VC460 valvetrain noise

[LJHoffman77]

I’m putting together a new VC460 with the NR 1.3:1 roller tip rockers. I’m using the valve springs, retainers and lash caps that came with the motor. After installing everything, when I turn the motor over by hand I’m getting a popping or clicking sound when the intake valve is closing. I can feel it if I’m touching the retainer when it clicks. I’ve tried removing the springs and reinstalling everything and it still clicks. I’m not sure what else to check?? Anyone else had a similar issue?


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[raydhd]

Start reading. I bumped the LONG click story

[LJHoffman77]

Originally Posted by raydhd

Start reading. I bumped the LONG click story

Thanks! I’ll check it out.... I need to get better at searching the forum [emoji12]


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[Shepard]

Looking at valve lash cap - where is the roller contacting the lash cap? Is it centered? Is it off to one side or the other? NR's roller rockers are great - I have a 460 with them in it. They are not a drop in or bolt on item. You need to read all you can on valve geometry. I had to raise the roller assembly - I cut up the push rod guide and used as a shim. Then I needed longer push rods so the lock nut was on more then 2 o 3 turns. We can help you if your interested, several of us run NR's rockers.

One thing you may want to consider -- the valve train in these engines are its weak point. Your doing the first half of the job - why not replace the valves with stainless steel ones with automotive style keepers - it's cheap insurance when you have so much time and money invested.


http://www.nrracing.com/product-p/nrvalvepack-390.htm

[LJHoffman77]

I've read over your notes on the valvetrain geometry, and I bought the cut-to-length push rods and an adjustable pushrod to get the correct length. I initially put it together with the pushrods that came with the motor that were the correct length for the champion rockers. Much to my surprise they actually are contacting the lash caps like you had shown in your pictures.

I may just spring for the SS valves since I'm going to be ordering shims for both the cam and crank. Since I have the cut to length pushrods still, I can use them if the SS valves are taller/shorter when installed and it messes up the roller tip contact.

Thanks for all the help!

Originally Posted by Shepard

Looking at valve lash cap - where is the roller contacting the lash cap? Is it centered? Is it off to one side or the other? NR's roller rockers are great - I have a 460 with them in it. They are not a drop in or bolt on item. You need to read all you can on valve geometry. I had to raise the roller assembly - I cut up the push rod guide and used as a shim. Then I needed longer push rods so the lock nut was on more then 2 o 3 turns. We can help you if your interested, several of us run NR's rockers.

One thing you may want to consider -- the valve train in these engines are its weak point. Your doing the first half of the job - why not replace the valves with stainless steel ones with automotive style keepers - it's cheap insurance when you have so much time and money invested.


http://www.nrracing.com/product-p/nrvalvepack-390.htm

[Shepard]

One item I forgot to include, lash caps. These are shorter then normal caps.

http://www.nrracing.com/product-p/4299nr-1.htm

I worked in a shop that sold and repaired lots of clone powered products. The biggest repairs were valve train related -- sometimes requiring full engine replacement because of damage from dropped valves.

I bulletproofed my 460 valve train by replacing the valves - titanium spring caps and keepers - I used the 460 valve springs, they'll close the valves up to 6000 rpm and not beat the camshaft at 32-35 lbs. Higher valve spring pressure contributes to harder starting and is only needed @ 6500 rpm and above.

[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?

[raydhd]

For the camshaft I used 5/8" arbors shims bought on amazon. There is quite a few different thicknesses in the kit.

[LJHoffman77]

Thanks! I found a 19pc kit on Amazon that should work.

Originally Posted by raydhd

For the camshaft I used 5/8" arbors shims bought on amazon. There is quite a few different thicknesses in the kit.

[raydhd]

Yes That is the one I used . The diameter fits the cam nicely. Sounds like you are building yourself a nice engine. I think it is really neat to assemble the engine and make it just so and know exactly how it was done.