93 K2500 Mechanical with an ATT ?

[bowtiebutler956]

Hello all, this is my first post even though I have been a member 4yrs now. Thats alot of lurking! Anyway, I decided to finally join the fun. Just to give a quick background on myself, I've been an auto mechanic all my life(I'm 39 yrs old), and I'm currently managing a shop that takes care of a fleet of vehicles. Primarily 1 ton Ford vans (gas) with both the 5.4, and 6.8 v10 engines. My diesel experience is very limited.
Back when I joined here I had a 93 K3500 4 door, 4x4, 6.5TD, Auto, and a 88 C30 with a 6.2, 4.56's, and a 4 speed (more like a 3 speed with a granny gear) trans, and a toolbox bed. A little after 300,000 miles the 94 6.5 started getting compression in the cooling system, and with rest of the truck being quite wore out, I deemed it not worthy of a new engine, and sold it. I continued driving the 88 C30, which was really a great truck, but with 4.56 gears, and no od, it topped out between 55-60. Not to mention that a 6.2 NA didn't have much power. I could be outrun by a VW bug. :rolleyes5: Eventually I got a 96 G30 van with a 6.5 NA, and a 4L80E. Even though its a 96, it came from the factory with mechanical DB2 (5088) IP. I believe the 96 G30 was the last year GM put a mechanical IP on the 6.5, but I could be wrong. This has been, and still is a fantastic service van, and runs very strong considering its 6.5 NA.
This brings me to the reason I started this thread. I just got a 93 K2500 extended cab 4x4, with a blown 6.5TD. Actually, I'll be picking it up next weekend, but the deal is done. The truck only has 124,000 miles, and they said it cracked a cylinder head, and the head is currently off the truck. As soon as I get it to my shop, I'll pull the engine out, and try to decide whether its worth messing with this block, by checking for stress cracks in the mains, etc.. If the block is ok, I'll rebuild this engine, if not, I'll pull the 6.5 out of my 96 G30, and put it in the truck. My budget won't allow for anything like a new Optimizer 6500, but it would be nice.
I recently read the 50+ page thread titled "Replacement Turbo" on the development of the ATT turbo, and I must say that was more like reading a book, than a thread!! I read for nearly 4 hours, and WOW, that is some good stuff. Once I'm a little closer to finishing my engine for the truck, I've decided I'll be ordering one. Being that my truck is mechanical, I can't get a KOJO tune. Would a good rebuilt DB2 turned up 1/4 turn, with rebuilt injectors, and a diamond eye exhaust be able to see as good, or close to the same results as a ATT, KOJO tuned, electronic 6.5 does? Any advise is much appreciated. Thanks, and I apologize for getting so long winded.

Matt

 

[NVW]

I can't remember who but I'm sure there are members running ATT's with db2's. There was also a member running stock with an ATT who had good results. A turned up db2 should spool the ATT just fine.

 

[ak diesel driver]

6.5l got 274 RWHP with a turned up DB2 and an ATT

 

[WarWagon]

Van engines... Center mount turbo and different heads are not friendly to going in a pickup let alone turbo upgrades. Yours is NA so you will not have to plug the oil supply and drain to the turbo, but, you can't use the van heads due to different intake/exhaust angles. With that many miles it would be a waste to pull the engine to find mains cracks or other cracks so common to the GM 6.X engines.

Better off getting a military surplus 6.2 engine and getting 6.5 turbo precup heads. 6.2 heads work in a pickup but are a tight fit to the turbo manifold and need bigger precups. Sell the running van for cash to get the surplus engine.

6.5 NA precups are on the small side for getting max power out of the ATT - it's what I run because no one knew any better when I built the engine. My 1993 runs good esp. with the gapless ring set. You will want 6.5 turbo precups or the newest diamond precups.

 

[bowtiebutler956]

I can't remember who but I'm sure there are members running ATT's with db2's. There was also a member running stock with an ATT who had good results. A turned up db2 should spool the ATT just fine.

Thank you for that info, I appreciate it! :thumbsup:

Matt

 

[bowtiebutler956]

6.5l got 274 RWHP with a turned up DB2 and an ATT

After you said that, I did some digging, and found 6.5l's dyno thread. Wow, those are some very impressive numbers for a 6.5 TD!! Thanks alot for the heads up on this build. I'll be reading more on his truck, as its the same mechanical 6.5 that I have. Much appreciated!

Matt

 

[bowtiebutler956]

Van engines... Center mount turbo and different heads are not friendly to going in a pickup let alone turbo upgrades. Yours is NA so you will not have to plug the oil supply and drain to the turbo, but, you can't use the van heads due to different intake/exhaust angles. With that many miles it would be a waste to pull the engine to find mains cracks or other cracks so common to the GM 6.X engines.

Better off getting a military surplus 6.2 engine and getting 6.5 turbo precup heads. 6.2 heads work in a pickup but are a tight fit to the turbo manifold and need bigger precups. Sell the running van for cash to get the surplus engine.

6.5 NA precups are on the small side for getting max power out of the ATT - it's what I run because no one knew any better when I built the engine. My 1993 runs good esp. with the gapless ring set. You will want 6.5 turbo precups or the newest diamond precups.

Thanks for the great advice WarWagon. However, my 96 G-30 van has a 6.5 N/A, and it uses the standard 90* intake bolts on the heads. Hopefully my pictures below, are clear enough to see this. Correct me if I'm wrong, but isn't it just the vans with turbos that have the 60* angle on the intake bolts? I appreciate the heads up on the pre chambers.
As far as the block goes, since the engine in the truck has to come out anyway, I figure there is no harm in running down to my machine shop to have it magnafluxed. If its cracked, then I guess its time to pull the engine out of my van. I'm no expert, but I thought that my van being an NA 6.5 might mean the block has had less stress, so less chance of cracking? Just a thought, and that may have nothing to do with it. I appreciate you taking the time to help me out.:thumbsup:

Here are a couple pics of the 6.5 in my van.

Matt

 

[Will L.]

Yep, correct. Same heads as truck heads. Cracking is anybody's guess, n/a blocks crack also.

 

[6.5L]

Actually with a little modification to the doghouse a centermount would be such a cinch to have on that. And I'd go somewhere between 1/4 and a 1/2 turn on the pump. With 1/4 turn I still had some problems spooling sometimes, but also I had a 5 speed, which is hard to respool a large turbo with. But with 1/4 turn on a 4911, made good power. Just my two cents.

 

[bowtiebutler956]

Yep, correct. Same heads as truck heads. Cracking is anybody's guess, n/a blocks crack also.

Thanks for the info. I guess I'll just have to see on the block.

Matt

 

[bowtiebutler956]

Actually with a little modification to the doghouse a centermount would be such a cinch to have on that. And I'd go somewhere between 1/4 and a 1/2 turn on the pump. With 1/4 turn I still had some problems spooling sometimes, but also I had a 5 speed, which is hard to respool a large turbo with. But with 1/4 turn on a 4911, made good power. Just my two cents.

I have no intention of putting a turbo on my van. I'm just thinking of the possibility of using the engine from my van if the block turns out to be shot in the 93 K2500 I'm picking up. I'm glad to see you respond to this thread, as I've really enjoyed reading through some of your build threads on your K2500, and especially enjoyed seeing your dyno results from different stages of your build. 274 rwhp is very impressive, and although I probably won't achieve that, I look forward to seeing what an ATT, turned up IP, and a diamond eye exhaust can do for me. Thanks

Matt

 

[6.5L]

Thanks. I'm sure it will be quite an improvement over what it was. I have been meaning to get back to the dyno but I'd really like to get the rest of the parts I have on first and get the transmission swapped. I am thinking sometime this summer I will be on the rollers again.

 

[GM Guy]

what trans is in the new project truck?

 

[WarWagon]

Thanks for the great advice WarWagon. However, my 96 G-30 van has a 6.5 N/A, and it uses the standard 90* intake bolts on the heads. Hopefully my pictures below, are clear enough to see this. Correct me if I'm wrong, but isn't it just the vans with turbos that have the 60* angle on the intake bolts? I appreciate the heads up on the pre chambers.
As far as the block goes, since the engine in the truck has to come out anyway, I figure there is no harm in running down to my machine shop to have it magnafluxed. If its cracked, then I guess its time to pull the engine out of my van. I'm no expert, but I thought that my van being an NA 6.5 might mean the block has had less stress, so less chance of cracking? Just a thought, and that may have nothing to do with it. I appreciate you taking the time to help me out.:thumbsup:

Here are a couple pics of the 6.5 in my van.

Matt

Only ever seen a Turbo Van 6.5 in person and couldn't use it at the junkyard when I needed an engine due to different heads and turbo oil ports. Interesting the NA van engines have the same heads. Thanks for posting pics! This could explain why my 1993 had a rebuilt NA 6.5 engine in it with the factory turbo. May have come from a van.

We like to see 6.5 vehicles stay alive... So if the van is in any decent shape at all it needs to keep it's engine. :hihi:

Member 6.5L has a manual trans and mine has a 4L80E. The auto sucks some power on the rollers , but, the precups also make a difference as to why I was way below 6.5L's numbers.

 

[bowtiebutler956]

Thanks. I'm sure it will be quite an improvement over what it was. I have been meaning to get back to the dyno but I'd really like to get the rest of the parts I have on first and get the transmission swapped. I am thinking sometime this summer I will be on the rollers again.

I look forward to seeing your truck on the dyno again. I'm curious to see how it does with the HX35 as opposed to the ATT. Thanks

what trans is in the new project truck?

The truck I'm picking up has the 4L80E in it. Thanks

Only ever seen a Turbo Van 6.5 in person and couldn't use it at the junkyard when I needed an engine due to different heads and turbo oil ports. Interesting the NA van engines have the same heads. Thanks for posting pics! This could explain why my 1993 had a rebuilt NA 6.5 engine in it with the factory turbo. May have come from a van.

We like to see 6.5 vehicles stay alive... So if the van is in any decent shape at all it needs to keep it's engine. :hihi:

Member 6.5L has a manual trans and mine has a 4L80E. The auto sucks some power on the rollers , but, the precups also make a difference as to why I was way below 6.5L's numbers.

My G30 is in very solid condition, with 150,000 miles on it. I would rather not pull the engine out of it, but if the engine in the K2500 is shot, I'm not sure I'll have a choice, as these 6.5's still command a pretty high price, even used. I will try to avoid pulling the engine out of my van, if possible. Thanks

Matt

 

[6.5L]

The HX35 to ATT comparison wouldn't even be accurate, because since I have dyno'd, I have updated my fueling from my injection pump, and added a FRB-5, WMI, and my custom air plenum. I'd almost be afraid to share because I know if I were to dyno more some jack off who thinks the ATT is a terrible turbo (I can think of a few) would come in and be like "well he made more power with the HX35 than with the ATT, so everybody should just never buy an ATT because they are junk", when in reality I have done a lot of upgrades since then. The ATT is still a great turbo and a great product and I still stand behind it. And when I dyno again I am going to have different parts still yet, like headstuds, a larger injection pump, and swapping precups, so it would be a even more terrible comparison between turbos.

And WarWagon, do we have different precups? I never changed mine in the Optimizer when I got it, I still have the 6.5L NA Military cups in. When I do headstuds I am going to swap to the precups out of my 599 block. Much larger. 2nd largest to Diamonds I think, and only by a tit hair. Should work nicely

 

[WarWagon]

Your other choice would be as follows:

Is the van worth less than $2500.00? Here is what you can do for $2500.

Looks like my favorite low mile 6.2 dealer Boyce Equipment out of Utah is up to $1500 for a tested low mile 6.2 diesel (up from $950.00 several years ago). Swap heads to 6.5 heads is optional as long as the precups are made larger or swapped. There is someone on here selling used heads for cheap. New rings and you are good to go.

The 6.5 engines do command more money vs. the 6.2 engine. It's not worth more money to get a bored to 6.5 from a 6.2 diesel engine. This is coming from some of the the most cash strapped members on here. I dropped in a 6.2 engine with ARP head studs, oil cooler kit, and a new starter for less than $2000.00. The price has gone up $600 since I did that and I recommend rings ($60 standard to over $300 for gapless P/N S5565) and precup changes since doing that. The differences like oil pan rear main seal, oil cooler line size, etc. are not worth the extra cash to get a used 6.5.

 

[bowtiebutler956]

The HX35 to ATT comparison wouldn't even be accurate, because since I have dyno'd, I have updated my fueling from my injection pump, and added a FRB-5, WMI, and my custom air plenum. I'd almost be afraid to share because I know if I were to dyno more some jack off who thinks the ATT is a terrible turbo (I can think of a few) would come in and be like "well he made more power with the HX35 than with the ATT, so everybody should just never buy an ATT because they are junk", when in reality I have done a lot of upgrades since then. The ATT is still a great turbo and a great product and I still stand behind it. And when I dyno again I am going to have different parts still yet, like headstuds, a larger injection pump, and swapping precups, so it would be a even more terrible comparison between turbos.

And WarWagon, do we have different precups? I never changed mine in the Optimizer when I got it, I still have the 6.5L NA Military cups in. When I do headstuds I am going to swap to the precups out of my 599 block. Much larger. 2nd largest to Diamonds I think, and only by a tit hair. Should work nicely

There are always going to be those people who will take your results and try to use them to they're advantage. In this case if they don't like the ATT, they will try to say this is proof that it doesn't work as well as they're favorite turbo, and they will ignore all of your other upgrades. The world is full of these types! However, I don't think this should stop you from posting your dyno results with the rest of us, as I find it quite inspiring to see you getting numbers as good as many newer diesels, out of your 6.5. I would hate to think that the rest of us would have to suffer, because of a few bad apples!:thumbsup:
When you say a your going with a bigger IP, how so? Also, can you help a rookie out, and tell me what a FRB-5, and a WMI are? I'm a little slow, but I will learn.

I look forward to future dyno numbers from you, as I often hear people talk about how much power they're making, but its oh so much better to see it on paper!:agreed:

Matt

 

[NVW]

WMI= water mist injection

FRB-5 is a discontinued "Walbro" lift pump. Leroy Diesel now sells the FRC-10

 

[bowtiebutler956]

Your other choice would be as follows:

Is the van worth less than $2500.00? Here is what you can do for $2500.

Looks like my favorite low mile 6.2 dealer Boyce Equipment out of Utah is up to $1500 for a tested low mile 6.2 diesel (up from $950.00 several years ago). Swap heads to 6.5 heads is optional as long as the precups are made larger or swapped. There is someone on here selling used heads for cheap. New rings and you are good to go.

The 6.5 engines do command more money vs. the 6.2 engine. It's not worth more money to get a bored to 6.5 from a 6.2 diesel engine. This is coming from some of the the most cash strapped members on here. I dropped in a 6.2 engine with ARP head studs, oil cooler kit, and a new starter for less than $2000.00. The price has gone up $600 since I did that and I recommend rings ($60 standard to over $300 for gapless P/N S5565) and precup changes since doing that. The differences like oil pan rear main seal, oil cooler line size, etc. are not worth the extra cash to get a used 6.5.

Thanks for the great advice, and it will be something to think about, if the block in the truck ends up being junk. I do like my van, as its been a great service van. It has both an air compressor, and generator mounted inside of it, which has made it very handy for service calls. While it might bring $2500, it would take time to sell it at that price in my part of the country, as older vehicles sell pretty cheap around here.
Do you happen to know what member is selling the heads cheap? If the block does turn out to be ok, it most certainly will need a head, and maybe two. Thanks

Matt