SkinnyG's '61 Apache

[SkinnyG]

Shifting:

1-2 and 2-3 are now both commanded at 4750rpm, and are all in by 5400. I did raise the rev limit to 6000 just for some extra. It's not a slow lazy shift at all - the motor just gets there fast!

Boost:

I may just leave the two springs in for now, but move the wastegate reference from the compressor (theoretically ideal, but does not take into account pressure drop through the charge pipes and intercooler), to what used to be the PCV fresh air port on the throttlebody. I'm currently seeing a peak of 8.5psi at 4000rpm and a low of 6.5psi at 5500rpm, I suspect it should be more consistent regulating right at the TB inlet.

In theory, this should maintain a much more consistent boost pressure since it is looking at the final pressure drop from the intercooler and piping and (hopefully) maintaining the wanted boost.

Sounds like a project for the weekend.

[SCOTI]

Originally Posted by SkinnyG

Shifting:

1-2 and 2-3 are now both commanded at 4750rpm, and are all in by 5400. I did raise the rev limit to 6000 just for some extra. It's not a slow lazy shift at all - the motor just gets there fast!

Boost:

I may just leave the two springs in for now, but move the wastegate reference from the compressor (theoretically ideal, but does not take into account pressure drop through the charge pipes and intercooler), to what used to be the PCV fresh air port on the throttlebody. I'm currently seeing a peak of 8.5psi at 4000rpm and a low of 6.5psi at 5500rpm, I suspect it should be more consistent regulating right at the TB inlet.

In theory, this should maintain a much more consistent boost pressure since it is looking at the final pressure drop from the intercooler and piping and (hopefully) maintaining the wanted boost.

Sounds like a project for the weekend.

I like the sound of the changes. Curious to see what it does.

[SkinnyG]

Today we got a peak of 8.5psi, dropping to 7.8psi, so we're doing well.

This is plumbed in at the TB, with two wastegate springs, no boost controller. I'm guessing I have a 4psi and a 5psi spring.

[SCOTI]

A 6# & 5# next or 2x 6# to see what it yields?

[SkinnyG]

None of my springs are labelled, I'm just guessing.

If the third one is a 6psi, I could try the 5 and the 6 and see if I get close to 11psi. Or add the boost controller back in for a few psi more.

But it might be wise to not be a in a rush. 8.5 is going to get boring soon enough. Let's ride it out a bit. That, and I'm going to put the truck away for winter by the end of the month.

I am, however, learning to roll into it - if I stab it, it'll break the tires loose for sure.

[SCOTI]

Originally Posted by SkinnyG

None of my springs are labelled, I'm just guessing.

If the third one is a 6psi, I could try the 5 and the 6 and see if I get close to 11psi. Or add the boost controller back in for a few psi more.

But it might be wise to not be a in a rush. 8.5 is going to get boring soon enough. Let's ride it out a bit. That, and I'm going to put the truck away for winter by the end of the month.

I am, however, learning to roll into it - if I stab it, it'll break the tires loose for sure.

Makes sense.

[SkinnyG]

With the new wastegate setup, I started noticing what I thought was some spark breakup at boost, and it was getting worse.

I checked the plugs, but found nothing exciting. This is 5000miles on them. Gap was originally set to 0.025" and had opened to 0.033":



Under the Otoscope I _think_ I see evidence of detonation, but the PCM never sees knock, I'm at 9.5:1 compression, 8.5psi boost and 17° timing, and spraying water/meth.

At any rate, new plugs in, gapped to 0.025" and went for a rip - it's sweet again!

[SkinnyG]

Made a tool to quickly set spark plug gaps:

[SkinnyG]

Oh my gosh you need to install these:

[SkinnyG]

Added some 3D-Printed "cupholdermakersmallerinators," because I apparently was a bit greedy in CNC-Plasma cutting my cup holder. This brings it down from 3.5" to 3.25":

[SkinnyG]

The parking brake operation has been elusive since I got this truck together. No amount of adjusting seemed to make a consistent difference.

I spent most of yesterday altering the truck's e-brake cables so I don't need the Earth's supply of cable clamps to make things work. Also fabricated a "stop" for the frame end of the cab cable sheathing - I don't think it's needed, but I made one.

I did stumble across the factory parking brake adjustment procedure for the LT1 Z/28 brakes, which I did. Pfft. Marginal/nothing.

Then I recalled that the parking brake handle seemed higher than usual. Looks like the sheathing into the cab is not secured properly, and thus reducing the "throw" of the handle. Probably why the lever was pretty ineffective.

I adjusted it down to the minimum grip I figured I could get away with, and noticed that there wasn't really a "stop" on its clamp. Odd. But there was a cut in it such that one could (and looked like someone did, some time ago) beat the edge of the clamp to be a "stop." And I did. Wow! MUCH better. Did I mess up the clamp originally? Or a previous Tech? Or GM from the factory? I feel so dumb.

This part:

[Braunschweiger]

It's good to have a functioning handbrake;
it's also checked during our two-year inspection, along with the service brake.
In my case, the return springs on the brake cable were too long, which resulted in excessive free play and the brake being ineffective.
Regards Harald

[SkinnyG]

Things have gotten expensive, so we have to downsize our costs.

SkinnyKid1 gave me this for Christmas:

[jkeating1]

Wow!

[SCOTI]

Now that is cool!

Gotta ask though.... Were you thinking you needed to up the ante on his x-mas gift after getting that?

[SkinnyG]

Originally Posted by SCOTI

Now that is cool!

Gotta ask though.... Were you thinking you needed to up the ante on his x-mas gift after getting that?

My Christmas gift to him was buying the parts and teaching how to rebuild his Pontiac 400 (so no.... not really (grin).).

[SCOTI]

Excellent deal!

[350TacoZilla]

Sweet on both sides.

[SkinnyG]

Helping my eldest move into his new place. And trying out his parking stall...

[SkinnyG]

Not the truck, but my eldest son's car, and still something we've been working on over here:



1968 Pontiac Catalina. California car, never parked outdoors, never seen winter. 25,000 original miles when we got it. These never came to Canada.

Interior shot when we bought it:



We did front brakes when we picked it up, and over the past year replaced the hoses, radiator, water pump, and heater core. Re-packed wheel bearings, patched a section of exhaust, fixed the horn, repaired the hammered front valence, re-sealed the steering box (poorly, my bad), replaced blown speakers with a 3D-printed adapter for two 5-1/4's. Kid's been loving it.

October to January:

• Engine pulled, re-ringed, re-bearinged, re-sealed
• Ported ('68 big-car-only) #15 heads, 3-angle valve job
• Summit 2801 camshaft (214°/224° 0.444"/0.466" 112°)
• Steering box fully rebuilt and (properly) re-sealed
• Transmission pump re-sealed
• Front Control Arm upper and lower bushings replaced
• 3/4 coil cut off front springs
• Re-aligned with -0.5°R/0.0°L Camber, +3° Caster, and 1/8" Toe-in.

I'm looking forward to getting this out of my shop (grin).

[SkinnyG]

Very mild winter this year, even here in Canada. Green Christmas for sure.

Lately it's often been above freezing, so I took the truck to work and to church a few times.

One of the things I've not been totally happy with, is I can datalog and tune and it's wonderful, but when it's cold start and cold outside, it runs pretty pig rich.

I was thinking that the Injector Flow Rate that I set might have been on the low side. These are decapped injectors, and I wanted to err on the side of small, so that at open-loop/WOT things would err on the side of rich. Except as you tune, you account for this in the VE table. Open-loop relies on math, and if some of the math is wrong (like injector size), you get the wrong fuel.

Cold start is one of those open-loop areas.

I set the flow at 73 lb/hr, but a more accurate number is 75. That's 2.7% out of wack - the injector will flow 2.7% more fuel than it is expecting to flow - which would explain the rich.

So I changed the IFR to 75 (2.7% more) and scaled the entire VE table up 2.7% to match. Driving is exactly the same in every way, except cold start is WAY less rich.

Win!

I know this might be a bit out there for the carb gang out here, but if you can tune a carb, you can tune EFI - and you don't even have to get out of the truck, or smell like gas. You'll love it.

[SkinnyG]

Drove two hours round-trip with the trailer to pick up some furniture. Sweet opportunity for datalogging and tuning!

ISSUE #1 - SPARK TIMING: Wow this thing has some knock issues under load in areas I haven't been driving in. Maybe the factory tune just leans on the knock sensors for those periods, that way you can still have good spark timing when unloaded.

I did some research into some P59 tunes in the Sloppy Mechanics Tune Cabinet, and found they really pulled a lot of cruise timing out as well - they were running what I was ending up at.

I also decided to "un-scale" the tune. A "scaled tune" changes things so you can have a spark table that goes higher than 7psi boost. It's telling the PCM that the injectors are half the size and making the VE table half the size (among other things). The PCM determines where you are on the spark table by how much fuel you are consuming, so "saying" you are using half the fuel puts you in the middle of the map instead of the end of it.

I will say that I think it's a lot more "stable" now without the scale. The downside - the spark table is maxed at 7psi boost - but if you set it for 14° in the last cells, you're pretty good to run 15psi boost from there on.

ISSUE #2 - SIGNAL STALK CANCEL MECHANISM: One of the signal stalk cancel mechanism springs broke inside the column and honked the horn for me. And the signals didn't cancel. I fabricated a new one (top) out of 0.045" round (RC Servo linkage wire?), and it's back in business.



ISSUE #3 - WIPER "PARK": It seems these wipers DO park. Not sure how I lost the case ground, but there we have it. I really can't get at the wiper motor easily (in the way: air ride gauges and hoses, PCM, and AC unit), so I ended up putting a hose clamp around the motor to hold an electrical connector to the case with a wire running to ground.

ISSUE #4 - WIPER SYNC: The wipers were a bit out of sync, so I took the cowl panel off and messed around with the linkage. There is no real evidence of worn out anywhere, but the rods can be "tweaked" and bit which moved things around. I took the lever arm off the motor and bent it about 3/16" more and reinstalled it. This would slightly shorten the driver's side "throw", and it "looks" better, but I'll know once I'm out in the rain again.

[SkinnyG]

I might be doing something different with the original drivetrain.

So far, I fabricated this body from scratch.

[SCOTI]

Sweet!

[SkinnyG]

Switched the rear shocks from Monroe (black) 37040 which felt too stiff, to Gabriel 82023 which feel dang near perfect!

The Gabriels are their "classic car" line, and the valving suits what I have really well.