I'm going to pull my diesel for a little "maintenance."

[arveetek]

Just thought I'd update ya'll on some of my diesel engine happenings.

I haven't had any problems since installing the turbo last summer. However, I recently started having an intermittant ticking noise that I've tracked down to a failing lifter. It's getting worse and getting on my nerves. The engine still runs great, but I can't stand to have something that doesn't work quite right. I can change the lifters with the engine in the truck, but, due to the design of the 6.2L block, I can't reach the lifters by pulling the intake manifold. They're hidding down inside the block under the heads. They can be reached by pulling off the valve covers, but it's really hard to do.

So, I want to change all the lifters, as well as install a gear drive kit to replace the timing chain. I'll have half the engine torn apart just to do these two items. Plus, my motor mounts are shot (again), so I'm going to have to jack up the engine just to do that. Now there's not much left holding the engine in anyway. So, I'm just going to go ahead and yank the motor and do it all on the engine stand where I can get to it much easier and do a better job.

While the engine is out I'm going to install the gear drive, install new water pump, remove heads, replace lifters, install new head gaskets, check engine over really well, install stud girdle kit on bottom end (ties three center main bearing caps together for extra strength), install new rear main oil seal, replace all other seals/gaskets, and install new energy suspension motor mounts in the truck. I'm also going to replace the O-ring on the turbo housing that's leaking a bit of oil.

I have all the parts except for the motor mount inserts and the stud girdle kit, which are on the way. I hope to get started this weekend or early next week.

I'll keep ya'll updated on the process!

Casey

[JustOneTruck]

Wow that sounds like a lot of work. But a pay off in the end. I`m new to the board but wanted to ask maybe if you would take a few shots as you work on the project.

My Question that I have waited to ask is this.

How does one turn up the fuel on the injector pump to get better power .I read that alot on the board here about doing this . Along with getting larger pipes to get rid of the exhaust. I already have factory duals from the manafolds back.
And I`m also thinking of cuting the air filter houseing to attach a second breather horn to maximise the air intake .

Whats your take on that

Thanks in advance

[arveetek]

Opening up the intake and exhaust is an excellent idea. I was going to do just like you mentioned, add a second air intake for more air, but I ended up doing the turbo instead.

Turning up the pump is relatively easy, but it involves a few steps that are somewhat complicated. I've been asked before, so I'm going to try and come up with some step by step instructions so that you don't mess something up. It involves taking the top of the injection pump off, and if you don't reinstall it correctly, you can end up with a runaway engine.

Casey

[67_C-30]

Please post pics and your sources for the gear drive and stud girdle. I have decided to do the turbo changeover (Thank you for costing me even more money!! ) I have already bought a set of 6.5L turbo manifolds. I will probably use the 6.5L turbo also since they are easy to come by. When you get it all put back together, please let us know if that gear drive is a noisy one (like race gear drives) or quiet. I had a gear drive on my Z/28 at one time, and that thing was very loud. I doubt the one for the 6.2L would be, but I'd like to know before I bought one. Thanks!

[67_C-30]

Casey,

I was just looking back through the pics on your webpage, and I noticed that you had a vacuum booster on your truck. All the 6.2L trucks I have had over the years had a hydroboost. Does your diesel have a vacuum pump that the other 6.2L trucks don't?? Thanks again!

[arveetek]

67,

I bought the gear drive from another DieselPage.com member that he never got around to using. But the best new price I found was from www.kennedydiesel.com for $275. I bought the stud girdle kit directly from the manufacturer at www.dieselservices.com for around $155 including shipping.

Most folks have reported being able to hear the gear drive at idle, but not during actual driving. The diesel is noisy enough to mask any extra noises.

I'm planning to take pics and report my findings.

All 6.2L and 6.5L diesels used in pickup trucks, Suburbans, and Blazers came equipped with vacuum pumps. These pumps were designed mostly to run the a/c door flaps, cruise control, wastegate control on later trucks, and transmission modulators on TH400 trucks. The 82-87 V-belt models used a vacuum pump mounted in the rear valley of the engine, where the distributor would be on a gas engine. The 88 and later serpentine-belt engines used a belt driven vacuum pump. I don't believe the military engines came with one, though. On those engines, and the later belt driven pump engines, there was a cover over the hole in the engine valley where the pump would have been. This cover includes a stub shaft, because the cover or vacuum pump is used to drive the oil pump as well.

My truck was originally gas, so I never bothered to swap over the hydroboost. You're correct in that all factory 6.2L diesel trucks came with hydroboost. I have found that a good healthy vacuum pump, booster, and an auxillary vacuum tank gives me satisfactory brake assist.

Casey

[67_C-30]

Casey,

Ok, I didn't realize that your truck was originally gas. My truck has no power brakes or power steering at the moment, so I am going to go ahead and go with the hydroboost since it will be easier. I am going to use the proportioning valve off the diesel 'burb also since I am running '81 model C-30 front suspension and rearend.

But I'm glad you are documenting and posting everything. I have found your posts and pictures very helpful because when I decided to do this conversion, I knew almost nothing about the 6.2L diesels. I knew I liked their sound, the torque they have, and best of all, since I'm building a dually, fuel economy. I knew any gas engine (especially the 454 I originally planned to use) was going to be a hog without an OD tranny. I wanted to keep it a straight shift, and the 5 and 6 speed trannys are expensive, and it would be more of a hassle to changeover since they usually have hydraulic clutches and mount differently. As I mentioned before, I am going to use a 3.42 geared 14 bolt, so it should fairly ecomical for what it is.

I more question about your set-up. Are you running an EGR intake? I have seen them with freeze plugs blocking holes where it mounted. Is there an advantage on a diesel to or not to have EGR?? I have an intake off of a CUCV military truck. Would it be better to use?? ....We don't have emission checks here....

[arveetek]

My engine originally had an EGR, but I threw it away and blocked the hole with a freeze plug. The EGR's are useless on diesels, and they are strictly for emissions. The light duty 6.2L's found in 1/2 ton trucks, burbs, and Blazers had EGRs, while most 3/4 and all 1 ton and military trucks didn't have EGRs. This is also the difference between the light duty VIN code C motors and VIN code J motors.

I later replaced my original C code EGR intake manifold with a later J model that was completely open, allowing the engine to breathe better. I would use the military intake if I were you. If it came off a hummer, you'll have to modify your air cleaner housing some, because the mounting bolts will be off by 90 degrees, plus the hummer intake is a little shorter. But it will breathe better. A standard CUCV intake should be a simple bolt-on. Whatever you do, ditch the EGR...it can cause problems if it malfunctions.

I've been meaning to take pics of my original EGR intake and the later J code intake so that folks can see what a difference there is. I'll try and get that done during my engine work.

Casey

[67_C-30]

That what I planned on. It came off a Military D30, so it is a derict changeover. The EGR on my engine looks restrictive. Do you have any HP and TQ figures for the C motors and/or J motors?? Did your turbo make a very noticeable difference?? The Banks kit makes big claims, but I was wondering if your changeover was a night and day difference. If the Banks kit does what it claims, there should be a huge difference in the overall power range.

[mustngr]

Motor mounts have been a real pain, torque from pulling horse trailer takes them out.
Think I'll give the Energy ones a try, myself. Special-ordered suspension bushings in black for my CUCVEE, couldn't hang with screaming red ones. lol

[mustngr]

C-30,

Unless you're going turbo, or really cranking up the volume with the pump, the 6.2 really doesn't benefit much from opening up the air. I've found slight gains from the double snorkel, but only if it's ducted to the firewall in such a way that it provides a ram effect. Turbo is definitely Night and Day.

[67_C-30]

Originally Posted by mustngr

C-30,

Unless you're going turbo, or really cranking up the volume with the pump, the 6.2 really doesn't benefit much from opening up the air. I've found slight gains from the double snorkel, but only if it's ducted to the firewall in such a way that it provides a ram effect. Turbo is definitely Night and Day.

I'm pretty sure I am going with the turbo. One of my good friends has CUCV and his truck has good power, but quite has much pickup as he (or I ) would like. He has also has an 83 C-10 4X4 Silverado 6.2L w/ the 700R4, and feels much a little quicker that the CUCV does. The 4.56 gears in CUCV are a little too steep for just driving around, but it pulls like a mule when loaded. His other truck has 3.42's and that is a sweet running truck. It gets awesome mileage, and has plenty of passing power. I am going with 3.42's and a 4 speed manual. The 4 speed will give me the low end lugging gear for pulling, and also fair ecomony. My truck currently has 5.13's, so I know and I gotta change that!!

[mustngr]

but it pulls like a mule when loaded

The reason it pulls like a mule is its gearing. At an optomistic 200 hp (turbo'd) you're not exactly building a monster. Personally, I'd consider an overdrive tranny and at least 3.73's if you're gonna haul with the truck, preferably 4.11's.

Arveetek?

[Beefcake]

arveetech- Thanks for all the info... Im currently rebuilding a 6.2. Im going to follow much of your procedure for adding a turbo. Is there any thing you'd consider doing diffrent at this stage??? While you have the motor out... Have you considered a turbo cam?? would there much of an increase?

[arveetek]

As far as I know, there's only two sources for any kind of performance camshaft for the 6.2L: Crane Cams and the Diesel Depot. Crane requires that you send in your current cam and they will tweak it. I believe that DD sells a new cam. Neither one has been used widely enough to get an accurate report of how much they actually help. The general consensus says that cam changes don't effect diesels like they do gas engines. In other words, I wouldn't bother, just use the stock cam. The 6.2L and 6.5L share the same cam, whether turbo or not.

If you can afford to do it all at once, I'd install the timing gears and stud girdle kit while you've got it out. I'd also install new lifters if you weren't planning on it. The roller lifters will last a long time, but they may quit pumping up correctly. I'd also use Energy Suspension motor mount inserts. The stock motor mounts don't last long under the torque and vibration of the diesel. I've had to replace mine at least twice in the last 9 years. Now they're shot again (The rubber gives out and the engine sags, and then the metal rubs against metal). That's about all I can think of right now.

I don't think there's anything different I would do (other than the motor mounts). I'm very pleased with the results of all I've done.

Good luck!

Casey

[arveetek]

Well, I got the shop cleaned up, borrowed my buddy's engine hoist, and pulled the truck into the shop tonight. It's all set for me to start pulling the engine out first thing in the morning.

I'm not really looking forward to doing this too much. In my younger days, I used to be able to pull an engine out in my parent's back yard in the dirt, in the cold, into the late hours of the night, and really enjoy it. Now I have a nice concrete floor, heated shop, and it doesn't seem as easy to do anymore! I've pulled quite a few engines, but I haven't done so for about 3 years. Getting a little rusty I think...

Gee, from that paragraph, you'd think I was approaching retirement age or something. In case you were wondering, I'm turning 29 in April!

Anyway, just as a refresher, I'm going to be pulling the heads, replacing the lifters, installing new head gaskets, replacing the timing chain with the dual idler gears, installing new water pump, pulling the pan for inspection, installing the stud girdle kit (which I hope arrives by Monday!), replacing rear main seal, replacing any other gaskets as needed, installing new Energy Suspension motor mounts in the truck, installing new hood blanket on the underside of the hood, and finally, putting it all back together! Whew! Hopefully it won't take too long. I hate it when my truck is down for whatever reason.

Wish me luck!

Oh, I will be taking pics, in case anyone is interested.

Casey

[67_C-30]

Originally Posted by arveetek

Oh, I will be taking pics, in case anyone is interested.

Casey

I'll be tuned in Get a few good shots of the gear drive and stud girdle if you can. I can't wait to hear a sound clip from bad boy. I bought a 6.5L manifold and turbo for mine last week. I can't decide if I am going to build a pressure chamber like you did, get a 6.5L intake and chamber. I got hold of some thin wall stainless tubing this week also. If I can get it bent, I am going to polish it and use it as my pressure tube. I did this on (except it was straight) on my Z/28 and my brother's truck and it looked really good. (see pics below)




This may be a good mod for you since you'll have everything apart if you like that look.

[Beefcake]

dig that 67-c30!!

areveetek:
sounds like your doing a lot at once... lots of pressure. I have 3 vehicles so if ones down no big deal. Im glad you addressed the 6.5TD cam... Seems your right, cam profiles dont do much for turbos. Im also glad that you mentioned the lifters... Mine looked great- but Ill take your advice and not reuse them- btw, I guess they're used on many other engines.... So you might wont to consider using them on a 350 gasser.

Got a couple questions for you:
My cylinder walls also had very little wear. I was wondering what your thoughts are on doing a .5 overbore.. Using the same pistons, but going with larger rings. My pistons where very clean,... My main consern is the 6.2 has such high compression, that a larger ring isnt a good idea.- whats your thoughts???

[arveetek]

Well, I got the engine pulled out on Saturday, tore apart on Sunday, and I was getting ready to reassemble it this morning, when I discovered some damage on the # 3 piston. Looks like heat damage to me. I also found similar damage on # 2. I pulled # 3 and found a broken lower compression ring. I did some measuring and discovered that the cylinders are getting really tapered and worn out. So now I'm looking at a total rebuild, with boring and installing oversize pistons. I'm pretty disgusted. I should have known! I only planned on having the truck down for a few days, not a couple of weeks. If I had known that this motor was needing a rebuild, I would have rebuilt the spare 6.2L I already had and then swapped out the engines. Would have saved me a lot of down time.

I do have another work truck, a '96 Ford Power Stroke, but my Chevy is my baby!

I did find the collapsed lifter, so my original diagnosis was correct about that.

I re-ringed this engine 9 years and 120K miles ago, so I guess I should have planned on doing a bore job. Oh, well. Life goes on.

In answer to your question, BeefCake, I would not advise doing a mild bore and reusing the pistons. These diesels have extremely high compression and low clearances, so I would bore and install oversize pistons.

Casey

[Beefcake]

Sorry to hear that casey, Look at the bright side though, atleast it didnt break on you while you where pulling that trailer somewhere far away..... Im going to take your advice (yet again) and throw in some new 6.5 pistons.... This is why I like the 6.2 anyway... I figure its a little cheaper to rebuild than most diesels... although paying 800 bucks for a rebuild kit kinda makes me gag..... keep up the good work buddy!

peace out...

[arveetek]

Well, I was rather disgusted that I was facing a major rebuild when I hadn't planned on it, but now things are looking up. The Diesel Depot is going to make me some custom lower compression ceramic-coated pistons for a pretty good price. This should drop my compression from 21.5:1 to around 20:1, and make the engine last much longer under the stress of the turbo. Now I'm starting to get excited!

Beefcake,

When you say, "throw in some 6.5L pistons," do you mean you want to bore your block out to a 6.5L? If so, do you have a 92-93 model 6.2L? Only those year 6.2L blocks can be safely bored to 6.5L dimensions. Earlier blocks can only be bored to .040 over std.

Casey

[Beefcake]

Ugh.... You must be talking about the 599 block.... I guess your right, Bummer... was hoping I could use 6.5 pistons for cost. Are 6.2 pistons forged?? I might get away with just a hone job...

[67_C-30]

What have you heard about head work to improve performance on a diesel? Do you know how they respond to a clean-up of the ports and maybe a bowl blend job. You would obviously want to leave the combustion chamber alone (unless you were a pro on diesels) because the CC is much more crucial on a diesel than a gas engine.

[arveetek]

I've uploaded some pics of my progress. I have more pics to post yet, but this is a good start:

http://community.webshots.com/album/286393940AoOzqp

Here is a pic of the damaged piston that led me to my complete rebuild; sorry it's not better quality:

http://community.webshots.com/photo/...86420409QqmfHy

I'll continue to update this album as I go along.

Casey

[Beefcake]

Well, from what I understand you can swap to 6.5 heads. They flow better... But I like the gas mileage on the 6.2 heads. I plan on doing some work to them to make them flow better (specially on the exhaust side).. but other than that... Im not going to go 2 crazy.