium retainers (and valves), but I think that there is a potential problem that Honda needs to address. My engine has ~ 18k miles, with ~5% of that I'd consider hard miles.

I'll will flow the head in the next couple of days and I'll publish the numbers on this site. I want to compare flow numbers at 10", 25", and 36" of water. I know that there is another group conducting air flow testing at 10" of water. I will see how the numbers compare.

gregstevens

Cracked valve retainers are a sign of a downshift over-rev. Did you ever miss a downshift and rev the engine off the tach?

As for replacements with Ti parts, I can't help you there. I don't know of any out there, but there may be. Perhaps someone out there knows where to source them at.

Wesmaster

Yep.

I have not heard of anyone having this type of problem without mis-shifting.

1Randyc

I think ProFlow has the Titanium retainers for S2000 application.
I either saw it on the magazine or on-line.

You may want to contact Proflow.

Wesmaster

S2000 Titanium Retainers - http://www.alaniztechnologies.com/parts.html

S2KYSK

I had one of my valve retainer crack as well with bent valves... Than again, my car had noisy valve traines from the beginning, way before had bent valves
If it's just retainers, I would think it be due to material fatigue. Our engines do rev. pretty high.

Wesmaster

Did you buy it new?

S2KYSK

Yeh, brand new with 17 miles on it. Took my car into get it checked out and service rep. told me that v-tec is noisy like that and end of story. I didn't feel comfortable with his explaination and I did compare to other members car prior and it was definitely louder so had him document my complaint. Good thing I did. My car is getting fixed under "good will" warrenty repair. It's been in the shop for over a month now.

Greenlight

Thanks for all the good information. I realize that the retainers experience the highest stresses during mis-shifts, high speed downshifts, revving in neutral, etc. because that's when the acceleration of the valve/retainer should be the highest (remember F=ma, for a given mass, the highest force occurs when the acceleration is highest). I'm also confident that Honda engineers too this into account in the design.

What concerns me is either fatigue failure, due to the continuing alternating loads, or residual stresses induced during the manufacturing process that are not "stress relieved" after manufacturing, or dimensional discrepancies between the retainer, the locks, and the valve causing a poor fit and increasing the stresses, or excessive valve "float" causing higher than expected acceleration of the valve train.

In my opinion Honda likely compensated for the mis-shifts, etc. but assumed the supplier of the retainer has/had the process under control when it comes the residual stresses, dimensional stability, etc..

My engine was built in December 2000 and perhaps there was a "bad batch" of retainers.

Who knows!!!!!!!!

I just want s2k owners to be aware of the problem and use this information to "battle" the dealer/factory rep. if they have problems.

00BLACKS2K

Greenlight,

Looking forward to the results of your flow testing at the higher pressure drops. Keep us posted!