2004 6.0 NV4500 Tahoe

[Dantheman1540]

I really do. I try to get focused on learning it, I just have a mental block. Once I think I can't figure something out, I have a real issue getting past that. I also don't wanna ask a million questions and annoy you or Randy

I don’t speak gen 4 so I’m no help lol. I totally get the mental block tho.

 

[iamdub]

Head chambers are 63cc which is perfect for 10.4:1 with the .041 gaskets.

 

[iamdub]

I misspoke and subtracted instead of adding the gasket thickness to the deck clearance. Quench should be safe at .045-.049 depending on deck height.

Gasket thiccness minus piston height. So, .041" - .006" = .035" (bare minimum, maybe dangerously close, maybe damagingly close)

If piston height is .008", that puts you at .037" which is in the safe zone. You should check with modeling clay as an extra measure. Don't forget to rock the piston when getting your measurements.

 

[Dantheman1540]

Gasket thiccness minus piston height. So, .041" - .006" = .035" (bare minimum, maybe dangerously close, maybe damagingly close)

If piston height is .008", that puts you at .037" which is in the safe zone. You should check with modeling clay as an extra measure. Don't forget to rock the piston when getting your measurements.

Ok ok hang on, so summit says it’s clearance plus gasket thicccness. If the deck clearance is +.008 wouldn’t that be .008+.041=.049?

Or because it’s positively out of the cylinder, meaning sticking up like a hard ****** .008 that means you need to subtract it because it obviously makes the quench volume less. Meaning .008-.041=.033/danger. I think this is correct and is what my initial thoughts were but then the summit wording got my panties in a bunch.

So if that’s the case the .041 gaskets are probably too thin to be safe but your saying I could check with modeling clay how? Put the heads on with clay on the piston and turn the crank over sinking the valves into the clay and then pull the heads off and measure compressed clay thicccness?


Thank you for your patients kind sir.

 

[iamdub]

Ok ok hang on, so summit says it’s clearance plus gasket thicccness. If the deck clearance is +.008 wouldn’t that be .008+.041=.049?

Or because it’s positively out of the cylinder, meaning sticking up like a hard ****** .008 that means you need to subtract it because it obviously makes the quench volume less. Meaning .008-.041=.033/danger. I think this is correct and is what my initial thoughts were but then the summit wording got my panties in a bunch.

So if that’s the case the .041 gaskets are probably too thin to be safe but your saying I could check with modeling clay how? Put the heads on with clay on the piston and turn the crank over sinking the valves into the clay and then pull the heads off and measure compressed clay thicccness?


Thank you for your patients kind sir.

You have NEGATIVE deck clearance when the piston comes outta the hole. So, you subtract .008" or whatever your clearance measures out to be. I have a bad habit of calling it "piston height", which is not technically correct. Piston height is the measurement from the center of the pin to the top of the piston.

Modeling clay lets you see the quench height but it's primarily for seeing PTV clearance. So, it's a two-fold benefit. I used an old stock gasket (.051" compressed), put some modeling clay on top of the piston (smeared a light coat of oil on piston and in chamber) and cinched the head down with old head bolts. I didn't fully torque them, obviously, but got kinda close. I turned the crank slowly by hand a couple times then pulled the head. I carefully sliced the clay with an X-Acto knife (using more pushing of the blade than dragging it) and measured the cut cross sections at the head surface and at each valve with a digital caliper. You have to use modeling clay- not Play-Doh, etc. I subtracted .006" from my measurements since I was planning on .045" gaskets.


OH! I forgot- you need to use solid lifters. I took apart two of my stock non-AFM lifters, flipped one of the pieces inside around (I don't recall the proper name of the piece) and reassembled them to make "solid" lifters.

 

[Dantheman1540]

You have NEGATIVE deck clearance when the piston comes outta the hole. So, you subtract .008" or whatever your clearance measures out to be. I have a bad habit of calling it "piston height", which is not technically correct. Piston height is the measurement from the center of the pin to the top of the piston.

Modeling clay lets you see the quench height but it's primarily for seeing PTV clearance. So, it's a two-fold benefit. I used an old stock gasket (.051" compressed), put some modeling clay on top of the piston (smeared a light coat of oil on piston and in chamber) and cinched the head down with old head bolts. I didn't fully torque them, obviously, but got kinda close. I turned the crank slowly by hand a couple times then pulled the head. I carefully sliced the clay with an X-Acto knife (using more pushing of the blade than dragging it) and measured the cut cross sections at the head surface and at each valve with a digital caliper. You have to use modeling clay- not Play-Doh, etc. I subtracted .006" from my measurements since I was planning on .045" gaskets.


OH! I forgot- you need to use solid lifters. I took apart two of my stock non-AFM lifters, flipped one of the pieces inside around (I don't recall the proper name of the piece) and reassembled them to make "solid" lifters.

Ok, we are on the same page now, I suppose the best-case scenario would be that the deck clearance is only .004 and I can run the .041 with a quench of .037. Somewhat unlikely tho I suppose, I guess I'll go ahead and order some .045s and return whichever I don't use. Kinda sucks because I wanted the CR to be the same between the heads to eliminate that variable from the swap.

I think I have one solid converted lifter to measure pushrod length with but I might have to scrounge for a second.

 

[Dantheman1540]

These plug wires are super nice and fit the round coils perfectly. No more wire burning for me!

 

[Rocket Man]

These plug wires are super nice and fit the round coils perfectly. No more wire burning for me!

When I bought those I was finally confident my burned plug wires were a thing of the past. Glad you like them. They’ve worked perfect for me, going on 2 years I believe.

 

[Dantheman1540]

When I bought those I was finally confident my burned plug wires were a thing of the past. Glad you like them. They’ve worked perfect for me, going on 2 years I believe.

First set of wires that don’t touch anything except the thing they are plugged into! Plus they are just really nicely done I’ll get a set for the RCSB as well. Thank for the tip!

 

[pwtr02ss]

Those look nice!

 

[findog78]

Ya god dang right I am!

The plan is cut everything off the other axle and weld it on this one with a plasma torch, re powder the beefy diff cover to my sparkly goodness (aka diamond dust). Put the old calipers off the front of the Tahoe with the power stop pads but get new H2 rotors. Gotta buy the pigtail that plugs into the electronic locker, a lube locker gasket, and gear oil, then finally paint it all blaccckkkk with cheap tractor paint/chassis saver.

Dantheman Is the 2004 2 WD with 5speed NV4500 from your profile the same one in your profile pic? Do you have any posts of the coil over conversion?

 

[Dantheman1540]

Dantheman Is the 2004 2 WD with 5speed NV4500 from your profile the same one in your profile pic? Do you have any posts of the coil over conversion?

Yep that’s it, if you got to page 124 of this thread you can see the start of the coil over swap.

 

[findog78]

Thanks.

 

[findog78]

They are really too nice for me. I'll almost feel bad blasting them with dirt from the farm roads I have to navigate occasionally.

How do you like the ride?

 

[Dantheman1540]

How do you like the ride?

It’s truly fantastic whether you want soft and supple or stiff and race car-like, you can adjust the compression and rebound adjusters and tune it to your liking. I used them to replace a basic 2/3” drop kit and got matching shocks in the rear and it is the best riding lowered vehicle I’ve been in. People who ride with me for the first time are always surprised.

I’ve seen some posts of people complaining about a harsh ride with the coil overs and IMO they either didn’t spend the time to properly adjust the shock settings, got way to stiff of a spring, or have some sort of suspension geometry issue unrelated to the coil overs such as a 4” drop in the front and stock control arms, or a 3” drop in the rear without doing the “free travel mod”.

I have Atomic’s setup on this truck and another that’s lifted and it rides even better!

 

[Dantheman1540]

26* this morning and it had perfect oil pressure on startup, she's such a random biotch.

I've been contemplating doing the oil pump as preventative maintenance and if I'm gonna do that and plan to spin this thing above 6k often then a decent timing set is probably a good idea. I tossed the question out on PT.net and a long-time buddy I used to work with/for suggested this https://www.corvetteforum.com/forums...-no-equal.html looks pretty sweet and the guy that suggested it has a badass C5 so I think I'm gonna try it.

Along with that, I bought a basic M295 melling pump and gasket set.

 

[Dantheman1540]

While overthinking this head swap again I ran some more numbers through the CR calculator and realized I may have been using the calculator wrong before. On the deck clearance box, I was putting a positive number thinking that since the piston is out of the hole .004-.008 it would want a positive number to calculate correctly. Well, I just put it in as a negative since having the piston out of the hole would obviously subtract from combustion volume and increase the CR and when I did the CR went up. So previously I was looking at 10.16cr if I used .051 gaskets and input the number as a positive. If I put it in as a negative I end up with right at 10.5:1.

If this is the case then the current setup runs a 10.75:1 which is more than I thought.

 

[iamdub]

While overthinking this head swap again I ran some more numbers through the CR calculator and realized I may have been using the calculator wrong before. On the deck clearance box, I was putting a positive number thinking that since the piston is out of the hole .004-.008 it would want a positive number to calculate correctly. Well, I just put it in as a negative since having the piston out of the hole would obviously subtract from combustion volume and increase the CR and when I did the CR went up. So previously I was looking at 10.16cr if I used .051 gaskets and input the number as a positive. If I put it in as a negative I end up with right at 10.5:1.

If this is the case then the current setup runs a 10.75:1 which is more than I thought.

All good numbers. With that cam, your DCR is still safe.

 

[Dantheman1540]

All good numbers. With that cam, your DCR is still safe.

I will probably end up putting on .051 gaskets to get close to 10.5cr in case I miraculously find some sort of Wuhan whirly boy to force-feed this thing.

Other good/bad news is that my low oil pressure on cold start issue seems to have eliminated itself and I think it was caused by a severe misfire which I recently solved with the new plug wires. The truck has not only started up with 40psi every morning but it doesn't act funny and buck/surge like it used to either. the bad news part of this is that I beta my head against my laptop for close to a year trying to solve the weird startup condition that I was convinced was tunes related. I think the entire time it had a severe misfire. Another reason I think this, is that when I did the plug wires the other day I was being bothered by a neighbor talking to me the entire time and I actually started the truck with 2 wires disconnected from the plugs #4/#6. The truck started up fine and I wouldn't have noticed there was an issue except I did a visual inspection before I closed the hood and saw them. My point is that these trucks will run remarkably well even down on cylinders.

 

[George B]

I will probably end up putting on .051 gaskets to get close to 10.5cr in case I miraculously find some sort of Wuhan whirly boy to force-feed this thing.

Other good/bad news is that my low oil pressure on cold start issue seems to have eliminated itself and I think it was caused by a severe misfire which I recently solved with the new plug wires. The truck has not only started up with 40psi every morning but it doesn't act funny and buck/surge like it used to either. the bad news part of this is that I beta my head against my laptop for close to a year trying to solve the weird startup condition that I was convinced was tunes related. I think the entire time it had a severe misfire. Another reason I think this, is that when I did the plug wires the other day I was being bothered by a neighbor talking to me the entire time and I actually started the truck with 2 wires disconnected from the plugs #4/#6. The truck started up fine and I wouldn't have noticed there was an issue except I did a visual inspection before I closed the hood and saw them. My point is that these trucks will run remarkably well even down on cylinders.

Glad you found it.