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6.5 Newbie

W

wyattearp

Member
Messages
73
Reaction score
3
Location
McCall, Idaho
I need some help and Bill Heath gave this site a thumbs up when I talked with him this past week. I have a 1985 K30 Crew Cab. I have modified the frame to accommodate a short bed. It is going to be a complete frame-off restoration. I would like to keep this all GM including the engine. I am not looking to win drag races. I am looking for good solid performance/fuel mileage as a daily driver and going into the mountains of Idaho to camp, hunt and cut firewood. I would also like NOT to use a computer and keep the motor all mechanical. I am trying to wade through the various vendors touting their so-called experience in the GM 6.2/6.5. as far as numbers go I would like hp no more than 250 and torque pushing 500. Any help, suggestion, ideas would be greatly appreciated.
 
Welcome to TTS

Keeping it under 250 hp will be easy:)

Do you have an engine to build off of? A db2 mech pump will keep it non electrical as well as a nv4500 trans.

4" exh and free flowing turbo will free up power, I recommend the ATT.
 
I don't have an engine yet. I purchased the truck without an engine, transmission and transfer case. Perfect for what I was planning on. I do plan on using the NV 4500 and a NP 241. The first obvious question is whether or not to rebuild or to maybe purchase a GEP. If I rebuild Bill said to find a 599, 629, or a 141 casting. Then the next question I have is I have noticed some advocating a lower compression ratio. I also understand the issues with cooling on these motors.
 
Some who have gone to 18:1 compression say to keep it at 20:1 minimum.

Cooling with your body style is much easier, just keep the rad and coolers clean and it should be OK.
 
Welcome to TTS! I'm personally not to knowledgeable about the DB2, but there is a wealth of talent and knowledge here and plenty who are. Just letting you know, if you go back in either the 6.5 or 6.2 general sections or here in the performance area, you'll find a lot of good reading, but don't be afraid to ask away.

What type of driving/hauling do you either do or want to do? Being in the mid 80's, are you planning on using your current 6.2? Hows the block and heads? Any cracks? Are you thinkin about just turning up the IP (injection pump) and doing exterior mods (add ons) or do you need/want to do a full rebuild? Theres a few things to consider for now. Again, welcome to TTS
 
nice to see someone with a similar truck!!

I'm going for more power than your goals but the build thread I have, motors motors motors should cover most of what you'll be doing.
 
Throwing this out: Your in a perfect spot to consider a 12valve Cummins, 4bt or Isuzu 4bd/6bd. About the same money output, but much more HP/tq capability. All mechanical too.
 
I appreciate all the comments so far. Yes I did consider the Cummins and even though it is a popular swap, it has a number of issues to consider. Least of which is cutting part of the front cross member. Again I am not looking particularly at trying to make a whole lot of hp. Reliability is number 1, adequate hp is number 2 and fuel mileage is number 3. I am also trying to keep this as much GM as I can. Thanks though.
 
Welcome to The Truck Stop! Advice for your build here is the best you'll find anywhere on the net.

These guys are pretty good at saving you money and grief!


Of course all the money they saved you? Their even better at spending it for you!:hihi:
 
So then what do I go and do. I buy Diesel Power Mag and they have a build going on where they are swapping a Cummins into and OBS Suburban. Hmmmm!:hihi:
 
6.2 crew cab for the win. I would go 6.2, nv4500 np205. Or a np241 tcase depending on funds.
Get a db2831 injection pump. Turbonator uses them and is up to 25 psi.

Read 6.2 turbo's threads before you decide on your engine. He doesnt use studs on the top or bottom ends.
I think a Holset turbo is a good option, very common in the used part world. Lots of people have extras laying around that are no good for cummins, but great for us.
 
get a donor truck, 92 or 93 with the 6.5 TD, they will be the 599 casting. it will be mechanical so no electronics. with the NV4500 there will need to be a new cross-member. drive-shafts can be done at home. keep the yokes 180 degrees apart. i have a little info on shaft shortening in my gearvendors install. if not wanting to tow/haul all that much, keep gears in the 3.52(?) or 3.73.
i like diesel world mag better. seems to keep it more down to earth on the builds. are you planning a doomsday build?
 
If I were building a project I would buy an Optimizer from Teds trucks on ebay, build it the usual way. Might throw some head studs at it, newest water pump with Dmax fan. A 4911 IP, ATT turbo (or possibly HX40II, waiting for the shake down on that one) new injectors and basicaly call it a day.
 
My understanding is the Optimizer engine was used in all military hummers after about 2000. I am assuming that I can put a turbo on a naturally aspirated engine. It seems that when GEP got involved with this motor they brought in International to help with the metallurgy. My understanding with the "599" block that they can still have a tendency to crack. Thought?
 
I'm running a 599 block in my build. Yes they can still crack although they are one of the strongest GM series blocks. Mine has about 130-140k miles with no cracks (motor is currently torn down on an engine stand). I'll be installing a stud girdle and ARP studs to help the bottom end hold together.

After 2000 there were still alot of gm blocks being put in as crate motors so its a crap shoot as to whether its a GM or a GEP block. All depends on how much you're willing to spend on this build in the beginning.

As far as your power level goals are concerned I'd start with a better flowing exhaust, better turbo such as the ATT or hx 40, feed the beast mod to your injection pump and tweak with the injection pump. For reliability if you don't want to tear the motor apart a higher output water pump with the dmax fan and the 4 core radiator that your truck should have. our trucks (mines an 87) have much better cooling ability than the 90's era. If possible go with the radiator that does not have the built in oil cooler.

If your willing to tear the engine apart check the mains for cracks. Up to you whether you want to install main studs and a girdle, mixed reviews on here about if a girdle helps or not. On the top side of the motor I don't think you will need to worry about head studs initially. If later you decide you want more power would be a good idea.

Another concern, drivetrain clearance. Because of the wheelbase length you may want to consider either raising your drivetrain or rotating your t-case so you dont catch it on something when your offroad. This also depends on how difficult of offroading you will be doing and how much lift your going to run, might be that you wont have to do this. On mine I'm using an ORD high clearance engine crossmember and their mounts, raised the engine 2" and moved everything 3" forward. T-case now is within 1/2" under the frame at its lowest point with the big block gasser, sm465 and np205. Similar issue with the gas tanks. Also make sure to box the frame at the steering box and run the longer bolts.
 
I will be running a 6" lift with 37" tires and 4.11 gears. this is not going to be a hard core boulder cruncher. Mostly a daily driver, camp, hunt, haul wood...that type of thing.
 
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