killerinparadise

iTrader: (2)

I'm installing an '02 z06 cam into an '03 6.0 LQ4 with Patriot Dual Extreme springs, stock heads and stock lifters. I have a set of comp 7.450" pushrods and was wondering if I would be able to use these or if I will have to go to a smaller pushrod length closer to the stock height of 7.400". I think the z06 cam has a smaller base circle than the ls1 and then the 7.450" would be ok to run but I'm not sure what the base circle is on the LQ4 Camshafts. Any help you could give me would be great.

bigboykilroy

iTrader: (48)

http://store.summitracing.com/egnsea...alse&N=700+115

slothy

iTrader: (2)

ya def get a pushrod checker - only 20 bucks to check , alot cheaper then a new valve train!

PREDATOR-Z

Yes check to make sure and you have way too much spring pressures for that cam (overkill).
If i were you, I would run a set of PAC 1218 0r 1518

killerinparadise

iTrader: (2)

This is going on a 78mm turbo car, would you still recommend switching springs? Will there be any adverse effects of running the Extremes opposed to the springs you recommended? I've ordered the pushrod checker so I guess I'll figure out what height is needed when it gets here later this week.

PREDATOR-Z

IMO, you need just the right amount of springs. The extremes have too much seat pressure for those cam lobes (even with boost) You are looking at cam with very negative overlap. Basicaly what I am trying to say is that you are straining your valvetrain for no reason.
Being boost though, I would look at a thicker walled pushrod for less deflection.

Look at the extreme specs:
Install Height: 1.800"
Max. Valve Spring Lift: 0.660"
Spring Pressure Closed: 155 lbs. @ 1.800"
Spring Pressure Open: 410 lbs. @ 1.140"
Coil Bind: 1.090"
Retainer Material: Titanium

These are the specs for the PAC 1518 (what I would run)


OD: 1.290"
130 lbs @ 1.800"
337 lbs @ 1.150"
Lift: 0.650

Now that is more than enough for that cam under boost.

killerinparadise

iTrader: (2)

Thanks for all your help Predator I'll look into getting the PAC 1518 springs and thick walled pushrods.

PREDATOR-Z

They do make 5/16th p-rods in thicker than .080 (0.105), those would work fine, 3/8th size might need head machining. Basicaly same outside diameter 5/16 but thicker inside walls.

vettenuts

iTrader: (4)

There is also the option of Manton 11/32" which many have used without head machining. Available on a per order basis and cost really not any more than top brands.