Cracked valve spring retainer.....
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Originally Posted by fireball,Apr 8 2007, 12:08 AM
is it entirely possible u guys havent seen an ap2 retainer fail/crack in the f22c bcos the f22c only revs to 8000 ?! whereas the f20 goes to 9000?
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From: Miami, FL
Originally Posted by RED MX5,Apr 7 2007, 07:16 PM
Maybe this would be a good time to review the "retainer issues," and also take a look at the related issues. I'll take a preliminary shot at it, and Billman can correct any parts I get wrong. If you're not already familiar with all this and own an S2000 with an F20C, you should at least understand WHY some of the cars have had retainer problems. If you have an F22C then all you really need to know is that this doesn't happen with the F22C.
The retainers crack during a mechanical over rev. During the over rev, the valves float, meaning that they never fully close. This leaves slack in the valve train, and the result is that the rockers end up literally hammering the valves like a tiny forging machine. Of course if you hammer any assembly hard enough, the weakest part (and there will always be a weak spot) is eventually going to give. During a mechanical over rev this hammering takes place several thousand times a second, so it doesn't take very long to hammer out the retainers. The retainers are of softer metal, so they stretch and crack as the keepers are hammered down into the center hole. Actually, the hammering is stretching the hole in the retainer and the retainer is walking up the keepers, but it *looks like* the valves and keeper are falling down into the hole.
The scary part of all this is that you can over rev an F20C enough to hammer out the retainers and the engine will still run perfectly. The valve clearance doesn't even change, so there is no immediate "problem." However, as you continue to drive the car with the stretched/cracked retainers, the retainers will continue to stretch and crack, until the keepers pop out. When the keepers pop out the retainer no longer holds the valve spring in place, so you have parts bouncing around under the rocker/cam cover, but worse, the valve falls down into the cylinder and impacts the piston. I know Bill has seen this more than enough times to make a grown man cry.
So guys, this is a non issue unless you have a mechanical over rev. If you have an F22C and there is damage from the over rev, you will know it, because the car will not run correctly, but if you have an F20C, then even if the car runs perfectly, there is a chance of impending catastrophic failure.
Avoiding the problem is SIMPLE. Don't miss shifts, and if you do, and suspect a mechanical over rev, then have the retainers inspected, even if the F20C is running perfectly. You may or may not have damage, but if you catch it before the keepers pop out you'll save your engine.
I drive my car very hard, and even though it is likely that I'll know if I over rev the engine, but spit happens, and it's quite possible to have a mechanical over rev without realizing it, especially when you're focusing on getting around an autocross course as quickly as possible, so we inspect my retainers at every oil change. This is NOT NECESSARY unless you have some reason to suspect that you may have had a mechanical over rev. OTOH, it only takes a few minutes, and I feel good knowing that I"ve looked at the things and that they look right.
Bill or anyone else ... please correct any of this that I've gotten wrong.
The retainers crack during a mechanical over rev. During the over rev, the valves float, meaning that they never fully close. This leaves slack in the valve train, and the result is that the rockers end up literally hammering the valves like a tiny forging machine. Of course if you hammer any assembly hard enough, the weakest part (and there will always be a weak spot) is eventually going to give. During a mechanical over rev this hammering takes place several thousand times a second, so it doesn't take very long to hammer out the retainers. The retainers are of softer metal, so they stretch and crack as the keepers are hammered down into the center hole. Actually, the hammering is stretching the hole in the retainer and the retainer is walking up the keepers, but it *looks like* the valves and keeper are falling down into the hole.
The scary part of all this is that you can over rev an F20C enough to hammer out the retainers and the engine will still run perfectly. The valve clearance doesn't even change, so there is no immediate "problem." However, as you continue to drive the car with the stretched/cracked retainers, the retainers will continue to stretch and crack, until the keepers pop out. When the keepers pop out the retainer no longer holds the valve spring in place, so you have parts bouncing around under the rocker/cam cover, but worse, the valve falls down into the cylinder and impacts the piston. I know Bill has seen this more than enough times to make a grown man cry.
So guys, this is a non issue unless you have a mechanical over rev. If you have an F22C and there is damage from the over rev, you will know it, because the car will not run correctly, but if you have an F20C, then even if the car runs perfectly, there is a chance of impending catastrophic failure.
Avoiding the problem is SIMPLE. Don't miss shifts, and if you do, and suspect a mechanical over rev, then have the retainers inspected, even if the F20C is running perfectly. You may or may not have damage, but if you catch it before the keepers pop out you'll save your engine.
I drive my car very hard, and even though it is likely that I'll know if I over rev the engine, but spit happens, and it's quite possible to have a mechanical over rev without realizing it, especially when you're focusing on getting around an autocross course as quickly as possible, so we inspect my retainers at every oil change. This is NOT NECESSARY unless you have some reason to suspect that you may have had a mechanical over rev. OTOH, it only takes a few minutes, and I feel good knowing that I"ve looked at the things and that they look right.
Bill or anyone else ... please correct any of this that I've gotten wrong.
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With this thread being the truth, the whole truth and nothing but the truth, so help us Billman 
(How's your sense of humor.. btw? 
) I guess its time to link this thread to the FAQ on top of UTH.
In this thread are the pictures of what to look for when checking your retainers, the difference between F20 and F22 retainers with part # and very usefull comments.
If this doesn't "belong" in the FAQ then nothing will IMO.
(How's your sense of humor.. btw? ) I guess its time to link this thread to the FAQ on top of UTH.In this thread are the pictures of what to look for when checking your retainers, the difference between F20 and F22 retainers with part # and very usefull comments.
If this doesn't "belong" in the FAQ then nothing will IMO.
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I'll just add this little tidbit.....it is unknown if the F22 can suffer a broken retainer and show no symptoms. It is not known that the fracture rate is beyond that which bends valves. In my opinion, F22 owners have nothing to worry about. It will be interesting when an F22 owner running an F20 ecu hits the money shift 
It is my theory that a catostrophic mis shift in an AP2 (say 5th to 2nd at redline ) will bend valves before it splits retainers.
-Replacing retainers does NOT require head removal. It can be done (if you've done it before) in two hours.
I'd allow 3-5 hrs for the average joe with decent mechanical ability. If you are not good with a wrench, I would definitely not recommend this as a DIY.
I'm going to try my hardest to split my retainers this weekend at the dragon, sans a money shift
It is my theory that a catostrophic mis shift in an AP2 (say 5th to 2nd at redline
) will bend valves before it splits retainers.-Replacing retainers does NOT require head removal. It can be done (if you've done it before) in two hours.
I'd allow 3-5 hrs for the average joe with decent mechanical ability. If you are not good with a wrench, I would definitely not recommend this as a DIY.
I'm going to try my hardest to split my retainers this weekend at the dragon, sans a money shift
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From: Dry Branch
Originally Posted by Billman250,Apr 8 2007, 05:41 AM
In part, yes. We've already had this discussion over a year ago.
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No. The speed of the CDV is not fast enough to affect mis-shifts.
I believe the CDV was not designed to protect the driveline. I believe it is needed to allow the extra time it takes for the heavy flywheel to decel.
Here's my AP2/F22 rant:
Since so many people can't drive, Honda had to make the s2k more reliable.
Step one: lower the redline to 8k, so in the event of a mis-shift, the engine would suffer no damage. It now has 1000 rpm more insurance.
Beef up the retainers to a point beyond valve float
step two: Add .2 liters to the engine, to make up for the loss in power.
step 3: Add a heavy flywheel, to fill the gap in the narrow, lame-ass powerband. I've put lightweight flywheels in the AP2. If you don't rev to 8100, and shift as fast as possible, it will fall out of VTEC every time.
Step 4: add the CDV, to give the heavy flywheel a fraction more time to decel, to prevent clutch slippage. How many posts have you seen where the CDV was removed, only to make the problem worse?
[/RANT]
I believe the CDV was not designed to protect the driveline. I believe it is needed to allow the extra time it takes for the heavy flywheel to decel.
Here's my AP2/F22 rant:
Since so many people can't drive, Honda had to make the s2k more reliable.
Step one: lower the redline to 8k, so in the event of a mis-shift, the engine would suffer no damage. It now has 1000 rpm more insurance.
Beef up the retainers to a point beyond valve float
step two: Add .2 liters to the engine, to make up for the loss in power.
step 3: Add a heavy flywheel, to fill the gap in the narrow, lame-ass powerband. I've put lightweight flywheels in the AP2. If you don't rev to 8100, and shift as fast as possible, it will fall out of VTEC every time.
Step 4: add the CDV, to give the heavy flywheel a fraction more time to decel, to prevent clutch slippage. How many posts have you seen where the CDV was removed, only to make the problem worse?
[/RANT]
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From: Dry Branch
Originally Posted by Billman250,Apr 8 2007, 03:35 PM
No. The speed of the CDV is not fast enough to affect mis-shifts.
I believe the CDV was not designed to protect the driveline. I believe it is needed to allow the extra time it takes for the heavy flywheel to decel.
Here's my AP2/F22 rant:
Since so many people can't drive, Honda had to make the s2k more reliable.
Step one: lower the redline to 8k, so in the event of a mis-shift, the engine would suffer no damage. It now has 1000 rpm more insurance.
Beef up the retainers to a point beyond valve float
step two: Add .2 liters to the engine, to make up for the loss in power.
step 3: Add a heavy flywheel, to fill the gap in the narrow, lame-ass powerband. I've put lightweight flywheels in the AP2. If you don't rev to 8100, and shift as fast as possible, it will fall out of VTEC every time.
Step 4: add the CDV, to give the heavy flywheel a fraction more time to decel, to prevent clutch slippage. How many posts have you seen where the CDV was removed, only to make the problem worse?
[/RANT]
I believe the CDV was not designed to protect the driveline. I believe it is needed to allow the extra time it takes for the heavy flywheel to decel.
Here's my AP2/F22 rant:
Since so many people can't drive, Honda had to make the s2k more reliable.
Step one: lower the redline to 8k, so in the event of a mis-shift, the engine would suffer no damage. It now has 1000 rpm more insurance.
Beef up the retainers to a point beyond valve float
step two: Add .2 liters to the engine, to make up for the loss in power.
step 3: Add a heavy flywheel, to fill the gap in the narrow, lame-ass powerband. I've put lightweight flywheels in the AP2. If you don't rev to 8100, and shift as fast as possible, it will fall out of VTEC every time.
Step 4: add the CDV, to give the heavy flywheel a fraction more time to decel, to prevent clutch slippage. How many posts have you seen where the CDV was removed, only to make the problem worse?
[/RANT]
Let's not forget slower steering and suspension revisions. In all fairness, these changes reflect what might be termed "customer demand," and in that light, they're all improvvements. They make the car easier to drive fast, more tolerant of driver error, and so on; They are intended to make the car appeal to a wider market segment.
I hate it when people short change the AP1 and/or F20C, and I try not to short change the AP2 and/or F22C. To me it seems entirely appropriate for more people to prefer the later cars, because the later cars have been changed in ways that were intended to appeal to a wider audiance.
And THAT ^^^ is why it doesn't make sense to argue that one is "better" than the other. The better car is the one that was targeted at the owners market niche. IMHO, they both hit their target market equally well.
Good luck cracking those retainers without a money shift.
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From: Miami, FL
So would you leave the CDV in your AP2?
I've got the toda flywheel with a stock clutch disc and ACT pressure plate and I can stay in VTEC without effort in all shifts except the 1st to 2nd, that one takes a seriously fast shift.
I never tried the upgraded clutch setup with the CDV though, I removed that while I was still stock. I noticed a big differance stock, not sure how much I would notice it with the upgraded stuff.
I do find your CDV reasoning interesting. I'd never heard any theories other than to protect the diff. I wish Honda would just post these things somewhere, lol.
I've got the toda flywheel with a stock clutch disc and ACT pressure plate and I can stay in VTEC without effort in all shifts except the 1st to 2nd, that one takes a seriously fast shift.
I never tried the upgraded clutch setup with the CDV though, I removed that while I was still stock. I noticed a big differance stock, not sure how much I would notice it with the upgraded stuff.
I do find your CDV reasoning interesting. I'd never heard any theories other than to protect the diff. I wish Honda would just post these things somewhere, lol.