Wrench's Engine Thread

[Wrench]

Sooooo,

Think I mentioned it already, but I recently bought a '93 6.5TD for $600, sold the transmission (2wd NV4500) for $700 and kept the complete engine, rad, and various other little things.

Today I hauled my free 6.5 inside and tore it apart. Everything looks in great shape excepting the block, which has cracks in all three middle webs on both sides. My original plan was to swap the entire engine in place of my 6.2, but I'm not about to use the cracked block.

I have a set of ARP head studs (purchased locally brand new for $120 from a fellow who also ended up discovering cracks in his block), 6.5 complete engine gasket kit (Victor Reinz) and set of 6.5 head gaskets that I bought on Ebay from a former GM dealer mechanic.

I also have a b/n Dodge intercooler ('97 I believe)that I picked up cheap, and silicone turbo hose to adapt the 2.5" GM turbo to the 3.5" intercooler pipes.

My plan now is to check my 6.2 for cracks first, and find a crack free block if it is cracked, preferably a later 599 6.2 block so I can use the one-piece rear main crank out of the 6.5 if I need to.

I will then use the 6.2 short block with 6.5 dressings (heads and up, serp. and accessories) and the intercooler. Stud girdle kit--ceramic coated pistons maybe--splayed mains?

My hope is not to have to do an actual rebuild--i.e. bearings and rings, machine work, the expensive stuff. I want to use a block in good condition and implement the best practices for ensuring that it never cracks.

I'm wondering about the ceramic coated pistons--it's my understanding that they go along with the turbo on the 6.5's, but there are dozens of turbo'ed 6.2's out there. Are those 6.2's not being used for heavy towing, do they suffer eventually, and to what extent does the intercooler assist in the heating problem? Anyone else ceramic coated their 6.2 pistons? I want to optimise the engine for towing, but do everything possible to ensure trouble free long life.

Thanks for the opinions guys

 

[Russell]

I have one of those 599 6.2L blocks sitting in my shop, I couldn't see any cracks in it, but it would most likely need an overbore...

I finally got my 6.5L and NV4500 pulled out on Saturday, and will be starting my build on this coming Saturday. If you were interested, you could take a look at my 6.5L's bottom end, and see if it is better than your's is. I bought it under the pretense that the crank was broken, or that it had serious bottom end problems, but discovered that the balancer's rubber is totally torn out, and the cause of the noise, so it is entirely possible the engine is perfectly good.

I was thinking about starting it on the shop floor after putting my 6.2L's balancer on, and if it is good, I'd be selling it naturally aspirated.

 

[Wrench]

coolness, now i am going to have to toodle on out there sometime . . . Anything you're still looking for?

I'm still trying to weigh the advantages/disadvantages of going 6.2 with complete 6.5 equipment or just going 6.5. As I'm looking at it the only difference would be the extra 0.3 litres of displacement and the coated pistons. My understanding is that the coated pistons are to help with the extra heat generated with boost?

 

[kennyw]

I bought it under the pretense that the crank was broken, or that it had serious bottom end problems, but discovered that the balancer's rubber is totally torn out, and the cause of the noise

Pull the oil pan no matter what on that motor... bad balancers cause broken cranks and cracked blocks on these motors.

 

[MaxPF]

coolness, now i am going to have to toodle on out there sometime . . . Anything you're still looking for?

I'm still trying to weigh the advantages/disadvantages of going 6.2 with complete 6.5 equipment or just going 6.5. As I'm looking at it the only difference would be the extra 0.3 litres of displacement and the coated pistons. My understanding is that the coated pistons are to help with the extra heat generated with boost?

The pistons aren't coated, they are hard anodized. The purpose of the anodize is to inhibit surface cracking in the pistons due to thermal stress. It was done to give a margin of protection during excessive temp spikes. The 6.5 doesn't have an EGT sensor like the newer diesels that the ECM can read and defuel if EGTs get too high.

Hard anodized pistons definitely help enhance durability under high EGT conditions, especially on older engines that don't have piston oil spray jets for cooling. One thing to keep in mind is that newer DI diesels don't have anodized pistons, and DI should theoretically put mote heat into the piston. My guess is that the oil spray cooling works so well that the anodizing isn't considered necessary (or desirable).

 

[Wrench]

Ok, that makes sense. Am I correct in believing that the 6.5TD pistons are anodized, and the 6.2NA pistons are not?

 

[MaxPF]

Ok, that makes sense. Am I correct in believing that the 6.5TD pistons are anodized, and the 6.2NA pistons are not?

That's correct. Of course, a good (i.e. aerospace quality) anodize shop can mask the piston with paraffin and hard anodize the crown. I thought about doing that to mine, but decided it wasn't really needed for what I am doing.

Another option is to ceramic coat an unanodized piston. I don't have any firsthand experience with ceramic piston coatings other than the OEM ceramic coatings on crotch rocket pistons - I don't know if the aftermarket coatings are the same though...

 

[Wrench]

Well, I picked up a good early 6.5 longblock (thanks Russell!!), so I will be going with the complete 6.5. Head studs and girdle kit will assist with longevity, and an intercooler should help with EGT's. I'll be using a new but factory timing set--the dual idler gearset is ridiculously expensive and I've got doubts as to the reliability. Unless someone wants to convince me otherwise . . .. I'll also turn up the pump a bit and perhaps experiment with a manual wastegate controller after I have EGT and boost gauges installed.

Next question--I have two sets of rocker arms, one off the original 6.5 and another off a set of 6.2 heads that I had lying around. The set off the 6.2 looks like a much better design and should bolt straight up, so I'm planning to use them. Does anyone know if the 6.2 set is stock or why they are different? FYI, the 6.2 set is the cast rockers and the 6.5 set has the stamped rockers.

Thanks!!

 

[Russell]

Your welcome!

As far as the rocker arms go, any 6.2L I've taken apart has had the stamped rocker arms as well, I am not sure if those are stock or not...

 

[tRustyK5]

my '83 6.2 and my '85 6.2 both have the cast rockers...

Rene

 

[Wrench]

Interesting . . . the cast ones seem like a better design to me, don't think it would be a weight issue as the diesels aren't high revving engines. Think I'm gonna go ahead and use the cast ones. I was browsing through my Haynes diesel engine repair manual and noticed that they show pictures of both types as well, so it must be an OEM design.

does anyone have strong opinions one way or another as to dual idler timing gears opposed to OEM timing chain and sprocket?

 

[MaxPF]

Interesting . . . the cast ones seem like a better design to me, don't think it would be a weight issue as the diesels aren't high revving engines. Think I'm gonna go ahead and use the cast ones. I was browsing through my Haynes diesel engine repair manual and noticed that they show pictures of both types as well, so it must be an OEM design.

does anyone have strong opinions one way or another as to dual idler timing gears opposed to OEM timing chain and sprocket?

From what I understand the cast rockers had oiling issues with the bushings, which caused them to wear prematurely. Personally, knowing what can happen if one of those stupid little plastic buttons breaks off on the later rockers, I would run the cast ones.

I'm running the gear drive on my engine. Lots of people run them on gassers and they seem to be fine reliability-wise. I agree they are overpriced if you buy them from DSG or Kennedy. They include a custom made reluctor ring for 6.5 electronic apps that we don't need on our mechanically-injected motors. The DSG/Kennedy drives are made by Pete Jackson, and it just so happens that Summit and Jegs both carry the same part, sans the reluctor ring, and they want a lot less for it.

The Summit Part # is PJJ-6-2-D, and lists for $251.39

The Jegs part # is 782-6.2D and they want $246.99 for it.

 

[tRustyK5]

That's a $200 saving...and I had no idea Pete Jackson made those and Kennedy and DSG were just marking up and re-selling them.

Thanks Max!!

Rene

 

[Wrench]

That's good to know about the rockers, might fiddle with them a bit and see if I can't figure out/improve the oiling issue, but confirms what I was thinking..

Boy, I never even thought to check Summit and Jegs for prices. Just think of all the money I'm saving: The $470 price tag scared me off, so I was going to go with the $80 OEM setup. Now I'm tempted to go with the $250 price, because I'm "saving" $220 over the other option. Wow, I'd make any Scot proud

The nice thing about DSG is that it's within driving distance--less than 2 hours. Maybe I'll call them and pester them about selling a set without the reluctor ring for a price comparable to Summit .

 

[Wrench]

I also didn't know pete jackson made stuff at all , but I did know that it was called a pete jackson gear drive

 

[Russell]

I personally just put a chain into mine. I considered the gear drive, but figured it wasn't worth the extra cost. I should be getting your girdle kit either tomorrow night, or Saturday morning. I head back to my apartment on Sunday night, and can meet you either in the city, or just make the trip out to your place whenever you are ready. How did unloading that engine without a crane go?



BTW, I pulled the valve covers off my engine today to clean them up and paint them tomorrow, and guess what, cast rockers! First time I've seen a set out of the four engines I've disassembled, lol

 

[MaxPF]

That's a $200 saving...and I had no idea Pete Jackson made those and Kennedy and DSG were just marking up and re-selling them.

Thanks Max!!

Rene

Well, DSG does make the reluctor ring they include with the 6.5 electronic kit. Still, the one they sell for the mechainical motors is just the PJ drive with a $170 markup

Wrench, both Summit and Jegs have fast shipping. No reason to not order it from one of those two if you decide to go gear drive...

 

[Russell]

One thing to be aware of is that both ship UPS, so be prepared for a brokerage fee between 50 - 130 bucks if you buy from them. Thats half the reason why DSG's cost as much as they do.

 

[kennyw]

You could buy it and have it shipped to a friendly US member near the border that could promplty re-address it and send it via the post office. I would guess that could save you something?

 

[tRustyK5]

Jeg's ship Fed-Ex internationally and the brokerage portion is up front...unlike UPS which holds your stuff for ransom when they get to the door with it. Fed-ex's brokerage is a lot more reasonable too. i bought my clutch kit from Jegs.

My ARP head studs I got through Summit and they used USPS at my request. Cost me nothing for brokerage and only had to pay the tax when it got to the post office here.

Ordering by phone is the best, that way you can discuss shipping options with a real live person. Both Jeg's and Summit really have it together with international shipping. They get a lot of practice and know all the issues. I wouldn't hesitate to order from either of them again.

Rene