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How critical is valve retainer replacement AP1

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How critical is valve retainer replacement AP1

Old 02-03-2019, 01:26 PM
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Cracked retainers are not related to mileage. The issue is caused by, and evidence of, a mechanical over rev. It can happen in the first mile, or after 300K miles. It won't happen unless you money shift the car, no matter the mileage. My feeling is that unless you are the original owner and you know there has not been a mechanical over rev, you should inspect the retainers when you buy the car, and maybe check valve clearances while you have the cover off just for the heck of it.

If you don't money shift, the original retainers will go forever.
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Old 02-03-2019, 05:52 PM
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When I owned my AP1, every year I pulled the valve cover, adjusted the valves, and inspected for sunken valve retainers. I had the kit to change to AP2 Intake retainers, but never used, didn't need to- why bother going thru the process if everything is fine? There are several threads showing cracked retainers from the top side so you'll know what to look for. Parts for the intake retainer and proper keepers ran just over $70 USD. Retainers are not a maintenance item and their replacement can be problematic if you're ham fisted. Just because you run OEM AP1 retainers and keepers does not mean your engine is at risk. As mentioned above, ONLY if you have a mechanic over rev will you be at risk.

What would have concerned me more is whether I had the 4 hole oil squirter banjo bolts running the supercharger. Mid 2002 Honda changed from 2 to 4 hole. Replacement can be tenuous and people have made a hash of it over the years.

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HarryD (02-07-2019)
Old 02-03-2019, 06:40 PM
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Risk assessment:
Probability - Low
Impact - High

They ONLY become problematic IF you overrev your engine by downshifting when you shouldn't have. Legend has it that the most experienced S2000 mechanic on this board still runs AP1 retainers with over 100k on the clock. How much is peace of mind worth to you and how hard do you drive? My assessment is if it's a track car or you can't stay out of 8000+ RPMs, it may be worth it for peace of mind. If you drive on the street and aren't at high risk of a mechanical overrev, why spend to change them? You're unlikely to experience the issue but it can cost you an engine.
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Old 02-04-2019, 06:34 AM
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I often say to be careful that your efforts to prevent an issue, don't inadvertently cause it.

You need to understand that if this procedure isn't done correctly, it will destroy your motor. There are risks it will go wrong, even if you bring it to a shop. Its just like there are risks to your life from even the most routine surgery.

Its possible your efforts to prevent a dropped valve destroying your motor will cause a problem that will destroy your motor (if the work isn't done correctly).

But if you need a surgery, the risks are totally worth it. Likewise, if you have cracked retainers, you totally need to have this retainers upgraded. If you don't have cracked retainers, its unnecessary risk.

Also, if you do accidentally money shift (that is, accidentally shift into a gear that is way too low for how fast the car is going, and the cars forward momentum forces the motor to spin way past redline. Aka, a mechanical overrev), its not like the motor instantly grenades (though in an extreme case, that is always a remote possibility). The typical scenario is it cracks a retainer, then years layer and many miles, you are just driving along not doing anything especially rigorous, and the retainer fails, valve drips into combustion chamber, and mayhem ensues. Motor destroyed.

The point is, if you don't take the unnecessary risk, if you later money shift, you have time to get it to a shop to have the needed upgrade done when you actually need it. When its worth the risk.
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Old 02-04-2019, 08:02 AM
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I did this on mine when I money shifted 3rd to 2nd. After reading up on it, the procedure was not hard at all. I all depends on your wrenching level. I did find that none of mine were cracked, but had already bought replacements and had it apart, so I replaced them anyway. That was about 40k miles ago.

If you know you over-revved, I would replace reguardless. If you haven't, but have no clue on the previous owner, Check them using the forum's write-ups and decide from there. If there are sunk valves/keeps, def replace them, as they are cracked. If not, I wouldn't worry about them.
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Old 02-05-2019, 12:32 AM
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To me, it is a no brainer.
- it is a critical, vital part that can fail and destroy the engine. No matter for what reason, no "maybe.." no "only if...", it can fail.
- Because of this, the part was even improved by the manufacturer.
- It is replacebale with a reasonable amount of money and time.
- Removing the valve cover and cheking the part every now and then is pointless in my eyes, you dont know what happens inside the engine between the checks. They maybe look o.k. but can fail later.
- Even if engines get destroyed at a only 1 out of 100 or 1 out of 1000 rate because of it, to me it is to much risk.

So, out with old, in with the new....
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Old 02-05-2019, 01:07 AM
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If you don't know the history since new you do one careful inspection.
After that you usually would notice if you rev it over ~10krpm, but if you never do that no need to change parts.
Sometimes it feels good to install new things though and you might do it anyways, totally understandable
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Old 02-05-2019, 08:55 AM
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When it comes to our toys, there is often this often misguided feeling of the need for perfection.

I once overheard someone say about a Cobra kitcar that had a smallblock, "I would never build one of those unless I put a 427 in it". The comment wasn't about authenticity, but rather performance. As if a sub 2,300 lb car with over 300 hp was somehow not worth it. Not worthy.

We feel like its gotta be all we dreamed of, or nothing. Its the reason people are willing to buy shiny new no name crap coilovers. Bling is somehow more appealing than dingy old stock stuff, even though the stock stuff performs better and will last longer and is already on the car.

So if we learn our special toy has some possible imperfection, our knee jerk reaction is fix it immediately! Ain't broke don't fix it somehow doesn't apply.

As we get older, wiser, and more pragmatic, we realize that potential issues are not the same as actual issues. Perhaps having to weigh the benefits vs risks for invasive fixes to our own bodies that come with age makes us more amenable to making the same thoughtfully considered decisions regarding our toys.

The bottom line. There is virtually zero risk if the retainers aren't already damaged. If you do damage them, you'll know it. If you do damage them, there is time to fix it before it becomes a real issue. There is inherent risk in trying to fix it. Add it all up, and it doesn't make much sense to fix something that isn't broken, may never break, and if it is going to break you'll have advance notice...
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Old 02-05-2019, 06:11 PM
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I agree with Car Analogy's argument. I'm the original owner of my S2000 and I've never come close to a mechanical overrev. Does it make any sense to replace the retainers? Absolutely not. I risk nothing by not doing it and save a lot of time and expense.
Some day I'll probably sell my car and when I do the added expense of AP2 retainers wouldn't get me a dime more on the sale. On the contrary, it proves to the buyer that the engine was never overreved. And I will be able to say the engine had zero work done on it except for valve adjustments.
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Old 02-06-2019, 01:02 AM
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To my knowledge, a failing valve retainer dont give you a advance notice. It just notice you with a big "KA-BOOM" that your engine is gone.
And while i growing older, i learned that this irish guy named Murphy is allways right.

But honestly i have to problems: 1. I am German. 2. I was aprenticed in a small company that produces loud, roaring tubes of metall. https://www.mtu.de/de/
This genetic german defect, a obsession about all mechanic thingis and the aprentice and profession with a "Zero failure" - STRENG VERBOTEN! attitude creates a little bit of a "Perfectionist" mindset in my poor brain that i can not overcome.
Therefore, and i am sorry for this, someone must explain me what a "misguided feeling for perfection is".

"Oh, sorry for the big airplane crash and all this bloddy mess with this boddy parts here. Sorry, we know that (Whaterver engine part) was prone to crack and fail, but we where under the impression that we can get away with a little visual inspection from time to time.... " "Ah, O.K., no problem. Next time you try to do it right..."

To me, it´s perfect or fix it. But that is my very own problem, i know.
And, as allways, dont forget: Germans don´t have Humor!
At least about engines.

P.S.: And not a single S2ki member that wrote here in the thread that is it not neccesary to change the retainers will open his own walltet, buy me a new engine and say "Hey, i was wrong!" if my engine exploded because of a cracked retainer, hmmm?
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