2001 Pewter WS6

iTrader: (43)

My cam kit came with 7.350" rods instead of the 7.4". I called the vendor and told him I had stock heads and they were not milled. They said they would be fine. Can you use the 7.350" rods with stock heads? The cam is a 220/226 .563/.570 114lsa. I would like someones expert opinion and why. Thanks...

2001 Pewter WS6

iTrader: (43)

Thanks, that is what I wanted to hear. I bought my setup from them also and they said it would be ok, but I wanted to make sure. How do you set the preload? Is that where it is at at 24# of torque on the rocker arm bolt?

JohnR

iTrader: (1)

The 7.350 pushrods work fine!
I bought my Comp cam from Internet Racer's Supply in Houston and they sent me the shorter pushrods. I decided to go ahead with the assembly and just check the lifter preload. I still have about 1.5 turns of preload...the car runs fine. I did notice alot of valve train noise compared to stock but I think that is due to the new heavier springs. It's been about a month and 1000 miles and the noise is alot less.

'99 Firehawk, Comp 216/220 cam, 26918 springs, Ti-retainers, and 7.350 pushrods.

JohnR

iTrader: (1)

A simple way to check the lifter preload is to tighten down the rocker bolt, lightly by hand, until the play between the top of the pushrod and the bottom of the rocker goes to zero. Then, place your socket wrench on the rocker bolt, begin tightening the bolt and count the turns until it is tight. Each turn of the bolt is approximately .075" of "lifter piston" compression. (Another post explained this real well a couple of days ago.) So 1.5 turns is 1.5(.075)=.112" of preload. If the pushrods were too short, you would not get enough preload and the valve train would be very noisy and if actually left loose, would be mechanically very harsh on the components. If the pushrods are too long, you will send the lifter pistons to the bottom and your valves will not be able to close completely.
I think the other post stated that .060 to .090 are ideal preload figures. My short pushrods give my engine about 1.5 turns of preload.
Hope this helps without being too wordy.
John