Here's my 2.2 theory...

The new engine design, along with the redesigned retainers and lower redline, was designed to withstand an over-rev of say 1200 rpm. Basically, to make the car more reliable and cut down engine problems/claims. If you're at 8k, and bang a wrong gear, you may hit 9k. No big deal, we already know the 2.2 can hit 9k intermittent all day long.

The small margin for intake retainer cracking in the car and showing no symptoms, which lies between intake valve float and exhaust valve float/bending, was eliminated with the new retainers. I'm sure it's possible for the new ones to split, but I think it may be beyond the point of exhaust valve float, which are always the first to bend.

The .2 was added to the engine to make up the loss in power between 8k and 9k.

I'm pretty confident this will never be an issue on an AP2.

 

Meaning because the engine will just grenade on an overrev past 9K rather than silently surviving it for a while? That extra 1200 rpm you are guestimating means close to zero margin for an F20C.

Obviously I don't know for sure, but on a high revving engine like an F20C I would be really cautious about adding weight to the moving bits without some sort of word from the Honda engineers saying it was OK.

 

Thanks Bill, that makes sense. However, I feel the say way Mike does; I'd upgrade to the new retainers IF Honda approves it, but I'm afraid that even a small amount of mass (too little to feel when holding the parts) might not be an advantage with the F20C. If I'm going to err I'd rather err on the side of caution.

 

I don't think Bill means 1,200 rpms for an F20C from 8k rpm's. The margin for an F20C would be 1,200 rpm's from 9k rpm's, which equal's 10,200 rpm's.

The only way to make a calculated hypothesis would be to weigh the MY04 and the pre MY04 retainers on a scale. At this point in time, I would say the very worst case scenario would be a slightly less efficient valve train due to the extra weight...if any. I would think that the extra weight of the MY04 retainer's...if any, would have a lesser effect than a stiffer valve spring.

After looking at the part #'s on Majestic's website, the MY04's and the pre MY04's have different part #'s for the valve springs. The retainer's on the MY04's are obviously mated to the MY04's valve spring's. What are the stipulations of using both the retainer's and spring's from a MY04 on an F20C?

Not that I want to do so, just curious

 

Forgive my ignorance, but does this mean that an over-rev would show symptoms all the time on a 2.2? I'm curious as I know that is a well disputed issue on the 2.0L F20C as to how long a car can go showing no symptoms of an over-rev. If so I'd say this is a big benefit.

 

Not really. The "symptoms" are pretty catastrophic and costly. You would rather *not* have it "show symptoms" as long as you caught the quiet damage in time.

 

Thats true I didn't think about it that way. But is my understanding correct, is he saying that a 2.2L would not limp along showing no symptoms with a cracked retainer, but rather just blow up? That being so if you had an over-rev that caused damage you'd know instantly? Just curious as it would be good information to spread around as it might keep a few less "did I do any damage" threads from starting (at least from ap2 owners).

 

the reason I used a straight edge Billman was to see if the middle of the retainer recessed and was no longer flush againsted the straight edge... worked on some of the other retainers i've dealt with.

 

[QUOTE=RACER,Jul 16 2006, 08:49 PM]
The only way to make a calculated hypothesis would be to weigh the MY04 and the pre MY04 retainers on a scale.

 

I accidently posted the previous post twice so I just put this here, having a bad day with the computer at work.