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Swapping AP1 retainers: reuse from old ap2?

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Old 04-05-2019, 04:32 PM
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Default Swapping AP1 retainers: reuse from old ap2?

Hi all, my 2006 ap2 motor blew up last year. Long story short I ended up buying a 2005 but was really a 2002. I was able to swap the AP1 motor into my ap2 and it's running great. Because I track the car I want to replace the intake retainers based on what everyone recommends. To save money, I pulled the exhaust and intake retainers and keepers from my blown ap2 motor and I'm wondering if it is recommended to reuse them.

The old motor had 155k miles on it when it blew up. Looking at the retainers and Keepers on the intake and exhaust side they look in really good condition. So, should I swap my AP1 intake retainers for these ap2 retainers? If so, should I use the intake or exhaust from the ap2?




Old 04-06-2019, 05:02 AM
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The AP2 retainers, as almost all other retainers on every engine around the world, are build to last "Forever" - As long as the engine.
Therefore, it is O.K. to reuse them. The one exception of this rule are maybe parts form a 500.000 Mile engine...
For peace of mind i would switch bot sides, inlet an exhaust.
Old 04-06-2019, 05:45 AM
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Originally Posted by Mr.Matchbox
The AP2 retainers, as almost all other retainers on every engine around the world, are build to last "Forever" - As long as the engine.
Therefore, it is O.K. to reuse them. The one exception of this rule are maybe parts form a 500.000 Mile engine...
For peace of mind i would switch bot sides, inlet an exhaust.
I was thinking about that but bilman said you only need to replace the intake side since that side is most prone to cracking?
Old 04-06-2019, 06:11 AM
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Quoting Billman250, "Change intake side only. Using AP2 retainers on the exhaust side will lower the float RPM it takes to bend them. It would defeat the purpose. The idea is to raise the over-rev RPM that can cause hidden damage."
Old 04-06-2019, 06:54 AM
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Probably OK, but why? AP2 retainers are $2.89 each new in factory bags and you need eight of them. A whopping, budget busting $23.12 plus shipping.

-- Chuck
Old 04-06-2019, 08:28 AM
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@ weenrock: The debate about switching only intake or both sides is going on an on. You will find a lot of information here in the forum.
My thinking is, there must be a reason why honda has changed intake and exhaust retainers on the AP2.
Old 04-06-2019, 11:01 AM
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Originally Posted by Mr.Matchbox
@ weenrock: The debate about switching only intake or both sides is going on an on. You will find a lot of information here in the forum.
My thinking is, there must be a reason why honda has changed intake and exhaust retainers on the AP2.
I don't think there's a debate on that -- just facts and math. You're forgetting that we're talking about mixing and matching AP2 parts into an AP1 motor, which Honda did not have to do at the time.

"Change intake side only. Using AP2 retainers on the exhaust side will lower the float RPM it takes to bend them [when the intent is to raise the float RPM to buy you extra safety]. It would defeat the purpose [of strengthening the AP1 motor]. The idea is to raise the over-rev RPM that can cause hidden damage [on an AP1, selectively using AP2 parts]." (Emphasis mine)
Old 04-06-2019, 11:16 AM
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Why did your engine blow if you don't mind me asking?
Old 04-07-2019, 05:46 AM
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Originally Posted by freddydela
Why did your engine blow if you don't mind me asking?
I am pretty certain the fuel pump blew up on the track. So, cyl 3 leaned out, got hot, both exhaust valves snapped off at the stem and ate my piston. Why do I think it was the pump? After I finished swapping in the new AP1, I went to drain the old fuel out of the tank by priming the pump, but it wouldn't prime. I put in a new walboro 255 pump and it primed instantly. Car started no problems.
Old 04-07-2019, 07:17 AM
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@ HarryD: Dont get me wrong, i am new and i have a lot to learn, but i am misisng the math and facts here.

But Honda has changed the valve retainers on the inlet and exhaust side on later models. But they let the valve springs untouched, they are the same through all years for the 2.0 engine.
There must be a reason fo this.... ?

You guys here have a awfull lot of expirience, somebody have solid data and math for me, a link, to convince me to just change the intake side?


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