Build Your Dream 6.2/6.5

[thirdstreettito]

I'll start it off with:

1984 Chevy C10 SWB

Full custom coilover suspension able to go over speed bumps.
Paint doesnt matter.
Autometer gauges
Recaro seats and Tuffy security console
Bang and Olufsen Sound system
4 wheel 6-piston disc brakes with Hydratech master cylinder/booster
3:42 Currie 9-inch with 5x5 drilled axles
Built T56 6-speed transmission
All aluminum driveshaft
Vintage Air under-dash A/C

Engine:

Brand New Moly CNC machined 6.5 block
Autorotor roots-type supercharger with separate lubrication system and 13 PSI pulley
DB4 Pump fuel screw turned 1/2
Cast aluminum hypereutectic pistons with anodized domes
Custom 4bolt main bearing caps and 1/2 inch stud and girdle strengthener with 12mm ARP studs in all positions
Cast Iron heads ported and polished with larger intake and exhaust ports
Silchrome steel intake and exhaust valves
Induction hardened valve seats and hardened stamped steel rocker arms
1141 SAE forged connecting rods with 10mm heavy duty connecting rod bolts
Roller lifters for increased performance and decreased friction
Piston oil spray cooling
Custom stainless steel exhaust manifolds, 1 5/8" to a 3 3/8" collector with aeroturbine 4040XL
Serpentine drive with gator belt
2900cfm belt driven fan and 3300 16" electric fan and severe duty fan clutch and 130gpm water pump
6 core aluminum radiator
Duramax intercooler with 3 1/2" tubes
120 amp alternator
Racor R60S 2 micron with water separator bowl with probe for water sensor
16 row GREDDY oil cooler
Custom Aluminum engine mounts
High torque starter
Dual 1200 CCA batteries
DSG Gear drive timing
4340 Forged steel crankshaft
Custom dual 3" aluminum and silicone fitting cold air intake
Clevite 77 main bearings
ARP head studs
Custom aluminum oil pan
A1 Customs Dual stage water/mist injection
A1 Customs ISS Ignition
SS Diesel High volume oil pump
65hp injectors
Schaeffer synthetic 15W-40
Felpro head gaskets
Delta Cams custom ground cam
Carter electric lift pump
Alternator electric tachometer hookup
Quick heat glowplugs

[thirdstreettito]

Come on, I know Im not the only one with dreams!

[DmaxMaverick]

Come on, I know Im not the only one with dreams!

Sure we dream, but that's a tall order. A lot of your list is: unrealistic; unobtainable; doesn't/won't exist; already being used since 1982; impractical; counterproductive; counterintuitive; cost prohibitive, and/or, in some cases, weaker than OEM. In the end, you probably won't have a streetable solution, and could do a lot more with a lot less. Or....Get 4x the power, performance, and reliability from a proven Duramax or Cummins, at 1/20th the cost. But, it's your dream.

[CleviteKid]

I have the 1984 C10 short bed short wheelbase. You supply the rest and I will think about it. :D

[CleviteKid]

Except, anything from A1 Customs will be shredded with the Mini14 on sight.

[thirdstreettito]

Sure we dream, but that's a tall order. A lot of your list is: unrealistic; unobtainable; doesn't/won't exist; already being used since 1982; impractical; counterproductive; counterintuitive; cost prohibitive, and/or, in some cases, weaker than OEM. In the end, you probably won't have a streetable solution, and could do a lot more with a lot less. Or....Get 4x the power, performance, and reliability from a proven Duramax or Cummins, at 1/20th the cost. But, it's your dream.

Wow, so unimaginative. What on my list doesnt exist?

[DmaxMaverick]

I've been tinkering with these things for near 30 years. Some things work, some don't. I'll hit some high notes and try to keep it simple:


I'll start it off with:

1984 Chevy C10 SWB

Full custom coilover suspension able to go over speed bumps.
Paint doesnt matter.
Autometer gauges
Recaro seats and Tuffy security console
Bang and Olufsen Sound system
4 wheel 6-piston disc brakes with Hydratech master cylinder/booster
3:42 Currie 9-inch with 5x5 drilled axles

Built T56 6-speed transmission
(1) Weak, no matter how you build it. Fine for a 'Vette or Viper churning 7K RPMs.

All aluminum driveshaft
Vintage Air under-dash A/C

Engine:

Brand New Moly CNC machined 6.5 block
(2) Doesn't exist. Engineering costs alone will exceed most high performance professional competitive engines available off-the-shelf. 10's/100's of thousands of dollars, and it may gain you nothing over what's available on the current market.

Autorotor roots-type supercharger with separate lubrication system and 13 PSI pulley
(3) Great for gassers. Junk for Diesels. 13 PSI is easily obtainable with a turbo, at a 90% efficiency advantage and a higher return. A positive-displacement compressor is not an advantage on a 4-stroke Diesel, other than elimination of turbo-lag off idle. No advantage after that.

DB4 Pump fuel screw turned 1/2
(4) Why 1/2 turn? Why not 1/8 or 3/4? Why a DB4, and not a higher volume DB2-4911? Of course, 4 is bigger than 2.

Cast aluminum hypereutectic pistons with anodized domes

Custom 4bolt main bearing caps and 1/2 inch stud and girdle strengthener
with 12mm ARP studs in all positions
(5) 12mm studs or piston oil spray. Pick one. It already has 4-bolt mains.

Cast Iron heads ported and polished with larger intake and exhaust ports
Silchrome steel intake and exhaust valves
Induction hardened valve seats and hardened stamped steel rocker arms

1141 SAE forged connecting rods with 10mm heavy duty connecting rod bolts
(6) See #2. Similar condition.

Roller lifters for increased performance and decreased friction
(7) Already has them, since 1981.

Piston oil spray cooling
(8) Late model 6.5L's have this.

Custom stainless steel exhaust manifolds, 1 5/8" to a 3 3/8" collector with aeroturbine 4040XL
(9) They sound nice, but snake oil other than that.

Serpentine drive with gator belt

2900cfm belt driven fan and 3300 16" electric fan and severe duty fan clutch and 130gpm water pump
(10) Why only 2900 CFM? Why not the OEM 10K CFM? If you plan on a lot power, you're gonna make a lot of heat. 2900 CFM and an electric won't keep up for more than a minute.

6 core aluminum radiator
(11) A 6 core aluminum radiator will be nearly a foot thick. Got room for that? 6 core or aluminum. Pick one.

Duramax intercooler with 3 1/2" tubes

120 amp alternator
(12) Too small.

Racor R60S 2 micron with water separator bowl with probe for water sensor
16 row GREDDY oil cooler
Custom Aluminum engine mounts

High torque starter
(13) Already has one.

Dual 1200 CCA batteries
DSG Gear drive timing
4340 Forged steel crankshaft
Custom dual 3" aluminum and silicone fitting cold air intake
Clevite 77 main bearings
ARP head studs
Custom aluminum oil pan

A1 Customs Dual stage water/mist injection
A1 Customs ISS Ignition
(14) Snake oil. All of it. (what ignition?)

SS Diesel High volume oil pump
(15) Same as any late model 6.5L pump. Or, you could pay double if you insist.

65hp injectors
(16) Doesn't exist. Prove it, if you think so.

Schaeffer synthetic 15W-40
Felpro head gaskets

Delta Cams custom ground cam
(17) Custom ground to what spec? How is this better than stock?

Carter electric lift pump
(18) Carter?

Alternator electric tachometer hookup
Quick heat glowplugs

If you're gonna dream, dream big. Problem is, you have to wake up, sometime. We've all been there.

[thirdstreettito]

I understand what you mean, I wasnt able to find info and some things.

1. T56 is one of the best transmissions. It is behind 2000hp twin turbo Viper's, Vette's, GTO's, and Stang's.

2. Southern Marine purchases this block all the time.

3. Bullet Cars has done many of these and have achieved great power and mpg.

4. Marine Diesel uses this pump on their 475hp engine and the DB on the weaker ones. Also, 3/4 is too much, 1/8 is too little. 1/2 is just right(testing needed of course)

5. I dont know much about that, so Im not keen on which is better.

6. Marine Diesel puts these in all of their engines.

7. Did not know that, thanks for the info.

8. I was specifying everything in the build.

9. I dont know what snake oil is, but SS is used on race cars, and with the large collector and smooth interior wall will yeild better flow.

10. I have done more research and will just use the stock mech fan.

11. I have talked to Bill Williamson at Ron Davis radiators and am waiting on his next email for more info. But it will not be a 6 core.

12. Why do you say that? My burb has a 90 and its fine.

13. Again, just specifying.

14. Again, I dont know what snake oil is. ISS = Ignition Switch Saver

15. Thanks for the info, now I know.

16. I cant find them now :(. I guess I'll just go with the 45hp.

17. I havent decided that yet, still havent worked everything out.

18. Yes, they make Fuel pumps, I had one on my previous truck, I may go Racor though.



Sources:

http://www.marinediesel.nu/

http://www.southernmarine.co.za/

http://www.bulletcars.com/

a1 customs (dot) com

[Robyn]

To build a great 6.5 is not a real expensive thing.

The DB2 pump can deliver more fuel than the engine can handle under most conditions.

The "moly" block is not doable

There are good aftermarket blocks available.

Coated pistons are common place.

A port and match job with the intake is a good deal too.

The factory valves are plenty good to flow all the air that a 6.5 can really use.

Any larger valves will generally result in cracks between the valve seats.

Dreams are a good thing.


Missy

[DmaxMaverick]

I understand what you mean, I wasnt able to find info and some things.

1. T56 is one of the best transmissions. It is behind 2000hp twin turbo Viper's, Vette's, GTO's, and Stang's.
Like I said, fine for the Vipers and 'Vettes. Their torque inside the Diesel redline is less than 1/2. HP is distance over time. Higher RPM's stretches the distance, but the time is constant. The same torque at 1/4 the RPM is 4x on the drivetrain. It just works out that way. If you insist on the T, get a lot of them and use quick-change fasteners. You wouldn't be the first to try this.

2. Southern Marine purchases this block all the time.
They don't. AMG and Peninsular have the best available on the current market. A lot of claims about, but not much in the way of proofing, except from AMG and Peninsular. If Southern Marine is purchasing the best on the market, they are getting it from Peninsular or AMG. There's only one other "overseas" supplier of engine blocks (read more about that in other recent threads).

3. Bullet Cars has done many of these and have achieved great power and mpg.
Are you intending this project for a bullet car? The first line in your dream is a pickup. Apples and oranges. Bullets are one-time, or very infrequent use. I can build a 2,000 HP 6.2L that will do that (with the stuff in my barn). No guarantees after the first 2 minutes.

4. Marine Diesel uses this pump on their 475hp engine and the DB on the weaker ones. Also, 3/4 is too much, 1/8 is too little. 1/2 is just right(testing needed of course)
The DB4 is NOT a "high performance" pump. It is designed and implemented for long term/duty use. Double plungers reduces the individual duty cycle by half. It is less capable than a 4911. I've seen many of them scattered when pushed outside their design, and the "high performance" DB2 parts aren't interchangeable.

5. I dont know much about that, so Im not keen on which is better.

6. Marine Diesel puts these in all of their engines.
Do they have their own foundry? I'd like to know where they get them. Otherwise, rods have rarely ever been a problem, even in the most extreme applications. In almost all cases, it's something else that causes rods to fail (which is still a failure, even when the rods hold up). I'd be more concerned with the wrist pins, than the bolts and metallurgic formulation.

7. Did not know that, thanks for the info.

8. I was specifying everything in the build.

9. I dont know what snake oil is, but SS is used on race cars, and with the large collector and smooth interior wall will yeild better flow.
I was referring to the resonator. Nothing wrong with large, smooth exhaust porting (which is negated by the snake oil muffler, incidentally).

10. I have done more research and will just use the stock mech fan.

11. I have talked to Bill Williamson at Ron Davis radiators and am waiting on his next email for more info. But it will not be a 6 core.

12. Why do you say that? My burb has a 90 and its fine.
Are you building your Burb with this dream engine? 2400 amp storage, stageshow sound system, electric fans, etc. are hungry. You'll need 160+ amps, or set your idle around 1200 RPMs, and keep a couple CS130/120A alternators in the glove box. A CS144/DR/150A+ will carry the load, and not burn itself up in the process.

13. Again, just specifying.

14. Again, I dont know what snake oil is. ISS = Ignition Switch Saver
SNAKE OIL (http://dictionary.reference.com/browse/snake+oil)

15. Thanks for the info, now I know.

16. I cant find them now :(. I guess I'll just go with the 45hp.
More snake oil. Show me more than seller claims.

17. I havent decided that yet, still havent worked everything out.

18. Yes, they make Fuel pumps, I had one on my previous truck, I may go Racor though.
Of course, they make fuel pumps. Carter (and even Racor, to some degree), would be like putting the cowboy between a $20,000 horse and a $2 hat.



Sources:

http://www.marinediesel.nu/

http://www.southernmarine.co.za/

http://www.bulletcars.com/

a1 customs (dot) com

I have and maintain several websites. I can make any claims I wish. To date, very few website vendor "claims" have been proved, and you haven't listed any that have (actually, they don't, because they know better, although they've been invited every time). Google is a very dangerous thing. Also, keep in mind, you can make all kinds of power when your radiator is a large body of water. Most all limitations of on-road vehicles is cooling capacity and space available. Not a problem for most marine applications. For example, Peninsular has been selling a 400HP+ 6.5 for over a decade. Not a problem for a vehicle with a billion gallon cooling system. Huge problem for a 4 gallon system. A 6 core aluminum radiator might get you a little closer. Science and laws of physics will keep getting in your way.


You don't have to dream to have a nicely built 6.5L TD. All you need is a deep pocket. In the end, you won't have more than what can be had off-the-shelf today. You can get a Duramax or Cummins take-out that'll do more out of the box for a fraction of the cost. Time and maybe some imaginative engineering is all you need.

[More Power]

4. Marine Diesel uses this pump on their 475hp engine and the DB on the weaker ones.

According to the Stanadyne literature I researched last year, neither the DB2, DB4 or DS4 can produce a fuel rate of 90mm3 at 2000-rpm because of mechanical limitations -and the fuel rate decreases with RPM (to about 77 at 3400-rpm). By way of comparison, the 2001 LB7 Duramax is emissions rated for 300 shaft horsepower with 91mm3 fuel-rate at 3100-rpm. So, I don't think a 6.5 can produce more than 300 on fuel alone when using a Stanadyne DB2, DB4 or DS4. ;)

[convert2diesel]

Wow, so unimaginative. What on my list doesnt exist?

Bradley:

For the most part, the people on this board are a pragmatic lot that view the 6.5 as a means to an end. When Jim started this site, the 6.2/6.5 engines were getting a bad rep for lack of HP and reliability. His motivation was to prove that you could make these engines both powerful and reliable. With the original "power project", he did that in spades.

Sure at times we have people trying to use these in competition with varying degrees of success but most just either want to keep their trucks running a little longer, a little stronger or in the beginning wanted to use them for professional hauling. In my case they presented me with an opportunity to continue driving my yankee tanks with out taking a beating at the pumps. The pros dropped the 6.5 and went to the Dmax in a heartbeat, not because these engines were bad, but rather they just weren't up to the task.

Building a diesel, any diesel, is just not as simple as picking out parts and assembling them. The major members of SEMA have done a great job in producing repeatable and predictable products for the gasser markets. It is now very possible to order a kit of parts or a crate engine and it does what the manufacturers claim right out of the box. We haven't achieved that level in the diesel stuff.

That is why boards like this are so important. You will always have someone try out something new and report back what works, and more importantly, what does not. If your motivation is to take your truck out on Saturday nights to suck the headlights out of some HonToyIssan, then theres are way more powerplants out there that will do a better job of this then a 6.5, regardless of how much coin you have sunk into it. An LT1 or LS6 gasser in front of your T56 with a few mods will run circles around any 6.5 and for about 1/4 the cost.

If you want a good reliable truck, with some get up and go or moderate towing capabilities then this is the place to be. Buy Jims publications, read the posts on this board, then decide what your "Dream 6.5" should be. Don't just open a webpage and list all the most expensive stuff. You will get called on it every time. Catalogue hot rods don't impress anyone here.

Designing a diesel is about knowledge, knowing how something works, tweaking here and tweaking there, watching your EGT gauge and your tailpipe and generally getting to know the engine. Most importantly, taking the advise of people who know and have tried all the stuff.

Over the years this board has spawned many products specifically aimed at this engine and the resourses and "imagination" of it's members has produced some incredible stuff. The genesis of the Dtech PMD, the stud girdles, water passage mods to the heads, exhaust modifications (who knew that 4 inch pipes would become so popular) etc. all started as ideas or issues discussed on this board. Most of the stuff you are finding on your on-line catalogues got their start right here.

Not trying to burst your bubble here but accusing the members on this board of not having imagination or dreams is just plain wrong and insulting. It is quite the opposite. If it wasn't for boards like this and the membership, these powerplants would have died long ago and would now be just idle curiosities or fodder for the C4C programs.

Read and learn.

Bill

[argo]

I just finished a 6.2L buildup and conversion quite opposite from what you want. I built a fuel mileage special on a budget based on the info I gained here, and at a few other places. I purchased all the 6.2L and 6.5L publications and read all the articles. I poured over them, and bought a factory 6.2L diesel engine training manual (GM publication number 16015.05-2, if you are interested) off of Ebay. I read and re-read these books over and over, planning my build up goals. My goal was to get a 5,500 LB Suburban to do 25+ MPG. I have a growing family, and need room. We also travel allot to visit family in other States, so I needed fuel efficiency. Due to what I learned here, and from other discussion forums, and the publications (both GM's and DieselPage's) I knew the correct combustion chamber design I wanted, pump calibration I wanted, exhaust parts I wanted, Intake I wanted, etc. Then I thought about the budget I needed to live with, altered my plan a bit to suit it, and proceeded. The project took 3 years. I wrenched on it part time for 9 months. The rest of the time was spent planning locating, and acquiring what I needed. The result of this combination of my work, the information available, and the helpful insight of others? A 27+MPG Suburban with plenty of room that is a smooth highway cruiser. It won't set any land speed records, but it is smooth, and certainly not sluggish. Most important, if it weren't for the people here who help each other and come up with ideas (such as the article about pre-combustion chambers and their effect on fuel economy, or what to look for on the cylinder block to make sure you don't put a dud together because it has main web cracks, etc), my project might not have been possible. In summary, these are imaginative and informative people, with great experience and knowledge. Listen, learn, and get the most bang for the buck! (Did I mention my entire project cost less than $4,500 including the purchase of the Suburban?)

[Edahall]

Argo makes a good point. The 6.2/6.5 worked very well for what it was designed for. Basically, it was designed as a light weight diesel engine to deliver very good fuel in a light truck. When it first came out in 1982, it put out 135 hp and would deliver fuel economy in the upper 20's. But later on, the desire for more power rather than good fuel economy became a priority so power output was raised and fuel economy went down quite drastically. But as others have already found out, there is a limit to how much power this engine can produce. In my opinion, block strength is probably the biggest issue. Sure, you can cram 40 psi with a big turbo and find ways to cram more fuel (propane injection) but something most likely will let go in a short period of time. The engine simply was not designed to support such a high power output. So basically, if you're looking for an engine that has the ability to produce excellent fuel economy in a light truck, the 6.2 is an excellent choice. Beyond that, there are other engines that are much better suited for that like the Duramax or Cummins that has been already mentioned. I can speak for both the Cummins and the 6.2L. My 82 Suburban has the 6.2L and delivers around 30 mpg driving easy on the freeway. The 135 hp it originally came with was super slow for todays standards so I made some modifications including installing exhaust headers. It really woke it up and I even noticed an increase in fuel economy. My 1990 Suburban has a Cummins in it. It has a lot more power than the 6.2L I can put a load behind it and hardly notice that anything is back there. It has more power than what I know what to do with. Fuel economy is good, but not quite as good as the 6.2L. In all, they are two different engine with different design goals.

[tomtaylor]

. I built a fuel mileage special on a budget - I needed fuel efficiency. I knew the correct combustion chamber design I wanted, pump calibration I wanted, exhaust parts I wanted, Intake I wanted, etc. A 27+MPG Suburban


Hey Argo sounds really great, any chance you can give the specific details of your selections, curious as to how it compares to what I am thinking about doing with my 6.2, thanks.

[HH]

I just finished a 6.2L buildup and conversion quite opposite from what you want. I built a fuel mileage special on a budget based on the info I gained here, and at a few other places. I purchased all the 6.2L and 6.5L publications and read all the articles. I poured over them, and bought a factory 6.2L diesel engine training manual (GM publication number 16015.05-2, if you are interested) off of Ebay. I read and re-read these books over and over, planning my build up goals. My goal was to get a 5,500 LB Suburban to do 25+ MPG. I have a growing family, and need room. We also travel allot to visit family in other States, so I needed fuel efficiency. Due to what I learned here, and from other discussion forums, and the publications (both GM's and DieselPage's) I knew the correct combustion chamber design I wanted, pump calibration I wanted, exhaust parts I wanted, Intake I wanted, etc. Then I thought about the budget I needed to live with, altered my plan a bit to suit it, and proceeded. The project took 3 years. I wrenched on it part time for 9 months. The rest of the time was spent planning locating, and acquiring what I needed. The result of this combination of my work, the information available, and the helpful insight of others? A 27+MPG Suburban with plenty of room that is a smooth highway cruiser. It won't set any land speed records, but it is smooth, and certainly not sluggish. Most important, if it weren't for the people here who help each other and come up with ideas (such as the article about pre-combustion chambers and their effect on fuel economy, or what to look for on the cylinder block to make sure you don't put a dud together because it has main web cracks, etc), my project might not have been possible. In summary, these are imaginative and informative people, with great experience and knowledge. Listen, learn, and get the most bang for the buck! (Did I mention my entire project cost less than $4,500 including the purchase of the Suburban?)

What size and kind of tires are you running?

[Robyn]

The dream 6.5 is sitting in my shop in pieces at the moment.

A brand new AMG/GEP 6.5 Block with all the tweek/tricked and cool updates.
A fresh set of the best heads ever produced (AMG/GEP)

A steel Scat Crank
Factory forged rods
Factory STD sized Pistons

All other parts 1995 GMC stock stuff, including a new radiator from Visteon.

I dont think one can find any better parts to build one with.

A new unused bare block for one of these is tough to get ones hand on, at least an AMG block.

Missy

[argo]

To HH and Tom Taylor:

Sorry I have been away for a while, but things have been busy at work. As for the specifics of what I did and tire sizes, they are as follows:

Tire Size: 235-75R15

Engine Specifications:
1987 "C" code heads with 1983 "C" code precombustion chambers (smallest throat for high turbulence/swirl)

1984 "J" code intake

1992 "C" code injection pump and injectors
Injectors serviced at local injection shop, pop pressure raised to
2500 PSI

Dual exhaust for 1984 2500 Suburban Diesel ( 2 1/4" pipes I wish I had just run a 3" single though)

Head Gaskets are extra thick Felpro (drops the compression to 20:1) and sized for .030" overbore (but I am running a standard bore size)

90G A/C Delco Glow Plugs

TH-700-R4 transmission

3.73:1 rear axle gearing (I want to change that to something taller at some point)

This is all off the top of my head; I have more details written down at home, and I'll post them up later.

[convert2diesel]

For what its worth, I ran the same size tires as you have on the Buick with the same trans, but had the 3:23 gears. Went taller to 2:93 to make towing in 3rd more livable and actually lost about 5% in mileage. With the 3:23 gears in 4th it put the revs at about 1,800 at 100kmh (63 mph). Just about perfect.

I am convinced that the key to mileage is constant speed at the top of the torque curve (best spec. fuel consumption). Its always a compromise between efficiency and performance.

Never got a chance to try it on a small bore DB2 but backing off the fuel delivery screw to limit full rack output (and power) could well have given me equivalant mileage to my old 5.7 diesels. Over 40 MPG (IMP) in a full sized Cadillac.

Bill

[argo]

How many of you have capped off the oil cooler lines on your engine? If so, did you remove the cooler bypass valve? I do not use the Suburban for towing. I have my F-150 for heavy work... the most this will ever carry is 8 people and luggage, so the potential for leaks is not worth the risk. The reason I ask is because I am not thrilled with my hot idle oil pressure. My line ports are capped, and at hot idle I only have about 15-18 PSI oil pressure. According to my GM service manual 10 PSI is the hot idle spec, but I would like to see over 20 PSI at hot idle. I am not worried, but I still don't like it. Oil pressure is fine at higher RPM. At 60 MPH I turn 1800 and I have 40 PSI, and at 75 MPH I am turning 2250 RPM and I have just under 60 PSI. I think that the bypass valve is costing me some pressure especially at idle, and I'd like to remove it. Has anyone ever done so, and if you have, what do I need to do? The Service manual is quite vague about the procedure, so any guidance anyone can offer will be greatly appreciated.

[tomtaylor]

To HH and Tom Taylor:

Sorry I have been away for a while, but things have been busy at work. As for the specifics of what I did and tire sizes, they are as follows:

Tire Size: 235-75R15

Engine Specifications:
1987 "C" code heads with 1983 "C" code precombustion chambers (smallest throat for high turbulence/swirl)

1984 "J" code intake

1992 "C" code injection pump and injectors
Injectors serviced at local injection shop, pop pressure raised to
2500 PSI

Dual exhaust for 1984 2500 Suburban Diesel ( 2 1/4" pipes I wish I had just run a 3" single though)

Head Gaskets are extra thick Felpro (drops the compression to 20:1) and sized for .030" overbore (but I am running a standard bore size)

90G A/C Delco Glow Plugs

TH-700-R4 transmission

3.73:1 rear axle gearing (I want to change that to something taller at some point)

This is all off the top of my head; I have more details written down at home, and I'll post them up later.

Hey Argo thanks for the update:
Is there any diff between 87 C & J Code heads other than precups (I have 86 J code)
Is the 84 J intake just the open plenum type?
Do you think the porting and polishing on the heads and intake was worth the cost now?
Any particular reason for the 92 pump and injectors other than that's what was on hand at the time?
And why that head gasket choice? trying to lower CR?
Thanks for the info.

[argo]

Hey Argo thanks for the update:
Is there any diff between 87 C & J Code heads other than precups (I have 86 J code)
According to my GM 6.2L diesel handbook, there is no difference.


Is the 84 J intake just the open plenum type?
No, mine is the older dual plane J code intake.


Do you think the porting and polishing on the heads and intake was worth the cost now?
I didn't port or polish the heads, you might have me mixed up with someone else.


Any particular reason for the 92 pump and injectors other than that's what was on hand at the time?
I wanted the C code pump for better efficiency and no smoke. As for the year, it was what was available, as I got a low mileage pump from a truck who's owner was swapping in a 4BT Cummins because the engine had blown a head gasket and he wanted a Cummins in the first place.


And why that head gasket choice? trying to lower CR? Thanks for the info.

Yes, and to move the fire ring back from the cylinder bore a bit. Both were done to improve reliability. My compression is 20:1 now.

[tomtaylor]

I didn't port or polish the heads, you might have me mixed up with someone else.




Thanks for giving the update more food for thought on my engine. I think I must have been thinking of another member who posted about hs porting and polishing in another thread, sorry about the confusion.

[argo]

Thanks for giving the update more food for thought on my engine. I think I must have been thinking of another member who posted about hs porting and polishing in another thread, sorry about the confusion.

Don't mention it. By the way, the later single plane J code intake is better. This was built on a tight budget, so I used what was cheap and available. I did allot of junkyard scrounging to gather the parts I needed. The dual plane J code intake is still allot less restrictive than any of the C code intakes.

[tomtaylor]

Don't mention it. By the way, the later single plane J code intake is better. This was built on a tight budget, so I used what was cheap and available. I did allot of junkyard scrounging to gather the parts I needed. The dual plane J code intake is still allot less restrictive than any of the C code intakes.

Yeah, a friend of mine talked me into sticking with my J code dual when i did head gaskets. he said the single would only help with higher rpm and power. and fuel economy would suffer. maybe this is truew with a gas eng but since air flow does not change fuel flow rate in a diesel I am thinking that it will improve efficiency. What do you think?

[argo]

I think that at lower RPM there is most likely no difference, but at higher RPM the single will flow more.