99 Montana 3800 swap project

[MattStrike]

Thursday night was the big night. After the last minute rush to get things sorted out, and a few hundred pounds of cargo loaded, the top swapped 3800 Montana was put to the test - full send, no holds.



Rear load levelling not doing it's thing...


10 years or so since the last time it's actually moved under it's own power - straight to the freeway!


180 miles later it's still going!


We found a random Holden!


Van did some work to make this happen - have to put that boost to good use!


Bugs are freaky gross.


Finally, 21mpg and 400 miles later, back home again!



The trip was not without incident. Exhaust drones between 2000-2500rpm. I tried to use a zip tie, but it melted. Cylinder 4 is misfiring at idle and once heat soaked under load (P0304). I tried to zip tie it, but no go. The air compressor for the rear shocks is not being an air compressor despite the air compressor noises it was making. Once again, zip ties were deployed. Unfortunately they didn't work. Finally, I swear, a Wookie has taken up permanent residence in the power steering system. As you might expect, zip ties were found wanting.. The L67 pump I had on hand decided it wanted to have a bad bearing, and of course that means moar bubbles in the fluid!

This exact same road trip is planned for next weekend, so there's work to do. Going to do a compression check on #4, have to look back to what I did with the plugs but might have to change them all again. Already swapped the PCM for another with the Grand Prix OS (that swapped the P0336 in favor of P0304), already swapped in a known good fuel injector. One of my other used MAS fixed the P0102 issue, etc. Cylinders and heads looked good when I put everything together, I'm hoping it's a bad (new) plug vs. the alternative bad (new) parts.

[MattStrike]

Cylinder 4 ended up around 85psi compression compared to the others I checked that were at 120 or so. Boroscope didn't find any chipped pistons (you never know, might have happened after getting it running). Ended up with this last night:


Soap water test - fill the runners with soapy water and see if each valve is sealing. Intake valves eventually started to get damp, but nothing major wrong there. Exhaust valves, well, you can see:


Water seeps past the exhaust valve on #4 about 1 drip every 2 seconds, and #2 was seeping about 1 drop every 30 seconds. Pulled the valves, sure enough they all were pitted and rusty. Tried to find replacements locally - turns out the only place I could find a set was on my own shelf, none of the parts stores carry these anymore so special order only.. I ended up grabbing them from the NA heads from my Camaro. They are in much better shape, and ended up lapping in just fine.


My guess is that the top swap donor sat with #2 partially open and #4 fully open long enough to make them rusty - so I'm adding the soap water test to the list of things to check whenever I go down the next project loop. I noticed that all the intake valves on this head have different valve guide seals, so they might have been changed already. At the moment the issue with the valves corresponds to the cylinder 4 misfire at idle. I have no reason to expect problems on the bottom end since I actually got to hear it running before I bought the donor engine - so I'm hoping exhaust valve leaks are all this was.

Goal for tonight is to get everything put back together, re-gap the plugs to .035 like I did with the Camaro. I took the power steering pump from the Bonneville (I put a 'new' pump on that which ended up still leaking) and warrantied it for the leak. Going to use that on the van for a few weeks until I can get the remote reservoir figured out and change it back to the new Camaro pump that I have. I also grabbed a new W-body pressure hose while I have everything apart, going to add a power steering fluid filter. If all goes well tonight then tomorrow I'm going to work out a solution for the exhaust resonating. The 1/4 wave works out to 29", I'm hoping I have enough left over 1.5" stainless tubing to put one right before each muffler.

Looking forward, here is the concept for the bubble separator for the reservoir I want to build:


The idea is that hydraulic fluid flows in tangentially to the side of a slightly larger tubing, which forces the fluid to rotate and tangential force makes the air bubbles get caught in the center. A vent tube that leads to the top of the reservoir allows air to escape, while the remaining fluid flows out the other side. In this application it would have to be submerged. I'm planning to rig up a test fixture to run the Camaro pump to an orfice and return to test the idea out. If I can find information on material compatibility it's possible I could 3D print this.

[MattStrike]

Exhaust valves passed the water test. Got everything back together and no more misfires! It pulls all the way to the shift points without any KR or misfires. Glad it ended up being something simple.

[retroren]

Suffering through a pinched neck nerve the last few weeks which cause sleepless nights. Wish I lived near you so I could come over and help you as you seem to not sleep as well. Amazing stuff Matt!!!

[MattStrike]

Finally had a chance to address the exhaust drone.


What you see here is a short stretch of cruising during the worst case drone, and after that idle. Based on this I came up with three frequencies that needed attention. 40hz (just off idle), 80hz (50-55mph), and 115hz (70mph)

Built up some helmholtzs things:




And after:



Well, I can say it's way more tolerable now but it's still there in there. Looks like I need to double them up in spite of the X-pipe, going to look into this a bit more first.

[MattStrike]

Not all LEDs are created equal.

Decided to upgrade to 9007 bulbs (due to availability of better quaility bulbs)


After some minor adjustment, who knew these halogen reflectors could come anywhere near a clean beam pattern?


Now I just have to figure out why turning the fog lamps on makes them switch to the high beam...

[MattStrike]

Mini fall color tour!

[Sirius]

I miss those trees! I remember taking my wife canoeing down the Au Sable river in October shortly after we were married. The colors were nothing short of spectacular. Odd that I never really noticed them when I lived there. LOL!

[ErikZR1]

*dang*. This is one of the best threads on the internet. Amazing work. And I love the fact that it isn’t a Camaro or Mustang that is getting all of the love.

If I find my dream Touring Sedan (does anyone else in the world dream of a 1992-93 Touring Sedan? Supercharged, of course!), can I send it to you for a once over. I’ve never met a mechanic as thorough as you are!

[retroren]

Yup Matt, it's been fun to read your posts and see how you have agonized over the smallest detail in order to make an improvement. Just curious, is there a group of co-workers that share your level of interest and actually get their hands greasy, cut and otherwise "non-engineer" clean looking? If there were, maybe the domestics auto companies would dominate once again. Passion, education, curiosity and ability....you have them all. Keep posting.

[retroren]

Hey Matt: What, no Montana updates? How's it running? I can't believe you have re-engineered something on it. Or is another project got your attention?

[MattStrike]

Nothing of real consequence to report on, but since the last update I've been fixing a bunch of little issues. Had to replace the LF door latch, both front window regulators, working on collecting the rare black switches with red backlighting (some olds vans got them), replaced the latch on the rear hatch, etc. Things I'll be working on soon include the rear HVAC blend door not working, a few random switches not working right still, figure out why the power sliding door on the passenger side quit working altogether, get the drivers side one to close all the way (about 1" from close it opens back up), and finish the overhead console 1080p screen install.

I've had a few minor issues along the way, like the one exhaust hanger won't stay up (slips off the hook randomly), snout seal is leaking vacuum at idle, and I think I have a dead spot in the TPS. Waiting on more parts and some extra trim clips before I dig too much further into it. And I hate cold/snow.

[retroren]

but she runs ok?

My neighbor traded me a 1957 Austin FX3 London taxicab for work I did for him. It's cool but I want to sell it.








I believe it have a Ford 2.2l diesel. My neighbor swears the drivetrain is good. He had driven it about 10 years ago then stored it.

[MattStrike]

but she runs ok?

Absolutely, due up for the next oil change already after a 300 mile or so round trip. It's been the dedicated kid hauler since October.

[MattStrike]

Well, the Montana van is due up for another oil change. So I did the right thing and put new tires on it instead:





I was a little late to getting the winter tires off, but the tire guy assured me I should be able to do stoppies now. The new wheels poke out a bit, which looks really good on the front. But I'll have to work out bump stops for the back so they don't rub the fender on those amazing Michigan roads..

[MattStrike]

It's been a while, I know, but I guess that's just what you get when you put a 3800 in something.

Van has been seeing daily driving duty since I last posted, things are for the most part working out as expected!

I'm actually (finally) getting some things done on this that were never finished, something about kids tends to put a hold on projects. First up: the Audio/Video system stuff!

Sub box, attaches to the jack mount bracket, amplifier is mounted behind it in the fender gap next to the body vent:


It's nothing too crazy, but the stock speakers just had no bass at all so this 10" woofer fills that gap.


I had some fun mounting this, my own doing, but finally I have the center console complete!


It's nice to have BT that works in the van.

And then I took it on HRPT again this year, found a wild G-body!


That was an interesting trip, it was over 100F for most of it, really put the 3D printed stuff in the engine bay to the test. At one point we were going up this hill with sustained 3600rpm to maintain 70 - yeah, stuff happened... I didn't have my scan tool, but after that hill climb the TCC lockup and 4th upshift were not happening. Our convoy had some other minor issues that we ended up pulling off for shortly after that, and after cooling off the trans was back to normal-ish. Checked the fluid later that day and sure enough the fluid was showing signs of overheating and smelled burnt.

A/C worked great all week! Though, one of the drivers side airmix controls isn't working - it blows warm air no matter what, the rest of the vents are blowing between 39F and 45F.

Anyhow, I guess I'll have to get another trans rebuilt on the side here since I'm sure that the overheat shrank some rubber seals. In the meantime I'll have to pickup some auxiliary coolers for the trans.

[Sirius]

...something about kids tends to put a hold on projects.

I thought you were just sittin' around on yo' a$$ doin' nuthin'.