Recently put a fresh 3.9 in my 86 rangie.
Ever since it has been putting out a heap more heat from then enginebay then the old motor did and even to the point were free revving around 1500-2500 i can get the exhaust pipes to start to glow.

Driving the car on the road even just putting around on a 15deg night i can feel alot of extra heat comming out of the engine bay and if i give it a little squirt (nothing over 3800rpm according to the log) i can get the pipes to glow.

After a 30-45min sedate drive the chassis rail near the exhaust downpipes are too hot to touch, and the steering shaft has a lot of heat in it. when you pop the bonnet you can feel the excess heat, way more then before.
Ends of the spark plug leads are also starting to discolour from getting hot.

I've pulled the plugs out and they look really good and this is backed up by checking the mixtures

its running an aftermarker ECU and I've got a wideband o2 gauge on it and the mixtures seem pretty much spot on.
Timing is on around 8deg BTDC
and coolant temp sits on about a 1/4 on the gauge (which is about 80deg)

engine has done about 250-300k since rebuild.

I would have thought timing or fuel would make the pipes glow, but these seem to check out ok?

rebuilt motor running hot as its still tight? would have thought it would have free'd up a bit by now?

just wondering if theres something i've missed?

Glowing exhaust normally points to a lean mixture - what is the colour of the plugs - do they show anything.

The engine maybe running hot as a result but with a good cooling system the heat in the engine may be being dealt with - glowing pipes reflects high combustion temps - often caused by a lean mixture or sometimes poor timing.

Garry

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REMLR 243

98 Freelander XEDI (the Hippo)
1977 FC 101 (Miss Piggy)
1957 Series 1 88" (Baby)
1957 Series 1 88" Station Wagon
1971 Jaguar V12 E-Type Series 3 Roadster

Check the timing is actually advancing when revving. Disconnect the vac advance and check that the timing advances at least 10 or 15 degrees above 2500rpm. Or take the dist cap off and see if the rotor button moves against the advance weights and springs back again.

If the timing is not advancing sufficiently, the still burning fuel charge will be heating the exhaust manifolds( and valves) excessively.

Leanness can also cause this, so even though you say that the mix seeems right when driving, these engines are pretty dirty and need more fuel to run at their best. Trying to run them at modern car engine emissions levels with stock injection and ignition systems will kill them off...at least yours is adjustable?

Tight engines DO work harder, but getting the manifolds to glow is(Apart from a good caning on a Dyno) a sign of incomplete combustion caused by timing or fuelling IMHO .

JC

what exhaust pipes do you have? extractors?
what engine did you replace?
if the water and oil temps are normal then i would consider the heat to be normal.
if you upgraded to a bigger engine then it would be normal to assume greater heat output due to bigger engine does more work.
or else it may be running leaner than you think.
if you have done 300km since installation you can safely assume it's run in and can run safely to max rpm.
another thing to ask is has the exhaust got a blockage, kinked pipe or something?

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harry

If timing is ok sounds like its running lean.Does it knock when laboured(Lean detonation) A small air leak causeng a thermal? I thought the O2 should pick it up. With EGTs that hot be carfull you don't drop a valve or burn/break a piston.
Tony

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Strange Rovers Down Under 4BD1T 120" 110 /3 Rangies:/ 3 series 1's/ 2 series 2's/2 series 3 88's/2
series 3 109's and a heap of rice burners

We ahd exactly the same problem when installing the Wold ECU on Jezzaol's 4.6 coil pack conversion.. The problem in the end turnd out to be massivly retarded timing as the trigger wheel was installed 1 hole out. This ment 8deg BTDC(indicated on the ecu) was closer to 22deg ATDC. How are you verfing Acutal ignition timing versus what the ecu is telling you?

What ecu are you using? does it have an ignition offset adjustment?

exhaust is a 2.5" from the downpipes back with a straight through muffler, stock exhaust manifolds and downpipes.

Engine doesn;t knock/ping actually drives pretty well. i'm not pushing it hard though due to this getting hot.
Haven't got them glowing cherry red but if i get into it a little bit it starts to glow in the thinner down pipes. exhaust manifold doesn;t glow.

AFRs are mostly around 14.8-15:1 and swing into the 13s under acc.

Inspected the plugs and they seem really good.

will have a play around with timing/ dizzy a bit more today and see how i go.

thanks for the help/suggestions, will keep you updated.

megasquirt fuel only ECU. timing is taken care of via std disco dizzy and coil

What sort of injector firing sequecing are you using?

Does the mega squirt have not ignition control at all?

Is the Cam standard or custom high lift/long duration.

With a lot of overlapp you can get glowing pipes.

If those levels are acurate then they are good so it's not lean and if it's not pinging then then timing sounds ok.

As JC said, tight engines normally get a bit warm while running in.

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