marc_w

I'm getting a ton of KR at tip in after my cam install, and I'm trying go through everything to make sure the whole setup is 'sane'. I have a lot of 'sewing machine' valvetrain noise, but I think it's normal.

What are you guys with TR cams with unmilled heads, running for pushrod lenght?

I'm using 7.4" pushrods. TR uses 7.4's in their cam kits, so I never gave it a second though until now.

At first I thought 7.4" was the stock length. Then I heard about the 7.35's.

Are TR cams on a -.030" base circle?

What's the real story here?

2xLS1

iTrader: (25)

I'm using T/R 7.4s with my TR220 114 and they are working fine.

marc_w

Excellent. I figured the PR's were fine.

Do you get much valvetrain noise?

I ran the 918's via the stock cam for a few days, and they were as quiet as stock. I heard someone say in an old post that it might be the higher-rate springs, but I have to say it's not them.

Lucian

iTrader: (1)

go with the 7.4's, unless your heads are shaved

equandt

iTrader: (2)

This is my exact set up as well. No problems here. It idles like a kitten and runs like a raped ape.

kossuth

iTrader: (12)

FYI 7.4 is longer than stock ok. Reason being most aftermarket cams have a smaller base circle than the stock cams. Basically the smallest part on lobes on the cam are smaller than stock cams in the same spot.

ArKay99

iTrader: (1)

I too thought 7.4" was stock length. After all that is what they are advertised as. Then I looked up the part number for a stock LS1 pushrod and found the stock length. It was 7.318". I know there is great variance in pushrod length depending on endcap size, style, and manufacturer measurement standards. It cause my eybrows to shoot up, because I just replaced my stock pushrods with TR 7.4's. I have had them in the car for about 1000 miles now and have been to the track a few times and nailed it a few more. Zero problems, and valvetrain is quiet as stock.

MyLS1Hauls

iTrader: (2)

My TR220 was noisy too...Its just the aggressive lobes on the cam.

marc_w

After listening closely, I am getting a bit of a 'tap tap tap' from the valvetrain.

Anyone have any insight or direction in where I should head?

Retorque the rockers?

Throw a couple of stock pushrods in to see how they fit with the rockers torqued down?

marc_w

I'm really second guessing myself now.

The chances are "slim to none" that I somehow put something together half-a$$ed, right?

I swapped the springs Friday night. Slapped it back together at 2am, and the thing was running perfect. I tore it all down again on Sunday for the cam swap.

Is it possible to not get a pushrod fully seated in the rocker? I doubt I'd miss something like that on a nice bright Sunday afternoon.

MyLS1Hauls

iTrader: (2)

Marc-I'm sure its fine. If you didnt seat a PR right, you'd know it by now. The tap tap is the valves slamming shut. My car's valvetrain is loud at 2000rpm...as is every other aftermarket cammed LS1.

marc_w

Thanks for the reassurance... that'll save me an hour tonight.

I'm glad you mention 2,000rpm - that's where mine's the loudest.