Bitter issues...any bright ideas?

[Rocket88]

Couple of weird problems on my newly acquired Bitter, which are a bit baffling. Just to explain, the engine is the old "cam in head" 3 litre Opel / Vauxhall straight six, stroked to 3.9 litres.

1] Exhaust manifold gets extremely hot [i.e.glowing!] pretty quickly. Have ruled out running lean, but apparently this car has been fitted with a new rear exhaust system, which was a smaller bore than the original. Would this cause the problem?

2] After starting, car seems to heat up [as far as the guage indicates] extremely quickly, goes to 3/4 the way up, and doesn't get any hotter. The rad doesn't seem to get that hot, although inlet and outlet pipe are hot. Also, I suspect that the cap on the expansion bottle is the wrong thread, as it doesn't seem to seat properly. This has only started happening since the fan belt snapped, and I lost most of the coolant, although I stopped pretty much as soon as this happened. It's since done 150 miles with the gauge at 3/4, but never gets any hotter, even in traffic, and displays no other failed head gasket symptoms.

 

Any ideas, shiteists?

[John F]

Hmm. Water pump failure?

 

Also, the narrower-bore exhaust won't help in terms of power development, not sure about the glowing manifold but I suppose this might occur if the back pressure is incorrect.

[Rocket88]

Ref pump failure...........good shout, hadn't considered that.

[Bobthebeard]

I had the glowing exhaust issue a couple of years ago. Admittedly on a motorbike but same principles I guess. The header pipes would get red hot very quickly after I replaced the noisy sports exhaust end can that it came with, with a secondhand, much quieter silencer. Seemed that the replacement silencer was slightly blocked causing a restriction. Ran ok though, but traffic light stops etc soon had the header pipes glowing red! Once cleaned out it was fine. Some wadding had become dislodged and was clogging the pipe.

[Rocket88]

That's exactly the same symptoms as I have................will take off rear box and see what's what.

[Bobthebeard]

Have just been told that the ignition timing can also cause the glowing manifold. If timing is too retarded can cause the still burning fuel to exit into the manifold as firing too late etc.

The guy who told me this used to have an old BSA motorbike with a manual advance/retard lever. He says that retarding the ignition fully at tick over caused the exhaust to glow red hot within seconds! Sounds plausible.

[Rocket88]

Had considered that, and will investigate

[dollywobbler]

Yup. Retarded ignition would be my first thought. That will cause the engine to run hot. My Skoda Estelle managed to fart sparks when it was mucho retarded!

[RedSparrow]

These things are the sex. Do you have a pictures thread?

[whitevanman]

This may sound daft....but stick with me for a moment.... glowing manifolds are down to incorrect combustion or cooling...end off...now the exhaust can play a part, as can timing, but while checking all these things, go check the plugs are the right temperature range and are in good condition