bl1300
Posted a lot
Posts: 1,678
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Jun 25, 2011 12:03:34 GMT
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This is an inherent problem on two cylinder dafs and is that the hotspot pipes rot away. New manifolds are next to impossible to get and most secondhand ones have the same problem. The problem is that the main body of the inlet manifold is cast alloy and the hot spot pipes that are used to preheat it are steel and have manifold temperature exhaust gasses running through them. Setting up an intermettalic corrosion problem. Now the cars will run without the hotspots but have reduced power, a flatspot and can be difficult to start in cold weather. The biggest problem is if it causes exhaust and inlet to mix. Any ideas on a way to fix the problem would be greatly aprreciated. This is the manifold in question  Any ideas how to fix the problem. |
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Current fleet.
1967 DAF 44
1974 VW Beetle 1303s
1975 Triumph Spitfire MkIV
1988 VW LT45 Beavertail
1998 Volvo V70 2.5
1959 Fordson Dexta
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Jun 25, 2011 16:42:11 GMT
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is it just a very weird way of heating up the manifold? If so, lots of solutions to the problem! Like changing the carb to something like an SU, that atomises fuel better.....
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You're like a crazy backyard genius! |
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bl1300
Posted a lot
Posts: 1,678
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Jun 25, 2011 16:45:47 GMT
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Yes basicly its manifold heating. Hot spot pipes are common on aircooled engines. Unfortunatly changing the carburettor is going to cause issues with the transmission
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Current fleet.
1967 DAF 44
1974 VW Beetle 1303s
1975 Triumph Spitfire MkIV
1988 VW LT45 Beavertail
1998 Volvo V70 2.5
1959 Fordson Dexta
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Jun 25, 2011 17:02:19 GMT
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simple, remove the steel bit, and replace it with a high grade ally one.
if my ac/dc tig welder was here i could do it for you
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Jun 26, 2011 12:13:00 GMT
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guessing the gearbox uses vacuum signals from the manifold? Any more info on what/how it needs it? Always ways around it  |
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You're like a crazy backyard genius!
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bl1300
Posted a lot
Posts: 1,678
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Jun 26, 2011 20:09:52 GMT
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Yes the variomatic change up is controlled by inlet manifold pressure, it also affects the cars braking as well, as when braking manifold vaccum causes the change down.
Basicly there is a vacuum diaphragm in each primary drive pulley. Manifold vaccum is sent to one side of the pulley making the car change up, when the throttle goes beyond a set position or the brake pedal is pressed a valve is tripped and the vaccum is then sent to the otherside of the diaphragm making the car change up. As you can imagine vaccum leaks or incorrect settings have serious implications on the performance of the transmission
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Current fleet.
1967 DAF 44
1974 VW Beetle 1303s
1975 Triumph Spitfire MkIV
1988 VW LT45 Beavertail
1998 Volvo V70 2.5
1959 Fordson Dexta
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Jun 26, 2011 21:14:47 GMT
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ooooh, clever! So, it's just a vacuum feed? I'd say fill up the holes caused by the hotpipes, fit an SU carb, and enjoy improved running,easier starting, and still have a running gearbox!
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You're like a crazy backyard genius!
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