EvanB
EvanB MegaDork
9/7/21 8:58 p.m.

Hopefully angry in a good way.

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
9/7/21 9:32 p.m.

Oh yeah.

 

I was really worried yesterday when I couldn't get it to fire on carb cleaner, and it was building no oil pressure.  FINALLY it started to build pressure after a lot of cranking.  40psi cranking at about 100rpm with a dying battery!

After I was able to put fuel in the tank again today (wanted to give LOTS of time for the fuel tank repair epoxy to dry)... and remembered that I had put the whole fuel injection system on a relayed cable coming straight from the battery, that I'd neglected to hook up... it fired with the old tune.  With 40% larger injectors, and a tune for something that had much more vacuum at idle.  After setting the injector constants and pulling up an old bridge port tune, I got it brapping to life.  It's.... angry.

 

 

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
9/8/21 6:14 p.m.

 

Brap has returned to the Batcave.

 

Next up, the elephant in the room.  Or rather, the stegosaurus.

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
9/10/21 10:24 a.m.

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
9/10/21 12:07 p.m.

Thermostat is still leaking.

It turns out it is not the thermostat.  There is a small crack in the water pump housing between the thermostat flange and the alternator boss.

Ugh.  Let's see how well RapidFix can deal with this.

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
9/10/21 4:58 p.m.

 

Hard to tell, but it is cracked all the way up to the thermostat housing.  Berrrrk.

TVR Scott
TVR Scott SuperDork
9/10/21 5:01 p.m.

In reply to Pete. (l33t FS) :

Can you grind it out and weld it?

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
9/10/21 5:15 p.m.

In reply to TVR Scott :

Not without removing it, or having a TIG.

 

Berk it.  Let's try Rapidfix.  It will work or it won't.

 

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
9/10/21 9:09 p.m.

It's still leaking, but only a tiny bit.  There is a tiny puddle of green on top of the water pump, not a waterfall trail down the lower radiator hose to the skid plate.  I'll call it good enough for the weekend.

 

I HAVE another aluminum water pump housing, as well as a ton of iron ones, but need time to modify them to work.  There is a hole in the aluminum housing that needs to be plugged, I'd tapped it to God-knows-what and am using it as the lower bolt for a much modified alternator bracket.  Past Me did that like twelve years ago.  Also need to remove the throttle body heat coolant nipple and tap it 1/4 NPT for the mechanical temp gauge.

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
9/11/21 8:28 p.m.

The RapidFix held-ish.  Made it home without having to add any coolant.

OVR PE... um... 2? 3? is down in the books.  Event was at Joe's Speedway, basically a figure 3 placed on the side of a hill.  Course was dry and grippy/dusty, I competed on my Black Rockets on the rear and snow tires on the front, all at 35psi.

 

The goods:  Oh WOW I forgot how much midrange torque this has.  It was accelerating quicker up the steep hills at Joe's Speedway than the '81 does on flat ground.  Sure I have 4.87 gears vs. the 3.91s in the '81, but I also have taller tires that mostly negate the gearing change, and also the '84 is noticeably heavier.

The diff works great, in the sense that I never noticed any bad habits.

Even as rough as the course was (getting all four off several times) the trans NEVER popped out of 2nd!  So either the bolts being loose or the Locker acting screwy was causing that.  Either way, issue resolved for now.

Engine seems to be running cool.  Was starting runs at 190 (new gauge bulb location, it never goes below 190) and finishing at 200, maaaybe 210.

The torque to pull out of corners, even uphill!

The stainless muffler managed to finish an event without cracking.

Snow tires on front worked remarkably well, never felt like I needed more front grip.  No more weird binding/braking problem mid corner, either.  Looks like it was a tire rub issue after all.

The bads:

The suspension definitely could use improvement.  I could have been pushing a lot harder if the car was more settled.  The course was rough with lots of little whoop-de-dos and small ditch crossings, so maybe I am asking a bit much?

Rearend is making new weird noises.  Might be pinion bearings.

Alternator is starting to crap out.  Got stuck in city traffic at night and it did not like low rotating speed + fans + lights, as normal, but turning the lights and fans off did not bring voltage back up until I got back on the highway a bit.

Tach still flails around over 7k.  I noted on the drive home that I could make the tach bounce by stabbing the throttle at 4k, so I am leaning more towards noise issue than bad tach.  I will look into what it takes to drive the tach by the Megasquirt.  Doing that would make all tach wiring in-cabin, without anything going past the ignition coils.

Still some holes in the tune in weird drivability regions, like gentle acceleration at 2000rpm.

it would be great if the exhaust was quieter.  I can hear it over the rearend.

Quick once-over once tucked away at home showed the rear main seal is leaking a lot, and the front-most engine dowel O-ring is seeping, somehow.  Looks like the engine has to come back out.  Later.

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
9/12/21 4:25 p.m.
Pete. (l33t FS)
Pete. (l33t FS) MegaDork
9/12/21 5:02 p.m.

Of course, it was not all fun and games.  I almost made it halfway around the course on my first run.

 

 

cghstang_chris
cghstang_chris Dork
9/13/21 9:28 a.m.

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
9/13/21 12:18 p.m.

In reply to cghstang_chris :

It was roughy and boingy.  I was boinging all four wheels off a lot of times, which worked great when boinging through a slalom.

 

Despite the DNF, I placed 2nd overall, something like .6 seconds from the top spot.  The only other person under 500 seconds (we were both at 496.x) was.... the stock class Model 3 that took first overall.  Thought you might be interested to hear that.

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
9/16/21 8:33 p.m.

Attempt 3 at writing this.  Somehow trying to add a pic cancels the post.

 

In the interest of always upgrading, and taking time to do things Right to fix bodges that somehow worked for the past eleven or twelve years, I addressed the water pump housing mods.  The '86-up water pump housing (aluminum!) has a fifth engine stud location that does not exist on the '74-85 engines such as this one.  The alternator bracket uses that location, which is also in a different spot, so the alternator bracket has to be deeply modified to work and clear the distributor.  Running out of time during the swap, Past Me shallowly tapped the hole to 10x1.5 and relied on a kind of inverse tapered thread effect and a precise length bolt to keep it from leaking past the threads.

Miraculously, it never leaked, but we don't want to rely on miraculous happenstance.  And so, by the same happenstance that the hole could be tapped 10x1.5 without drilling, it also can be tapped for 1/8 NPT without drilling.  So, the engine side of the housing got tapped and plugged.

The other end got much deeper 10x1.5 threads for a regular bolt for the alternator bracket.

And speaking of alternators, money was spent, and today a mammajamma showed up.

 

Let's see if THIS overheats.

Project822
Project822 New Reader
9/20/21 12:42 p.m.

Pete, 

Let me know if you want to stop by with that aluminum water pump housing for a permanent fix.  Free labor offer.  

 

What caused the DNF?  

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
9/20/21 8:11 p.m.

Nah, that water pump housing is done.  Besides the crack, it has some corrosion holes in the lower hose inlet that required strategic clamp placement, and one of the thermostat housing bolts broke off and was badly drilled out by Past Me, requiring a through bolt.  I have this one, and another one that has a funky elbow welded on that can be undone fairly easily, or really I'd like to eliminate the whole mess and go with an electric water pump.  The ones from BMW N51/52/55 engines look fairly swappable, as is the one from Fusion hybrids.  Just need to find out what it takes to control them and use a generic output on the Megasquirt to control it.  You can do a 2D map based off of whatever functions you'd want.

The 3" crank pulley is strictly there because the stock pulley (4.5") spun the water pump into cavitation over 6000.  The underdrive solved a major overheating problem I had.  An electric water pump would allow me to run a 6" trigger wheel, and a standard crank pulley so I can have an alternator that actually charges at idle. 

Speaking of which.  The 160A alternator suuuuucks.  It has less output in the areas I am concerned with.  Even at 2000rpm, turning the lights and low speed fan on will drop system voltage down to 12v.

 

DNF was one of the fuel injector power wires liberating itself from the tyranny of the add-on fuseblock.  Injectors 1 and 2 have their own fuses, so I was still able to run on one rotor.

Project822
Project822 New Reader
9/21/21 6:58 a.m.

In reply to Pete. (l33t FS) :

It sounded like a one rotor situation, and I was hoping for something uncatastrophic.  

Regarding that housing, it can still be saved, corrosion holes and all.  I have done it before for FIAT thermostat housings.  But if you don't actually need it, then that's fine also.  

infernosg
infernosg Reader
9/21/21 9:15 a.m.

Interesting that you're having charging issues. I guess the 160A alternator just doesn't want to output power at low RPM. I've gone through several combinations of alternator and alternator pulley. With an FC alternator and Racing Beat alternator pulley it wouldn't charge below 1000 RPM, which is about my idle speed. I ended up with a FD alternator and Banzai Racing conversion pulley. With exterior lights, engine fan and cabin blower all on, which rarely ever occurs, I'll see voltage drop to ~13V.

I also run the Racing Beat crank shaft pulley to slow the water pump. Seems to work adequately as I'll see maximum 200F water temperatures on track even on nearly 100F days.

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
9/21/21 9:24 a.m.

In reply to infernosg :

My fans draw 75 amps on high.

Turning the fan on at low speed will drop the idle from 1500 to about 1000...

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
9/21/21 9:17 p.m.
Pete. (l33t FS) said:

 

2021 starts out at this mileage.  Volvo is 10k behind, but at the rate it is racking up miles it will probably pass it before I park this for the winter.

 

 

Today while stuck in traffic as three lanes merged painfully into one...

 

The '84 is currently just shy of 260k, the new engine went in at 259243, and I basically drove it to the rallycross and back, and to Summit once.

 

Yes, teh R has a horsepower/torque gauge now.  And, apparently, a dead downstream oxygen sensor, probably another casualty of the boating incident last month.

dannyp84
dannyp84 New Reader
9/21/21 9:31 p.m.
Pete. (l33t FS) said:

In reply to infernosg :

My fans draw 75 amps on high.

Turning the fan on at low speed will drop the idle from 1500 to about 1000...

I run a Be Cool fan from summit on my 12a, it moves a serious amount of air and I think it only draws something like 7 amps.. extremely noisy though if that matters to you.

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
9/21/21 9:50 p.m.

In reply to dannyp84 :

My fans are something like 4000 or 5000cfm.  They're the OE units from a Chrysler 300M, very very beefy and move a lot of air.  When I had a street port non turbo Turbo II engine, I could finish a dyno run at the same coolant temp as when I started.

I have a 16" Flex-a-lite (Black Magic?) S-curve fan on the '81.   At the Detroit event last month, if I started a run at 180F, I was finishing sixty seconds later at about 230F.  I really don't want to deviate much from stock, but Prepared rules allow larger radiators and larger oil coolers, so I am thinking of getting the biggest oil cooler I can find, a Mishimoto inline thermostat, and a full height radiator instead of the 16" shorty.  Prepared rules also allow underdrive pulleys, so I'll get a double row unit from Atkins, so I can keep the air pump belt and A/C pulley, since both are mandatory for Prepared.  As is the stock ~50 amp alternator.  I know the current oil cooler is caked with mud and vegetation that I haven't really been able to clean out, and it is also weeping oil at the lower fitting.

dannyp84
dannyp84 New Reader
9/21/21 9:57 p.m.

In reply to Pete. (l33t FS) :

The FC oil cooler was such a massive improvement for my car, the little beehive cooler was not up to the task of keeping things cool at the track ..

infernosg
infernosg Reader
9/22/21 12:10 p.m.

I run some no-name brand I picked up from Summit years ago. 16" that's supposed to pull 3000 cfm and I have it on a 30A fuse. It kicks on at 205F since the stock thermostat isn't even fully opened until 203F. It generally only turns on if I let the car sit and idle for an extended period of time but it'll drop coolant temps to 185F and turn off within 2 minutes. Idles speed drops like 50-100 RPM after it stabilizes. Could be better but I have no IAC valve to control idle. As mentioned above my coolant temps max out around 200F but most of my driving is high speed track stuff. I could see lower speed stuff like autox and rallyx causing issues.

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