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mshort07

Beginning my next project

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9 hours ago, docbainey said:

Use a weber 32/36, the carb off the j13 will be to small and will need re-jetted.

 

Where did you end up finding a 5th gear steel syncro ring? $$$?

 

Typically you should replace the ring, blocks and bands as a unit as all of those parts are the 'synchronizer'.

 

Nice Roadster

I know a guy 😀. A friend in the next town over had a few lightly used ones for me. 

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5 hours ago, iceman510 said:

I have numerous Weber 32/36 carbs if you are interested.  Some of them probably jetted for L20B already.

 

 

How much for a carb?

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A new question for you all today. 
 

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The spring exhaust flap in the exhaust manifold. How does it work? My guess is that at low rpms the flap is in the position seen in the photo above directing hot exhaust gasses up towards the heating plate sandwiched between the exhaust and intake manifold. When the rpms go up, the exhaust gasses increase in pressure pushing the flap open allowing the gasses to flow more freely through the rest of the exhaust system. When the rpms come back down, the spring and lack of exhaust gas pressure allows the flap to close directing more heat to the heating plate. ??? Am I right?

 

so is the flap needed? I don’t plan on doing much cold weather driving. Heard something along the lines was what the heating plate was for. The flap looks very restrictive. Can I just do away with it or position the flap so it is always open (least amount of restriction of gasses flowing through the exhaust system and out?

 

thanks

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Your kinda right. The flap is moved by the temperature of the 'spring' on the manifold. As the spring heats up, it pivots the deflector plate so the exhaust gases flow more freely. Its an aid to warm the engine up faster.

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Works somewhat like the choke coil. That strip tightens up when cold holding the flap  open so exhaust can warm up that plate with the ridges under the carburetor so fuel droplets will vaporize. Ten or fifteen seconds is all it takes and the engine runs smoother and burns more of the fuel. Fuel in droplets won't burn it has to be vaporized. Don't forget this is a cold engine. As the exhaust heats up that metal coil it slowly unwinds and closes that flap and the exhaust by passes it.

 

The problem is it it's not maintained the coil can rust or erode away from the heat and it doesn't work. Worse the shaft can rust and seize in the open position and not work when you need it or worse in the closed position baking the incoming air on hot days when not needed. It can seize in any position in between and why I'm not a fan.

 

Yours looks good. As long as it's loose and free to move I'd just leave it. Check it when it's cold every now and then

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1 hour ago, datzenmike said:

Works somewhat like the choke coil. That strip tightens up when cold holding the flap  open so exhaust can warm up that plate with the ridges under the carburetor so fuel droplets will vaporize. Ten or fifteen seconds is all it takes and the engine runs smoother and burns more of the fuel. Fuel in droplets won't burn it has to be vaporized. Don't forget this is a cold engine. As the exhaust heats up that metal coil it slowly unwinds and closes that flap and the exhaust by passes it.

 

The problem is it it's not maintained the coil can rust or erode away from the heat and it doesn't work. Worse the shaft can rust and seize in the open position and not work when you need it or worse in the closed position baking the incoming air on hot days when not needed. It can seize in any position in between and why I'm not a fan.

 

Yours looks good. As long as it's loose and free to move I'd just leave it. Check it when it's cold every now and then


yes. It’s in good working order. Moves freely. So it’s a bi-metallic spring. Makes sense. When cold, it’s short and closes the trap pushing air to the heat sink. When hot the spring metal expands allowing the gasses to easily open it. When the engine is off again, the metal spring will cool and shrink closing it back off again for the next start. Sounds good. 
 

Now is there much harm in disabling it? I’m not planning on doing a lot of cold driving. Or just leave it alone. It’s still working after 40 years. It will keep working. What do you think. 

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I would get rid of it and find a exhaust manifold from a L16 and y pipe that clears your torsion bar. But it cheaper to keep what you have if your exhaust is still good Just a pain to work with.

 

it just a flap to heat the intake in winter so the carb don’t freeze.early cars had a hot water line to the intake and head had holes for the water to go into

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Time to buy more parts and wanted to get some input first. Remember I’m fitting this L20B in my ‘68 520. I know there will be cutting and welding but was trying to stay away from cutting the firewall. So I need to get a water pump and a radiator. What do I buy? Do I go stock, ‘78 620 water pump with clutch fan (that was original to the engine). I don’t see any original style radiators on eBay, only aluminum ones. Would that combo be too deep and not fit. I heard, and it looks like it’s going to be tight. Also, the ‘68 520 face has four head lights with a space of 23 inches between where the radiator needs to go. What about an L16 water pump with a fixed fan? Will that save space? Any different options on the radiator? I’m looking forward to reading anybody’s thoughts. Thanks

Edited by mshort07

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Next question. According to this book. 
 

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the L20B has these cast bracket mounted to the bottom back end of the block to bolt to the bell housing of the transmission. 
 

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My engine didn’t have it when I bought it. I guess the pervious owner got rid of them. 
 

Do I need them?

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Called gussets. I would rather have them than not but I drove my truck for years without them and didn't know.

 

They come in lighter weight aluminum too

 

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8 hours ago, mshort07 said:

Does anyone know where I can get a pair of gussets?

 

 

I've ran several L engines without them. Even a mild LZ23. No issues at all with not running.

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Getting there. Just waiting on a few more parts and it will be all back together. Spent too many hours cleaning and polishing the valve cover today. 
 

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