What to do to '05 LQ4 bottom end?
10-15-2010, 06:09 AM
#1
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What to do to '05 LQ4 bottom end? When I put in my F14 cam, I noticed some copper showing in the #1 and #2 cam bearings. Also, #1 had a deep score from some apparent dirt on the first cam intall. From what I gather the copper is pretty common. I've heard mixed feelings on cam bearing replacement. Some say GM line honed the cam tunnel after bearing install and some have had cam bearings spin after replacement. Should I leave them alone? Or replace them?
I have the bearing install tool and the motor will be out. I will pull the crank out anyways to inspect the main/rod bearings.
Or do I just leave it alone? The journal on the cam I pulled out was perfect, not like the bearing is doing any damage with a score (its not raised). Motor makes zero noise, only has 45k miles (last 5k have been hard miles), and holds 40+lbs of oil pressure hot, in gear, with 0w-30 German Castrol Synthetic.
Basically this is a street/strip car that runs mid 11s NA and I'm gonna smack it with a 150-200hp plate kit, basically as much as the pistons and my transmission feel like taking.
Also, the motor never see's over 7000, is it worth while to upgrade to ARP rod bolts? Again, I've heard mixed feelings on spinning rod bearings after if you don't resize the big ends, which I am not doing.
For reference, the motor makes around 475hp NA and on the bottome will make 625-675hp. I'm not really going to ask much more out of it since the car will only be certified to 9.99 anyways.
I have the bearing install tool and the motor will be out. I will pull the crank out anyways to inspect the main/rod bearings.
Or do I just leave it alone? The journal on the cam I pulled out was perfect, not like the bearing is doing any damage with a score (its not raised). Motor makes zero noise, only has 45k miles (last 5k have been hard miles), and holds 40+lbs of oil pressure hot, in gear, with 0w-30 German Castrol Synthetic.
Basically this is a street/strip car that runs mid 11s NA and I'm gonna smack it with a 150-200hp plate kit, basically as much as the pistons and my transmission feel like taking.
Also, the motor never see's over 7000, is it worth while to upgrade to ARP rod bolts? Again, I've heard mixed feelings on spinning rod bearings after if you don't resize the big ends, which I am not doing.
For reference, the motor makes around 475hp NA and on the bottome will make 625-675hp. I'm not really going to ask much more out of it since the car will only be certified to 9.99 anyways.
10-15-2010, 07:20 AM
#2
I took a brand new LQ4 rod and had it checked for size both before and after swapping to ARP bolts. It did not change.
I say replace those cam bearings while they're accessible.
I say replace those cam bearings while they're accessible.
10-15-2010, 08:56 AM
#3
Have you ever replaced cam bearings before? If you haven't, I would probably leave them alone, but if you feel comfortable doing it then I agree, you might as well do it. Stock cam bearings usually do have some copper showing, so it's probably not a big deal.
As for rod bolts, it's probably not worth it since it only turns 7000RPM. ARP's may or may not change anything on the LQ rods since they are quiet a bit beefier than earlier LS rods and would likely be more resistant to deformation.
Good luck with it...hope those pistons hold up!
As for rod bolts, it's probably not worth it since it only turns 7000RPM. ARP's may or may not change anything on the LQ rods since they are quiet a bit beefier than earlier LS rods and would likely be more resistant to deformation.
Good luck with it...hope those pistons hold up!
