Modded 93 6.5 finally ready to Install !

[robscarab]

Hi folks,

Well I am just about finished dressing my rebuilt 6.5 TD and will be installing it soon. I followed the recommendations of the members here and ended up with this:

1993 "599" block cleaned and inspected for cracks by magnafluxing

bored .030 over
Mahle 18:1 pistons
Polished stock crank
Resized stock rods
DSG stud girdle kit
New Clevite bearings including cam bearings
New Heads from DSG
DSG Phazer timing gear kit
New DB2 IP turned up 1/8th turn
DSG oil cooler kit with SS lines
New GM 8 turbo
Turbomaster wastegate controller
New DSG marine injectors + install kit
AFE complete high flow intake system
Banks "stinger" complete exhaust system incuding X-over pipe and downpipe
DSG dual thermostat cooling system with HO waterpump, new style fan clutch and composite 9 blade fan upgrade
HD torque converter and stock 4l80E transmission completely rebuilt by a well known and highly recommended Trans expert

Gauge package: EGT, Boost, IAT, WT, Oil temp, trans temp

I have a few questions for the members here please :

I was unable to have the rotating assembly balanced due to time constraints, and am very concerned that I have made a big mistake! I spent a lot of money on this rebuild and I am hoping that my haste in building this beast will not bite me later on! Has anyone here installed the Mahle pistons without rebalancing the engine? I weighed them and they are slightly lighter than the OEM pistons. Will this throw the balance off too much or is balancing mainly an added precaution that is not completely necesscary? The machine shop that did the work on my block said they have done alot of 6.5s like this (without balancing) and have not had any returns or warantee issues.
Perhaps a fluid dampener would help here?

Also, I have a self contained engine test stand that I use for cam break-in and leak checking gas engines that I build. I would like to put the 6.5 on this stand to check for leaks and make sure everything is working ok before putting it in my dually. What electrics do I need to hook up to function the DB2 and glow plugs properly for a test run? Can I just simultaneously hook up 12 volts to all the glow plugs for a few seconds before cranking or do I need to put the controller in the circuit? They are the original glow plugs that came with the truck and I cleaned the carbon from them, and checked the resistance on all of them. 2 were burnt out and I replaced them with new 1993 glow plugs as supplied by Napa.

Lastly, I am curious about the rad this truck came with. It is an original 1993 6.5td 1ton crew cab dually that has been VERY well maintained. I was surprised to see that the rad appears to be a GM 2 core deal, and I would think that it should be a 4 core? The rad on my 93 gas suburban has a core that is as thick as the plastic tanks on each side, but the core on the dually does not cover the full thickness of the tanks? Is this normal? Perhaps the previous owner installed the wrong rad during a repair? Anyway, if someone here could recommend a good stock or aftermarket rad I would consider changing this one. I have also considered an intercooler for this rig and if she runs too hot while towing that will be next on the list...

One more quick question: How much hp and torque do you folks think this set-up will give me ? I have a g-tech and will eventually measure it after it is broken in properly, but I would love to hear some estimates now, and I will report my actual readings next month.

Thanks for all the help so-far everyone! Although I havn't posted much, believe me, I have been lurking here almost every day! The search function here has been used for every step as I have built this engine. The collective knowledge here, and your willingness to take the time to share it with others, has been invaluable in creating this beast ! You all have saved this single Dad a TON of money so far, and given my sons and I a great amount of satisfaction in being able to DIY our first diesel project. Ya just gotta love the internet, and the people like you that contribute to it !!:D

Pictures to come soon...

Rob

[robscarab]

Sorry, forgot to ask this one:

This may primarily be a question for Robyn I think, and it is about the fuel line relocate procedure. I was just wondering if anyone may have any pictures of the fuel lines after they have been relocated from the tight factory position, to the place where Robyn and others have been moving them? I have read all the threads and was just wondering if I could get a visual of this to help? And speaking of the fuel supply, I was wondering if there is a consenses as to the best lift pump set-up, OEM or some other aftermarket type? I will be installing a Racor filter in the low pressure fuel system as well so perhaps the OEM design is too weak to function well with the added (slight) restriction of an auxilliary fuel filter?

Thanks

Rob

[More Power]

robscarab,

You should see at least 200 fwhp, maybe more, it depends on the boost pressure and fuel rate. An intercooler would help if you're running above 10 psi.

The cores used in the copper/brass rads are usually less wide than the end tanks. The last one of those I had recored using a special order 5-row core, which did use the full width.

Incidentally, the 1994+ aluminum radiator, top rad mounts and fan shroud are a bolt in mod for the 1993 and earlier trucks. The aluminum radiator is a couple or three inches taller than the copper/brass version. If I had a 1993 or earlier truck that needed a new rad, I'd be inclined to install the newer aluminum version.

Balancing the rotating assy is an option, but usually a good one. The perf 6.5 I last built ran very smoothly at idle and above. I'd have it done the next time.

The DB2 equipped engines just need a hot wire to the fuel shut-off solenoid to run. You could rig a temporary glow system to light them up on the test stand. If you're using AC-60G or any of the newer PTC glow plugs, you could glow them for most any reasonable length of time without risk (10-30 seconds). We've tested the AC-60G and the Quickheat for much longer than that, but there's no real reason to go longer than 30 seconds.


Thanks for all the help so-far everyone! Although I havn't posted much, believe me, I have been lurking here almost every day! The search function here has been used for every step as I have built this engine. The collective knowledge here, and your willingness to take the time to share it with others, has been invaluable in creating this beast ! You all have saved this single Dad a TON of money so far, and given my sons and I a great amount of satisfaction in being able to DIY our first diesel project. Ya just gotta love the internet, and the people like you that contribute to it !!:D


Speaking for everyone -You're welcome!

Jim

[robscarab]

Thanks for the detailed response Jim !

I am learning how to post pictures right now and will display some photos of the rad I have. Perhaps you can tell me what I have by looking at it? It may already be the updated 94+ rad you speak of. I want to make sure my rad is up to the task of cooling this rig after upgrading all the other componants!

I was considering limiting my boost to 8-10 psi while I am breaking in this engine. I will be using the truck to make a cross-country trip shortly after I get the engine installed. It will be hauling 10,000+ lbs and I hope this won't be detrimental to a good ring seal. I have heard 2 conficting stories as to how to properly break-in a diesel. One method states to drive it fairly hard after the first hundred miles or so, apparantly to facilitate high cylinder pressures, thus creating a good ring seal? The other method states that I should be taking it easy for the first 5000 miles before using lots of throttle while pulling hills with a load etc.

Any thoughts on this?

As far as horsepower goes, I was hoping for 200 to the rear wheels with all these mods. It sounds like I was being way to optimistic LOL! How much boost will be required to achieve this goal....or am I looking for trouble with boost levels beyond 10psi ? I don't mind springing for an intercooler if it will help me achieve 200 rwhp safely. Actually I am more interested in torque in the mid range. I was hoping to change to a 3.42 ratio from the current 4.10 if I can produce enough torque down low. What do you estimate my max torque will be as it is built right now? When I get my intercooler and go for 15lbs boost, how much torque can I make then? I cant seem to find the thread that states the #'s achieved with the "6.5TD power project, but perhaps a link to that would answer my questions more easily.

I had a modded 02 Dodge 5.9 with 240 rwhp on a dyno, and was completely happy with that level. I cant remember the torque but I believe it was over 600lbsft. If I could get close to those numbers with this GMC I would be really happy. The Dodge ride and handling just never appealed to me and I really missed driving GM products during those years! This website convinced me to build a 6.5TD for my family heavy hauler..

Thanks,

Rob

[robscarab]

Oops, forgot to ask about the glow plugs.

Should I replace all my glow plugs with the newer style units while the engine is out? As I mentioned I tested the ones that came in the blown engine and reused 6 of them. I am not sure how much time is on them but some are bosch and some are AC. What is the expected average life of a 6.5 glow plug? What are the best gp's to install into a lowered compression 6.5?

Thanks All,

Rob

[j_k_auto]

Oops, forgot to ask about the glow plugs.

Should I replace all my glow plugs with the newer style units while the engine is out? As I mentioned I tested the ones that came in the blown engine and reused 6 of them. I am not sure how much time is on them but some are bosch and some are AC. What is the expected average life of a 6.5 glow plug? What are the best gp's to install into a lowered compression 6.5?

Thanks All,

Rob

I would say replace them for what it is worth while you have the engine out. From what I read they should be replaced every 100,000 miles but to each is there own.:)

[More Power]

I'd want to put at least 500 miles on the engine before towing heavy and to provide enough of a shake-down before driving long distance. Then change the oil & filter.

If you have the 4L80-E automatic, you should be able to reach the transmission input torque limit of 440 lb-ft pretty easily with 10-12 psi boost pressure and enough fuel to produce a barely noticeable smoke level at full pedal. Your best towing performance will come at 2000-2400 rpm. That's where I'd run it on the flats (~2000-2200 rpm in OD) and while climbing hills (~2100-2400 rpm in 2nd or 3rd). If you'll be towing a lot, an intercooler would be a wise investment.

If your engine has the older AC-9G glow plugs, I'd change them as soon as possible...

Jim

[ronniejoe]

For the record...

The bigger aluminum radiator that was installed in the later trucks was not done to improve cooling. It was done to reduce cost. Aluminum is much less expensive than copper.

Copper has a thermal conductivity of 401 W/m-K. Aluminum has a thermal conductivity of 237 W/m-K. this is a 41% reduction in thermal conductivity, which roughly equates to a 41% reduction in cooling effectiveness. The increase in size of the radiator when switching from copper to aluminum was an attempt to regain some of the lost cooling capability.

GM was not thinking about us and our overheating issues when they made this decision.

High boost will increase the ring seating force and cause the rings to seat more quickly. I started towing with mine within the first 100 miles. I did change the oil after about 500 miles and didn't get too far from home until after that.

With intercooler and substantial external mods (stock turbo), I made 225 hp and 435 lb-ft at the rear wheels on Kennedy's dynamometer in 2004. My new engine runs at 23 psi boost at 3600 rpm and is now considerably more powerful, but no numbers yet.

[JohnC]

I'm with RJ on this. No reason not to load it up right out of the gate.

The only reason to go easy on a new truck is to allow the ring and pinoin(s) to wear in without overheating.

[robscarab]

Thanks guys, I'll hook my 5th wheel (8500lbs) to it for a tank of fuel before heading out on the big trip. The main idea seems to be to check it out first before getting too far from home. I will be able to regulate boost with the turbo-master ,so any thoughts on what to set it at for initial run-in? I was thinking about 10 psi with the LC pistons. Perhaps I should let the EGT gauge be the judge on that?

Interesting stuff on the rad. I have decided to go with a new one, so what year rad should I purchase? I looked up the part# on the rad I have ,and it is not the correct rad for my truck! It appears to be a 350 rad for a 93 GMC 1 ton.

Has anyone here ever run with aftermarket pistons without balancing the rotating assembly? That is my biggest concern since they weigh less than the OEM slugs. I didnt realize the weight difference until I had everything back from the machine shop. The balancers in my area are backed up for several weeks ,so I took a chance after the machinest told me they build them unbalanced all the time... I would love to hear from someone here that they are running an unbalanced engine long term without crank failure..

Thanks

Rob

[More Power]

Hey RJ,

How does the heat conductivity vary between cast iron and aluminum? I'm thinking about the aluminum Duramax cyl heads.

Jim

[ronniejoe]

Cast iron will be in the neighborhood of 80 W/m-K depending on the chemistry.

The aluminum cylinder heads will actually hurt efficiency some, since they transfer heat out of the combustion chambers more quickly. This heat is lost and not put to productive use. The advantages come in the form of strength to weight ratio and other factors. It's a trade-off when you decide what material to use.

[robscarab]

As for the cast iron vs. Aluminum cylinder heads I had an interesting experience. A friend of mine asked me to build him a small block 383 for his shortbox chevy. I used cast iron vortec heads, ported them and smoothed and polished the chambers. I used hypereutectic pistons with a slight dish to create an 8.5-1 compression ratio, since he used this truck to tow his boat sometimes and wanted to run regular gas. This summer he asked me to put some Edelbrock heads on it. I told him to get some flat-top pistons as well so I could increase his compression to 9.5-1 . He didn't want to spend that much, but wanted the look of aluminum heads anyway. I lightly ported them and we put them on. According to my G-Tech he lost at least 15 hp, likely more ! I have carefully set the timing for max power and did a leak down test etc. The engine runs very well but, as expected, the aluminum heads do not convert as much heat/energy into work. I have read about this thermodynamic law for years ,but this is the first time I have witnessed it.

Anyhow, any thoughts on the best OEM rad for my rig folks?

94+ or newer?

Thanks,

Rob

[More Power]

I used to get an occasional copy of "Movin' Parts" magazine/newsletter from the local GMC dealer. This mag dealt with the automotive service industry. The August 1998 - vol. 24 No 8 issue contained an article, entitled "The Allure of Aluminum", that discussed the transition to aluminum radiators in the service parts business.

In this article, ACDelco manager of heating & cooling Derrick Thompson said:


"...it's stronger, lighter weight, corrosion resistant, and transfers heat more efficiently. The radiator's design allows it to outperform the copper/brass versions. The brazed aluminum design allows for improved heat transfer and low pressure drop."

I suspect there's more to heat transfer efficiency that simply the metal alloy used. Based on what I know now, if I were replacing the radiator in one of these trucks, I'd go with aluminum. JMHO... :)

Jim

[ronniejoe]

That's funny... When Caterpillar was faced with a heat load problem a few years ago in their track-type tractors, they planned to go away from aluminum to copper for the radiator with a cost penalty booked.

I have personally sized heat exchangers before and know a little about heat transfer. If I had the choice, I'd choose a copper radiator over aluminum any day. The key word preceding the quote above is "manager". No one in his right mind would ever say that aluminum transfers heat more efficiently than copper, unless, of course, he knows nothing about heat transfer.

One must be careful to discern between marketing spin and engineering principles.

If (and it's a big if) the designers were able to increase the surface area significantly beyond what is required to make up for the difference in thermal conductivity, then maybe one could say that the "brazed aluminum design allows for improved heat transfer and low pressure drop." I doubt that is the case. If one were to make a copper radiator the same size as the aluminum one, it would outperform the aluminum one handily.

Remember the GM folks bragging about how tough and durable the 6.5 was back in 1992?

Believe whatever you want to believe.;)

[More Power]

I suspect there's more to heat transfer efficiency than simply the metal alloy used. ;)

[robscarab]

Can anybody tell me if my 1993 1 ton CC dually came stock with a 4 core rad? The rad in it when I bought it is a 2 core aluminum with plastic tanks, large inlet and outlets, built in tranny cooler and an unused built in engine oil cooler? The rad in my 93 5.7 tbi Sub is a 4 core aluminum with smaller outlet and inlet openings, built in oc and tc, but is physically about 10% smaller. It seems strange that my 1/2 ton Sub with towing package has more cooling capacity than my 1 ton 6.5 TD ?

I am thinking that the proper OEM rad for my rig would be a 4 core aluminum, large outlet/inlet, built in tranny cooler, but no integrated oil cooler. Engine oil was cooled by the aux. OC and the tranny was cooled by an integrated tranny cooler + an aux connected in series? Am I correct or is this 2 core rad OEM stock for this application? (the truck does have AC if that matters)

Thanks

Rob

[More Power]

The total wetted surface area of those tubes is more important than the number of cross tubes. Generally, aluminum rads use larger oval shaped cross tubes than those used in a copper/brass radiator.

Jim

[john8662]

Taken from MP's Post above...

In this article, ACDelco manager of heating & cooling Derrick Thompson saiid:



"...it's stronger, lighter weight, corrosion resistant, and transfers heat more efficiently. The radiator's design allows it to outperform the copper/brass versions. The brazed aluminum design allows for improved heat transfer and low pressure drop."

Just one thing from that statement really hits home about cooling efficientcy.

The part that I placed in bold.

If a radiator remains primarily corrosion-free, then it simply will maintain it's capacity to transfer heat properly.

I suspect that a newly depolyed brass/copper radiator quickly loses it's peak ability due to corrosion starting internally, which has to affect the ability the radiator/device to transmit heat as well as it did when in it's pure (non-tarnished) state.


And, to draw attenion to what Rob is asking concerning the correct radiator that's supposed to be in HIS truck :) Cause I ain't got no '92-93.

J

[robscarab]

I cant find one thats in stock at any of our local parts stores here! I was hoping to have a look at it, and if it is different from what I have than I will purchase it. They are pricey (700.00) and I really dont want to end up with the same one. Even if you dont have a 92/93 perhaps members here could describe what their trucks are equipped with? (2 core or 4 core) I would be interested to know what changes (if any) occured after the cooling system upgrade took place in 97... Im wondering if maybe I have a rad designed for an NA 6.5 or 6.2 ?

[dieseldummy]

My '93 and all others I've seen from that time frame have 4 core units. A 2 core unit won't be enough to keep a stock 6.2 cool much less a higher HP motor. Ideally I would have a 5 core unit made as big as possible to have maximum cooling ability.

[robscarab]

Thanks for confirming that. Ordering an OEM rad tomorrow. I will be asking for the 1993 unless anyone here has info on a better year to ask for? Do you think they upgraded the rad in 97 when the cooling system was improved?

Rob

[dieseldummy]

If you get a later model alluminum radiator you'll have to replace the lower radiator hose and coolant resevior. I don't know that either one will give a cooling advantage.

[robscarab]

Thanks DD, Ill keep it simple for now and get the stock unit so I can get it up and running this week!

[scabbybooger]

Could you tell me the brand/part numbers you used for your Radiator Cooling Fan Clutch and Blade?

[jggiedeman]

Hello,
My FIL came to me for assistance in locating the correct radiator for his 93 C3500. I was his fifth attempt. Autozone, Pep Boys, O'Reilleys - They have creative part numbers for them and it was easy to confuse a 6.2 for the 6.5L. Also the brass one has no engine cooler installed while the newer aluminum unit does.
I had him buy the brass unit and the Autozone guy gave him a big discount to not come back.
His original lasted 19 years.
As for changing your system to 94 and newer - you have more parts you would need to purchase to make that work. the pressure cap would be mounted on the surge tank, newer updated hoses, etc. A lot of work.
The best you could do is as Jim B mentioned - a custom built unit that sheds the heat.