Swapping in a 6.5l

[NH2112]

The 6.2l in my '85 C1500 is in bad shape and I'm going to swap in the 6.5l I bought for a project. It's a '99 Goodwrench but from what I was told it has an earlier serpentine belt setup. I won't need the AC compressor so I'd like to get rid of it, but doing that would leave me with a vacuum pump I don't need, so I'd like to just get rid of everything on that bracket. So, I guess I need to know if GM ever did offer a serpentine 6.5l without AC or belt-driven vacuum pump.

Also, the 99 alternator has only 1 wire on the alternator plug, how does this connect into the 85 harness which I'm pretty sure has a 2-wire plug on the alternator?

[john8662]

Hmm..

I think it's going to just be easier to "treat" your 6.5l like it's a 6.2 and bolt everything from your old 6.2 onto the 6.5 block.

So swap on the front timing cover (the electronic one has a hole in it for a crank pos sensor) the waterpump and plate from the 6.2, then bolt all the other accessories onto the 6.5 block, they won't know anything different.

Then bolt on your 6.2 IP and lines, etc.

Otherwise, someone on here might know how to get the accessories from the 99 to work in the '85.

So, whats up with the ol 6.2?

[NH2112]

I thought of doing that, but I don't want to get rid of the 130gpm water pump and high-output alternator. The engine itself (506 block) has a mechanical pump and none of the doodads needed for the DS4, and in any case I can always leave the AC compressor on since it's declutched anyway.

As far as what happened to the ol' 6.2l, I'm not 100% sure because I haven't even done any troubleshooting, but it sounds like either a bent pushrod or valve - maybe more than one. It's a little down on power and a lot up on noise, and I figured what better excuse to put my 6.5l in? I'll just look for a Cummins to go in my project truck, or maybe I'll save up the money to get that TD60 in like I planned a few years back. smile.gif I'm going to tear it down after the swap is done and see what the problem is, because I'm trying to convince a friend to put a 6.2l in his YJ rather than the 305 he's planning on right now. If it's an easy fix, I'll let him have the complete 6.2l, along with the SM465 I gave him. Who knows, maybe it'll still fit with my ATS turbo bolted on LOL

[rlvelin]

'93s had mechanical injection, a serpentine belt setup, no vacuum pump, and possibly some models didn't have AC either. This summer I switched all of my '93 accessories from a 599 block to a new 506 block when I replaced the engine. I also added the 130 GPM water pump and dual thermostat coolant crossover, you need a custom bracket for the throttle and cruise cables when using the dual thermostat crossover.

You could leave the AC compressor on and plumb it to be an onboard air compressor.

Ryan

[NH2112]

Well, I just blew the #$%#$ out of the 6.2l, while hauling what had to have been 3000lb+ of masonry to the landfill. So, it's all academic now - I'm putting it in the way it is, and will take care of the pulley situation later. Thanks for the advice!

[NH2112]

Well I pulled the 6.2l out yesterday after searching high & low for an engine crane. While it was still in the air I pulled the pan off and found most of a piston in it, along with noticing that the #5 rod was bent and twisted, and shoved through the cylinder wall as well. I'm going to tear it the rest of the way down after getting the swap done and I should have some good juicy pics LOL

Got the 6.5l sitting in the engine bay now, had to pull the tranny out to get the engine in - the problem being we're doing the swap in a dirt driveway where the crane won't roll, using a crane with casters that pretty much don't, and there's at least 3,000lb of chimney in the bed. We were using a Jeep to roll the truck back and forth to line things up! :eek: Noticed the tranny mount was busted too so tomorrow I'll get the tranny back in and see how much a mount costs - I lost my job 1 1/2 weeks ago so I'm kinda doing this on the cheap, but you can't get by without a tranny mount. Then it's just a matter of figuring out how to connect the single wire coming off the alternator to the 2-wire truck harness, and seeing what I can do about the exhaust. Can anyone tell me how the stock 6.5l fuel filter's "drain" pipe is normally plumbed? I already have an electric fuel pump in the truck so I'll just run a line up the driver's side framerail to the inlet, and the outlet to the pump is pretty simple. But, there's a tube that runs back under the intake manifold, which I believe is the return to tank. Yes/no/maybe?

[BobND]

If you look closely at the old alternator, next to the 2-wire connector, it's labeled "1" and "2".

Splice the wire that was connected to #1 on the old alternator to the BROWN single wire comming out of the connector on the "new" alternator.

You will NOT use the wire formerly connected to #2 on the "old" alternator.

[NH2112]

Thanks, Bob, that was the only potential problem I saw.

Of course, now I find out that the slave cylinder and driver's side exhaust manifold both want to occupy the same space so I have to see if the "other" style slave cylinder will fit. Otherwise it'll be time for something unexpected, maybe I'll have to make a new hose or steel line to connect the 2, bleed the system with the slave cylinder unhooked, then mount it upside down because it looks like it'll clear that way. Or else maybe some angled shims to angle it slightly away from the exhaust will work.

After that comes the exhaust, which may or may not be a bitch. It "looks" like there's just enough room to sneak it between the passenger side exhaust manifold and frame, but probably only if I weld instead of use a clamp.

Still, even with the few problems I've run into along the way it's not that bad - when you consider that I'm putting an engine into a chassis it was never meant for, backed with a transmission that never came behind the engine, a few minor fitment problems are really nothing smile.gif

[john8662]

About the slave cylinder, which exhaust manifolds are you using?

Are you using the factory 6.5 turbo hardware on this engine? Or are you going to use a 6.2 turbo kit on the 6.5?

At 275hp with a MFI pump on it, I'm not thinking that you're going N/A.

[NH2112]

I'm using stock 6.5l turbo exhaust manifolds, with the slave cylinder that's about the size of 2 "D" batteries and the line attached on the side facing the middle of the vehicle. I'm going to look at using an elbow for clearance and just cutting the end of the line off without a bend and reflaring it. I'm not going to let something like this stop me for very long....but the cold rain we're having now sure can LOL

[john8662]

You could easily use the 6.2L exhaust manifold on the driver's side and adapt or have a new crossover pipe made that would have the extra bend to meet the output of the 6.2 manifold.

Besides, if the 6.2 didn't have issues with clearance in this area in your chassis, using the 6.2 manifold which will bolt right onto the 6.5 makes a good fix.

There will be no benefit of using the 6.5 manifold on that side verses the 6.2 manifold. The only thing I know you will want to do is remove the EPR valve assembly off the 6.2 manifold, which is simple enough, with a stud extractor or some good vice grips.

[NH2112]

That's one of the things I was thinking of, it just looked like I'd have to unbolt the engine to get the exhaust manifold off and was trying to avoid that LOL

[tom.mcinerney]

>>how the stock 6.5l fuel filter's "drain" pipe is normally plumbed?

The base of the OEM 6.5L fuel conditioner assembly has one inlet (marked 'IN')on one side, and two outlets on opposite side (the feed to FIP is marked 'OUT' ; the unmarked outlet is the drain). The inlet hose barb is 3/8" from tank feed; I recall (?) both outlets (they originate from same space in cannister) have 1/4" barbs . The output-to-FIP gets a molded hose from dealer(??) , the drain is a generic hose to a drain valve mounted to thermostat tower, or location of your choice. The drain hose follows the FIP feed hose along valley floor forward, then up drivers' side of pump vicinity....

Given opportunity , i'd suggest use the OEM 6.2L fuel filter arrangrment, [since it has two] , or at least use something for emergency filtration between the Stanadyne conditioner assembly and the FIP. The Stanadyne conditioner is a nice unit if perfectly configured. The old fuel heaters fail, and leak.

[NH2112]

I decided to keep the same filter arrangement I've been running for a couple years, with the Stanadyne Model 80 mounted on the radiator support, under the air inlet, as the primary filter, and a 2-micron Racor 445 as the secondary mounted on the firewall. All I need to do now is run the fuel return hose that goes under the intake manifold (I'm assuming that's what it is) back to the tank, since the exhaust will be too close to the hose if I run it to the stock fuel return pipe location.

Maybe I'll salvage the fuel heater and WIF sensor wiring from the old truck and install one of the spare diesel instrument panels & bezels...although I've been doing just fine for 3 years without a fuel heater.

[tom.mcinerney]

Misinterpreted quest re fuel return!

The stock 6.5L fuel has small hoses feeding overflow from injectors forward ; a 'crossover' at front connects flow fr both heads. A steel fuel return pipe runs along inner side psgr head (under InMan) , securing clips attach to the inner(central) studs that fasten the starboard thermo tower , and rear head outlet port , respectively. About a 6" (5/16"ID) hose runs from the pipe aft to the steel lineset which meanders back tankward.

I've located pics of most of items aforementioned here , if want them emailed send a note to tbhpmciAT hotmail dotkom....

[NH2112]

Thanks, Tom. I think I'm just going to cut the steel return line behind the engine in a location that will keep the rubber hose away from the exhaust, and extend the rubber hose that already runs under the intake manifold to the pipe. It would be easier to just run the hose to the stock fuel return line location but I don't really want a fuel hose looping up and over in the engine bay like that.

[mhagie]

I have a 6.5 w/mechanical injection that I have in old blue I used all the 83 blazer donor parts including the return line that exits on front passenger side of block right by the 6.2 mechanical fuel pump, everthing lined up and fit perfectly even when converting it from a small block.
This conversion was so easy to do it was pathetic, thats why it only took me a couple of years at my warp speed.
Merle

[NH2112]

After taking a good look at things I decided I'm just going to run the return line up from the tube and loop it down to the stock tube on the frame. It's nowhere near the exhaust or turbo so there shouldn't be any safety issues.

All I managed to do today was make the new crossover pipe, using the top 6" or so from a 6.2l exhaust welded to the 6.5l crossover pipe. It actually fit almost perfectly just by putting it on backwards, I had to cut a wedge about 1/2" wide at its widest point to get the angles right. So hopefully tomorrow I'll be able to get everything else done and get it running. The worst part will be getting the AC11Gs out and putting in my Kennedy plugs form the old engine.