My change over to 6.5 injectors

[crew84]

I had plenty of discussions with pump rebuilders about replacing my Injection pump with a DB2-4911 or having one rebuilt to 4911 specs. Accurate pump rebuilder told me that I could put in 6.5 injectors and my pump, DB2-4267, should handle it. I finally got new 6.5 injectors and later injection hard lines with larger ID holes. I have not been happy with my rebuilt 6.2 injectors which I have had two of them stick open in the first ten thousand miles.
I replaced them Saturday the 28th and gave it the finishing touches today. It smoked bad at first but stopped. The idle is strong. I took off driving it and was surprised at the quick throttle response but not with high EGTs. I drove it on the highway and the EGTs were 100 degrees lower with good power. I took it up a grade that would normally push the EGTs to the max by 1/3 of the way up with WOT. I had problems getting the EGTs up to that point because of the speed I got up to. I got to the max EGTs at 78mph @ WOT 1/2 of the way up. I will probably turn the IJ pump down a little. I am quite pleased with the results.

[84 Convert]

Sounds great! I'll have to keep this info in mind as I progress with my truck. It is good to hear you have found at least a partial if not complete cure for your EGT problems.

Gregg

[odee]

What are the specs on the engine? Where did you get the other line set from early mech. style 6.5 parts? I'm in the process of finding parts to build a engine to swap over into my dually. Is your engine turboed? If so what parts did you use buy a kit or pieced it together.

[crew84]

Too bad we lost all the past posts because I had a long topic on my engine rebuild as it was being done. I started the project with a 6.2 engine I bought out of a wrecked 85 GMC in 1988 which had 29K on it. They had to burn it out of the bent front end. I disassembled it and took it to a machine shop. It was first cleaned and Magnafluxed for cracks. It was then decked which meant the top of the sealing surface on the engine block where the head seats was remachined in reference to the crankshaft mains. This was to improve the factory tolerances which are not that fine. I had the engine bored 0.020 OS using a special machined plate bolted to the top of the cylinders to keep the bore holes round. It was then power honed and all of this was done sitting on jig to keep the bores in line with the crankshaft. Of course it did not work to my advantage since I had to have one cylinder sleeved because it did not clean up. I had the heads resurfaced. I had the cylinder heads water passages sleeved and special umbrella 427 BBC valve guide seals used. The engine was then balanced. The pistons were sent out and the tops were ceramic coated and the sides graphited coated. I pretty much used the TDP Rebuilding guide to assemble it. I ran into problems fitting each main bearing. It was a time consuming task. I Plastigage each and everyone of the mains/rod bearings. I had to buy bearings to fit from GM to keep tolerances equal.I had to have the rods remachined and rebushed offset to bring down the piston height to just below deck height 0.005-0.010. I replaced the cam and lifters. I added the dual idler. I put on the front timing cover and then set Top Dead Center by using a dial indicator on number one piston top and bring it up within 0.20 TDC. I then marked the crankshaft damper at the TDC mark on the cover. I then reversed the rotation of the crankshaft and brought number one piston up to the same 0.20 reading. I marked the crankshaft damper again at the TDC mark. I then measured the halfway spot between the two marks I added. That was TDC. I double checked it. I then rotated the crankshaft and put the new mark on the damper to the TDC mark on the cover. I loosened the metal TDC marker on the cover and moved it to the factory TDC on the damper. I put in the new style rocker arms. I completely assembled the engine. I pretty much replaced everything from the radiator back to the transmission which I had rebuilt.
The 6.5 Felpro head gaskets were not compatable with my engine and leaked. TDP did an article on this. I had two of the rebuilt injectors stick open on me about in 3K miles causing me problems. I had the Injection Pump reworked about 3K miles by another rebuilder after the second injector failed.
An aftermarker gear-reduction starter which I pulled out because of hard starting when it got warm. I should have bought the factory one.

It has a Banks turbo system
Hummer intake
DB2-4267 injection pump with 4911 advance piston
Dual Idler
Total Seal piston rings
180 degree Robertshaw thermostat
Gear Vendor OD
I also just installed a 7 blade fan which was an option in 1982 for the HD Trailer Package for the 6.2. I know they must have had to discontinue it because it was time consuming to install it without the spaces the 5 blade fan allows for reaching the mounting nuts. I will let you know if there is an improvement in cooling.

I went to a wrecker who specializes in pickups. He removes the hard lines on bad engines and hangs them in his GM diesel container. He let me hand pick what I wanted. I compared them and came out with the larger ID so I can not tell you what year. I can tell you it took a minimum of bending to fit the 6.5 short injectors. The first set of hard lines I used were a bitch to fit.

[britannic]

What's the name of the wrecker and where are they located?

[crew84]

I got them at Cordova Truck wreckers about a year ago. That is in Rancho Cordova

[odee]

thanks,I wanted to find out what turbo setup you had used. I'm gonna clean up my lastest core engine to find out what kind of parts I got in the deal. Hopefully I will have a good block to start with. When you rebushed the rods did you go with new bolts and resize the them or do any other hot-rod tricks of polishing the beams or shot peening them? What about the offset bushing whats it made of?

[crew84]

If I would have known then what I know now I would have put in a 6.5. I would still used a banks because it fits my bodystyle. I am going to haul a 29ft fifth wheel around. The money I spent on the 6.2 would have been only slightly more and I would have had more HP. I had the rods resized. The engine had low miles on it. Rods are not the problem these engines have. Broken crankshafts, web castings, and pistons overheating are the main problems. Most people have the pistons machined and then ceramic coated. I got ahead of the game and found out after the pistons were coated that they were too high in the block. I would not worry shot-peening the rods. The main thing is to measure clearances and adjust to tolerances. Have the crankshaft checked and DO NOT have it ground undersize. I could have bought a 6.5 engine on Ebay which I did not have when I bought the first engine.