2002 Denali Camping Build

[Buggdave]

I use my Denali for towing a travel trailer, about 5,000 lbs, though the mountains at least monthly. I regularly reach elevations at 10,000 ft here in Utah. Over the summer I traveled into Wyoming and was at 11,500 ft. When I reach these elevations, i was having trouble keeping the engine cool on some of the uphill long pulls. I researched and decided to add a Mishimoto radiator. This thing is a beast.

My research had shown that with a few of the other 3 row aluminum radiators did not have the overflow connection design correctly. They did not have a flow reducing bushing which causes the engine to have a hard time warming up. The solutions to fix this was simple, put a washer in the overflow line at the radiator, but i happened on an open box Mishimoto radiator from Amazon that was about the same price as the no-name radiators, so it was a no brainer. The documentation for the Mishimoto Engineering is impressive and had me sold. The install was a breeze any my electric fans mounted to the radiator just like factory. I have seen a reduction in towing temp to about 200 degress. Prior to the install, i would stay around 220 to 230 degrees on even the slightest of grade.

 

[Tonyrodz]

I regularly adjust my settings on the shocks depending on if I am towing, offroading or daily driving. This feature is why i like the double adjustable Viking shocks. The the other area that has helped handling was the addition of the Hellwig swaybar for the front. I noticed that my OEM sway bar was not performing as well as I expected when traveling some road construction on my daily commute. I adjusted my shock settings (Rebound and Compression) but this did not produce satisfactory results. After installing the Hellwig product, I can say i noticed improved stability when traveling over the uneven portions of the road. The roll and pitch of the vehicle as I hit the uneven areas of the road surface, was drastically improved. I will update the rear sway bar in the future but right now the need is not as imediate as the front was.

A few of us have the front and rear Hellwig bars. Very nice bars.

 

[Buggdave]

@Tonyrodz that is how i found out about them, hearing the reviews from others here convinced me that they were the way to go.

 

[Tonyrodz]

I follow this guy. Check this out.

 

[Buggdave]

During my summer trip this year to the big horn mountains in Wyoming, my Yukon started to show its age, now at 203,000 miles. I struggled to climb some of the grades to get to the high mountain lakes we were targeting. So little investigation ensued. My cranking compression is lower than i expected, about 75 to 80 PSI. The leak-down test showed that my rings are failing. My valve seats seem to be ok, but I did hear some air escaping into the intake manifold, though most was heard through the dipstick. I have also been dealing with a rear main seal that is leaking which has been driving me crazy. This is the catalyst i needed to start planning my engine re-build.

 

[pwtr02ss]

During my summer trip this year to the big horn mountains in Wyoming, my Yukon started to show its age, now at 203,000 miles. I struggled to climb some of the grades to get to the high mountain lakes we were targeting. So little investigation ensued. My cranking compression is lower than i expected, about 75 to 80 PSI. The leak-down test showed that my rings are failing. My valve seats seem to be ok, but I did hear some air escaping into the intake manifold, though most was heard through the dipstick. I have also been dealing with a rear main seal that is leaking which has been driving me crazy. This is the catalyst i needed to start planning my engine re-build.
View attachment 354343

Sounds like a great excuse for some power/powertrain upgrades!

 

[Buggdave]

I have heard nothing but rave reviews about Vinci Cams from my fellow NBS owners so that is where I turned first to get some advice on my build and pick a camshaft to meet my goals for this Denali. I can echo that Roger is amazing and is a wealth of knowledge. I explained to him my desire for a tow capable rig for high elevation. I have never been comfortable of revving my engine over 5k, so I wanted all of my gains down low being this is a tow rig & mountain road most of the time. I am also not ready for FI yet and don't know if I will ever be, wanting to be able to repair this engine in remote towns if ever the need arises, following an overlanding mentality. He recommended their Max Torque Series camshaft, VHP 556, DUR @ .050" 208*/ 216* LIFT .578 / .578 LSA 113* 5A.
For this camshaft to perform well, he recommended that I target 11:1 compression ratio. I sourced a set of 862 heads from my local junkyard and as per Roger, I have been planning to have them milled down .030 to get my LQ4 to 11:1.

 

[Buggdave]

@pwtr02ss I have been looking for excuses since i got this Denali. As you know, the "more power bug" is an epidemic and it only takes time before you start showing symtoms, "cough, cough, cough".

 

[Buggdave]

I have been working on my new heads. I had some 243 heads decked at my machine shop. I did a bowl blend and then lapped the valves.

purchased the full cam kit from Vinci, so I started installing the new valve seals getting ready for the dual springs.

i need more cleaner before I install the springs. I still have some residue from lapping the valves. I hope to have both heads put back together this week.

 

[Geotrash]

I have been working on my new heads. I had some 243 heads decked at my machine shop. I did a bowl blend and then lapped the valves. View attachment 354965View attachment 354966
purchased the full cam kit from Vinci, so I started installing the new valve seals getting ready for the dual springs. View attachment 354968
i need more cleaner before I install the springs. I still have some residue from lapping the valves. I hope to have both heads put back together this week.

Really enjoying this thread, thanks for sharing.

Whatever you do, DON'T use the lifter trays that Roger sells you. Use new GM trays only. I got a set of trays from him that ate up 2 cams before I figured out what was going on. I also had one of the valve stem seals pop off (yes, it was seated correctly), and one lifter that wouldn't fit in any of the bores (which he replaced). The lifters he sold me also had a much narrower wheel on them than either the factory or any of the well-known brands including Morel and Johnson (see pictures below to see what I mean). My learning from the experience is that he makes a great cam and provides fabulous support but I would source lifters, trays and valve seals elsewhere.

Damaged Morel 6504 lifter:

Damaged Vinci lifter:

Damaged cam lobe showing scar evidence of the lifter twisting in the tray:

 

[Buggdave]

@Geotrash thanks for the info!! I will make changes to my plans accordingly.

 

[Buggdave]

The final piece for my build came today to help with my high altitude horse power. I purchased a new matched set of OEM LS2/LQ9 flat top pistons and balanced crank. I have gen 4 rods to round out the rotating assembly. I am converting my Lq4 into an iron block LS2. The crank is for a 2005 corvette with a 24X reluctance wheel to match my ECU. I tried and failed twice to find used LS2/LQ9 pistons. The first set was mislabel and the measured out to be for a LS1. The second set was from a 44K corvette engine but upon measuring them, the skirts had collapsed and my piston to wall clearance would have been almost 0.004”. Stock PTW clearance with the hypereutectic pistons is 0.0009” - 0.0012”.
I want the OEM pistons because the compression height of the OEM pistons allow me to maintain the 11:1 CR i am targeting. The other replacement flat top pistons are “reduced compression” and they would also need to balance the crankshaft. By keeping the OEM pistons and crank, I am able to maintain the stock balance of +/- 4 grams on the bob weight.

 

[Buggdave]

I am using a Mahle head gasket that is 4.0 bore and a compressed thickness of 0.05”. The OEM piston compression height is 1.336”. I am estimating that the piston will be 0.005 above the deck. This will mean my quench will be 0.045. This should help prevent detonation because i can only get 91 octane in my area. If I had E85, i would be running my 862 heads which would give me almost 11.6:1 CR. I would have to pull a lot of timing with a CR this high and from my research, not the best path to go, so I am going to run my 243 heads.

 

[Geotrash]

I am using a Mahle head gasket that is 4.0 bore and a compressed thickness of 0.05”. The OEM piston compression height is 1.336”. I am estimating that the piston will be 0.005 above the deck. This will mean my quench will be 0.045. This should help prevent detonation because i can only get 91 octane in my area. If I had E85, i would be running my 862 heads which would give me almost 11.6:1 CR. I would have to pull a lot of timing with a CR this high and from my research, not the best path to go, so I am going to run my 243 heads.

If you know this already then please forgive me, but it seemed worth mentioning that at higher altitude there is less air to compress, hence why 91 is considered "premium" fuel in the western mountain states. It provides pre-ignition margins similar to 93 at lower altitudes for normally aspirated engines.

 

[Buggdave]

@Geotrash, thanks for the clarification. I understand that the ASTM specifications allows for a reduction of the octane number based upon how high you are above sea level, and agree with the pre-ignition margins as you stated. What I am currently concerned about is how high my dynamic compression ratio is calculating. My cam has the IVC at 32 degrees ABDC. With my static compression estimated at 11.11:1, and using stock rods (6.098") I calculate that my DCR could be 10.55:1. I am researching to see if using 91 (93 @sea level) will cause me to have to pull timing due to knock retard. Since I do not have the ability to use E85 (approximate equivalent octane of 100-105), do i need to adjust my CR by changing my head gasket or going back to my 317 heads. I really wanted to run my 862 heads but i was afraid of the calculated 11.54:1 CR and 10.95:1 DCR and not being able to optimize the tune with the available fuel here. This is why i sourced the 243 heads. I am just chasing ghosts and just run the 862 heads?

 

[Buggdave]

I have been playing with a program called Dynosym5 and have "built" my LQ4 and my proposed build to compare potential gains. I am estimating a 22% increase in my torque @ 3500 rpm and 38% increase in hp at 5500rpm in this re-build. My build is simulated with mild porting of the 243 heads and using the 87mm tb on the TBSS intake with the Vinci MT556 cam. My estimated timing will be about 35 degrees at peak hp. I hope to have the engine out over thanksgiving weekend.

 

[Buggdave]

So, I think I have genuine GM lifter trays but after @Geotrash shared his experience I am doing my research. From all of the things I have seen online, I think I have genuine lifter trays. The trays do not have that shiny black plastic that I see on the knockoffs, but are gray in color and do have the correct part number.

 

[Geotrash]

So, I think I have genuine GM lifter trays but after @Geotrash shared his experience I am doing my research. From all of the things I have seen online, I think I have genuine lifter trays. The trays do not have that shiny black plastic that I see on the knockoffs, but are gray in color and do have the correct part number.

Looking good. They should be hard to flex as well.

 

[GMT800LUVR]

love the build im planning a refresh of my 170k LQ4 with very similar specs....do you still have your old torsion keys? think i wanna raise my truck about 2"

 

[Buggdave]

@GMT800LUVR I don’t think I still have the torsion keys as I recycled them when I removed my torsion bars and converted to a coil over front suspension. I did lower my ride hight back to stockish when I downsized to 31.5” tires. I was running about 2” when I had my 33” tires and I liked how it handled most dirt roads. I did add an energy suspension bumper on my lower control arm so that my jounce stops were in contact with the drama as per spec. I went to the factory sized tires when I started towing my camper trailer more. My gas mileage and low end power suffered a little with the 33’s.