Bender - The Silver 60

[Cruisertrash]

Good to know! Love all of the knowledge here.

I will probably keep this dizzy, and try to return to an OEM igniter. Engine has not had pinging issues as it is currently setup.

The OEM igniter is for electronic dizzies. Yours is points. So either keep what you have, or switch to an igniter after you have 4Cruisers convert the dizzy. Or go back to the igniter and have Jim C recurve a stock 60 dizzy.

What are thoughts here from the CO crew on the HAC system?

It’s a good thing. In addition to adding 4-5 degrees of static timing at idle (which, yes, you could just add by twisting the dizzy), it also adds more air to the carb mixture below the venturis. At altitude with stock jets these trucks run VERY rich. Even here in Denver with the HAC disable I’m at like 12 on my A/F gauge. So I do run the HAC most times. It adds kind of an excessive amount of air at cruise down here at 5000’ but it’s very helpful as you go up. It seems to stop adding more air around 11-12k, but at least it’s doing something. Down here I run a VTV to choke the air down a bit, but above ~7000’ I remove it and run the HAC straight.

As far as vacuum routing all I have is.

1. Brake booster
2. Vac advance from the distributor
3. Gas evap (right now just venting to air)

Evap canister is probably bad anyway if it’s original, replace with AC Delco, I think it’s the VC-120. Takes some creative plumbing which is spelled out on Mud.

4. PCV (venting to air, soon back to the carb hat)
5. The big line from the left side cover to the carb spacer. I do not know what that one does!

#5 is evap. If the black & white valve on the drivers side is still in place it’s guaranteed bad and leaks vacuum. Get the black/blue 80 Series valve from City Racer to replace it. Did I say that already a few posts above? I forget.

The distributor vent system is worth reinstalling. Otherwise the dizzy apparently generates ozone (O3) inside which causes corrosion. That’s per Chenoweth, hidden somewhere deep on Mud. The valve for that is another black/white vac thing exactly like the evap one over by the carb, it normally clips to the underside of the air cleaner above the dizzy and has some other plumbing that you can find in the FSM. You’ll have to find a new spot or fab a bracket for it with your new air cleaner setup.

On the carb side. Is the one electrical connection on the AISIN carb a thermosensor for the carb fan?

Fuel cut solenoid. Necessary. The other end hangs below the carb fan when it’s not connected.

Throttle linkage looks complete with nothing removed for the weber.

The horizontal rod between the firewall hanger/bracket and the carb has two arms coming off of it. Short arm towards the firewall, long arm at the carb. If it’s backwards your acceleration will be dismal! Also I found recently that my long arm had somehow gotten bent and was rubbing on the throttle return spring on the carb - in fact it was getting stuck. Sticky throttle are exciting! Keeps you on your toes! Just make sure that when the throttle rod operates that it’s clear of the spring.

I ordered new carb studs. Really trying to minimize the number of parts I will need to order mid project.

Good luck with that

 

[Cruisertrash]

@KC Masterpiece Edit to add: thermosensor for the carb cooling fan is on a bracket bolted to the exhaust manifold. Go on the driver’s side, look to the right of the downpipe (towards the firewall). It’s hard to see.

 

[RDub]

The single wire to the thermo switch takes a lot of guff. It’s frequently in need of repair within the last 6-9” near the switch.

 

[60wag]

I thought the HAC circuit is an on/off arrangement rather than something that continues to adjust the mixture as altitude changes. The switch over point is something like 3500 ft so anything from Denver to a high mountain pass is the same “high” altitude setting. The truck could likely be set up to run well without the HAC. I wanted to to have all of the OE systems intact so I kept it.

 

[Cruisertrash]

I thought the HAC circuit is an on/off arrangement rather than something that continues to adjust the mixture as altitude changes. The switch over point is something like 3500 ft so anything from Denver to a high mountain pass is the same “high” altitude setting. The truck could likely be set up to run well without the HAC. I wanted to to have all of the OE systems intact so I kept it.

It has seemed continuous to me above 4000’. I drove to Omaha a couple years ago and watched my A:F gauge like a hawk. The change happened at almost exactly 4k’, just like the manual said … but it was slowly changing prior to that. I think 4k is fully closed off.

Replicating the HAC changes are easy for the dizzy. For the mixture it requires changing jets. As it stands with my stock jets, I can “tune” the HAC with VTVs on the vac line- much easier than swapping jets when I drive to the mountains.


I carry a green one (50cc) and a red one (25cc, out of 80s mini trucks) depending on how the A:F looks. Or, above a certain altitude, I just run a straight hose. I keep the VTVs in my door card pocket and they take about 30 seconds to change.

The other vac hoses on the HAC also contribute air to the carb post-venturi, but the top one flows the most air.

 

[Rzeppa]

The distributor vent system is worth reinstalling. Otherwise the dizzy apparently generates ozone (O3) inside which causes corrosion. That’s per Chenoweth,

I have had a number of phone conversations with Jim and among the subjects was the factory venting on later 2F distributors. He never said anything to me about ozone or corrosion, but rather that the factory setup, where the clean side of the air cleaner housing (which always has a somewhat vacuum whenever the engine is running due to the difference in pressure from the clean side to the outside) sucks air into the distributor cap which comes from a hose that comes from the glove compartment. This is mainly to keep the high voltage cap area dry!

 

[Rzeppa]

I thought the HAC circuit is an on/off arrangement rather than something that continues to adjust the mixture as altitude changes. The switch over point is something like 3500 ft so anything from Denver to a high mountain pass is the same “high” altitude setting. The truck could likely be set up to run well without the HAC. I wanted to to have all of the OE systems intact so I kept it.

That is correct, it is on/off. IIRC from the factory emissions manual, it is set to add around 3° of static advance at about 4,000 feet elevation, so pretty much anywhere in Colorado it is advanced.

Generic knowledge: Old school distributors (as in pre-computer controlled) have three ways to advance the spark timing. First is static advance, which is where you rotate it in your F or 2F engine and then tighten it down. Second is vacuum advance, which is controlled by whatever is making the vacuum. Some stupid years had a vacuum RETARD which is stupidly retarded, but was for emissions compliance. Third, and here's what Jim (@Cruisertrash) is talking about above when he refers to "curve" is centrifugal advance, where the spark timing is advanced by RPM, and this varies a LOT and where Jim Chenoweth's expertise is, pretty much expert.

 

[Cruisertrash]

I have had a number of phone conversations with Jim and among the subjects was the factory venting on later 2F distributors. He never said anything to me about ozone or corrosion, but rather that the factory setup, where the clean side of the air cleaner housing (which always has a somewhat vacuum whenever the engine is running due to the difference in pressure from the clean side to the outside) sucks air into the distributor cap which comes from a hose that comes from the glove compartment. This is mainly to keep the high voltage cap area dry!

Like I said, the ozone tidbit is something I dredged up from the long-ago depths of Mud. Whatever the case may be, the dizzy vent system isn't "evil smog equipment sucking the power from a 2F" - it's harmless - and I think too many people rip it out when they desmog. They see a vacuum hose and they start seeing red and foaming at the mouth.

HAC advance is 6 degrees per the manual. I know that supposedly the valve is either on or off, but in my real world driving experience with an aid/fuel gauge I've seen it have some variation within the "open" setting. That's with two different HACs in fact. It could have something to do with how they operate as they age, I don't know.

Another tidbit is to replace the stop pin bushings inside the dizzy. It's a plastic sleeve that Toyota put on a post to stop the centrifugal advance weights. The plastic gets old and falls apart, and the advance weights can swing another several degrees. Easy to replace with some stuff from the hardware bins at an Ace or True Value so that the dizzy doesn't "over advance" when it's all-in. I forget the size, but a handful of little aluminum spacers probably costs less than $2. Size is maybe around 1/8" ID on the spacer. You want a tight fit on the metal pin in the dizzy. Easy to do yourself.

I'm getting kind of far away from KC's stuff here, so I'll leave it at that.

 

[KC Masterpiece]

You all are such a world of knowledge. Feel free to vamp on this thread. Its all good learning for me.

I am leaning towards keeping the dizzy as is since the big cap is NLA. Guessing thats why it was converted.

If I felt it needed to be vented it seems like it would be easy to tap the cap and run a vent line somewhere.

Waiting for the 80 to return before I pull the carb. The 60 is my daily until then. 80 is currently down at Keith's Garage getting the top end rebuilt. Turns out I was correct in my diagnosis and the HG went on cylinder 1. The good news is that the head is in good shape, and the bottom end looks great. New gasket, some machine work, and we will be back in action.

I really miss having Imelda as the daily. @Johnny Utah give her a kiss for me.

 

[Johnny Utah]

 

[KC Masterpiece]

New wheels look good!

 

[KC Masterpiece]

So thats why the clutch flet a bit off.