Hot Rods AD_NAPCO's 39 GMC Rocket 324 Build

It's hard to believe that there are not tons of rears out in Ca. I'd be using a advanced C/L site to search for Olds rears or Olds parts car that someone might part out.

That 3.07 is more likely the 3.2 A/T gear, sticks were 3.4, but others were optional, so you need to spin them and count.

What would I do? I would not see the need to demand the stronger 57 up, nor need a posi, but if both were available-same price, like a pre 57 open rear with 3.2 and a 57 with open 3.2, I'd take the 57. But you won't break the earlier one IMO

 

All the big public yards I know of have been picked over and lots of great stuff crushed in the last few years. A lot of yards that used to be public are now private and the owners impossible to get in touch with... The only C/L search site I know of no longer functions for C/L because C/L made them cease and desist... The seller quoted saying "The 54 looks to be right about 3 to 1, and the 59 looks to be about 3 and a half to 1" so my guess was 3.07 or 3.23 for the 54 and 3.42 on the 59... So, F&J, you'd go with the 59 3.42 over the 3.23 54?

 

If you were a little closer I could get you some for in the 100 to 150 range as there are quite a few 50s Olds in the older junkyards I frequent around here.go with the 54 if it has 3.24s.

 

I wish there were older junkyards around here.. Problem with the People's Republik of Mexifornia is that the damn EPA is forcing all the older yards out of business and they are having to crush their stock in order to avoid total losses and have something to retire on/leave to the grand kids... I am going to miss a lot of things about California when I leave. Born and raised here (in the uncongested country, not the city) but I can't abide the political climate.

End rant... I wish I were closer, Jeff!

Most yards I've called all over the country have wanted between 75-150 just for the rebuildable dropout diff plus the ride which so far has been around $90-100, just for the diff. $30-50 a piece just for backing plates, and around $20 to ship them. Oklahoma, Texas, Illinois... I figure if I can get the whole damn rear end, complete drum to drum for $350, and the only shipping I'm paying is for around 7 hours of freeway driving, I'm not doing too bad comparitively

 

Ok, well, up at 4:00 AM, and waiting for the fiance to get back from the gym and then we head out to get that rear end. Gonna go ahead and just pick up the older 3.23 unit.

In other news... Finally picked up a decent compressor off of craigslist yesterday.
I've been trying to work with little weenie 2 gallon craftsman POS for the last few years.
Work ten seconds with the die grinder and wait two minutes for it to pump back up...
Infuriating! So this one is a 1974 manufactured American Eagle brand 60 gallon compressor with a 2 horse Baldor motor. All new guages, compressor pump and motor both been rebuilt, new water separator, two ports one directly off the tank and one off the regulator, and on nice new casters for easy mobility. Purchased from the original owner, a retired fireman so it's been maintained... Like I said, purchased new in 1974 for $650.00!!! I paid $350 for it yesterday. The same compressor is available brand new, still all USA made and it'd cost close to $1400!!!!

Anyway... It's not a huge compressor but it'll make a huge difference in what I can get done.

 

Just back from the long drive up north. Picked up the 54 olds rear end. It is a 3.23. I think it must have been a pretty early wreck because the axles and gears show basically zero wear. That's awesome. I think I'm going to have to move the spring perches inboard, but I'm not totally sure yet.

Got a question on the choke spring cover plate... When that plate is on, and the carb is cold, should the choke be resting in a closed position? I notice the cover can be clocked to richer or leaner. Should I just start it in a totally neutral/straight up and down position and go from there?

Forgive my ignorance... I have really only worked on one and two barrel manual choke carbs.

Thanks!

 

Choke flap will be closed when cold if you depress the gas pedal first. Then when the motor starts, vacuum will pull the choke unloader piston to open the flap to a certain spec. You normally check that spec with a drill bit that is close to the book spec on that motor. Drill bit goes vertical between the flap and the carb opening.

Also, the original heated pipe to the choke had insulation on it, so that the heat could get to the choke better. Depending on climate, you may not need that.

You may need to readjust the choke if it stays on too long, or not long enough; that's the "lean-rich" setting.

 

Thanks Frank, that was a good explanation, and I have a better idea of what I'm going to be doing. I was really hoping my shop manual would show up in today's mail but no such luck. Got some other things figured out so the day wasn't a total waste.

 

Ok... My shop manual finally got here today. Got my rocker stand torqued properly, oil and filter changed, and now I need to locate all my plug wires. Changed my cap, rotor, points, coil and condensors, and now to figure out where #1 is. The shop manual doesn't give an illustrations as far as I can see of the timing marks, only a verbal description.
I have to assume, because I am green with these motors, that the pin coming out of the block is the point I'm lining the notch on the pulley up with. Best I can describe the notch, is "tooth-notch-tooth." When the book describes leading and trailing edges, are we talking the outside edges of the two teeth? If so, therefore, the half way between would be the space between the teeth?

 

Got it to fire just at sunset tonight!! Actually managed to get TDC on #1 and the rotor lined up and the plug wires routed properly the first time. I don't have an ignition switch wired in yet, just the critical ignition wires and a remote starter switch. Dribbled some gas down the carb, and some playing around with advance on the dizzy, and I got her to fire. One question I have is, can someone post a picture of the dizzy hold down? Mine doesn't have anything locking it from spinning anywhere it wants. Gotta get that figured out. Only had it running for a second or two at most. No radiator hooked up and no fuel feed. I need to get my fuel pump rebuilt. Any recommendations? I have used an outfit in Massachussetts but if there's a good reputable place near by me in CA, I'd like to give'em a shot. I picked up an electric fuel pump but I really don't wanna use it if I can avoid it.

In any case, major milestone today, getting it to fire. I'm encouraged!

 

..If I can remember to take a pic of the dist clamp... It's just a Y shape with a bolt.

 

I've seen those covers. The "57" stood for the reliefs on either end of the inside of the cover to clear the '57 rocker shaft assemblies, which were a bit longer than on '49-'56 engines. I've also seen several sets of aluminum covers that were "field reengineered" to clear the '57-'58 shafts.

 

Well, progress has been very slow, but I did manage to finally get a compression check done today.

Granted, the engine is cold, but I can't really let it warm up.

1)125
3)95
5)75
7)120

2)131
4)132
6)132
8)120

The only place I can find compression numbers is at secondchancegarage.com
and it say compression should be at 120. I assume that's 120 warm.

What do you guys make of these numbers?

Obviously got a couple really low cylinders which is a bummer. Maybe that'll come up warm? I somehow doubt it'll come up that much though.

I'm going to send my stock fuel pump off to get rebuilt, and in the meantime have blocked off the fuel pump port. I picked up a carter P4070 electric fuel pump to replace the one that is on the truck already. I was hoping that one would work, and it might, but it's pretty well solidly full of varnish and the electrical connections are a bit wobbly, so I bit the bullet on a new one.

The P4070 I picked up is rated at 72 GPH, and max 5 psi. Is that ok for fuel pressure? Do I need to run a regulator. I'm thinking I want to run the mechanical pump, and use the electric for backup, but in the mean time, I will just run the electric for starting purposes.

 

Run it.

I don't bother with comp tests. I can tell if it has a low hole or not, just by listening to it crank over. I'd run it on the road a few weeks before condemning it. Then see if it has blowby out the draft tube or filler. If it does not, don't worry.

I ran a cheapie AZone or Advanced Auto small pump on my gas heater in a D.D. '57 VW for 4 winters, it never quit, so there is no reason it would not work on a car engine, either fulltime or backup. What carb? "5psi-max" means probably less, should be fine.

 

Hey Josh guess that email must be broken?...

Congratulations on the fire in the hole on the "Honey truck"... I'm with F&J and just run the silly thing and see what seats.. your sweat'n the details again... Haha

 

Dude... Sorry I've been spacing on replying. Public apology. How's that?

It's a stock newly rebuilt 4GC, as seen earlier in the thread, and so not being totally familiar with electric pumps I figured I'd ask.

Now, I gotta figure out carb linkages, get some coolant hooked up, and hopefully my distributor clamp and thermostat housing will show up soon.

 

Just busing your chops...

If I remember right those carbs are only running at something like 3-5 lbs.. probably closer to 3.. probably the same with the pump.. closer to 3..

I can't see you having much trouble unless you start really hammering it or the pump out and out dies..

Should be able to build an adequate linkage out of rod or threaded rod and Heim joints...

Added a few "Honey" shots for fun since I threw in that 'lil jab... probably should have posted them to your about the '39 thread...

 

Ok...

So, today was interesting. Didn't get a ton of time in on the truck but did get the radiator set up, thermostat in, and hoses hooked up, temp guage hooked up, and filled with water. Right away, before cranking at all... It's pissing out of the water pump weep hole. SHIT. Not crazy fast, but leaking pretty bad, so now I need a water pump.
Dilemma... My fan/pulley hub on a non A/C water pump is four studs. All the replacement waterpumps I'm seeing online have an 8 stud pattern that looks to be spaced further apart than my four stud pattern. Strangely enough, I see pics of the with A/C rebuild units with a four stud hub... Looks like its gonna take a week to get a pump once I order it. Just wanna be sure I can bolt my fan on once the new pump arrives.

Next thing. I guess I must need to read "Electric Fuel Pumps for Dipshits" or something. How are they supposed to work exactly? My 4GC flooded REALLY bad, REALLY FAST! I'm thinking this is a sign that I need a regulator to keep the thing from gagging.

What's the method for starting supposed to be with the electric pump? It's instantly on with the ignition. Should I wait til it's primed, or assume it's already primed and just hit the starter?

I know these are dumbass questions...

Thanks for your help with this.

 

What's the method for starting supposed to be with the electric pump? It's instantly on with the ignition. Should I wait til it's primed, or assume it's already primed and just hit the starter?

Just start it as normal, no priming needed, the fuel is already in the bowls for that purpose. If you run the pump too long before you crank it you run the risk of flooding the engine if the pump overpowers the needle.

Don

 

Alright... Well, no joy. I took the carb off. Dumped all the fuel out of it. Pulled the plugs, dried them off. Reinstalled the carb, and dribbled some gas down the throat and she fired like normal using the remote starter. Hit the ignition switch to bring the electric pump on line and started cranking immediately and same thing. Flood city.

Any ideas?

 

Sounds like you need a pressure regulator in the system.

 

No fuel filter and shit jambing the needle valve?

 

If I had the carb off and drained out, I always flip them upside down and blow into the gas inlet. Then you can tell if the needle is not sealing.

Carbking posted once about debris sticking real good to a neoprene tipped needle. That could be what's wrong. I's suspect that before thinking the pump has too much pressure, because you listed the max pressure...which was low.

 

well, I can get it to fire but I just can't get it to idle, so my suspicion is something wrong with the carb. I don't think it's crap in the carb as I had a filter on it and I was pulling out of a clean gas can.

I've never screwed with a four barrel carb before so opening this thing up is a little intimidating.

I'm always afraid i'm going to open something up and some little check ball or spring is going to go flying off into the abyss of the garage never to be seen again...

 

Hey Josh man,
Looked at a diagram of that carb.. Looks fairly clean when you pull the top.. Clean area, white towel and in a sheet pan isn't bad thing to work in/on.. Just watch which way the linkage arms go.. those are the clips that always want to sail..and do no prying with the screwdriver...

May also look at the float levels..looks like you have two sets .. should be pretty much horizontal with the top flipped over.. had a couple that were screwed with for one reason or another (shipping?).. also check for fuel in the floats.. that was just the problem on that CB350...

 

I'd be suspicious of the so called rebuilder if I was sent a carb that had no provision for a heat riser. Who knows what else is wrong in there.

 

Yeah, you're right, it's actually not that hard a carb to dig into. I actually think this is easier than some of the one barrels I've opened. More room to work.

So far, the only thing that I'm seeing that makes me wonder, is this threaded port that is open to the secondaries. I never noticed it before, and now I'm wondering if I don't have a huge damn vacuum leak causing the thing not to want to stay running once it fires.

From what I'm seeing, nothing is sticking.

Next step is checking the float levels and seeing about all the adjustments per the manual when I put it back together.

The port I circled in the picture that's open to the secondaries... What should that be plumbed to, and should I just plug it for now? I have the vacuum advance port plugged.

Initial settings on mixture screws? I haven't read that far in the manual yet, but anyone got a good number of turns out off snug that is a good place to start?

Oh, and what the hell do some of these guys even bother with the shitty gold carb paint for? A drop of gas and that stuff shits the bed and looks fucking terrible. I wish I had a tank of stripper so I could just go back to a bare casting. Better than this fake paint plating.

Thanks again for all the help!

 

Plug that port,it was used to hook up a brake booster or it could be used for a pcv system in the future.

 

I usually start with 1-1/2... if parallel the floats are to the the top of the deck your in the neighborhood..
Sorry to hear nothing obvious other than plugging the hole..my do it...

 

Ok... Carb is back together. No extra parts! I went through and adusted everything for clearances according to the manual that could be done off the motor. Going to reinstall tomorrow morning. Hopefully this problem is a combination of vacuum leaks and minor adjustments being made.

I'm also missing a spring, I'm pretty sure, anyone have specs for it or know if there is a supplier that carries these?