New to me donor 6.2L engine

[dbrannon79]

Howdy everyone. I had already posted some stuff on this engine that fell into my lap on another thread, but since I had planned to open it up and see if I can possibly use it as a replacement for my current 6.5l in my truck I figure I better start a new thread here and post up all the details and pics as I go along.

I know there will be several questions from me on what things to do and not to do and so fourth. so here goes!...

to start off with, I received a call from a buddy at work who had told me the shop who I had install the new ring and pinion set in my truck had a diesel engine he pulled from a 94 K3500 pickup. the owner of the pickup was converting it to a gasser. I ran by the shop and low and behold there was a complete engine that he said ran fine but just leaked oil badly and had some type of issue with the IP. He sold the whole enchilada to me for $100.

Oh and I have to give credit and a shout out to Jerry and Casey from Rodgers Racing who installed the gears and thought of me when this engine came available. Here is a link to his FB page. Don't know why it shows up in spanish lol

Rogers Racing & Performance | Seguin TX

Rogers Racing & Performance, Seguin, Texas. 2,565 likes · 1 talking about this. Pro mud racing team! We also build and install engine's ,transmissions ,rollcages and suspension!

www.facebook.com

Now to dig into the details of the newly acquired engine. at first glance I had thought it was a 6.5L since it had came from a 94 truck, also noted that it has the DB2 IP and a factory GM-3 turbo. I cleaned up the areas on the block so I could see the casting numbers and learn some details on the engine.

Block casting number is 14022660 and stamped on the front of the block reads GM 6.2L.

so learning that this is a 6.2L with a turbo tells me this wasn't the factory engine in the truck they pulled it from. There are some other casting numbers and symbols that I took pics of hoping to try and identify what year the block is and learn more details about it. Hoping this is a good one to work with.

below are some pics of the engine as it was when I got it and after using the power washer on it cleaning it up some on the stand.

 

[dbrannon79]

Ok, here are some more pics. I found while inspecting the engine that the crank pulley was shot but the HB was still in tact. it had beat up all 4 bolt heads to the point a socket would not go on them to remove. I thought about it a minuet and remembered I had in my toolbox never used fancy socket that was made for this sorta situation. lol it paid for it's self here!!




Here are the pics of the oil pan. not sure if it's the one @ak diesel driver was asking me about.






I noticed the pan was missing a couple of bolts in the front area of both sides.

 

[dbrannon79]

@Husker6.5 is this the t-stat cross over that is the rare bird? I took these pics late and it was beginning to rain!

 

[dbrannon79]

And here are the various pics of the casting numbers I found on the block. the more I can learn what year and how good or bad this block is, the better lol.

Behind the left (drivers) head


next to the OPS port on left side (drivers) rear near the valley



inside the valley looking from the flywheel side in. the bolt head is plugging off the fuel inlet hose to the IP


behind the right (passengers) head



the crankshaft casting number (after I pulled the pan I took this)

 

[dbrannon79]

Now here is where I flipped the engine over and pulled the pan off to look for webbing cracks and other obvious things. everything looked very clean other than some minor surface rust beginning to form on the crankshaft lobes. there was a little water in the bottom of the pan as it was sitting out in their back yard with the CDR off and the OPS port open to the elements. I drained the water out before flipping it over. also loosened the oil filter to see if water had been in the oil when it was running before. Nice black oil came out of the filter so I was happy there.

I know these pics don't do much justice, but I did only find one crack on the third main webbing opsite side of the oil filter (passenger side of the block) all the others I didn't see any cracks. I also noted that shining a flashlight down into the cylinders at the bottom of each piston, I could clearly see all the hash marks from the honing of the cylinders when it was build or re-built (don't know if it's ever been into before)

the pan has clearly been off before and looks to be recent because the gasket had a thin layer of soft blue silicone and the gasket was flexible, it came off with ease after taking the bolts off. Also noted the globs of red silicone on some of the bolt heads too.




passenger side rear main cap


Passenger side 2nd from rear main


Third from rear passenger side ( found crack) looking from front of block


same crack looking from rear of block.

 

[dbrannon79]

More pics..... now these I lost count on which main webs these were. when I connected my phone to the PC to sort though the pics, it wasn't easy to figure out. I think I will need to re-take each one and post up. after blowing up the ones I just posted in my previous post, I think I see another small crack!

 

[dbrannon79]

I also noted when I pulled the GP's that they are AC Delco's not sure which ones they are but they all came out with ease. the numbers I can read on them are 00 271 107

 

[Will L.]

Ok, the main web cracks are minor. That balancer is obviously wasted and the belt drive insanely worse. Dollar to a donut they are why the cracks started. Loose those two and fluidampr and your choice of Delco/ Leroy on the pulley.
Loose the main bolts and get studs at minimum, girdle kit from Chris is better.
balance the rotating assembly if you can at all afford it.
Choose what you are gonna do for compression ratio- lower is better for the engine to last longer but $$ add quick. All these things help that block live longer.

Buy coating the pistons top, bottom, sides and they should do as good as if it had oil squirters.

No building this guy for power. 240hp and 480 torque would be the max to push for. Because of the cracks- not because 6.2 or 660- normally good choices for bigger power.

Inspect the heads- expect cracks between valves and cracked precups. Clean them REALLY GOOD and post pics.

Once pistons are out- clean and inspected 7 & 8 cylinders REALLY WELL for cracks

 

[ak diesel driver]

Use a propane torch to heat the areas where cracks normally form. It will make them stand out as the oil in them tries to ooze out

 

[dbrannon79]

I plan to pull the heads and do a good inspection there as well, but with this weather it might take a while. I can't get the engine into the garage right now due to the disaster in there lol. not to mention a VW Jetta sitting in the way that won't move under it's own power. I have the engine in the front driveway of the house on the stand. had to seal everything back up after I had the pan off because of the rain that was coming!

I would like to source a flexplate and starter so I can do a compression test on the engine before I start pulling the heads. not sure if that is a good idea to do as it is now.

I do have a couple of questions here on this 6.2. I know they weren't originally turboed, though this one apparently had one put on in the past. what kind of results would I see on my truck setting this engine up as a spare or even fixing it up to drop in already with intentions of using the current 6.5 as a spare. I'm talking about the loss of power between my current one and this 6.2. What can be done on the cheaper side to make this 6.2 better match what my tired 6.5 is able to do so to speak lol

the one thing I fear is dropping a smaller engine in where it would have issues pulling it's own weight as a daily driver lol.

 

[Will L.]

You will see ZERO difference in power going 6.5 to 6.2 if everything else is the same.

In all honesty, if you don’t want to spend much money- don’t even buy the stuff like balancer, flex plate, ip, injectors, etc. Just get the lower end up to snuff by balancing rotating assembly. Reuse your current ip, starter, flexplate, balancer and pulley, etc.
Then see if the heads are worth doing.

Have the 6.2 as a bare bones long block prepped and wrapped up.

 

[dbrannon79]

I will be replacing the balancer that's a must. I have the flywheel that was on it I could use, just need to get a starter to do the compression test.

I also have thought about the gap-less rings too depending on what I find once I get the heads pulled. not sure what that will improve. if the block is worth it maybe even the piston coatings too. I will have to reach out to Chris on that, but it also depends on the condition of the cylinders.

with the cracks in the webbing. is it safe to pull the crank to have it all balanced ?

 

[EWC]

I wouldn't do anything but see if it runs . I can't tell you how many blocks I went thru until I found one without any cracks . Pouring money into an already known cracked block didn't make any sense to me . See if it runs and then go after leaks , damper , etc .

 

[dbrannon79]

I'm very tempted to attempt fireing it up on the stand before pulling it any further apart. I want to at least get the compression test done first though

 

[MrMarty51]

I have wondered about those lock and stitch kits to hold together those cracked webs.
Good ?
Bad ?
Indifferent ?

 

[Will L.]

Yes lock and stictch works, but doing the main webs is next to impossible because you can’t get a normal drill in there. And to spend hours with a 90° adapter is stupid hard.

It is a coin flip wether to leave the bottom end undisturbed and keep running it as is. (Leave crank in place.) You can still pull pistons and do the rings if needed.
If a guy is really tight on money, that is the thing to do.

My theory is if you buy the stuff intended for long term ownership- girdle kit, Fluidampr, billet pulley, etc. All those things come off the engine when it dies and gets used on the next one. If you have the money and you ant the engine ready to the point that it is a one day swap- yeah buy it all for the spare and the one in the rig. But I don’t have that many spare nickels so I have to put it all in the rig, and have a good long block spare. Pull the engine then pull the goodies off it to put on the other engine. Then drop it in. So it would be a two day event basically.

Sure compression test and test fire it on the stand. But unknown ip and injectors can thwart running. Honestly even of compression is a little low- overheated and or worn rings is most commonly the cause. Could be cylinders are too far gone- but if cylinders are half gone, the rings are always shot. I have put together ones that had one or two cylinders (almost always #7 & 8) that are just out of spec. Got the piston skirts coated because they will rock a hair more. New rings push the ring gap to the high side as much as possible. Then that engine went back in the fleet. Sure it will start blowby at the 125,000 mile mark instead of 175,000 mark. And it has a little shimmy you feel at idle or sustained rpm with cruise control on the freeway from the slight unbalanced compression. But so what? There is a lot of miles that wouldn’t have happened. Most drivers can’t feel the difference, they can’t tell when the injectors are unbalanced.
Again it becomes not a hot rod engine, but still can be used alright for work.

If the mains do let go, it is possible to pop the crank bad enough to ruin a girlde, so that going on is a gamble of it helps vs it will get ruined. Usually a good starter is the worst that loosing the crank hurts outside the block. But even that is rare. That crank usually pops and the mains push straight down. Oilpan is always victim.

 

[dbrannon79]

I have a curiosity on the GM3 turbo that came installed on this 6.2 I got. it has an actuator on it that does not have a vacuum port. I did try moving the actuator with a pair of pliers and could not get it to budge. not sure if it's just rusted shut, but I assume there is a heavy spring in the actuator similar to how the turbo master works so it doesn't need a vacuum pump to operate.

are these pre-set to a given PSI for the boost? if so does anyone know what it's set at? and is this a better actuator setup than what the newer turbos have?

I've been reading up on turbos with 6.2's and I see other forums are saying it's not a good idea to have one on a 6.2 unless the precups are changed and pistons are coated preventing a melt down. the only reason I have been looking into this is wanting to learn if the 6.2's were plagued with the same restrictive problems as the 6.5's and if a 6.2 would even push enough exhaust to spin an HX series or other aftermarket turbo since the pistons are smaller.

most of the other threads here and other places, folks are saying change the precups, coat the pistons and run a GMx turbo on the 6.2's is the best option. keep PSI under 10 (6-8) to keep the block from cracking at the main webs.

any advice? if I do end up setting this motor setup to run in my truck?

I haven't done anything more to it yet since I pulled the pan. I want to clean out my garage first so I can have a place out of the weather to tear it down for a full detailed inspection.

 

[Twisted Steel Performance]

Boost is affected most by the amount of fuel pored into it.... then turbine sizing, etc.... less fuel = less boost for the most part...

 

[ak diesel driver]

The only real difference you have is the precup, it might be a little smokier with the smaller 6.2 precups. They aren't anymore prone to cracking than a 6.5 so I wouldn't worry too much about that. IMO overheating and HB failure is the main reason for cracking

 

[Will L.]

Agree about the cracking and. 6.2 vs 6.5.
As to an hx35 being worse than a gmX —nope.
N/A 6.2 and 6.5 cracked as often as the 6.5 td, and when worked hard cracked sooner in my experience.
GmX makes the engine last longer and run cooler than n/a when it is getting worked (high temp area, going up and down hills, city driving- not even considering if you tow heavy) Basically anything worse than grandma getting groceries.
Then the hx35 is a easier on the engine because it lets go of the heat better than gmX.

There is a few companies making modified gm6/7 centermount turbos and adding wicked wheel for hummers. The price is silly, the hummer tax adds on. A basic 14cm hx35 beats the modified gm7 (same specs as a gm8 except centermount). Better power, same mpg, lower egt, more controlled boost.

Keep in mind performance and reaction is different on 10psi boost of a gm4 than 10psi boost on an hx35.