What did you do to your NNBS GMT900 Tahoe/Yukon Today?

[Just Fishing]

Yours has a #2 thrust bearing? We might've found your problem. lol




Even the stock LMG, at 9.6:1 compression, benefits from 89+ octane. At least, during hot weather. If you lowered the CR of your 6.0 to something more suited for ~87, you'd lose a lot of the peppiness you have now, even with the tune optimized.

You can change the cam without removing the heads by removing the rockers and spinning the cam a few times to push the lifters up into the trays, then sliding dowels (5/16" works fine) into the oil galleys to hold them while you swap the cam. Since you already have your rockers removed, you could slap on them 1.8s. Just be sure of your geometries. Oh, larger than stock cams tend to sacrifice small amounts of low end for mid-and upper-RPM power. That's just physics. They need a higher SCR to achieve a net DCR to make up for the losses. So, keep your CR and quench where you're at, unless them 1.8 rockers put you in the PTV danger zone.

Lol no i replaced it once already.
rolled in place and was able to set and confirm endplay from under the truck.

And yeah, i don't want to change the config and how it runs.

 

[Just Fishing]

man i seem to be doing everything but working on the hoe today.

I did locate that transmission pressure gauge, so yay!
it's this: https://www.summitracing.com/parts/...MIsMD9jsfc9AIVVGxvBB3dVAN8EAQYASABEgJQ0vD_BwE

Now I'll need to find a housing for it...
Pita part is the size
2 5/8 in (67mm)

 

[Just Fishing]

Yours has a #2 thrust bearing? We might've found your problem. l




Even the stock LMG, at 9.6:1 compression, benefits from 89+ octane. At least, during hot weather. If you lowered the CR of your 6.0 to something more suited for ~87, you'd lose a lot of the peppiness you have now, even with the tune optimized.

You can change the cam without removing the heads by removing the rockers and spinning the cam a few times to push the lifters up into the trays, then sliding dowels (5/16" works fine) into the oil galleys to hold them while you swap the cam. Since you already have your rockers removed, you could slap on them 1.8s. Just be sure of your geometries. Oh, larger than stock cams tend to sacrifice small amounts of low end for mid-and upper-RPM power. That's just physics. They need a higher SCR to achieve a net DCR to make up for the losses. So, keep your CR and quench where you're at, unless them 1.8 rockers put you in the PTV danger zone.

I'm pretty happy with the cam i have now, I'm happy with the low end.
Biggest complaint I had with the 5.3, low end power sucked balls.
With the 6.0, even with the timing pulled way back, the low-end was very nice.


And the 1.8 ratio rockers went in with the AFR heads install / engine build.
Full rollers.

Decided since i went with those fancy heads, i might as well make use of the more lift.
+ AFR recommended rockers with roller tips.

Part of why I'm being so **** about checking the oil filter and not willing to run it too long.
I have a ton of money in this build, and i do not want to get metal in the brand-new parts.

But yeah, the more i think about it.
I should just pull the engine this time around. ugg.

I'll pull the pan first either way,
Then i can check out the crank, and it's easier to unbolt the converter that way anyways.

 

[Bill 1960]

Check your Drip Weatherstrips fellas!

The top portion is just friction fit, you can pull them up and clean under there and put them right back, wish I'd known this years ago.View attachment 357711View attachment 357712View attachment 357713View attachment 357716

Yes indeed. I don’t have rust but it tends to accumulate dirt and debris up there.

 

[89Suburban]

Yes indeed. I don’t have rust but it tends to accumulate dirt and debris up there.

And tree sap.

 

[Just Fishing]

I just finished building a 6.6L and I have close to 200 miles on my build. No noises or anything. I however didn’t reuse anything except my oil pan. Everything is new. Block crank rods the whole nine. My build when finished tuning should make around 750ish to the wheels.

If the surface on the polish is rough or turned the wrong way the crank journals now have like a circular saw blade effect on the bearings. It has teeth going into the turn instead of laying on the turn. This will most definitely eat up a bearing.

Think of like sharpening a knife. The tip rolls on the opposite side of the sharpened side right? Now has what we call a burr. Same applies to crank polishing. The burrs still exist after polishing but you need them to be roll over on the rotation not against the rotation.

There are tons of videos online that show this in great detail.

This is why when shopping around for machine shops you need to be mindful of experience and word of mouth not lowest price. Just making a statement. Don’t read into it.

I hope you get this fixed.

Just thinking about this...
I'm curious how the tuning differs from the stroker crank (iirc that's what you're doing).

If i have to replace the crank anyways...

but then i'm looking at new pistons, but that's doable.

got a build thread, or just going to continue the current one?



Things for me to think about.



We could be build buddies!
(not in a creepy way, but maybe)

 

[08z71bgm]

Just thinking about this...
I'm curious how the tuning differs from the stroker crank (iirc that's what you're doing).

If i have to replace the crank anyways...

but then i'm looking at new pistons, but that's doable.

got a build thread, or just going to continue the current one?



Things for me to think about.



We could be build buddies!
(not in a creepy way, but maybe)

Only thing you change is cylinder volume when you change displacement!

I used all summit pro ls stuff! Quite happy with the quality and balancing. No Mallory needed. Bought a whole rotating assembly in 4.0 stroke and bore. Brand new ly6 block too.

Forgot to add that my whole valvetrain is stock gm stuff. No high lift cam here. 558/553 lift with 1.7. Didn’t want the lope or valvetrain issues with high lift cams and tons of long life and mileage from oem parts.

 

[Just Fishing]

Only thing you change is cylinder volume when you change displacement!

I used all summit pro ls stuff! Quite happy with the quality and balancing. No Mallory needed. Bought a whole rotating assembly in 4.0 stroke and bore. Brand new ly6 block too.

Forgot to add that my whole valvetrain is stock gm stuff. No high lift cam here. 558/553 lift with 1.7. Didn’t want the lope or valvetrain issues with high lift cams and tons of long life and mileage from oem parts.

Happen to have a link to the parts?

 

[08z71bgm]

Happen to have a link to the parts?

I bought everything from summit racing. Only one kit 58x 4.0 stroke and bore. Comes with bearings and everything. Upgraded to the tool steel wrist pins. They said to be 1000 and over it would be required. So for only like 30 bucks it was worth the upgrade.

 

[Just Fishing]

I bought everything from summit racing. Only one kit 58x 4.0 stroke and bore. Comes with bearings and everything. Upgraded to the tool steel wrist pins. They said to be 1000 and over it would be required. So for only like 30 bucks it was worth the upgrade.

Looks like this one...

CHEVROLET Summit Racing SUM-R58400008 Summit Racing™ Pro LS 6.0L Rotating Assemblies | Summit Racing

Free Shipping - Summit Racing™ Pro LS 6.0L Rotating Assemblies with qualifying orders of $109. Shop Engine Rotating Kits at Summit Racing.

www.summitracing.com

Drops me down to 9.98 CR due to 72cc heads.

That's not terrible.