Rocker arm assembly - Paired? Matched? How critical?
05-18-2019, 09:56 PM
#1
Registered User
Thread Starter
Rocker arm assembly - Paired? Matched? How critical?
I just made a very stupid mistake.
While upgrading the valve retainers, i want to reassemble the complete rocker arm subassembly. (camshaft bearings, all rocker arm assemblys on shafts, the whole subassembly) What i dont get was that the assembly is lose after removing. My impression was that there must be some kind of hidden screws holding things togehter... how wrong.
I have stored the assembly in a box, with a rag under it. While pulling it out when reassembling everything, i manged to make it wrong. It disasembled, a few of the rocker arrm assemblys slides from the shaft and fall into the box.
Assembly for Cylinder 2+3 where fine, still on the shaft. Cylinder 1, only two rocker arms fell down, no problem. I see the postion where they landed in the box, just slide them back in the correct position.
Cylinder 4 was bad. The Exhaust assembly was completly falling in the box, from the intake assembly only 1 of the rockers (with Screw) was left on the shaft. So i was ended up with a puzzle of 5 Rocker arms in the Box.
I reassembeld it, noticing that the rocker arms with screws are handed left-right. Makes one from the puzzle in the box logical the oposite to the one left on the shaft.
Therfore only 4 rocker arms remains as a puzzle. Two "Big" ones and two with screws. I just reassembeld them, watched carefull the orientation left- rigth position etc. according to the assemblys from Cylinder 3 + 4.
I dont feel any sort of "Play" on on side and "To tight" on the other side while comparing exhaust and intake side. Everything moves as smooth with thight tolerances as it should be.
So, should i worry or i am fine? The Workshop manual states that the rocker Arm assemblys are paired as sets of 3 and should be handeld this way, and honda only sell them as set. Makes me wonder why. These parts are machined with so tight tolerances nowadays that they should be interchangeable, theoretical.
Long term effects on wear?
While upgrading the valve retainers, i want to reassemble the complete rocker arm subassembly. (camshaft bearings, all rocker arm assemblys on shafts, the whole subassembly) What i dont get was that the assembly is lose after removing. My impression was that there must be some kind of hidden screws holding things togehter... how wrong.
I have stored the assembly in a box, with a rag under it. While pulling it out when reassembling everything, i manged to make it wrong. It disasembled, a few of the rocker arrm assemblys slides from the shaft and fall into the box.
Assembly for Cylinder 2+3 where fine, still on the shaft. Cylinder 1, only two rocker arms fell down, no problem. I see the postion where they landed in the box, just slide them back in the correct position.
Cylinder 4 was bad. The Exhaust assembly was completly falling in the box, from the intake assembly only 1 of the rockers (with Screw) was left on the shaft. So i was ended up with a puzzle of 5 Rocker arms in the Box.
I reassembeld it, noticing that the rocker arms with screws are handed left-right. Makes one from the puzzle in the box logical the oposite to the one left on the shaft.
Therfore only 4 rocker arms remains as a puzzle. Two "Big" ones and two with screws. I just reassembeld them, watched carefull the orientation left- rigth position etc. according to the assemblys from Cylinder 3 + 4.
I dont feel any sort of "Play" on on side and "To tight" on the other side while comparing exhaust and intake side. Everything moves as smooth with thight tolerances as it should be.
So, should i worry or i am fine? The Workshop manual states that the rocker Arm assemblys are paired as sets of 3 and should be handeld this way, and honda only sell them as set. Makes me wonder why. These parts are machined with so tight tolerances nowadays that they should be interchangeable, theoretical.
Long term effects on wear?
Last edited by Mr.Matchbox; 05-18-2019 at 11:15 PM.
05-19-2019, 01:13 AM
#2
Sorry say it, but this is exactly why you should not mess with retainers unless you know they are bad 
I think you could be fine though but to be sure you should test the assemblies you are unsure of.
From this thread https://www.s2ki.com/forums/s2000-un.../#post21967997
I think you could be fine though but to be sure you should test the assemblies you are unsure of.
Each rocker is a 3 piece matched set that should not be interchanged, but you can do so as long as you test them.
You will have to do a manual VTEC pin test on each of the 8 assemblies, to be sure the pins dont bind (since they are now mismatched)
Just make sure that the VTEC pin slides freely among the 3 piece rocker, once you have slid them onto the rocker shafts.
They may also have a 3 piece combined width which can be measured by micrometer. This will ensure there is no excessive oil clearence, or a tight rocker.
You are welcome to send it to me and I will return it assembled.
You will have to do a manual VTEC pin test on each of the 8 assemblies, to be sure the pins dont bind (since they are now mismatched)
Just make sure that the VTEC pin slides freely among the 3 piece rocker, once you have slid them onto the rocker shafts.
They may also have a 3 piece combined width which can be measured by micrometer. This will ensure there is no excessive oil clearence, or a tight rocker.
You are welcome to send it to me and I will return it assembled.
05-19-2019, 04:08 AM
#3
It reminds us all of the old adage, "If it ain't broke don't fix it." Sorry this happened to you. Similar stuff has happened to me in the past and probably most folks here have had similar experiences. Unfortunately we humans have to make mistakes to gain knowledge. Fortunately in the modern age we have the internet forums and we can get advice. That Billman post is a nice find! Should solve your problem. You were right not to just slap it all together and call it good.
On this whole ap1 retainer thing - there are differences of opinion. Personally, I am leaving mine alone. I have inspected carefully and there are no signs of cracks. I am the only guy driving the car. In the very unlikely event that I suspect a mechanical over-rev has occurred, I'll open it up and inspect again.
On this whole ap1 retainer thing - there are differences of opinion. Personally, I am leaving mine alone. I have inspected carefully and there are no signs of cracks. I am the only guy driving the car. In the very unlikely event that I suspect a mechanical over-rev has occurred, I'll open it up and inspect again.
Last edited by rpg51; 05-19-2019 at 04:31 AM.
05-19-2019, 06:26 AM
#4
Registered User
Thread Starter
Thank you all.
- I have done the hand VTEC-test, pins slide when the 3 rockers are assembeld on the shaft. .
- Assembled the subassembly, middle rocker moves freely. Both assemblys moved the same way, smooth and thight with no play, as the rest.
- Assembled the camshafts, torqued everything down. Middle rockers still moves freely, i can press them down with my thumb against the lost motion spring.
- Checked valve leash, i am a lucky Son of....... both exhaust and intake where in spec, i think i i choose the correct ones intake-exhaust wise.
- Keep my fingers crossed and started the engine, runs smooth as allways.
Will test drive the car later.
A important not to every hobby mechanic who read this:
The rocker arm subassembly is NOT secured by screws. It can fall apart. You have to insert 4 screws at the camholders 1 and 5 to secure the rocker shafts to avoid things fall apart.
This is not clearly explained in the Workshop manual and i never have read or seen this advice in the internet.
Dont make my mistake!
- I have done the hand VTEC-test, pins slide when the 3 rockers are assembeld on the shaft. .
- Assembled the subassembly, middle rocker moves freely. Both assemblys moved the same way, smooth and thight with no play, as the rest.
- Assembled the camshafts, torqued everything down. Middle rockers still moves freely, i can press them down with my thumb against the lost motion spring.
- Checked valve leash, i am a lucky Son of....... both exhaust and intake where in spec, i think i i choose the correct ones intake-exhaust wise.
- Keep my fingers crossed and started the engine, runs smooth as allways.
Will test drive the car later.
A important not to every hobby mechanic who read this:
The rocker arm subassembly is NOT secured by screws. It can fall apart. You have to insert 4 screws at the camholders 1 and 5 to secure the rocker shafts to avoid things fall apart.
This is not clearly explained in the Workshop manual and i never have read or seen this advice in the internet.
Dont make my mistake!
05-19-2019, 06:52 AM
#5
Did you insert the four (4) bolts into the rocker shaft holder before removing the assembly from the cylinder head? There's two on each end of the assembly. Are the "screws" you mentioned?
Clearly specified and pictured on page 6-35 of the 2000-2009 Service Manual. Page 6-30 of the old on-line 2000-2003 version with the Japanese bikini model on the cover so the procedure seems to remain unchanged.
-- Chuck
Clearly specified and pictured on page 6-35 of the 2000-2009 Service Manual. Page 6-30 of the old on-line 2000-2003 version with the Japanese bikini model on the cover so the procedure seems to remain unchanged.
-- Chuck
05-19-2019, 10:31 AM
#6
Registered User
Thread Starter
Bolts.. Screws... sorry. I allways mistake this. Bolts, yes. 
Yes, i read this step in the Workshop manual and tried it this way at first. My impression was that the bolts are used only as a "Pry bar" to brake the subassembly lose from the cylinder head. It is not mentioned exactly in the instructions that they also act as "Keys" to keep the subbassembly togehter as one piece.
I dont had luck this way, the subassembly dont came loose and i was concernd to damage the aluminum cam holder and the threads in the cylinder head with the threads of the bolts when i wiggle the bolts while trying to brake things loose.
Therefore, i removed the subassembly by carefull prying it from the cam chain side first and removed it this way. At this point, i was thinking by myself that there is no need for the bolts anymore. The whole subassembly feeled solid like screwed togehter as i layed it in the box........
This scenario was a complettly trap, and i stepped in.
Yes, i read this step in the Workshop manual and tried it this way at first. My impression was that the bolts are used only as a "Pry bar" to brake the subassembly lose from the cylinder head. It is not mentioned exactly in the instructions that they also act as "Keys" to keep the subbassembly togehter as one piece.
I dont had luck this way, the subassembly dont came loose and i was concernd to damage the aluminum cam holder and the threads in the cylinder head with the threads of the bolts when i wiggle the bolts while trying to brake things loose.
Therefore, i removed the subassembly by carefull prying it from the cam chain side first and removed it this way. At this point, i was thinking by myself that there is no need for the bolts anymore. The whole subassembly feeled solid like screwed togehter as i layed it in the box........
This scenario was a complettly trap, and i stepped in.
05-19-2019, 11:09 AM
#7
Trap? Maybe.
I think they put those little pictures in the manual for guys like me. Shows the rocker shaft holder lifted off the engine with the bolts inserted.
Regardless your experience and posting is highly valuable! Thanks for posting it.
-- Chuck
I think they put those little pictures in the manual for guys like me.
Shows the rocker shaft holder lifted off the engine with the bolts inserted. Regardless your experience and posting is highly valuable! Thanks for posting it.
-- Chuck
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05-19-2019, 11:33 AM
#8
Registered User
Thread Starter
Yes i have seen the Picture. But in this case the picture is worthless without a explantion, what the purpose of the Bolts is. My guess was "use the bolts as a pry bar..." becasue removing such things is allways a hassle.
"Insert the Bolts (A) into the rocker shaft holder, then remove the rocker arm assembly(B)" (My guess: use the bolts as some sort of pry bar)
vs.
"Insert the Bolts (A) into the rocker shaft holder to hold the Assembly together after removing then remove the rocker arm assembly(B)"
"a little difference - a big effect" as we say in germany.
"Insert the Bolts (A) into the rocker shaft holder, then remove the rocker arm assembly(B)" (My guess: use the bolts as some sort of pry bar)
vs.
"Insert the Bolts (A) into the rocker shaft holder to hold the Assembly together after removing then remove the rocker arm assembly(B)"
"a little difference - a big effect" as we say in germany.
Last edited by Mr.Matchbox; 05-19-2019 at 11:38 AM.
05-19-2019, 12:04 PM
#9
If you don't back out all the valve adjustment bolts its very easy to snap the cam caps when torquing them down, or even when loosening them.
Sounds like you didn't do this? If so, consider yourself lucky again
Sounds like you didn't do this? If so, consider yourself lucky again