LS3 - Valvetrain noise
05-06-2015, 07:55 AM
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LS3 - Valvetrain noise I put in a Vengeance Racing VRPD-2 cam (231/239) with BTR dual valvesprings and 7.4" hardened pushrods last weekend in the vette.
I can't tell how much power it's made yet because it's still running 11 to 1 after the install, and i'm tuning it next weekend.
I've putted it around town for about 100 miles getting back home from the shop, and I gotta say.. the valvetrain is twice as loud as my last cammed ls vehicle. It's sewing machine sounds, no clacking or abnormal broken lifter/rocker/etc. sounds.
I'm wondering if 7.4" is the correct pushrod length for an aftermarket cam? I know they were the same length as stock, but I would think the base circle may not be exactly the same as the stock cam, warranting different pushrods?
Thanks
I can't tell how much power it's made yet because it's still running 11 to 1 after the install, and i'm tuning it next weekend.
I've putted it around town for about 100 miles getting back home from the shop, and I gotta say.. the valvetrain is twice as loud as my last cammed ls vehicle. It's sewing machine sounds, no clacking or abnormal broken lifter/rocker/etc. sounds.
I'm wondering if 7.4" is the correct pushrod length for an aftermarket cam? I know they were the same length as stock, but I would think the base circle may not be exactly the same as the stock cam, warranting different pushrods?
Thanks
05-06-2015, 01:04 PM
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Did you verify lifter preload? Count turns?
Not familiar with the cam your using, but I can tell you I didn't realize how loud my valvetrain was until I switched from a COMP/Tick cam to a CamMotion cam which has milder ramps. Went from a clatter machine to almost non-existent. Very impressed with CamMotion...
Maybe your new cam has some really aggressive lobes?
Not familiar with the cam your using, but I can tell you I didn't realize how loud my valvetrain was until I switched from a COMP/Tick cam to a CamMotion cam which has milder ramps. Went from a clatter machine to almost non-existent. Very impressed with CamMotion...
Maybe your new cam has some really aggressive lobes?
Last edited by 74u; 05-06-2015 at 04:11 PM.
05-06-2015, 06:06 PM
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My brother did the install, so I will validate that he did that.. but I seem to remember him saying that he did and that each turn represented a certain amount of preload. I will check with him though.
We are due to install a set of rockers with the trunion upgrade on Friday, so I will have him re-verify. Thanks for the tip.
I will say though, that I forgot that my prior cam was spec'd by Patrick G and done by EPS. He told me it would be super quiet... and it was. I'm thinking that this could be the difference.
It definitely does have considerably more aggressive lobes than the old cam.
We are due to install a set of rockers with the trunion upgrade on Friday, so I will have him re-verify. Thanks for the tip.
I will say though, that I forgot that my prior cam was spec'd by Patrick G and done by EPS. He told me it would be super quiet... and it was. I'm thinking that this could be the difference.
It definitely does have considerably more aggressive lobes than the old cam.