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Rebuild for mileage and emissions
https://slantsix.org/forum/viewtopic.php?t=64507		 Page 6 of 12
Author:  SlantSixDan [ Wed Jun 24, 2020 5:33 pm ]
Post subject:  Re: Rebuild for mileage and emissions
Quote:
I'm wondering what temperature thermostat I should use. I was going to use a 195 for best combustion, but my machinist recommended 160 to avoid detonation on regular gas
That's wrong—that's not how this works. The thermostat sets the engine's minimum operating temperature, not its maximum operating temperature. Read this.
Author:  Rick Covalt [ Wed Jun 24, 2020 6:05 pm ]
Post subject:  Re: Rebuild for mileage and emissions
No reason that you can not run at least a 180 degree thermostat. Get the timing and the timing curve set and you should be good to go.
Author:  rich006 [ Wed Jun 24, 2020 6:23 pm ]
Post subject:  Re: Rebuild for mileage and emissions
Quote:
Quote:
The thermostat sets the engine's minimum operating temperature, not its maximum operating temperature. Read this.
I've read that before, but I think I understand it better now. I think what you're saying is that the thermostat controls the coolant temperature, but not the temperature of the combustion gases. So the answer to my question is: higher compression doesn't change my thermostat needs. I have previously run 195 and 180, and both seemed the same with regard to idle and hot starting. I've done the fuel line mod, for what that's worth. I think I'll go with the 195.
Author:  SlantSixDan [ Wed Jun 24, 2020 8:18 pm ]
Post subject:  Re: Rebuild for mileage and emissions
Try the 195°, sure. If you experience heat-related carburetion problems, drop back to the 180°. And if ping control is crucial, I strongly recommend the waterless coolant as described here. It is expensive and very much worth it, in my experience.

(Of course, make sure you're running a good radiator, an appropriate fan, etc.)
Author:  Dart270 [ Thu Jun 25, 2020 2:39 am ]
Post subject:  Re: Rebuild for mileage and emissions
I second trying the 195 and dropping back to 180 if needed. I hope you are planning to recurve the distributor mechanical advance. The factory curves were not so great.

I am not a fan of the waterless coolant myself, especially if you plan to drive the car long distances. Any leaks/seeps you have will eventually deprive you of coolant, and you cannot apparently add water or normal coolant to the waterless stuff. You cannot buy this stuff in most locations. If you are driving locally mostly and/or can keep some spare coolant in the car at all times, then fine.

Lou
Author:  rich006 [ Thu Jun 25, 2020 3:53 am ]
Post subject:  Re: Rebuild for mileage and emissions
The waterless coolant is intriguing. I have the original non-AC radiator and fan. According to Evans, you can add water in an emergency, but should replace the coolant ASAP if you do.

I wasn't planning to recurve the distributor right away. From DI's tutorial, it looks like a hell of a lot of fiddling as you take it all apart, change something, put it back together, and test. I don't really know what initial and full advance numbers I would be looking for, and I don't have any old distributors, extra springs, etc. I'm thinking of that as a future project along with HEI.
Author:  Dart270 [ Thu Jun 25, 2020 6:37 am ]
Post subject:  Re: Rebuild for mileage and emissions
If Charles Brooks is still selling his recurve kits, I can vouch that they are very nice. I just recurved a dist for the first time with his kit and it did exactly what I wanted. Of course, I have a lot of experience curving and mapping advance curves, so this is biased advice.

Lou
Author:  SlantSixDan [ Thu Jun 25, 2020 12:24 pm ]
Post subject:  Re: Rebuild for mileage and emissions
You can add water to the waterless coolant if you have to. You don't have to throw it away afterward, either, you can heat it up to boil off the water. That, plus the much reduced leak tendency (no pressure) and much reduced seriousness of a leak (with no pressure, goes drip-drip-drip instead of PFFSHHHHHHHHH!!!!!!) means there's no reason to fear long trips.
Author:  rich006 [ Thu Jul 02, 2020 10:50 am ]
Post subject:  Re: Rebuild for mileage and emissions
Looking ahead a bit: when I had my exhaust redone at a shop a few years ago, they used some kind of orange sealant at the manifold flange. When I took it apart it seemed to have held up well. Should I use sealant there when I put it all back together? If so, can I use the same stuff I'll be using on the gasket between the intake and exhaust manifolds (red or copper high-heat RTV)?
Author:  SlantSixDan [ Thu Jul 02, 2020 4:50 pm ]
Post subject:  Re: Rebuild for mileage and emissions
It is very much worth your while to get the good gaskets for the manifolds-to-head, intake-to-exhaust, and headpipe-to-manifold junctions. Do not use goop.
Author:  rich006 [ Thu Jul 02, 2020 6:52 pm ]
Post subject:  Re: Rebuild for mileage and emissions
Quote:
It is very much worth your while to get the good gaskets for the manifolds-to-head, intake-to-exhaust, and headpipe-to-manifold junctions. Do not use goop.
Well, I just carefully followed your instructions here. We'll see how it goes. :-)

For what it's worth, I used the copper sealant (which looks like the stuff that was on the manifold flange gasket from the exhaust shop) on the head side of the gasket and nothing on the manifold side. I believe I should be OK with the "regular" gaskets because I'm putting all the same parts back together, and the machinist ran lightly over the manifold surfaces to make sure they were straight. But if I have to do it again I will be smarter the next time. ;-)
Author:  rich006 [ Thu Jul 02, 2020 7:19 pm ]
Post subject:  Re: Rebuild for mileage and emissions
By the way, thanks for posting the link to the manifold end lock nuts (here if anyone is looking). I needed one when this happened as we tried to open up the old nut to reuse it. (For now I have used a regular nut, but I'll be installing the lock nut when I get it.)

Image

Also, someone might be amused to see the assemblage of tools I connected in series to tighten the center-most lower manifold nuts. My only swivel is 1/4" drive, and the only torque wrench I have that goes low enough is a 3/8" drive, and I don't have a 3/8 to 1/4 adapter. But a 1" socket fit perfectly on the hex-shaped driver handle. Oh, and of course the 1" socket had a 1/2" drive. Fortunately I do have the 3/8 to 1/2 adapter.

Image
Author:  rich006 [ Mon Jul 06, 2020 3:51 am ]
Post subject:  Re: Rebuild for mileage and emissions
How worried should I be about sand in the water jacket? When I had the engine on the stand, every time I flipped it upside down and then back upright, a sprinkling of sand appeared in the water pump pocket.
Author:  SlantSixDan [ Mon Jul 06, 2020 11:42 am ]
Post subject:  Re: Rebuild for mileage and emissions
Was this playing at the time?
Author:  rich006 [ Mon Jul 06, 2020 11:57 am ]
Post subject:  Re: Rebuild for mileage and emissions
Quote:
Was this playing at the time?
No, but I was wearing the same suit as the guy on the right.

So, either nobody thinks it's a big deal, or nobody wants to tell me I have to take my engine apart again to hose out the block. I guess there's been sand in there for 46 years and it's just going to keep sitting in the bottom, as long as I don't start driving upside down.
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