Projects Mild custom '51 Pontiac Chieftain

Don't know your tire size (IIRC they should be 7.10 or 7.60 X 15), but I'd try bumping to 30 or 32 psi. You'll be amazed in the easier steering and probably improve mileage.

 

It's got 6.70x15 bias ply whitewalls. I think it should be 7.10 like you say; previous owner's tire choice there.
I'll try put a bit more in and see how skittish it gets.

 

So, I put the tires up to 30psi all round and went for a short drive to Walgreen's to get a few items.

Things to note:
1) Ride is smoother.
2) Car tramlines worse but is tolerable.
3) Steering is noticeably lighter.
4) No perceptible change in throttle.

I'll keep it at 30 for now, it does ride better.
The ignition timing seems to make the most economy difference at this time.

Phil

 

Coker Classics are radials (at least mine are). While the 26 psi may be proper for bias plies (it's about what the owner's manual for my '51 says), the radials like more. Try 32 psi. Also, running tires under-inflated allows them to flex more, which can lead to failure (blowouts).

 

No, these are bias ply. I agree on sidewall flex creating heat in under-inflated tires, leading to failure.
It's not bad with these at 30. Might bring it down a little though, it feels a little light.

Phil

 

You're right; they come both ways. I stand corrected. I would check with Coker and see what they recommend. I think you're right about the 7.10's on a Pontiac. Do you have an owner manual? If so, what does it say?

 

Research says 7.10 and 26 psi.
Narrower tire should probably have a few more pounds, admittedly.

6.7 to 7.1 is a 5.5% change so 26 + 5% is 27.5 psi.

 

That sounds low just by PSI but I don’t know what bias ply are supposed to run at. I bought radials from Cali White Walls at an affordable price and run 38psi. My leaf springs are super soft and I have a 4” drop so I need the stiff ride.

 

All the sources I find quote between 24 and 26 psi for bias ply.

 

Phil, do you have (or have access to) an owners manual? Be interesting to see what the Head Poncho had to say about pressure. The other thing to remember is that a small size will require more pressure to match the load capacity of the 7.10s (not a big issue, small size builds more heat).

 

Only what I can find online, which suggests 24-26 psi on 7.10-15 tires.
I went out again tonight and it is happy at 30 so I might just bring it down a smidgeon to 28-29 and see how it fares.

Today was a nice day though, I recieved a big box full of Pontiac goodies from the gentleman @Nikkerton all the way up in the frozen North.

Originally an offer for a spare fan motor, a veritable trove of parts landed on my doorstep.


One interesting part- the GM fitment e-brake warning light, standard on later models but an option (not fitted) to mine.


Reassembled, cleaned up. Nice old glass lens, too.


Ignition on, pull the e-brake and it sits and blinks at you as a reminder to release the brake.

Neat!

So, I said I would attempt to repair the non functional clock from Nik's car because it's a nice feature of the center of the dash and I like having a clock, particularly one that works...


First order of work, take it apart, check the coil (good), check the points (bad), clean the points and test.


Then a jolly good clean.


Pull the (frankly nasty) old paint off the hands,


And put a new coat on. That's drying overnight and can go back together tomorrow.

Next fun part- the fast/slow mechanism is missing a gear and the adjuster knob is sheared off. That's gonna be fun to fix!

Phil

 

Well, at least it looks pretty.

Phil

 

Right twice a day!

 

It's supposed to rain tonight so I took the car for a quick drive before parking it up.


Typically I get a mile and catch the bridge, waiting for the world's slowest double barge to pass.


Clouds are pretty. Nice evening for a drive.

Phil

 

Spent a little time last night tuning the car up, ignition timing.
Got the baseline again by punching it in gear with the brakes on and adjusting the distributor for maximum RPM.
Then, with that set, tweaked it slightly for peak torque at 2000-2200 RPM on the highway using the seat of my pants as the measurement tool.

I ran out of time but I want to carry on with that, didn't get it quite right but it's gotten down to a few degrees now.

Happy with that!

 

Also neat, the fuel pump/vacuum pump rebuild kit just arrived in the mail.


That's all new, very nicely machined.

Phil

 

...and upon taking my pump apart, someone's rebuilt it with 1958 innards, so I've got the correct vacuum pump diaphragm coming on the way.

Phil

 

These valves are staked in with no access to the other side.


What y'all reckon the best way is to get these out is?
Knock the peened edges back or destroy the valve and dress the edge back after?

Phil

 

I would work the peening back, with whatever works. Xacto blade? Looks like they can be re-staked next to the original staking. With all you've fixed already you're probably already done,,,,

Sent from my SM-G973U using The H.A.M.B. mobile app

 

Well that's a bummer! I would carefully determine if I could destroy the vales and remove them, then you could get a more complete look at the staking. The housing(s) appear to be die cast, so re-staking may be a challenge (without cracking), and an alternate method of mechanical retention may be needed (Loctite, small screws, etc).
Good luck!

 

I'm not sure if there was electrical current passed by the staking tool to soften the metal before it was punched.

 

Is it possible to put the valves in the freezer without damaging them? This would make them shrink a little bit. If you find a secure way to warm the housing, the valves might go in much easier and when everything's back to normal temp you will have a tight fit.

I have to admit that I have never repaired such a vacuum pump but I have done this in similar cases ( fragile castings on vintage motorbikes) and it always worked.

Sent from my Moto G (5S) using The H.A.M.B. mobile app

 

All new everything. Just waiting on the vacuum diaphragm now.


The lower portion, the fuel pump, goes together with few issues- the valves sit on paper seals and are clamped in by a spring loaded set of fingers.


The upper portion- well, brute force and ignorance was rule of the day here. Removed the old valves, cleaned up and put in new seals.


In this section the tolerances were a little less tight, so I knocked the valve in gently against the seal then gently staked it in place. The other one is clamped in against the top clamshell.
The top I carefully skimmed the swollen parts down with the edge of a screwdriver, cleaned up and then used a half inch socket as a drift and knocked them in place.
I also replaced the spring that holds the arm against the eccentric on the cam, the bushing and shaft also. The old one wasn't too bad but the kit had it in so hey. Why not.

Phil

 

I knew you'd do it, looks good!


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Correct parts arrived.

It's all back in at lunch time and it even works.

Phil

 

Driver's door window kept getting stuck.
Find out why, the lower channel has adjustment in and out, but was rusted up. I freed it off and adjusted it central.

Now the window doesn't get hung up.

Phil

 

Went out for a drive earlier being as I had fixed the pump.


Got back in, checked to see as before the breather would spew significant volumes of oil. Now, no oil. All dry. Very good.

In fact, you can see the chassis cross-member there is beginning to dry out.

Phil

 

Looking at the tailpipe in the light today... You can't really ask for that to be any better.

I think I got it set up just right.

Phil

 

Busy day today. I just picked up a new project.
Unfortunately it's a 1966 model so I guess just keep your eyes open for this thread instead. Not forgetting the Chieftain, just yet.

Phil

 

It's been inspiring to follow along while you tweak this old Pontiac back into shape. I've been fab'ing up a new hood release cable for my 50 coupe.