VC460 valvetrain noise

[Shepard]

Originally Posted by LJHoffman77

So far I've added the stainless valves (31 x 6.5 & 36 x 6.5), titanium retainers & keepers, lash caps & 0.030" spring shims. This is all in addition to the shims for the crankshaft. I will plan to use the stock VC460 valve springs.

While I'm at it I'm adding the NR Racing rod bolts as well as their stud kit for the side cover and head.

I need to order shims for the camshaft as well, but wasn't sure what size they should be? I don't currently have the motor apart to where I can measure it. Any suggestions on where to buy shims for the cam? NR Racing doesn't offer them, just the crank shims.

Anything else I'm missing to make this valvetrain as "bullet-proof" as possible?

One thought to keep in mind - these parts are manufactured in several different countries and the tolerances used to keep them in "spec" are very large. I don't know what numbers they use but I have 2 extra heads and you can see differences with the "naked eye" in the valve spring pocket. I wouldn't be surprised if we [3 or 4] builders disassembled our engines an had them measured in a lab setup, none would be perfectly the same. That's why we have different measures as we build.

[LJHoffman77]

So I finally got my shims and had a chance to measure the endplay on both the crank and cam. Both of them measured around 0.018" of play. With the shims I was able to get the crank to 0.005" and the cam to 0.045".

I reassembled everything and I'm still getting the same "pop" on the intake valve. It always happens just before it's closed, and if I rock the engine backwards a few degrees and then go forward it will do it again. To me it sounds like it's coming from the valve spring itself, as I can feel it if I put a finger on the retainer. The exhaust valve doesn't make any noise at all. I'm at a loss as to what I should check next.

Anyone have any suggestions??

[Shepard]

Deleted

[KRAZYMATT]

i just started setting up my valves and I am getting the same clicking but I have just started messing with it. I am also using the NR 1.3 shaft mounted billet roller rockers. Have stainless valves, titanium keeps and lash caps. The push rod guide interferes with the push rods so I have removed that as I read it is not needed with these rockers. On mine I get a click while rotating it over each revolution but it sounds to me like it is the compression release springs on the side of the cam gear. Which cam do you have I put in the Vegas carts torque cam. Mine really really sounds like it’s coming from the lower end area. Almost like rod knock...

[scottykify]

When I was trying to pinpoint this strange valve train noise with my 460. I realized I could remove the rocker arm, and push hard on the pushrod with my hand and I could still hear the noise when I turned the engine over. To me this eliminated the entire top end of the engine being the cause "valve to piston contact, valve to valve guide clearance, keeper/retainer issues, rocker arm contact, etc.."

I also had a noise similar to a rod knock, very solid steel noise and it ended up being a gear lash issue between crank and cam gear "I believe". and it would make the noise ever so slightly as the valve opened, and much louder as the valve was closing.

[KRAZYMATT]

Originally Posted by scottykify

When I was trying to pinpoint this strange valve train noise with my 460. I realized I could remove the rocker arm, and push hard on the pushrod with my hand and I could still hear the noise when I turned the engine over. To me this eliminated the entire top end of the engine being the cause "valve to piston contact, valve to valve guide clearance, keeper/retainer issues, rocker arm contact, etc.."

I also had a noise similar to a rod knock, very solid steel noise and it ended up being a gear lash issue between crank and cam gear "I believe". and it would make the noise ever so slightly as the valve opened, and much louder as the valve was closing.

Yes I read through these 2 thread extensively. I remember you said either case or the crankshaft gear and leaning more towards that... i am now seeing I assume the same issue you were having. I am using the torque cam from Vegas carts but may swap it with the stock 460 cam next week and try again to see if it changes anything. Also looking at a few cheap used Oem gx390 cams on eBay to try as one user said the genuine Honda cam helped a lot. If this does help it and the gears mesh tighter with the genuine camshaft I will order a new one to put in the motor... this is where I am at right now. I do have a predator 420 in my ds but I don’t really feel like ripping into it as it is together complete and runs fine... (predator has stock cam but heavy duty springs, NR racing 1.3 roller rockers and chromoly push rods) no knocks or clicks on that motor though.

[KRAZYMATT]

To me it reminds me of the rod knock on my lycoming aircraft motor. On that it goes away once it’s warmed up. Very strange...

[raydhd]

You could always try genuine billet cam with one of the milder grinds. Probably a more precise fit BUT $130 or so.

[KRAZYMATT]

Originally Posted by raydhd

You could always try genuine billet cam with one of the milder grinds. Probably a more precise fit BUT $130 or so.

That’s what I am thinking in my mind. Pick up a cheap used stock gx390 cam and see if it improves because of size and fit. If it does then I will go from there if I desire a performance grind I will see the options at that time I just want to see if indeed a Hindu wine Honda cam will stop the noise first.

[KRAZYMATT]

Hopefully we will gain some ground/insight after this test. But it seems to be the crankshaft gear that drives the cam which kind of sucks as as far as I know there’s only 1 company producing these 69mm crankshafts but a million sources for the cams! Just hoping that maybe a ginuewine Honda cam maybe just enough to close up that gearlash enough to quiet it down!