Exhaust Manifold Question

[Rock Lobster 28]

Hey guys,

 

I've just rebuilt my engine, put it back together again and got her running. The only problem being that there seams to be a huge amount of heat coming from the exhaust manifold/downpipe? I realise these do get very hot anyway but it does seem excessive, even to the point that the speedo and clutch cable feel a bit soft to touch after I shut her off! This has me worried!

 

Would there be any reason why this could be happening? Or do I have the cables routed too close to the manifold?!

 

Any help or pics much appreciated!

 

Cheers

[EdCherry 34 1 Cars]

Got the heat shield in place?

[GLPoomobile 958]

Isn't excessive exhaust temp something to do with incorrect cam timing or the mixture being lean, or something along those lines?

[Rock Lobster 28]

This is what i was worried about, I've read something like that somewhere too! I thought it was something to do with the timing?

 

Heatshield? Didn't know there was one! haha!

 

Anyone got a pic? or a spare even!?

[Grim.Badger 15]

There is a heatshield attached to the bulkhead that covers the coolant pipes going to the matrix, most people shove the speedo cable back there but I've never seen the point.

 

From what I know of cam timing, you would notice if it was out as you'd either smash your valves to pieces or have a sluggish engine, but that may be the extremes so I'd check with one of the engine builders one here; imo though it's difficult to get the timing wrong on an 8v.

 

If it's running lean you will be able to tell by the spark plugs, can't remember what happens to them but there are pictures in the back of Haynes; I think they vitrify and go all glossy

[Tom Fenton 1,542]

If ignition timing is too retarded, it will run hot.

[Rock Lobster 28]

So am I right in saying that the advance/retard can be altered by the distributer position? I think mine sits roughly in the middle of the adjustment slot.

[Shepp354 0]

Exhausts do get hot but there are a few things you might want to try to see if the engine is running properly

 

Ignition timing is controlled by the distributor position which is held with two 11mm bolts. One towards the top and one below. Release these and you can twist the whole dizzy (from the cap end) and change your ignition timing.

 

Moving it towards the windscreen (clockwise) will increase advance and the other way retard. Make sure the vacume advance is working first. There is a tube from under the throttle body (throttle cable area, right of but underneath I think) that connects to the dizzy. Fish around and you should find it. If that is connected then pull off at the throttle body end and with the engine running at idle suck on it hard. All being well you should hear the engine pick up speed. If all is good then put it back on.

 

To change the timing I'd check that everything is ok as the other posts suggest before changing anything and mark it with a line to the head so you can return it to as was before getting carried away. Timing should be done via a timing light and service book but they are a bugger to do and most these days are not set that way.

 

If you're confident then one way of setting it is via road testing. Get the car to working temp first. Advance the dizzy bit by bit and go for a drive, each time getting a feel for performance (if it seems better or worse). When you're happy or even each time then find a hill and a put the car in a high gear (4th or 5th) so it is on low revs (2-2.5k max) and drive up on full throttle. If you hear it pink (light high pitch almost metalic sounding rattling from engine that you haven't heard before) then it is to far advanced so retard and repeat. With a bit of time you can find a position you like.

 

If you really want then to finish off the 'setup' you can drive hard in a gear and then cut the engine on the key and knock into neutral (only cut engine don't let the steering lock kick in while you are moving) and pull in. Take out a spark plug and have a look at the end, it should be light grey brown in colour with a dusty deposit to show a good mixture. If it's black then she is probably rich and bright white probably too lean. Check the spark plugs are right for the engine before getting too carried away though.

 

If the engine is setup properly then I wouldn't worry too much about the exhaust temp unless you see the manifold glowing or something!

 

Some advice......Disclaimer... Has worked for me but you're on your own if the engine blows, the cat gets sucked in or you end up in wheelchair

 

 

So am I right in saying that the advance/retard can be altered by the distributer position? I think mine sits roughly in the middle of the adjustment slot.