M715 project underway 305 chevy with 200-4R auto

[jeeper]

Thanks George. I will try the gold lens.

I haven't been in the garage much the last couple of days. I've been working out of town. I did a 25 hour shift yesterday. I didn't work today because I was too tired.

I did start looking at options for my oil cooler. The 6.5 block has 1/2" ports for the oil cooler. That got me wondering if my oil cooler lines on my 6.2 could be causing me problems?

I have 3/8" lines from the block to my oil cooler on my current 6.2. Is that too small a diameter for oil cooler lines? How critical are the oil cooler lines on these engines? Would/could 3/8" lines negatively affect the oil pressure?

[jeeper]

I found a thread on another site about installing a turbo on a 6.2. One modification they made was to bring their oil return back to the fuel pump mounting plate. I wouldn't have thought there was enough room but I was wrong.

I used 1/2" EMT conduit for my oil return pipe. It is only slightly smaller than the original return pipe. The original rubber hose clamps down on the EMT pretty well. I cut the pipe at an angle and welded it to the plate after I cut an oblong hole in the plate.



I ended up using some JB-weld around my welds because I didn't have my drain pipe down quite as far as I should have. I had to grind off the weld at the top of the drain pipe. I also sealed the inside with JB weld.

[Barrman]

That is so cool. Thanks for sharing.

[jeeper]

I am not making very good progress on testing out my 6.5 turbo engine.

Being an electrician I thought it would be simple to bend up a short piece of conduit between the output flange on the turbo and my new drain pipe under the fuel pump. I spent a couple hours trying various routings. It turns out to be more challenging than I thought. The pipe coming out of the turbo is made at an angle. To keep the oil line away from the exhaust manifold I want to point the pipe away from the exhaust manifold. This makes it difficult to fit conduit because both pipes are pointing the same way. They both point away from the engine block.

Thin wall conduit does not bend well into a tight radius, It needs sidewall support to prevent the walls from kinking. An electrician uses a one-shot conduit bender to make a 90 degree bend in one sweep. That is fine for electrical work because a gradual radius is required by code. You can't pull wire through a tight bend easily anyway.

I am in the process of trying a plumbing 90. If that works I'll post up pictures.

I have also spent most of the day today getting a stuck glow plug out. When I tried removing the plug it sheared off with all of the threads still in the block. I didn't get a picture but it was stuck in there like it was welded.

I drilled it and tried an easy out. I don't know why they are called easy outs. They sure don't make the job easy. I drilled and tried every size of easy out I had. That glow plug was probably put in by GM in 97 or 98 and it was not coming out the easy out way.

I ended up finding a drill bit that fit pretty snug into the glow plug hole but didn't cut into the threads. I drilled the plug with a letter "R" bit. I called a few places and found out the NAPA distribution Center about 20 miles away had the tap I needed. I bought a 10x1.0 tap and tapped the threads back into the head. To get the tip of the plug out I had to drive it into the cylinder and fish it out of the injector hole with a mini spring claw. A little compressed air and a thorough vacuum and the glow plug fits in nicely.

I have also built an oil supply line. It is solid 3/8" line with standard flare fittings on each end. It is a female flare at the turbo and a male flare at the block. I put a 90 fitting on the turbo and pointed it toward the intake. I am wondering though why GM didn't do it this way. They used a flexible line with a 180 degree sweep at the end.

So now for a couple questions for anyone that has read this far.

Could I use a rubber hose for my oil return line?

Do I need a flexible line from the turbo to the block?

When I was at NAPA today I checked if they had any rubber line that could be used as a return line. I made sure to tell them that it needed to withstand hot oil continuously. They didn't have anything that big. The ID of the stock oil return line is around 3/4" or 7/8".

[Barrman]

I have 2 vastly different turbo charged engines in my class room. A 6BT and a VW Bug flat 4. Both have braided steel flexible oil supply lines to the turbo. I will have to look tomorrow, but I am pretty sure both have braided steel return lines as well that are not near as big as you are writing about. I will look.

[jeeper]

Thanks Tim.

I should clarify my dimension for the return line. The ID of the rubber hose is about 3/4" which allows it to fit over the hard line.

The stock '98 had a solid line routed near the exhaust manifold and ending just above the tube in the plate where the lift pump goes. They used a piece of rubber hose about 2" long to join the tubes together and held that on with hose clamps.

My plan was to use that same idea with a different routing and 1/2" conduit.

I did piece together a new line that uses plumbing 90s. It allows for a more compact installation but still doesn't look professional.

I may try building my own flange that comes perpendicular out of the turbo. It doesn't look like a complicated piece to make.

My pressure line has extra bends in it similar to the way a brake line does that allow a little flexibility.

[jeeper]

Well I got the engine to fire up yesterday. It runs terrible. It belches black and gray smoke to the point I had to exit the garage after a short run time. It actually stalls out when I try to let it idle. It needs about half throttle to even run.

I started looking at the timing and realized there actually is a timing mark on the 6.5 that I hadn't noticed before. I tried moving the pump to align the marks but there isn't enough movement available on the pump to get them aligned. My pump is about 1/4" to the drivers side and is hitting the end of the slot in the pump.

When I compare the ds4 to the db2 the front of the pumps look pretty much the same. The timing marks look to be in the same relative position.

When I look at the timing mark on the 6.5 engine and compare it to the 6.2 they look to be in the same relative position.

So now I am at a loss. Why isn't there enough adjustment to align the timing marks?

I will be modifying my stand and adding a radiator soon. I plan to get this engine up to temperature so I can see what happens to the oil pressure.

But first I need to figure out why my timing is so far off. Is the pump gear in the 6.5 set at a different location? Is the gear off by a tooth maybe?

[jeeper]

Well this is how I started my Labor Day weekend this year. I spent the day in my M715 yesterday and drove about 150 miles each way for this.




It was a long day but happened with only a minor hitch. I didn't get home before dark. This wouldn't normally be a problem except that I haven't finished my 12 volt conversion. What I mean by that is I haven't added a relay through my 3 lever switch to control my lights. The entire lighting circuit goes through the circuit breaker in the 3 lever switch. This hasn't been a problem when I don't have a trailer connected but with the added draw of the trailer lights I blow the breaker.

So on my way home my lights went completely out several times. There was no moon light either. When the lights quit I would pull over and wait for the breaker to reset.

After several times of dealing with that I decided to put the 3 lever switch from the M715 on my trailer into my tow vehicle M715. My plan was to drive on that until it blew the breaker and then switch it back. Sounded like a good plan except the switch didn't work!

When the lights went out the next time it finally occurred to me that I needed to reduce the load if I were going to get home safely. I pulled out one headlight and unplugged it. That dropped the load enough that I was able to make it home without tripping the breaker again.

[Mikel]

I had the exact same problem with a 300 mile trip to pick up a 1975 cherokee. The additional draw from the trailer lights was causing the switch to overheat. I'm thinking of opening the switch and bypass the thermal breaker.

How did the truck tow?

[jeeper]

I'm thinking of opening the switch and bypass the thermal breaker.

How did the truck tow?

I had a similar thought originally. I was thinking of up-sizing the breaker. I haven't researched that enough yet. My concern is that I don't know what the total draw on that circuit is yet and I don't know what gauge wire is in use on that circuit. If it is a 14 ga. wire the max fuse size would be 15 amps. Any bigger fuse and there is a risk of starting a fire. If the wire is 16 ga. then the max fuse size is even lower than 15 amps.


The truck towed great. It didn't know the load was back there except on acceleration. The 6.2 in my M715 is still naturally aspirated. It took a bit to get to speed but didn't suffer with the gradual inclines once I was up to speed. There weren't any real hills between here and there.

I wouldn't attempt to tow that load if I didn't have trailer brakes though. I have stock axles and brakes.

I figured out I have one front brake that is adjusted slightly tighter than the rest. With the delay on my brake controller set like it is I will lock up one front tire before the trailer brakes kick in. But that only happened once when I was stopping fast.