Sad Suburban

[BadDog]

Oh, and something I should have mentioned with the post on the new interior, I got a bit of schooling there as well.

There were several reasons I selected a late square body for this build, most of which turned out to be false. First, that square body parts were cheap and plentiful. It seems that during the time when my knees were stopping me from doing much of anything, square bodies got somewhat rare and hard to find nice parts for reasonable cost. I was amazed going to a junkyard and seeing maybe 6 or 7 well picked over square bodies TOTAL, I was used to rows of donors, many mostly complete. Wow, that was a wakeup call!

But the real problem turned out to be something I thought I knew, but found out otherwise. I've been messing with square bodies for decades in many different forms. I thought I knew most everything about them, and a big part of that was most everything interchanges between them. And if it didn't come with it, upgrades are usually just a bolt in affair unless good reason otherwise. New problem, I never fooled with Subs before. And I learned that the rear gate is almost completely different from the K5. I had originally planned on using the seats (and bases) from the K5, since I reasoned it should have the flat 1st-2nd row floor like the later K5s. WRONG! Another fun fact, the Subs got truck floor plans for some bizarre reason, complete with the hump for the gas tank (Nick spotted that one). So K5 seats are a non-starter. How about that Subs don't come with floor brackets and reinforcements for bucket seats unless ordered with buckets? Yeah, the conversion sub was ordered with a bench, so the center seat mounts for buckets don't exist. I made some for strap, but really??? I also originally thought swapping barn doors would be easy, but quickly learned that only the early square body subs had the provisions for barn doors when equipped with a tailgate, so I'm keeping the gate.

So much for my reasons in selecting a square body for my last build...

 

[imiceman44]

Oh, and something I should have mentioned with the post on the new interior, I got a bit of schooling there as well.

There were several reasons I selected a late square body for this build, most of which turned out to be false. First, that square body parts were cheap and plentiful. It seems that during the time when my knees were stopping me from doing much of anything, square bodies got somewhat rare and hard to find nice parts for reasonable cost. I was amazed going to a junkyard and seeing maybe 6 or 7 well picked over square bodies TOTAL, I was used to rows of donors, many mostly complete. Wow, that was a wakeup call!

But the real problem turned out to be something I thought I knew, but found out otherwise. I've been messing with square bodies for decades in many different forms. I thought I knew most everything about them, and a big part of that was most everything interchanges between them. And if it didn't come with it, upgrades are usually just a bolt in affair unless good reason otherwise. New problem, I never fooled with Subs before. And I learned that the rear gate is almost completely different from the K5. I had originally planned on using the seats (and bases) from the K5, since I reasoned it should have the flat 1st-2nd row floor like the later K5s. WRONG! Another fun fact, the Subs got truck floor plans for some bizarre reason, complete with the hump for the gas tank (Nick spotted that one). So K5 seats are a non-starter. How about that Subs don't come with floor brackets and reinforcements for bucket seats unless ordered with buckets? Yeah, the conversion sub was ordered with a bench, so the center seat mounts for buckets don't exist. I made some for strap, but really??? I also originally thought swapping barn doors would be easy, but quickly learned that only the early square body subs had the provisions for barn doors when equipped with a tailgate, so I'm keeping the gate.

So much for my reasons in selecting a square body for my last build...

View attachment 292566

Yeah that's why I bought so many .
I have plenty of squares including 2 suburbans.
One with tailgate bench front seats and a 6.2 with a turbo and the other is barn door bucket seats and a 350 tbi both with 3 row seats.

 

[Bent77]

Lots of good looking updates!

 

[BadDog]

One of the items I would never have thought of at the appropriate time if Nick hadn't mentioned it is dealing with the thermal/noise insulation over the heater fan. Who ever thought it was a good idea to put a glued on and impossible to r/r cover over the ac fan motor really should be taken out and flogged. In any case, while it was nice and easy to access, I made a nice straight cut to remove the dome over the fan motor. I then took some 20 ga flashing and made a strip/lip that was poprivited into the remaining cover edge such that the cut-off dome would slip over that new lip. I then added a couple of small "posts" (basically a thumb nut on a screw) in the area that will soon (I hope) be inaccessible with the front cap installed. And the rest of it was drilled for a number of screws.

The result is that I can hook the dome over the pins, slip it over the lip, and lock it in place will screws. Thereby keeping most of the original function while being able to access the fan.

I still have to modify for the rear AC fan resistor bank.

 

[tRustyK5]

Nice to see you back here, and back at it...even if your luck hasn't changed much.

As for 6.2 intakes there are a couple, maybe three version of the J-code. One is split plenum like you have, there is another that is wide open, and then the low rise HMMV version. For giggles, grab some intake gaskets and lay them "best average" over the intake ports on the engine side, and on the actual intakes. The casting accuracy on these is at best. Seeing how bad mine was led to my very first port matching adventure. I'm sure all those intakes vary, but on mine there were ports where over 1/4" was removed and blended on one side of the port to get it to match. Fortunately the engine side of things was actually pretty good.

 

[BadDog]

Thanks.

In some ways it's good to be working on another truck project, but there are lots of time I wish I had just gone to my next machine tool rebuild or something else. I seem to have better luck on those. But really, most of the bad luck on this thing has been more aggravation and unexpected delays than anything of substance. So, one foot after the other. Things should improve once I get the engine in and minimally mobile. In a switch-up with the mall crawlers, it will likely first move with only a front drive shaft. I still have to figure out if I want a LONG rear drive shaft, or go with a carrier bearing and shorter shafts...

Yeah, I knew there were a couple of different J code intakes. I'm using the split plenum shown because that was handy and in really good shape requiring very little cleaning. But I had previously put an open plenum J code on my NA C10 SWB step-side beater. However, I had never seen a military intake until I got this surplus take-out.

I didn't match the intake ports, mainly because of things I read regarding these motors with turbos. The gist was that even a C code intake works as well as a J code intake for all practical purposes. We have only the air charge to worry about due to direct injection, and we don't have high rpms and with associated high flow where a bit of turbulence starts limiting things. However, the guy that tweaked a NA 6.2 to see what he could get out of it without forced induction did note gains from doing that, but of course he didn't have a pressurized air charge. This is already turning into a WAY bigger build than I wanted, and it was something I could punt on (hopefully) without regretting it later, so I did.

 

[BadDog]

I guess it's over due to get another step posted.

As the motor started coming together, I eventually had to make some decisions on the turbo. Part of that was choosing among 2 different turbo exhaust manifolds. One was an old BAE, and the other was a Banks sidewinder. I thought that was an easy decision, but it turned out to be another huge mess. It started with choosing the banks manifold.

The first thing I noticed was that the fresh rebuilt turbo that came with the crate motor purchase didn't fit. As I recall, the turbo was a T4, and the Banks manifold was a T3. And after discussions with Nick (who knows turbos much better than I do) the Banks turbo, with its bulbous hot side and lazy spooling characteristics wasn't appealing, much less needing a rebuild. But Nick did have a Holset "Baby H1C" from his early Cummins experiments, and that provided just the ticket. And it even worked well enough to retain most of the banks pressure side plumbing. One problem solved.

My next issue was not having any love for the bastardized Banks exhaust crossover and proprietary lower radiator hose. As I came to learn later, that hose was the least of it, but I'm getting ahead of myself. And the cross over runs RIGHT under the harmonic balancer. In my case, that's a fluid damper that cost me a very dear part of my anatomy, and I found has a rather surprisingly low max heat tolerance after talking with their techs. So the Banks location was a non-starter from that side as well.

Looking at the Banks crossover pipe, it was easy to see what the problem was. That funky shoe horn cross member under the front of the engine on GM square body 4x4s (I'll ignore issues with other variants). "Ok, I've replaced those before to provide cross over steering clearance and such, I'll just do it again..."

So I stuck the sub's original locked up 6.2 back in for reference. Then out came the drill, air chisel, and recip-saw, and out came that cross member. I after some careful measuring and deep thinking, I decided to do something different than ever before, I was going to use the end pieces of that cross member to make my new cross member that would bolt into the factory rivet holes (~3/8"). And I was going to design it so it drops free on one side making the idea of possibly doing in-frame servicing of the bottom end a bit more tolerable.

Below is what I came up with. The pictures show the frame rails free of the scoop cross member, the cut crossmember ready to donate it's ends, a point near the end of the fabrication, and finally the finished cross member hanging under the new mill ready to start fabricating the crossover pipe and oil return.




Note that in the image below you can see the reinforcement from the left side end still riveted in place. I also removed that and will reuse it with the new cross member, but bolted together with 3/8" G8 bolts and lock nuts.



Note that below one of the reinforcement end plates that provides structural integrity without the missing parts of the stamping has not yet been welded on. That eventually got a big notch cut out of the angled part to provide more clearance for the crossover pipe to pass by.

 

[BadDog]

Next up, fabricating the crossover pipe. I didn't get a lot of the actual pipe fabrication, but it was just a bunch of tedious sections of 3 mandrel bend 2" "U"s .

The first image below shows the mockup I made with conduit that was laying around vs the Banks crossover. Routing is rather different. The new pipe will go down, then back along the passenger side of the oil pan, between the sump and the new cross member, then back along the driver's side of the sump, and finally up to the stock driver's exhaust manifold with a donut.



The finished pipe is shown as you would see it from the front of the motor.



The next pic shows a close up of the flange. It was cut off the old pipe and bored out for reuse. It was also quite warped, apparently from the Banks factory welding, and was several thou from flat with the biggest gap between the bolts. No wonder it blows gaskets. So I made it flat on both sides by surface grinding before welding it (carefully) to the new tube. It's now out by less than a thou after welding. And that gasket is apparently a known weak point for Banks the banks system, so an extension was added to extend into the manifold a bit, hopefully shrouding the gasket from the worst of the pulses. That gasket was to become my next headache discussed in the next post (running out of time today).



The final pic shows it right after initial fab of the tube but before adding the flange. You can see how it slips past the (re)modified crossmember end piece.

 

[BadDog]

That last post brings it up to the point just after I started this thread.

What came out of that is that it appears Banks used a common 2" exhaust flare flange as the welded flange at the turbo end of the crossover pipe. Which means you can't find a decent gasket to fit it, because it was never a gasket flange! Not being designed as a gasket flange also means it's not particularly flat, or rigid. The one I had was quite warped. After removing it from the old cross over, and boring it out to fit the new pipe, I surface ground it flat before carefully welding it to the new pipe.

It appears Banks found some application with a roughly suitable gasket that's offered as part of their ridiculously overpriced $55 gasket set (all but that 1 gasket available cheap locally). But whatever the original application for that gasket was, I was unable to find it, and it's not a good fit for the flange anyway (as evidenced by how often they leak, thus providing Banks revenue from the attempted lock-in).

So, I made my own gasket to fit. I was seriously considering a custom copper "o-ring" type seal, but eventually rejected that because I could just see the headache getting a ring to stay put with the canted flange even with a substantial ring groove. Also considered dead soft copper sheet for a gasket. But eventually I decided on the heavy thick "Mr. Gasket 5960 Ultra Seal Exhaust Gasket".

When I got it in, it really seems much heavier and more rigid than any of the OEM gaskets I was pouring through looking for an alternative to the Banks set. But it was heavy enough, and with stainless steel sandwiched, I didn't like the odds of just free hand cutting or using gasket punches.

So I made an accurate drawing of the flange seal surface. I then cut 2 blocks of 1" MDF just a bit bigger than the pattern, which was transferred to one of the MDF blocks along with a similar sized band saw cut section of the gasket sheet.

These were then clamped together and taken to the drill press where I pilot drilled out the 3 bolt holes, and counter sunk the top. Those holes were then used to screw the stack together before taking it to the vertical bandsaw to cut the perimeter. Next back to the mill where I used a hole saw to provide the center hole. And finally, the screws were removed one at a time to drill and replace with bolts.

The pictures show the results.

First steps:








This is the rogues gallery. Top left is the best gasket I found available to fit the bastard flange. It's a Walker 31305. But it fit rather poorly, and after slotting the holes to fit the donut cone flange spacing, there was little material left to seal inside the bolts. and less than I would like between the bolts. Top center is what's left of the Banks gasket. Like the Walker, it's far bigger on the inside than needed, thus hurting it's longevity in that application. Top right is my pattern. Bottom left is a rubbing I made of the flange before welding it to the crossover. Bottom center is my shop-made gasket, and to it's right the pattern that will go on my shelf with "6.2 stuff" just in case I ever need to make another.


And finally, this is the new gasket on the cross over flange


My best and strongest advice, avoid Banks turbo systems if you can. It's really not what you might expect.

 

[BadDog]

The next headache was the oil return.

I had planned on modifying an existing return to provide at least part of the solution. But that proved to look worse than starting from scratch. I also entertained using a standard ebay "kit" turbo oil return kit based on stainless braided hose and -10 AN fittings. But Holset strongly recommends a 7/8" return, all of which was discussed in this thread. In the end, while I think the 7/8" return is overkill for the -4 oil line fed H1C, I just couldn't go with the -10 AN < 1/2" restriction, PLUS the problematic issue of providing a good steady downward grade while routing around all the hot things in the way.

Speaking of hot things, the hose has to drop down and go right under the hot side housing before making a sharp turn to the rear and then starting a ~70* arc around the cross over pipe, under the passenger side exhaust manifold, to connect with the lowest point on the oil pan that the return could possible be placed...

So again, I should have just made it myself to start with.

I began by finding a piece of scrap from a 1" tube 3" radius bend from one of my previous projects. I wanted to use a standard nipple, and didn't want to fool with trying to tap the 1" tube 1/2" NPT that close to a bend, so I turned down a coupler to weld onto the end of the pipe. If the pipe had been longer, or my bender were easily setup to produce 1 small bend, I would have done it differently.

Then I started the flange by using the Cummins return as a pattern. It seemed to fit the Holset oil port very well. So I cleaned up a piece of 1/2" hot roll plate scrap, blue'd it up, and transferred the flange to the plate (scribe and transfer punches). I then found the center by using a simple geometric technique of 2 arc from the bolt transfer punch marks combined with a line connecting the bolt punch marks, and punched that as well. Close enough for an oil flange...

The bolt clearance holes were then drilled in the mill along with the 3/4" pilot hole for the center drain. I then took the square piece to the lathe in the 4 jaw chuck, and dialed the 3/4" pilot hole true before boring it out for a tight hand-slip-fit with the 1" scrap tube piece. One side was also opened a bit oversize to make the next step easier.

With the tube fitted and clocked appropriately on the turbo to maximize the location and angle for the silicone hose section, I then clamped it in a vise and punched the junction of flange and tube for location. Next I got out the O/A torch along with some "hard" silver solder (aka silver brazing), removed the tube to apply flux to both pieces, reinserted the tube and clocked to line up the punch marks. After cutting off 2 section of the very hard silver brazing rod and bending them to fit the 1" tube profile, it was just a matter of heating it up to dull red and watching the silver rod "run" the joint.

But now I had silver solder and a slightly protruding 1" tube where I needed to seal a gasket. So I took that to the surface grinder and made it all nice and clean and flat.

All that remains is to install the nipple, the 5/8" silicon hose (rated at 400*), and add the high temp ceramic insulating sleeve over the lot of that.

 

[imiceman44]

The next headache was the oil return.

I had planned on modifying an existing return to provide at least part of the solution. But that proved to look worse than starting from scratch. I also entertained using a standard ebay "kit" turbo oil return kit based on stainless braided hose and -10 AN fittings. But Holset strongly recommends a 7/8" return, all of which was discussed in this thread. In the end, while I think the 7/8" return is overkill for the -4 oil line fed H1C, I just couldn't go with the -10 AN < 1/2" restriction, PLUS the problematic issue of providing a good steady downward grade while routing around all the hot things in the way.

Speaking of hot things, the hose has to drop down and go right under the hot side housing before making a sharp turn to the rear and then starting a ~70* arc around the cross over pipe, under the passenger side exhaust manifold, to connect with the lowest point on the oil pan that the return could possible be placed...

So again, I should have just made it myself to start with.

I began by finding a piece of scrap from a 1" tube 3" radius bend from one of my previous projects. I wanted to use a standard nipple, and didn't want to fool with trying to tap the 1" tube 1/2" NPT that close to a bend, so I turned down a coupler to weld onto the end of the pipe. If the pipe had been longer, or my bender were easily setup to produce 1 small bend, I would have done it differently.

Then I started the flange by using the Cummins return as a pattern. It seemed to fit the Holset oil port very well. So I cleaned up a piece of 1/2" hot roll plate scrap, blue'd it up, and transferred the flange to the plate (scribe and transfer punches). I then found the center by using a simple geometric technique of 2 arc from the bolt transfer punch marks combined with a line connecting the bolt punch marks, and punched that as well. Close enough for an oil flange...

The bolt clearance holes were then drilled in the mill along with the 3/4" pilot hole for the center drain. I then took the square piece to the lathe in the 4 jaw chuck, and dialed the 3/4" pilot hole true before boring it out for a tight hand-slip-fit with the 1" scrap tube piece. One side was also opened a bit oversize to make the next step easier.

With the tube fitted and clocked appropriately on the turbo to maximize the location and angle for the silicone hose section, I then clamped it in a vise and punched the junction of flange and tube for location. Next I got out the O/A torch along with some "hard" silver solder (aka silver brazing), removed the tube to apply flux to both pieces, reinserted the tube and clocked to line up the punch marks. After cutting off 2 section of the very hard silver brazing rod and bending them to fit the 1" tube profile, it was just a matter of heating it up to dull red and watching the silver rod "run" the joint.

But now I had silver solder and a slightly protruding 1" tube where I needed to seal a gasket. So I took that to the surface grinder and made it all nice and clean and flat.

All that remains is to install the nipple, the 5/8" silicon hose (rated at 400*), and add the high temp ceramic insulating sleeve over the lot of that.

View attachment 298008 View attachment 298009 View attachment 298010

Wow.
I need to step it up.
I used to do all kinds of stuff like that when I was in my 20's and 30's in my dad's shop, with the lathe and the other machinery he had.
Now I just cut and weld and bolt parts.
I have a lot in my mind and in my notepad but I don't have machining equipment.
I hope I don't need that much work to get my perkins turbo diesel mated to the nv4500 and using the updated holeset turbo, putting it all in my 89 crew cab.

 

[BadDog]

It's all just another level of frustration. It still always seems that I don't have "that thing" that I really need. As a result, I've got more machine projects than vehicle projects. But like the Sub, I keep telling myself that G8 belt grinder, 72x2 belt franken grinder, 2nd 2J Mill, Slotter, Green engraving machine, (etc, etc) will sure be nice when they are done. Still looking for a ~16" Universal Shaper, maybe a K&T 2CH and/or rotary head, and a turret lathe, and... What can I say, I'm a tool junky.

And try as I might, I can never seem to find a direct path in anything. I chose a square body and 6.2 long block to "keep it simple", get good mileage (for a water buffalo) and I had every intention of keeping this a "freshen it up and go adventuring'" build. Add a small turbo from a popular kit vendor to "wake it up" and deal with elevation changes along the path that I image (likely also a pipe dream). Only to find out that Suburbans break the standard square body mold I'm familiar with (and invalidate quite a bit of my parts hoard). I knew it was going to be new territory with the rear air and such, but I kinda expected it to be a long K5 with extra doors and seat, little did I know the Sub went it's own way in ways I never imagined. Plus I had NO idea how bad even the "premium" conversion companies could be (downright unsafe AND downright mess too). And of course the "bolt on kit turbo" turned out to be anything but, unless I wanted to make HUGE compromises and submit to extortion from Banks. I've said I wish I had just bought a totaled 12V Ram from auction and gone that route for the mill, but Nick assures me that would have been far worse even though I would have less problems with the larger bay of the square body (compared to his 72 Sub).

Anyway, I've also long considered the Perkins option, so I'm interested to see how things go. Good luck!

 

[Greg72]

I’m addIng you as an honorary member of #ONIONCLUB

WELCOME BACK!




-G

 

[Big Ray]

Wow. You have me thinking about going with a gm 6.5 setup for simplicitys sake...screw going around the front of the engine with the crossover. Hell, an 8.1 is looking better all the time.

 

[imiceman44]

Wow. You have me thinking about going with a gm 6.5 setup for simplicitys sake...screw going around the front of the engine with the crossover. Hell, an 8.1 is looking better all the time.

My ats setup is a good setup.
I was under the impression that the banks turbo setup was better and I had the suburban I wanted with it, barn doors 2" lift, 33" tires 700r4 and 6.2 banks turbo and it did good but had some rust and I needed money so a good offer and I sold it.
I am hoping once I get it running I will not be disappointed with the ats.

 

[Big Ray]

I was just in the garage, I can't seem to locate the turbo manifold. I wanted to see how different it is from a stock manifold at the exhaust port. I was thinking maybe it could be machined to accept a standard donut and weld a flare on the crossover.

 

[BadDog]

That was another path I considered but didn't go down. My manifold opening through the gasket flange was "as cast", and too large to be modified to accept a donut. It also formed a bit of a knife edge, and opened up immediately behind the flange face. I did consider making an adapter plate, but that's one more source of leaks (that would need a custom gasket) and extra work. Likewise for welding the cast, or any other avenue I could come up with. I was also not entirely sure what would happen regarding stability with 2 donuts and flares. With all the stuff going on there, snaking between the custom crossmember and the pan sump, and basically forming a U hanging like a swing nearly a foot below the donuts, would it be stable enough in all scenarios to not get cocked sideways and rub a hole in sump and/or crossover? Considering all that together put that idea in the bin for me. If the manifold opening hadn't been difficult/messy, I might have given it a try.

 

[Big Ray]

I' hoping my manifold didn't get lost in the move. Be my luck...

 

[BadDog]

Good luck. But based on my experience, might be a blessing in disguise. Of course there seem to really be few good options.

The BAE is awkward in turbo location and flange form factor, though in some ways that's the one I wish I had used. For one thing, jutting forward as it does would have opened up a lot of free room for the oil return and cross over. However, I really like the turbo option that came my way, and that wouldn't have fit the BAE flange.

The ATS seems nice, and their $tuff usually is. But it's a big honking thing with an odd angled turbo placement and quite expensive, so not common or readily found.

And the 6.5 puts the turbo hot side into your air conditioning evaporator box's personal space.

 

[imiceman44]

Good luck. But based on my experience, might be a blessing in disguise. Of course there seem to really be few good options.

The BAE is awkward in turbo location and flange form factor, though in some ways that's the one I wish I had used. For one thing, jutting forward as it does would have opened up a lot of free room for the oil return and cross over. However, I really like the turbo option that came my way, and that wouldn't have fit the BAE flange.

The ATS seems nice, and their $tuff usually is. But it's a big honking thing with an odd angled turbo placement and quite expensive, so not common or readily found.

And the 6.5 puts the turbo hot side into your air conditioning evaporator box's personal space.

Yeah I bought my suburban with a non running engine because it had the ATS turbo.
It helped that the body and interior were nice, paint faded and peeling was ok with me