Hello,

This is my first post. So I'll be looking for suggestions and help about my project. I was recently given a 1993 Chevy WT 1500 2wd. It's got 265K on the factory 4.3 V6. Power? whats that? :rolleyes: I have to drive 120+ miles M-F every other week. I've always lusted for a diesel. I thought about installing a toyota diesel into my tacoma but gave up due to price/complexity.

The 6.2 is so simple in appearance I think it's a good canidate.

I recently won a complete 6.2 off ebay for $300 flywheel to fan with anything else I need to get it to run. It's got a blown head gasket or ring? (has blow by in crank case) I've heard the 6.2 was bad about blowing head gaskets, is this probable?

I noted also that new complete head castings ready to run can be had for about $300 of ebay as well. But they only list a 6.5 head. Are these interchangable?

The past owner had the Injector pump and injectors pulled and rebuilt at any sign of trouble. Also the engine has recently been rebuilt about 40K ago. (perhaps they resused the head bolts? I think the bolts are a torque to yield)

Any how I plan the following setup.

6.2 with a 6.5 turbo system (and heads if they work) manual boost adjustment to limit it to about 7-8psi to be safe
700r4 (freshly rebuilt) 4x4 with the diesel HD converter
NP208 T-case

As for the running gear. I have a 3.73 14bolt 10.5 FF. And know where a 1/2 front is I could swap spindles and everything else with a 8 lug.

OR

possibly a X Military M1008 truck. (I don't know the condtion of the truck just seen it about 100ft away.) I know it still has the axles under it. Only problem is the axles themselfs. I know ALL of the CUCV 1tons came with 4.56 gears. I know this is to low for a hwy truck. I plan to run 3.73ish gearing with the OD to allow for about 2000 rpm @ 70mph with 33" tires. Is this a good RPM for these engines? I know they don't like to be rev'd high and long.

I don't plan on constaintly pulling a trailer. But it might see one for a short trip every now and then (3-4 times a year TOPS) the most it would see is two dirt bikes in the bed for the most part.

Any ideas suggestions about my plans?

Another question. How many PSI does the 6.2's fuel system run at before the injection pump? I think the TBI gas pump in the truck is rated at 14psi.

Thanks
Andrew

Oh I forgot to explain. If I do get the M1008 I'll probably just swap the 93 body over to it.

I was looking at an 84 1/2 4x4 silverado. but the price is too high. So I guess I'm back to the conversion of the truck. (I've still got to find out about the M1008) I do have good news! I bought a parts blazer for the running gear. It's all original. I found the build sheet in the glove compartment and found that it is a 3.42 geared axle with a locking diff! Not bad for a $175. Course it's a 10 bolt rear. But if all I'm going to do is drive around town with the truck and never go over 33" tires it should be ok.

Looking at that gearing, it should put me about 1850rpm at 70mph. Is that a good powerband for the 6.2? (I plan to turbo it one day)

I'd suggest staying away from the turbo with that many miles on the engine and known head gasket/blow-by problems, you'll just end up killing it. 6.5 heads are practically identical to 6.2s, exhaust valve is a hair smaller in the 6.5s, but what you lose in size you gain in head strength so less likely to crack. 33" is a pretty tall tire with 3.42 rear, 3.73 would be perfect if you really want to go that size. Is the M1008 a CUCV(blazer) or truck? If its the blazer, it has the same 10-bolt 3.42s as the one you got, if its the truck it has Dana 60 front/70 rear with 4.11 ratio. Still a little short for what your planning, but not as extreme as the 4.56. Swapping in a front axle, transfercase and making it all work is quite a task, it has been done by some, but always easier to start with a 4x4. Same with gas to diesel swap, it can be done but...geez! Everything from the tank to motor mounts to fuel filter/lines, I say buy the M1008!

I'd suggest staying away from the turbo with that many miles on the engine and known head gasket/blow-by problems, you'll just end up killing it. 6.5 heads are practically identical to 6.2s, exhaust valve is a hair smaller in the 6.5s, but what you lose in size you gain in head strength so less likely to crack. 33" is a pretty tall tire with 3.42 rear, 3.73 would be perfect if you really want to go that size. Is the M1008 a CUCV(blazer) or truck? If its the blazer, it has the same 10-bolt 3.42s as the one you got, if its the truck it has Dana 60 front/70 rear with 4.11 ratio. Still a little short for what your planning, but not as extreme as the 4.56. Swapping in a front axle, transfercase and making it all work is quite a task, it has been done by some, but always easier to start with a 4x4. Same with gas to diesel swap, it can be done but...geez! Everything from the tank to motor mounts to fuel filter/lines, I say buy the M1008!
A m1009 is a blazer. they came with 3.08's gov lock 10 bolts

a m1008 is a 1 1/4ton truck. It came with a dana 60 front and a 14bolt rear. 4.56 gears with a detriot locked rear.

This isn't my first project swap. (sbc in a s-10, sbc in a toyota 4x4, 1 ton running gear into a 68 caddillac herse) I'm well aware of what I'm up against.

The only problem I foresee is steering. But I plan to use about 1/2 of the 2wd setup and create a crossover steering setup. (I have access to a machine shop BTW, a big one that keeps alot of airplanes in the sky :D )

As for the turbo. If it comes down to a rebuild. I plan to use some 18:1 pistons and 6.5 heads. If not I'll probably end up just using a set of 6.5 heads anyway to prevent cracks. Is there a steel head gasket simular to a SBC for when you mill heads? Seems like it'd be a feaseable way to lower the 6.2 down from it's 21:1 ratio?

The intent of this truck is serveral reasons:

1. pull a small trailer (12x6)
2. pull a 17' boat
3. daily drive about 120 miles
4. be happy at 75+ mph

I would think that the 3.42 gears with a 33" tire would be good for the truck. Currently it's a 4.3 v6 with 3.08 gears and about 28" tall tires. at 85mph the truck only turns over about 1750rpm. 33" tires are not what I really want to run. I'd be happy with 31". But I've got an almost new set here so there's no use in letting them go to waste.

I have no intention of being "fast" in it. My main concerns are fuel milage and hwy rpms. (I spend 2-2.5hrs a day on the road)

I plan to install the front end probably next week. I have a backup truck so I can tinker with this one. perhaps the following week install the rear axle. then move on to installing the transmission and transfercase as I can. and leave the engine for last.

I'll also be checking on the m1008 next week as well. A body swap would be simple, but I hate having to setup new gears in the axle. (although a 14 bolt is a breeze to do)

Inspected the 6.2 today. The blowby is a gray vapor that only "puffs" with one crank rotation. How bad is unexceptable? this is about consistant with a kettle.

BTW the engine is in a well maintained 86 1ton. I checked the VIN and the 8th digit was a J. I believe these are "good" motors?

I now have the engine home. From everything I've read in the techbook I got at the parts store the blow by is coming from the rings. (or perhaps a cracked piston like a post I've seen here) If the pistons aren't cracked I'll re-ring. If they are I've found a source for pistons and rings in 19:1 for $500 (is that a good price?)

I know I'll need some things for the swap. Does anyone have any of the following?

The connectors for the glow plug relay and fuel filter/pre heater/water sensor

I also know the truck had a TH400. I've got a brand new 700r4 to install. But I need to setup the TV cable. Any ideas? Was there a stock setup for a J code engine?

Fuel pump. Can I remove the mech. pump and use my trucks in tank pump. I think the TBI engines pumps made about 15psi. I don't know if thats too high. Or should I drop the tank re-run straight through lines and remove the in-line filter.

Also where is the temp-control for the glow plugs? I've got a diagram on how things need to be wired up. But I don't know if it's simply mesuring resistance from the plugs or if there is a "sensor".

I don't know the condition yet of the blazer's tank I have. But an idea I've had is to build a mount for it in the spare tire location on my truck to have dual tanks. The truck is a long bed so I'd give up some space for that. Estimating the tanks both hold 30 gallons each and if the truck will get 18mpg I should have a range of about 1080. That would mean I'd only have to fill up once a month. (course that fill up will cost me right over $100)

I'll post pics up of everything I'm working with.

BTW anyone got a 700r4 Torque converter for a diesel (new) and a flexplate?

Your TBI pump won't pump diesel very long before it gives out, 15lbs is too high for a mechanical pump anyway. You can however, use an electric supply pump like the '92-up 6.5 engines have, this would be better than the original mechanical pump for sure.

Your TBI pump won't pump diesel very long before it gives out, 15lbs is too high for a mechanical pump anyway. You can however, use an electric supply pump like the '92-up 6.5 engines have, this would be better than the original mechanical pump for sure.
Umm maybe you mis understood. it's a TBI (throttle body injection) setup the pump is an in tank unit. :confused:

I'm also considering a 4wd convertion for my 82 suburban, but 1st problem is rear end ratios. It had an 700r4, but it's a four seed now. I run standard size tires on 15" rims not sure what numbers are exactly. What rear end should I have to be running about 1800 rpm @ 70 mph?

I'm also considering a 4wd convertion for my 82 suburban, but 1st problem is rear end ratios. It had an 700r4, but it's a four seed now. I run standard size tires on 15" rims not sure what numbers are exactly. What rear end should I have to be running about 1800 rpm @ 70 mph?
your manual 4 is probablly the 3 speed with a L correct? If so it's a 1:1 for the final gear. If you're truck is running a 31" tire that would put you around a 2.41 gear. I don't see that though, not if it was orignially a 700r4. Are you certain your speedo is setup correctly? There is a good chance the speedo drive gears are a different ratio.

For starters on your project, 1) Do a compression test, anything below 320 is suspect. A healthy engine should yield about 350+. 2) Since it is out of the vehicle, do a bottom end inspection(bearings) timing chain and if any question at all pull the heads and check the bores. I have seen 6.2 that were maintained well still have honing marks in cyl. bores at 200k. I have also seen engines that were neglected or used wrong oil that had excessive cylinder wear after 60,000 miles. As for the heads, 6.2 and 6.5 heads like to crack(but you knew that), but what you probably don't know is that only about 1 out of 10 (a rough guess on my part) leaks coolant or combustion from the cracks. This only applies to cracks between the valves. If there are any other cracks on the head, scap it. There is also a very easy fix for piece of mind for cracks between the valves, there is a kit that any reputable machine shop should have that uses a reamer to ream out the water jacket that goes between the valves and then inserts a bronze valve guide into the reamed hole to seal the crack. This repair works very well, but like I said previously most heads are condemned because someone sees cracks between the valves and thinks they have a problem, even though there is no sign of coolant seepage around the crack. I used to have a plate made up to vaccuum check the combustion chambers. Never found one that leaked. Usually the problem was a blown head gasket. With the newer design of head gaskets they stand up much better. Just remember to always use new bolts and follow torque angle procedure. I have also seen brand new bolts that were no good and would not hold torque. Can you say ARP head studs? As for turboing, do it. Limit boost to 12psi if you like to go fast, just keep an eye on water temp. High water temp is the main culprit to blowing head gaskets with the newer revised gasket material. As for controls for your 700 r4 they were used exclusively in 1/2 and 3/4 tons in 83 and 84. In 85 most 3/4 tons got the turbo 400. As for gearing, 4.10 with the 700r4 will yield the best mileage and power with 33 inch tires. 3.73 could yield slightly better mileage at the cost of power because you will be lugging in O/D. Also if you want to lower your compression a little extra for turboing, there is a Fel-Pro head gasket made that is .010 thicker that stock to make up for decking the block that will help you lower the compression a little. If you decide that you want to use 6.5 heads, be aware that you will have to tweak your injection lines or purchase a new set that are made for engines built after 1992, because the injector angel in the head was changed. Also, there are lots of different valve sizes on 6.2 heads and 6.5 heads, with early 6.2 heads having the largest valves. (yes they tend to crack more between the valves, but remember what I said earlier about the cracks). The 6.5 heads will also lower your compression slightly over a 6.2 head because the precup has a larger flash hole than the 6.2 precup, (more volume=less compression). I am currently running some 6.5 heads on my daughters 86 6.2 Blazer. One other item, if you decide to go with 18:1 pistons, make sure they are Mahle or original GM. I have had some bad experiences with silvolites that turned to gravel inside of the engine! Also the military sued silvolite for similar failures with 6.2 pistons. A 6.2 TD's weak link is head gaskets and pistons, keep water temp below 220 and keep egt's below 1150 and don't advance timing too much. Use A/C 60G glow plugs or one of the other aftermarket dual coil glow plugs and a manual push button glow plug switch, very easy to wire. Kennedy diesel is a good source for the glow plugs as is e-bay. If you go with 18:1 pistons you will need a longer glow plug cycle to build enough heat to start. Let me know if I can shed any more light.:ro)

I've done a little math.....

Your gearing/tire combo:


<code> Differential Gear = 3.73 to 1</code>
<code> Transmission Gear = 0.76 to 1</code>
<code> Tire Diameter (Inches) = 33.00</code>
<code> Vechicle MPH = 70</code>
Computation Results:

<code> Computed Engine RPM is 2021</code>

A 3.42/31" tire combo.....



<code> Differential Gear = 3.42 to 1</code>
<code> Transmission Gear = 0.76 to 1</code>
<code> Tire Diameter (Inches) = 31.00</code>
<code> Vechicle MPH = 70</code>
Computation Results:

<code> Computed Engine RPM is 1973</code>


There's only about 50rpm difference. I think I'll go with the 31" and the gears I have in the axles now. The engine will be lugging a bit more, but it shouldn't matter due to the reduced rolling mass/resistance.

Thats interesting about the head gasket and 6.5 heads. If I do need heads, how much do you think the comp ratio would lower with 6.5 and a .010 oversize head gasket?

I'm trying to track down a manifold now for a turbo. Plans are to use a banks or GM manifold, a powerstroke intercooler, and a turbo. (the only other power adder will be a homemade propane setup with a cutting torch regulator to dial in a small amount of propane.)

Propane tends to lower EGT correct?

As for the 700r4, I've got a freshly built one that has had several improvements, (servo, clutches, exc.) I've been looking at the IP. it looks like I can use the gassers throttle mount bracket and fab a bracket for under the intake.

I got started last night on scrapping the blazer. I've cut the front sheetmetal off it right now. I plan to get the top and a few odds and ends out tonight. I decided to try and salvage the entire frame. (mainly so I can use the spring mounts if need be) and I'm going to inspect the fuel tank. (if it's any good I could relocate my spare tire and double my range! http://www.dieselplace.com/forum/images/smilies/rockon.gif)

I have found one thing I will need badly. I need a harness for the glow plug relay and the fuel filter, water sensor, pre-heater. http://www.dieselplace.com/forum/images/smilies/frown.gif

For starters on your project, 1) Do a compression test, anything below 320 is suspect. A healthy engine should yield about 350+. 2) Since it is out of the vehicle, do a bottom end inspection(bearings) timing chain and if any question at all pull the heads and check the bores. I have seen 6.2 that were maintained well still have honing marks in cyl. bores at 200k. I have also seen engines that were neglected or used wrong oil that had excessive cylinder wear after 60,000 miles. As for the heads, 6.2 and 6.5 heads like to crack(but you knew that), but what you probably don't know is that only about 1 out of 10 (a rough guess on my part) leaks coolant or combustion from the cracks. This only applies to cracks between the valves. If there are any other cracks on the head, scap it. There is also a very easy fix for piece of mind for cracks between the valves, there is a kit that any reputable machine shop should have that uses a reamer to ream out the water jacket that goes between the valves and then inserts a bronze valve guide into the reamed hole to seal the crack. This repair works very well, but like I said previously most heads are condemned because someone sees cracks between the valves and thinks they have a problem, even though there is no sign of coolant seepage around the crack. I used to have a plate made up to vaccuum check the combustion chambers. Never found one that leaked. Usually the problem was a blown head gasket. With the newer design of head gaskets they stand up much better. Just remember to always use new bolts and follow torque angle procedure. I have also seen brand new bolts that were no good and would not hold torque. Can you say ARP head studs? As for turboing, do it. Limit boost to 12psi if you like to go fast, just keep an eye on water temp. High water temp is the main culprit to blowing head gaskets with the newer revised gasket material. As for controls for your 700 r4 they were used exclusively in 1/2 and 3/4 tons in 83 and 84. In 85 most 3/4 tons got the turbo 400. As for gearing, 4.10 with the 700r4 will yield the best mileage and power with 33 inch tires. 3.73 could yield slightly better mileage at the cost of power because you will be lugging in O/D. Also if you want to lower your compression a little extra for turboing, there is a Fel-Pro head gasket made that is .010 thicker that stock to make up for decking the block that will help you lower the compression a little. If you decide that you want to use 6.5 heads, be aware that you will have to tweak your injection lines or purchase a new set that are made for engines built after 1992, because the injector angel in the head was changed. Also, there are lots of different valve sizes on 6.2 heads and 6.5 heads, with early 6.2 heads having the largest valves. (yes they tend to crack more between the valves, but remember what I said earlier about the cracks). The 6.5 heads will also lower your compression slightly over a 6.2 head because the precup has a larger flash hole than the 6.2 precup, (more volume=less compression). I am currently running some 6.5 heads on my daughters 86 6.2 Blazer. One other item, if you decide to go with 18:1 pistons, make sure they are Mahle or original GM. I have had some bad experiences with silvolites that turned to gravel inside of the engine! Also the military sued silvolite for similar failures with 6.2 pistons. A 6.2 TD's weak link is head gaskets and pistons, keep water temp below 220 and keep egt's below 1150 and don't advance timing too much. Use A/C 60G glow plugs or one of the other aftermarket dual coil glow plugs and a manual push button glow plug switch, very easy to wire. Kennedy diesel is a good source for the glow plugs as is e-bay. If you go with 18:1 pistons you will need a longer glow plug cycle to build enough heat to start. Let me know if I can shed any more light.:ro)

Another idea I'm pondering.....

How would a 4" straight pipe sound with a 6.2 turbo setup?

I probably have some spare wiring harnesses around. As far as compression changes go, one would have to cc the volume of the precups. The 6.5 precup opening is about 1/2 inch wide while the 6.2 is about 5/16 to 3/8 (going from memory) I have lots of heads still lying around, I could check. Another trick is to use 6.5 head gaskets on a 6.2 block. It puts the fire ring in a different location and further increases dead space thus also lowering compression. I have heard of this trick but have not done it.

UPDATE!

I've gutted the blazer.

I've got the front axle and springs removed. Also the rear axle. I've done some measurements. The front end springs measure 35" to the outsides of the springs. The front of the 2wd truck would be simple to mount. I'll just use a plate of 1" steel to provide a good mounting space. (I'll gusset it as well) I can fab the spring mounts out of simple C channel.

I had a brainstorm torching up the old blazer frame. I saved the spring mounts from the rear ends front mount. They space the springs 1.5" out from the frame. The 2wds inner frame rails are boxed in the area where I need these mounted. The rails are spaced 40" apart inside to inside. I can use the spring mounts plus some of the 1" plate steel to reinforce the frame and equal up the 2.5" of spacing I needed. I also saved the rear shackle to use it in that mount. I can shim the axle if needed, but I think after I've fabbed my mounts the springs will ride flat.

As for the rear end. I'll have to cut off the current spring mounts and move them outward a total of 5" (2.5" each side) nothing major. (I will allow me to adjust the pinion angle too.

I've got a number of driveshafts laying around. I'm certain one will work out. (or I can have it cut)

Here's what I'm working with.....


Front and rear ends.....

http://superbike.dyndns.org/superbike/dsc01141.jpg


http://superbike.dyndns.org/superbike/dsc01142.jpg

The 700r4 and NP208. (used ones)
http://superbike.dyndns.org/superbike/dsc01143.jpg

The blazers gas tank. (I'm going to mount this into the spare tire mount area)
http://superbike.dyndns.org/superbike/dsc01144.jpg

The spring hangers I'm going to use on the front.

http://superbike.dyndns.org/superbike/dsc01145.jpg

The shackles I'm going to use
http://superbike.dyndns.org/superbike/dsc01146.jpg

the actual truck....
http://superbike.dyndns.org/superbike/dsc01149.jpg
http://superbike.dyndns.org/superbike/dsc01150.jpg

The "J" code 6.2
http://superbike.dyndns.org/superbike/dsc01151.jpg

Here's my "machine shop" http://www.dieselplace.com/forum/images/smilies/wink.gif
http://superbike.dyndns.org/superbike/dsc01154.jpg

A freshly rebuilt 700r4
http://superbike.dyndns.org/superbike/dsc01155.jpg


I've also got the radiator. and all the other stuff that went with the 6.2 I didn't think to take pics of them. I've also got another NP208 case.

I think I just found a complete 6.5 turbo setup.......

Hit the local boneyard(s) and check out an '89-up 3500 lo pro truck, with the straight front axle - has the correct front spring perch brackets for your frame.

Late '97-up 6.5L heads were redesigned in the pre-cup\valve problem area for better coolant flow, reducing thermal retention, preventing cracks between the valves.
This was done as prep for the 215hp turbo upgrade, which upgrade never saw production.
The heads are an improvement for all turbo use.

'82 heads had larger exhaust valves, discontinued in '83 because of the cracking problem.

6.5L pre-cups come in several versions - n\a, emissions turbo, and H\O turbo.
N\a and emissions can give better fuel economy.
H\O speaks for itself.

As much as I'd love to put a 1 ton axle up under it. I'd be out of my range. The truck you speak of? I've never heard of it. Unless you're talking about the 3500 HD (wich has a 10 lug pattern if I'm correct) Nothing is going to "bolt in" for a 2wd frame.

Here's a daylight pic of the truck....

http://superbike.dyndns.org/superbike/DSC01174.JPG

Hit the local boneyard(s) and check out an '89-up 3500 lo pro truck, with the straight front axle - has the correct front spring perch brackets for your frame.

Late '97-up 6.5L heads were redesigned in the pre-cup\valve problem area for better coolant flow, reducing thermal retention, preventing cracks between the valves.
This was done as prep for the 215hp turbo upgrade, which upgrade never saw production.
The heads are an improvement for all turbo use.

'82 heads had larger exhaust valves, discontinued in '83 because of the cracking problem.

6.5L pre-cups come in several versions - n\a, emissions turbo, and H\O turbo.
N\a and emissions can give better fuel economy.
H\O speaks for itself.