Should I? '91 Golf VR6 project

In reply to AAZCD (Forum Supporter) :

I don't disagree, but little bro has a hard-on for VR6s, and as much as I hate to admit it, I'm developing a liking for them as well. Not to mention, it's close as it is. The details need tidied up, but we had it running. A new drivetrain would be a new set of problems.

Bro put a feeler out on his IG page and heard back from a guy in KC with several heads he'd sell cheap in the spirit of budget building. There was a mostly complete engine at the pick-n-pull when I went looking for a water pump, but that's been months now; I'll have a look over the holidays.

Broseph is meeting a fellow car guy in KC this weekend, says he has a shelf full of 12v heads in various states of disassembly. He's familiar with the Challenge and we may wind up with a very reasonably priced head or two out of the deal.

And the local salvage yards have one of each flavor of VR6 in the inventory, a 2.8l 12v in a Jetta and a 3.2l 24v in a Toureg. One or both of those may come home with me over the holidays, we'll see.

Naked head - $1. 

Ported but we're unsure to what extent. Needs a thorough rinsing to remove metal chips and shelf dust, then we can start pulling the good bits out of the other two heads and installing in this one.

Had a closer look at the #3 piston. Was really hoping with some careful abrasive application, we might be able to smooth down the sharp edges where the debris damaged the piston.

Those cracks were enough for me to talk myself back out of that idea.

Pulled a piston out of the spare block and #3 out of the car, and installed the replacement piston in the car with the rod bearing halves and rod cap that were on the damaged piston.

Debating rod bolts now. Re-use, replace with stock, upgrade to ARP.

Rinsed the new head thoroughly with gas and a brass scrub brush. Strained the gas back into a can and got this mess out:

Got the funk out this evening and called it a day when the two heads were fully stripped.

The head that was in the car:

And the spare that came to us with a bent valve and a burned cylinder:

Need to run the valves on a wire wheel and get them cleaned up before I lap them into the new head.

We've got the full gasket set, just waiting on the head and rod bolts. If I have time before they get here and before I have to go back to Alabama, I may try to smooth out/port the exhaust manifolds, downpipe, and lower intake runners to match the head.

In reply to JohnInKansas :

I just stumbled upon this VR6 GTI for $800 in Slidell, LA if it's anything that could help you out. 

In reply to Pete Gossett (Forum Supporter) :

My wife would murder me. And then you, for suggesting it.

In reply to JohnInKansas :

It sounds like she'd get along well with my wife. 

Ground out the inside of the lower intake manifold. Light port only, smoothed out the parting marks from casting and sharp machined edges just downstream from the injectors.

And the same for the exhaust. VR6 has a pair of short cast iron manifolds that empty into a welded steel two-into-one downpipe. The downstream end of the manifolds and upstream end of the downpipe got gasket matched, which wound up being an increase of about 1/4" diameter. The flanges on the upstream end of the downpipe are welded on the inside from the factory, and the boogery welds really disrupt flow, so I welded the flanges on the outside so I could remove most or all of the inside welds.

Note: the lug bolt in the driver's side manifold is evidently the preferred method for blocking off your unused EGR port. I'd like to come up with a more elegant solution than that, eventually.

One of the manifolds was missing one stud and had a bolt in place of another (and upon reinstall, we broke another one off entirely), so we have a set on order.

Practiced my lap dancing.

Verified for peace of mind that the head is, indeed, pretty damn near flat and true. Enough.

Finally got some mail.

ARP head studs and rod bolts and the spring compressor recommended for VR6 heads. The ARP stuff isn't the cheap answer, but since we don't know how many more times we're gonna need to take the head off (or if/when we'll apply boost), made sense to get hardware that wasn't single use.

Head studs installed. Head gasket is a metal MK4 unit that came as part of a top-end rebuild gasket set; we only used the head gasket, so it will go on the budget at partial price. The MK4 gasket is slightly thinner than the MK3 gasket, supposedly raises compression by .5-1; would love to try it on the butt dyno, but we have no baseline, so we'll never know.

Head on and timing chain set.

Squirted maybe half an ounce of oil over each of the cam journals and into each of the spark plug holes and turned the engine by hand for maybe 15 minutes to make sure everything was lubed and the timing wasn't horribly wrong. Or that I'd left a bolt in one of the cylinders or something, you know.

Figured this was a decent juncture to see if we had any compression. Little nerve racking to crank with power for the first time knowing the last two heads on this car got valves crashed into pistons. But nothing untoward happened, and all cylinders showed between 100 and 120 psi.

After this, everything went back together pretty fast. Valve cover, spark plugs, intake, exhaust, wiring, fuel lines, refill with oil.

Had to relearn the fuel pump relay (for my own future reference, the reason the pump won't run is there's no power from the ignition switch making it to the relay to activate it during "start" and "on"; hotwire from the black and yellow wire on the ignition switch to the small pin on the relay).

And it ran. And the brothers saw that it was good. So they rested.

I'm back to school in Alabama, brother is back to full-speed-ahead on his MK4 R32 build, so we'll revisit this again this summer with the goal being to drive it 2400 miles roundtrip to the 2021 Challenge.

In reply to JohnInKansas :

Congrats on the successful start! 

In reply to 10001110101 :

Thanks. Sorry we didn't get you out to the shop this time, we got some fairly serious family health stuff going on and all the car work was "as I have time". I should be back in Kansas for good in June, and it should be a little easier to schedule work sessions then. Or if you want to go wrench on it solo, I'm not against that idea.

In reply to JohnInKansas :

Woohoo!

Right, how about an update.

Wasn't sure there were valve stem seals in the new head when I built it, so I pulled the valve cover and cams and one set of valve springs. Already had seals in it. Sweet. Put it all back together.

Hooked up the radiator and refilled with straight water to flush the system out.

Car still starts and runs, and idles pretty nice to be honest. Will rev up to and hold about 15 or 20% throttle happily enough, but opening the throttle quickly or trying to sustain more throttle opening than about 20% makes the engine stall.

I suspected fuel delivery was the culprit; Mk2s had two fuel pumps, one in-tank lift pump and one in-line pressure pump. The lift pump in the car is used, and the in-line is missing in action. I stole the inline pump out of my Beetle and wired it in, but didn't change the stall issue. 

Need to check fuel pressure at the rail just to be sure, and maybe rig up an AFR gauge to see if that gives me a clue. Could be vacuum related, but could be as simple as too little restriction upstream from the throttle body (the MAF is the only thing upstream at the moment, no filter, no piping).

My 1984 Scirocco did the same thing and it turned out the little length of rubber hose in the tank had split in two. 
 

Fuel pressure was low. Not sure if I had the stolen inline pump wired/plumbed incorrectly, or if it is failing, but the new universal inline pump brought pressure at the rail up from 20 to 50+. 

Made the inaugural parade laps around the yard to confirm brakes and steering, double checked fluids, and went for a little drive.

Its probably the illusion of straight piped V6 and stiff suspension, but great googly moogly does it RIP. Pulls really really nice right up through red line.

Seemed a little long in first gear, which didn't really make sense until we went for reverse in the lockout and found the real first gear. Had been starting off in third gear. Adjusted the cables and got that sorted, and backed it uphill into the shop under its own power for the first time in our ownership.

Was a good weekend.

We're about ready to get the paperwork straightened out. Fit the gauge cluster, make sure the lights work, tidy the wiring and keep working on systems checks. This probably won't be a 2021 Challenger, but 2022 could absolutely be our year.

Thats great news!

VR swapped MK2s are a riot. Glad to see it's moving under it's own power. 

Yeeees

Sweet, another VR6 lives!

Right, time for another update.

Got the front bumper mounted with hardware that came with the car. Minor drilling required.

Found a collection of light bulbs in a plastic bucket in the spares bin, so I got the rear lights all reconnected. Everything seems to work except reverse lights and the right front turn signal (missing the pigtail, socket, and bulb). Also missing both front turn signal housings/lenses.

Flushed the cooling system out, and immediately started having overheat issues. Surprise surprise, it was a thermostat failure. Bane of my existence, thermostats. The spring pressure was definitely lighter at boiling, but it never opened up. Should have opened at about 180. Gutted it and reinstalled. This will be a 98% warm weather car anyway, so we'll just bear in mind to let it warm up thoroughly in cooler weather. Since then, no issues. Still flushing crappy old coolant out. I have another 48 hours before our first scheduled freeze, so going to try to get a couple more fresh fluid changes and heat cycles before then.

Made a gas station run yesterday and was reminded just how loud it is. It didn't want to run real smooth at partial throttle; was fine at idle and at wide or nearly wide open, but was hesitant at partial throttle. Which meant that I had to rev the piss out of it at the stop sign in town right next to the nursing home. If anything will make a guy self-conscious, it's a 6k straight-piped VR6 launch next to the old folks' home on a quiet Sunday afternoon. Came home and dug through the leftovers of the 2012 Beetle exhaust build and sure enough, I have a new-in-box Thrush that fits perfect. Knew there was a reason to hang onto it through 9 years and 4 moves. Got it installed this afternoon. Much quieter, though still fairly rowdy at full chat. Got a flex pipe and a set of rubber hangers ordered, that should just about legitimize the exhaust (will still need to replace all the gaskets and some of the header studs).

On the short list: seats/sliders bolted in, belts (and harness bar?), get the Mk3 gauge cluster installed in the Mk2 dash, finish the lights, go get it inspected by the highway patrol, and get tags and title. Then on to more serious shakedowns. 2022 is a real possibility. 

Bit the bullet and jumped into the exhaust system with both feet.

One of the six studs that hold the downpipe to the manifolds was broken, and I'd band-aided two others, not to mention reusing very tired old gaskets. There was enough pipe to get back behind the rear axle, but not all the way to the bumper. No muffler, no flex pipe, no hangers (think there may have been a zip tie/hose clamp daisy chain serving as one, though).

Replaced the manifold studs today, did the whole set. Manifolds will go back on tomorrow, with new gaskets to the downpipe and from downpipe to exhaust pipe. Glue the new flex pipe in and fab some hanger brackets out of the scrap bin, and we ought to be good.

Pretty sure I have a faulty MAF sensor, based on preliminary testing and the sensor discussion last week, but having the exhaust tight will at least rule out the known exhaust leaks as the culprit. 

Turns out exhaust fitting is super frustrating when you're trying to recycle the leftovers of somebody else's attempt with the car on jackstands on gravel. Gets much less frustrating when you knuckle down and cut out some of the questionable bend choices and refit the salvageable scraps in a simpler, more elegant solution that doesn't require creative swearing or blood sacrifice to install. Still a bummer not being on concrete with the car on a lift, but beggars and choosers.

Soup to nuts, we have one full set of new M10 exhaust studs and nuts, a pair of new manifold-to-downpipe gaskets, a new exhaust hanger rubber, a hanger bracket that lived a former life as a truck shock mount u-bolt, and a Thrush Turbo muffler. Spitballing, that's about a $45 investment. I need to fit one more hanger at the muffler, but I can't lay hands on the bracket that I took off the car and reshaped a week or ten days ago, so that's on hold until the bracket resurfaces amidst my other crap.

I did finally get enough coolant flush cycles done that I was getting almost clear water out after running to operating temp. If we get some decent temperatures this weekend, I think I may refill the cooling system with antifreeze and see if the exhaust made any major difference in the running condition. 

In classic missing piece form, hours after I tell the internet of its absence, the missing exhaust hook appears right next to the car in plain sight where I've been looking all week. Little bastard.

So the other half of the scrap-bin shock mount u-bolt became the last hanger for the outlet of the muffler, added one more hanger rubber and an exhaust clamp for the muffler inlet, and we're fully in business.

Running one more flush with distilled water before filling with coolant for the winter. Exhaust sounds good, can't find any leaks. Nice stable idle so far.

Coolant filled for the winter.

Still happy with the exhaust, is quiet enough that the in-line fuel pump is now annoyingly loud by comparison. 

Idles a little slow. I've fooled with the idle stop screw, so it may just need to be readjusted now that the exhaust is tight. Idled it up to temperature and without particular warning the idle slowed gradually until it stalled at about 300rpm. I still suspect the MAF sensor, but I'm open to suggestions from the peanut gallery.

Whipped up a set of don't-pull-the-bolts-through-the-floor plates to tie the seat rails to the car. The stock floor pans have a lot more shape than I anticipated initially, so my fastening system will need some refinement, but the seat and rails are bolted in and the seat will adjust fore and aft. Still need to come up with a good solution for attaching the back of the seat to the rails; neither is a particularly good shape to play well together, so that's going to take some sitting and staring. 

A lot of the bits I'm piecing together are out of my scrap steel bin, including recycled hardware. I'm thinking of weighing the finished pieces and charging to the budget at current new steel market price. Is that fair? Too fair? Not fair enough?