RX-Ben

iTrader: (7)

I'm looking for confirmation on my measurement of the base circle of the TSP MS3 cam- I got a base circle that is a whopping .13015" smaller than stock.
Can anyone confirm this?
With a head shaved .040" and a headgasket @ .040" thickness, I've calculated that I'll need 7.366" pushrods (assuming a stock length of 7.380").
Can anyone confirm this?

Thanks
Ben

RX-Ben

iTrader: (7)

I think I went in the wrong direction- the base circle is smaller than the amount shaved so I need to ADD the difference to the length of the stock pushrods. Sound correct?

Here is the math:

base circle = .13015" smaller
.065075" smaller radius

head is .052" closer vs. stock. It is shaved .040" and headgasket is .012" closer vs. stock headgasket


.065075" (smaller base circle) - .052" (distance moved closer to cam) = .013075" longer pushrod needed

7.8000 (stock pushrod length) + .013075" (to make up difference between base circle and new rocker height) = 7.813075" (new pushrod length)

It looks like a need 7.8125" pushrods?

Thanks
Ben

LS198TA

iTrader: (1)

stock pushrods are 7.400 i have milled heads and im running comp cams 7350s

RX-Ben

iTrader: (7)

I've heard that, but I've also heard that they are 7.380

https://ls1tech.com/forums/showthrea...pushrod+length

Thanks
Ben

luv2spd

iTrader: (1)

Yeah stock is shorter than 7.4 thats why most people get 7.4 w/ aftermarket cams to account for the smaller base cirlce. This is with umilled heads though.

BADFNZ

iTrader: (19)

I still don't see where you're getting 7.800 from.

If stock is 7.38 and you need to add .013, you'd need a 7.393. You should be OK with a 7.400 since the hydraulic lifters compensate a bit for the added length.

RX-Ben

iTrader: (7)

Hmm...I have no idea where I pulled 7.8 from. In any case, 7.38 is what I meant to put there. 7.4s sound good to me too.

Ben

PREDATOR-Z

This is what you need:


From Thunderracing

fast98

iTrader: (16)

from what u have up there i calculated 7.393 but go get a pushrod length checker like above

muraoka

iTrader: (2)

7.8 is stock length for gen1 blocks. the easiest way to check length is to get an adjustable pushrod. assemble the rockerarm and adjust the pushrod till the rocker is centered on the valve stem. pull out the pushrod and measure it.
matt

RX-Ben

iTrader: (7)

I have 2 lifters that leaked down (they are completely soft) and the others are still pumped up (very hard, I can't squeeze them by hand). Can I use the "hard" ones with the adjustable pushrod?

Thanks
Ben

fastsspr

iTrader: (49)

yes you can do it.

RX-Ben

iTrader: (7)

Thanks guys. I already have the adjustable push rod, I'm just waiting for my modded LS1 rockers to come back from Harland Sharp. The bearing mod has taken over a month for them to do.

Ben