Restoring Rusty

[rich weyand]

Follow-up:

The location of your up-and-over-and-down hose in the pic on p 154 of this thread is correct. Lots of nice pics of different pretty ways to do it are here:
https://www.google.com/search?q=vort...h2CLUQ_AUIBygC

You need to do it, because you do NOT want to be circulating coolant through your heater in the summer. I put a valve on mine so I could shut it off, because there is minimum amount of heat you get from the heater even when it is shut off. And when it gets hot here, any amount of heat is too much.

[rich weyand]

One other thing you could do. Run the bypass hose with a selector switch in it that can select the heater core OR the bypass. So one selector valve and a T. Then you can have the heater core for the winter, and bypass it in the summer. The one thing you can't do is just shut it off.

What you need is a 1/2" NPT 3-way valve. Search that on Amazon or google. Looks like 30 bucks for a competent one. Here's an example: Industrial Grade 1PZA1 Three Way Ball Valve, 1/2...
Basically it hooks up between the heater hoses like an H-pipe in the exhaust, with the valve in-line on the smaller hose, and a hose across to a T in the other hose.

[Valarius_Starchaser]

Originally Posted by rich weyand

One other thing you could do. Run the bypass hose with a selector switch in it that can select the heater core OR the bypass. So one selector valve and a T. Then you can have the heater core for the winter, and bypass it in the summer. The one thing you can't do is just shut it off.

What you need is a 1/2" NPT 3-way valve. Search that on Amazon or google. Looks like 30 bucks for a competent one. Here's an example: Industrial Grade 1PZA1 Three Way Ball Valve, 1/2 In NPT, Brass: Amazon.com: Industrial & Scientific

We get guys doing that up here and they are also the guys coming in to get their heater core flushed every winter because the lack of flow forms a sludge and makes it work poorly just my .02

[rich weyand]

Originally Posted by Valarius_Starchaser

We get guys doing that up here and they are also the guys coming in to get their heater core flushed every winter because the lack of flow forms a sludge and makes it work poorly just my .02

Yeah, you gotta turn it on and let it flow a bit once a month or so to keep that from happening, just like the guys with the garage queens should start their vehicle and let it run for a bit once a month during the winter.

[rich weyand]

One more thing. You can get those 3-way valves with electric actuators, so you could hook it up to run through the heater core when you selected Heat, and otherwise switch to bypass.

[Jake Wade]

Try bumping your initial timing up to 14º-16º. You have a larger camshaft now and this is a good number.

Your vacuum reading at idle most likely will not be over 16-17 with that camshaft, and that's well tuned.

[Gregski]

Originally Posted by Jake Wade

Try bumping your initial timing up to 14º-16º. You have a larger camshaft now and this is a good number.

Your vacuum reading at idle most likely will not be over 16-17 with that camshaft, and that's well tuned.

bumped the initial timing to 16* and with manifold vacuum hooked up to the canister on the distributor the engine is set to idle at 850 RPM and it pulls a perfect (steady) 20 inches of Mercury (that is as close to perfect as you can get) I honestly don't see my camshaft as much of a performance cam, its moderate at best

I don't think this will impact my engine running hot (notice I did not call it overheating) but only a test drive or two will tell, and for that we will have to wait until tomorrow

[rich weyand]

Originally Posted by Gregski

bumped the initial timing to 16* and with manifold vacuum hooked up to the canister on the distributor the engine is set to idle at 850 RPM and it pulls a perfect (steady) 20 inches of Mercury (that is as close to perfect as you can get) I honestly don't see my camshaft as much of a performance cam, its moderate at best

I don't think this will impact my engine running hot (notice I did not call it overheating) but only a test drive or two will tell, and for that we will have to wait until tomorrow

OK, so you're getting steady vacuum and idle now with the vacuum can hooked up. Good.

I went looking around, because I thought stick shift idle was supposed to be lower than auto trans idle, but it looks like I misrecalled. You look good to go right there.

[Gregski]

ok, so lets sum up the situation code name WATERGATE (you like that? I came up with it all by myself)

In the beginning with no bypass hose we were running hot as so...

[Gregski]

then we added the bypass hose from the intake manifold to the water pump, or water pump to intake manifold which ever way you swing

... and that took us out of red line aka out of critical but still East of the middle on the gauge

[Gregski]

next we added Antifreeze Coolant into the system, so now we are running 50/50 with water mix, and that did nothing, the reading is exactly precisely the same [pause to scratch head]

[enaberif]

Without knowing what those ticks reference in regards to numbers who knows what you are reading.

[Gregski]

Originally Posted by enaberif

Without knowing what those ticks reference in regards to numbers who knows what you are reading.

Now on this we can agree 1,000%, I hate gauges without numbers, do you know what you call a ruler without numbers? a stick, do you know what you call a gauge without numbers? NOT A STINKIN' GAUGE, that's what!!! ha ha

[Gregski]

Originally Posted by enaberif

Without knowing what those ticks reference in regards to numbers who knows what you are reading.

Gentlemen sometimes you just gotta MacGyver the snot out of something (honk if you be old enuff to know who MacGyver useta be) ha ha

so we used our digital thermometer as a baseline control, we decided to boil some hot water and we stuck the 1974 water temp sending unit in the pot as well, we were making Vortec Soup, both were suspended in the water and not touching the bottom hot plate, the sending unit was connected to the gauge with its green wire and its housing grounded to the battery negative terminal to ensure proper and reliable ground (ignore the color red wire, an aligator clip is an aligator clip)

brilliant if you ask me

so with the truck off but the key in the on position (not start, just on) as the water begun boiling the digital control gauge started climbing, our truck gauge didn't for a while, it was a bit slower to react (a bit discouraging at first, but then...) then it started to move

I recorded the first notch as 190(ish)* F

I recorded the middle notch as 210(ish)* F

since water boils at around 212 that was as hot as we could get and the wife caught me using her pot so I couldn't add no Antifreeze to it, ha ha

but we might have some reference digits now

[SkinnyG]

I have a 195° thermostat in my truck, and the operating temp is a tick below the first line (1/4 of the gauge).

I have an electric fan, which is switched on at 212°, and off at 192°, and the needle never passes the first line.

My truck is a '77, with original gauge and presumably sender.

[Gregski]

Originally Posted by SkinnyG

I have a 195° thermostat in my truck, and the operating temp is a tick below the first line (1/4 of the gauge).

I have an electric fan, which is switched on at 212°, and off at 192°, and the needle never passes the first line.

My truck is a '77, with original gauge and presumably sender.

thank you so much, excellent detail, I hope to hear from conventional fan folks as well

[Gregski]

... we now step away from WATERGATE momentarily and join Timing Adjustment already in progress...

[rich weyand]

On temperature, I have an original guage, and a reproduction sender to match the original. Note: not a substitution gauge, a reproduction gauge with the same resistance curve as the original. American Autowire did it for the Corvette restorers, whose gauges read in degrees. It drove them nuts not to have them read right. It turns out they use the same resistance sender as squares up through (I think) 79.

The full details on senders are in this thread: http://67-72chevytrucks.com/vboard/s...d.php?t=630399

My gauge now reads just shy of straight up when everything is operating normally.

[Gregski]

Originally Posted by rich weyand

... My gauge now reads just shy of straight up when everything is operating normally.

Thank you very much Rich, so we are aiming at West of middle.

I pulled the trigger on this gorgeous Summit brand digital water temp gauge SUM-G2984-1G for $35 and its accompanying sender SUM-G2984-1S for an additional $10, and knowing Summit they may arrive today.

[rich weyand]

Originally Posted by Gregski

Thank you very much Rich, so we are aiming at West of middle.

If your sender matches your gauge, yes. The problem is that a lot of senders were replaced with book substitutes after 1513321 was obsoleted, and the book substitutes don't have the same resistance curve. Getting the true reproduction (see pointer in thread I posted above) will guarantee the gauge reads correctly.

[Gregski]

so took the truck for a standard 30 minute test drives now that I think I have the timing dialed in, gentlemen the truck sounds good to me, it sounds like a fine tuned Swiss Tractor, lol, no seriously it do sound good, but it still ranned hot

when I got home I felt the radiator cap and it didn't feel too hot, so I did what you aint supposed to do, unscrewed it, then I shoeved the wives favorite turkey thermometer in it, and it read 164* F

now I know and you know that I know that, that's in the radiator and not in the cylinder head or not in the intake I get it, but heck we got some sort of a reference digit, know what I mean bro

[daddyjeep]

Very nice test here. Don't trust anything. It kinda reminds me of my engineer days.

[Gregski]

Originally Posted by daddyjeep

Very nice test here. Don't trust anything. It kinda reminds me of my engineer days.

Thank you, I thought about these numbers and realized we must remember that the cooling system in a vehicle is under pressure perhaps 15 PSI which would make water not boil until it reached 250* F and those numbers would change again if we added Antifreeze / Coolant

good stuff, good to know / remember

[Jeramy]

my reading comprehension is bad. you already a running the test i was typing out.

[Gregski]

what I am going to do next is test the flow by removing the thermostat again, and taking the truck for another 30 minute test drive

Wait, didn't we start out with the thermostat out? yes we did but at that time we had no bypass hose nor were we running the heater core (essentially the same deal) and now we learned the Vortec heads require the bypass hose\heater core.

if this lowers the temperature I will put the thermostat back in and drill one 1/8th hole in it like some people have done with this problem on other forums, and test drive it again

I will keep drilling holes one by one I think to see if magic happens up to three total