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Essex V6 Cooling discussion

Posted: Mon Sep 11, 2017 11:28 am
by V6pushfit
The fuel vapourisation is still an issue and part of the investigation has been to replace the water pump - the old one on the left has the impeller more inset than the Burton one on the right which is proud of the flange, the inset will mean the impeller face is further from the back plate so will draw from the sides and be less efficient. The Burton one fits perfectly. This is just a note really so anyone with an inset impeller should be wary of fitting it.
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...it made a slight difference but the old girl still gets too hot so something else is amiss. So I have a question:

Does anyone have the cooling plumbing arrangement for the Essex V6 with auto choke? This is to check that someone hasnt done something daft? Is there a schematic or reliant drawing etc of this?

Essex V6 Cooling discussion

Posted: Mon Sep 11, 2017 12:38 pm
by scimjim
In which car? Reliant plumbed it differently in 5 & 6 series.

Essex V6 Cooling discussion

Posted: Mon Sep 11, 2017 12:57 pm
by Roger Pennington
And other cars may be different again, apologies if I'm wrong, but is yours in a TVR?
FWIW, the Ford Capri used the same system as the 6-series, with the exception that it didn't have the crossflow radiator that Reliant chose to use.

It's difficult to see impeller on the left-hand pump in your photo - is it cast or pressed? The pressed-impeller pumps, are a less good aftermarket option which are generally considered to be inferior, due to the less effective impeller shape and it's proneness to corrosion?

Essex V6 Cooling discussion

Posted: Mon Sep 11, 2017 1:25 pm
by V6pushfit
Its a 1969 TVR Tuscan which used a lot of scim spec parts, and with the zodiac engine. So its a 5 series I suppose.

The impellers are both cast - the left one being inset more as I mentioned so less effective

I'll try to do a hand drawn schematic of the full cooling system and put it on.....

Essex V6 Cooling discussion

Posted: Mon Sep 11, 2017 3:18 pm
by scimjim
So you have a water take off point at the rear of the inlet manifold - near to the brake servo vacuum pipe? And the water pump uses the top inlet (both blanked on the 6 series) and you have a pressurised expansion tank with a large pipe to the rad and vent to the top pipe (stat to rad)?

Essex V6 Cooling discussion

Posted: Mon Sep 11, 2017 3:42 pm
by scimjim
assuming 5 series type then:

The water pump sucks coolant (into the largest inlet) from the bottom of the rad and pushes it into the right hand bank of the block.

coolant flows around the back of the block to the LHS and up into the heads via graduated holes.

when cold, the stat is closed, so coolant travels via the bypass pipe, through the auto choke and back to the water pump top inlet. When the engine warms and the stat opens, the coolant flows from stat, to top of rad, down the rad and is sucked into the water pump again.

The cabin heater is fed from the back of the inlet manifold, round the matrix and back to the water pump rear inlet. If you have a valve, it may bypass this flow or shut it off entirely (both types can be fine).

The expansion tank has a large connection to the top of the rad, a smaller vent tube to the rad top pipe and an overflow pipe at the 10-14 psi cap.

HTH

Essex V6 Cooling discussion

Posted: Mon Sep 11, 2017 5:03 pm
by V6pushfit
An incredibly concise description there Jim. Thanks.

Essex V6 Cooling discussion

Posted: Thu Sep 14, 2017 9:05 pm
by V6pushfit
Water pump done, manifolds wrapped and carb itself seems to be keeping relatively cool. Still getting overheating dammit.
Driving normally all ok, but once warmed up if I stop for say 5-8 minutes then heat builds up and engine splutters and stops.
Any ideas?
Are essex engines known for it?
I did nearly 3 hours motorway driving on Tuesday and all ok until I had to stop at a level crossing.
Car starts and idles really well - but could timing affect it and would too retarded or too advanced give these symptoms?
If it's timing it's possibly a b@@@@rd because there's no anti clockwise travel left due to the vacuum unit touching the thermostat housing and I'm reluctant to take out and refit the distributor in case the pencil drive drops in!! - is this a real possibility?

Sorry about all the the questions!

Essex V6 Cooling discussion

Posted: Thu Sep 14, 2017 9:40 pm
by rebel alliance
The distributor sounds like it's in wrong .I think you will need to refit it and then move the HT leads around ....They do heat up when your not moving do to lack of airflow ,sounds like you need a better electric fan...if the retaining clip is still on the pencil drive you will have no problem removing the distributor

Essex V6 Cooling discussion

Posted: Thu Sep 14, 2017 9:42 pm
by scimjim
Have you got a fairing under the engine? Assuming it IS fuel vaporisation, there must be a reason that the heat isn't escaping properly when you're stationary. Where is the coil mounted - have you checked for fuel and spark when it starts to splutter? The other thing is mixture, if it's lean, it'll get hot at idle. I'd sort the timing first (pencil drive should have a clip at the oil pump to stop it coming out but just take it slowly to check), and confirm mixture before condemning underbonnet heat.

Essex V6 Cooling discussion

Posted: Fri Sep 15, 2017 7:48 am
by Rev Light
Jim, if you recall, I had an issue with stalling/dying at junctions when fully up to temperature, where the car was then really difficult to start. The choke body had rotated slightly on the carb, meaning that the choke was never fully off. When I was at your place you cured the issue by resetting the choke housing, and all has been well ever since.

Cheers

Steve

Essex V6 Cooling discussion

Posted: Fri Sep 15, 2017 8:28 am
by V6pushfit
rebel alliance wrote:
Thu Sep 14, 2017 9:40 pm
The distributor sounds like it's in wrong .I think you will need to refit it and then move the HT leads around ....They do heat up when your not moving do to lack of airflow ,sounds like you need a better electric fan...if the retaining clip is still on the pencil drive you will have no problem removing the distributor
If I refit it the leads should still be in the correct place relative to the distributor, but yes I'll see if I can do it the other way first by rotating and swapping leads although with a protractor it doesnt look like I've got 60 degrees the other way without hitting the head. Good news about the pencil drive I just hope its held fast enough at the bottom !

Essex V6 Cooling discussion

Posted: Fri Sep 15, 2017 8:36 am
by V6pushfit
scimjim wrote:
Thu Sep 14, 2017 9:42 pm
Have you got a fairing under the engine? Assuming it IS fuel vaporisation, there must be a reason that the heat isn't escaping properly when you're stationary. Where is the coil mounted - have you checked for fuel and spark when it starts to splutter? The other thing is mixture, if it's lean, it'll get hot at idle. I'd sort the timing first (pencil drive should have a clip at the oil pump to stop it coming out but just take it slowly to check), and confirm mixture before condemning underbonnet heat.
No fairing but like the SE5/6 limited bonnet vents to get heat away. The manifold wrapping made a HUGE difference to the engine bay background temperatures and I would say they are acceptable now, and not like opening an oven when the bonnet is opened.

The coil is between the rad and the block on a cross member so does get hot with the air from the fan - is that what you were thinking of?

Essex V6 Cooling discussion

Posted: Fri Sep 15, 2017 8:38 am
by V6pushfit
Rev Light wrote:
Fri Sep 15, 2017 7:48 am
Jim, if you recall, I had an issue with stalling/dying at junctions when fully up to temperature, where the car was then really difficult to start. The choke body had rotated slightly on the carb, meaning that the choke was never fully off. When I was at your place you cured the issue by resetting the choke housing, and all has been well ever since.

Cheers

Steve
Interesting one - I believe the auto choke is set correctly and yes its a thing that could get missed as the adjustment is in the rotation. I'll check that too but believe the flaps are fully open when hot.

Essex V6 Cooling discussion

Posted: Fri Sep 15, 2017 11:00 am
by Landy109s2a
:roll: The age old problem with the Essex V6 fitted into the Reliant Scimitar."OVERHEATING".an issue from day one of manufacturer.Ford fitted the V6 to many models of there cars,
Granada,Capri etc.They had very few problems with overheating. WHY, Fords had good air circulation and in the engine bay.Allowing the excessive heat to escape.By contrast
Reliant, fitted the V6 into a fibreglass box engine bay with very poor air circulation.Trapping the heat in the engine bay at the top of the engine.Now you have the carb and fuel inlet
sitting in a hot spot.Owners of the early SE5-SE6,used to solve the problem of overheating by raising the rear of the Scimitar bonnet,by fitting washers between the hinges and bonnet.
This allowed a gap between the bulkhead and the back of the bonnet. Acting as a air vent,allowing the excess heat to escape.Did not look tidy,but the idea worked.On my own 1968 SE5
and now the 1980 SE6a,i cut air vents into the bonnets. RS2000 style.Never had a overheating or fuel evaporation problem since.And yes,i was driving a Scimitar 69/70 period.