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Essex V6 Cooling discussion

Posted: Fri Sep 15, 2017 11:23 am
by AJL Electronics
Landy109s2a wrote:
Fri Sep 15, 2017 11:00 am
1980 SE6a,i cut air vents into the bonnets. RS2000 style.Never had a overheating or fuel evaporation problem since.
I have never cut holes in a perfectly good bonnet and never had an overheating issue that was not the result of a fault.

Essex V6 Cooling discussion

Posted: Fri Sep 15, 2017 1:59 pm
by scimjim
Where is the "good air circulation" in a Ford engine bay then?

Essex V6 Cooling discussion

Posted: Fri Sep 15, 2017 2:01 pm
by scimjim
Landy109s2a wrote:
Fri Sep 15, 2017 11:00 am
:roll: The age old problem with the Essex V6 fitted into the Reliant Scimitar."OVERHEATING".an issue from day one of manufacturer.
And this is in a TVR, not a Scimitar.

Essex V6 Cooling discussion

Posted: Fri Sep 15, 2017 6:27 pm
by V6pushfit
Yes 1970 Tuscan V6 and maverick sister to your Scims. Very similar lack of ventilation but this happens when the bonnet is open and also the manifold heat wrapping is very effective. At the weekend I'll shield the coil and see if I can change the distributor position so at least I can retard/advancing not just retard, and also richen the mixture.....

Essex V6 Cooling discussion

Posted: Mon Sep 18, 2017 7:37 am
by V6pushfit
Didn't get a chance over the weekend, but I'm also going to try something else: the antifreeze I put in is about 50% - I'll reduce it to 25% and add the Redline 'Wetter Water'.Both of these should increase the systems capacity to remove heat, and it may just tip the balance.

Essex V6 Cooling discussion

Posted: Mon Sep 18, 2017 7:48 am
by scimjim
I thought it was an engine bay temperature problem? If the engine coolant isn't overheating, water pump and coolant won't affect that.

Essex V6 Cooling discussion

Posted: Mon Sep 18, 2017 8:39 am
by V6pushfit
The manifold wrapping had reduced the bay temperature a lot but there's still vapourisation. As I mentioned it's on idling after a run so my theory is if the pump and coolant are more effective it should help as the inlet manifold should be a tad cooler?

Essex V6 Cooling discussion

Posted: Mon Sep 18, 2017 9:01 am
by scimjim
Have you got a spacer plate under the carb? Fuel vaporisation in U.K. is almost always a fault with pipe routing or owner modifications. Underbonnet temps in a standard setup (inc 200bhp engines) won't cause vaporisation alone IMO.

Essex V6 Cooling discussion

Posted: Mon Sep 18, 2017 9:04 am
by V6pushfit
Spacer plate in place, and pipes routed well and also now wrapped with heat protection. Fuel regulator keeps quite cool.

'Owner modifications' - yes if it includes timing, coolant or something else !

Essex V6 Cooling discussion

Posted: Mon Sep 18, 2017 9:41 am
by scimjim
Once you've confirmed timing and mixture you will be closer to confirming/denying fuel vaporisation.

Essex V6 Cooling discussio

Posted: Mon Sep 18, 2017 12:40 pm
by scimjim
Apologies if it's sucking eggs but thinking aloud, back to basics:

Fuel vaporisation won't occur in European temperatures (including sat in traffic for ages outside Le Mans in the mini-heatwave of 2010 - with a tank full of their finest E10 :D ) in a standard setup.

Underbonnet temps are a byproduct of two main things (assuming coolant temp in the block is pretty constant) - radiator output and exhaust manifold temps.

The cooling system can mask mixture or timing problems by maintaining the coolant at the correct temp but increasing radiator output temp.

Incorrect mixture and timing can raise exhaust manifold temp dramatically (to the point of glowing red!)

To get true vaporisation, you need to boil the contents of the carb float chamber completely (could happen with engine turned off after long enough at a high enough temp), or boil the fuel as it comes through the jets in the carb (to do either of these, the carb would have to be very, very hot!) or boil enough fuel in the pipes to prevent fuel getting to the float chamber - no mean feat at idle.

Apart from mixture and timing, main causes are probably incorrectly routed fuel pipes, low fuel pressure, modified/faulty radiator ducting.

Similar symptoms could be a fault in the ignition side of things?

Fitting a bilge pump in the engine bay certainly won't cure it :-)

Essex V6 Cooling discussion

Posted: Mon Sep 18, 2017 12:59 pm
by AJL Electronics
scimjim wrote:
Mon Sep 18, 2017 12:40 pm
Apart from mixture and timing, main causes are probably incorrectly routed fuel pipes, low fuel pressure, modified/faulty radiator ducting.
Also perished fuel pipes, especially under a veicle where they are easy to inspect / replace. I have seen that many times on Scimitars, no reason why the TVR shouldn't have the same issues.

Essex V6 Cooling discussion

Posted: Mon Sep 18, 2017 1:13 pm
by scimjim
Hmm, possibly but they normally show up as lack of power or spluttering when driving first, not at idle when fuel demand is lowest?

Essex V6 Cooling discussion

Posted: Fri Sep 22, 2017 10:13 am
by V6pushfit
Agreed the cooling system can certainly mask timing issues, and the timing will be looked into. The car starts and drives faultlessly and can idle for a long time without issue until the temperature creeps up, and on a long hard run is without issue as well its the stopping when hot that leads to temperature creep and stalling.
I have a WW2 jeep which suffers vapourisation on a hot day so yes its not that uncommon and in that case its partly due to fuel feed route and partly carb position over the exhaust manifold.

Essex V6 Cooling discussion

Posted: Wed Sep 27, 2017 12:10 am
by Dennis Nicholas
Landy109s2a
Strange.....I never had the overheating problem on my standard SE6a......whatever the weather......standing still or moving. No mods were done for venting....it was just a standard set up. Overheating not an age old problem.......the problem is usually down to something else ...like blocked radiator, too much muck in block, blocked heater matrix etc.