Valve lapping

[mdmcinti]

When I replace them cam and lifters on my Yukon xl. Since then heads are going to be off, I was going to clean and rebuild them on my kitchen table. I was seeing videos and threads where people would lap the valves when doing this. I also have read where a member on here did a cam swap and afm delete on his 6.2 Denali and and machine shop didn’t lap the valves because they sealed perfectly fine. I was planning on removing the valves and doing the scotch brite cleaning method with a drill and the help of of an acetone/tranny fluid mix ( there is a video on YouTube of this working wonders on carbon like magic). What are your takes on this?

Btw I am going to drop in a summit 8718R1 cam into my rig since it can run on stock tune and springs until I have funds for a tune and some ls6 springs.

 

[Tonyrodz]

When I replace them cam and lifters on my Yukon xl. Since then heads are going to be off, I was going to clean and rebuild them on my kitchen table. I was seeing videos and threads where people would lap the valves when doing this. I also have read where a member on here did a cam swap and afm delete on his 6.2 Denali and and machine shop didn’t lap the valves because they sealed perfectly fine. I was planning on removing the valves and doing the scotch brite cleaning method with a drill and the help of of an acetone/tranny fluid mix ( there is a video on YouTube of this working wonders on carbon like magic). What are your takes on this?

Btw I am going to drop in a summit 8718R1 cam into my rig since it can run on stock tune and springs until I have funds for a tune and some ls6 springs.

If you're motivated enough, and the heads are already off--why not? I can't see it hurting.

 

[taylorb71]

If you take the valves out just make sure to keep them in the same holes they came out of. Shouldn’t need to lap them if they are in order.
What I did was carefully use a 3m bristle brush and a good power wash with purple power (diluted of course) and they came out pretty good compared to what they were before. Engine was a sludge puppy

 

[mdmcinti]

If you're motivated enough, and the heads are already off--why not? I can't see it hurting.

If you take the valves out just make sure to keep them in the same holes they came out of. Shouldn’t need to lap them if they are in order.
What I did was carefully use a 3m bristle brush and a good power wash with purple power (diluted of course) and they came out pretty good compared to what they were before. Engine was a sludge puppy

I was planning on doing one cylinder at a time. Removing valve spring, the seal/seat the valve. Clean and put In back together. The lapping took and compound is only $10 total and probably adds a few extra minutes to the reinstall time.

 

[mdmcinti]

Would it be okay to reuse the stock springs for now until I funds to put some ls6 springs in? I don’t run the truck hard or anything and it’s going to be on factory tune for a while so it won’t go past 5500 rpms or whatever it maxes out at. The improvement I want to see from the cam is more torque and not having to down shift when I go up grades on the highway. The motor has 254k on it. The inside is in great shape because I replaced the oil pan gasket and it was clean just the typical amber color on the components but no sludge.

 

[iamdub]

Would it be okay to reuse the stock springs for now until I funds to put some ls6 springs in? I don’t run the truck hard or anything and it’s going to be on factory tune for a while so it won’t go past 5500 rpms or whatever it maxes out at. The improvement I want to see from the cam is more torque and not having to down shift when I go up grades on the highway. The motor has 254k on it. The inside is in great shape because I replaced the oil pan gasket and it was clean just the typical amber color on the components but no sludge.

They may be okay, but for how long? They already have a quarter of a million miles on them, and now they're about to be getting squashed with different harmonics. If it were me, I'd get the LS6 springs now and swap 'em while you have the heads off- it's way easier than with them in the vehicle.

Are you getting the cam new from Summit? They sell it as a kit with springs and valve stem seals.

 

[mdmcinti]

They may be okay, but for how long? They already have a quarter of a million miles on them, and now they're about to be getting squashed with different harmonics. If it were me, I'd get the LS6 springs now and swap 'em while you have the heads off- it's way easier than with them in the vehicle.

Are you getting the cam new from Summit? They sell it as a kit with springs and valve stem seals.

Yup that’s the plan to get the cam from summit racing. I saw that package for $394. I am unsure about their valve seals. I have heard nothing but good things about the fel pro seals. On my rockauto parts list I can get Melling valve springs for $54 and fel pro seals for $19. Still $20 cheaper than the summit cam package. Hopefully they go on sale soon.

 

[mdmcinti]

I found this one on sdpc but the lift is really low and the Lsa will kill the low end on the truck. Cheapest option though.

https://sdparts.com/i-24132274-sdpc...wzGksXWKLOu33eQQC4io1hcIqV6uM2qBoC1XoQAvD_BwE

 

[Tonyrodz]

I found this one on sdpc but the lift is really low and the Lsa will kill the low end on the truck. Cheapest option though.

https://sdparts.com/i-24132274-sdpc...wzGksXWKLOu33eQQC4io1hcIqV6uM2qBoC1XoQAvD_BwE

If it kills the low end--you'll regret it.

 

[mdmcinti]

If it kills the low end--you'll regret it.

yeah a 116+4 is kind of garbage compared to 112/114 unless I am not understanding the 116+4 deal lol.