Still Having cooling problems
Discussion
The ‘Gaydon Supercar Sunday’ thread has gone a little off topic but the issue of overheating is still an important one so I thought I’d start another thread and put in my two pennies worth.
I too have to agree with Stig that there are a number of things which can or should be done to address high water temp at low speed or when stationary. Last year with standard set up I overheated several times and was forced to pull over to avoid damage when water temp soared from 80C to above 105C (Oil temp was raised slightly but to a lesser extent) and it then continued to climb for a short time once the engine was switched off. That was despite switching off the Air Con and switching the heater on, to get as much water through Radiator as possible (It was a little hot in the car at this point)
I have since found the following all helped to some degree.
1) Removed grill behind radiator fans and rear grill around exhausts.
2) Up rated radiator fans to 'Pacet' with pull twice the capacity of air than the stock items
3) Fitted additional 8” 'Pacet' fan to oil cooler (this moves air through engine bay)
4) Ceramically coated complete exhaust system
5) Thoroughly bled coolant system to remove any trace of an airlock
6) Fan override switch for radiator and Oil cooler for use when approaching slow traffic. It is much easier to keep cool rather than lower temp once already hot.
7) Replaced Accelerator cable with better Teflon lined cable. (Although this does not directly affect the temp the old one used to stick on when hot thus increasing the idle speed)
The most difficult but probably the most important of these was bleeding the system to get all the air out. Just when I thought I had got it all out I followed the advice in a previous posting (sorry but I can’t credit the writer with the good advice as I forgot who it was) and jacked the back of the car up which seemed to get rid of quite a bit more air. This advice went against my own thoughts as I figured that the swirl pot needed to be raised higher if anything to trap all the air at the front. With the Swirl Pot in mind I have looked at a few cars and wonder if the pots should be raised even higher – especially on the CanAm where they have sometimes appeared to be lower than the top of the engine.
With the above precautions there was a marked improvement in water temperature when I was again stuck in traffic on the way home from LeMans. I was able to keep temp down to about 95C if I switched the Air Con off, and it took considerably longer to get to this temp. Still not satisfied (I wanted the Air Con back on) I opened the rear canopy and crawled along in the mostly stationary traffic. Temp almost immediately dropped to mid 80’s and that was with the Air Con switched back on.
This all points back to the fact it needs more ventilation to let the heat dissipate.
I now intend to swap all mesh on the engine cover with something else.
The sidepod scoops are the part I am unsure of as they will be ineffective at the low speed the overheating occurs at, but I was wondering whether they could be fitted with just the outer skin with just a wire grill on the front instead of the fancy pipe work which I have seen in pictures. Or maybe I should just swap the side Mesh for wire, which will allow the air to move more freely.
At the other end of the spectrum when pushing the car hard or cruising at high speed (about 150mph) the water remains at reasonable temp but the oil temp soars to well over 100 degrees C. Now this is where the scoop may come in useful. – I’m open to ideas and would appreciate any suggestions.
I too have to agree with Stig that there are a number of things which can or should be done to address high water temp at low speed or when stationary. Last year with standard set up I overheated several times and was forced to pull over to avoid damage when water temp soared from 80C to above 105C (Oil temp was raised slightly but to a lesser extent) and it then continued to climb for a short time once the engine was switched off. That was despite switching off the Air Con and switching the heater on, to get as much water through Radiator as possible (It was a little hot in the car at this point)
I have since found the following all helped to some degree.
1) Removed grill behind radiator fans and rear grill around exhausts.
2) Up rated radiator fans to 'Pacet' with pull twice the capacity of air than the stock items
3) Fitted additional 8” 'Pacet' fan to oil cooler (this moves air through engine bay)
4) Ceramically coated complete exhaust system
5) Thoroughly bled coolant system to remove any trace of an airlock
6) Fan override switch for radiator and Oil cooler for use when approaching slow traffic. It is much easier to keep cool rather than lower temp once already hot.
7) Replaced Accelerator cable with better Teflon lined cable. (Although this does not directly affect the temp the old one used to stick on when hot thus increasing the idle speed)
The most difficult but probably the most important of these was bleeding the system to get all the air out. Just when I thought I had got it all out I followed the advice in a previous posting (sorry but I can’t credit the writer with the good advice as I forgot who it was) and jacked the back of the car up which seemed to get rid of quite a bit more air. This advice went against my own thoughts as I figured that the swirl pot needed to be raised higher if anything to trap all the air at the front. With the Swirl Pot in mind I have looked at a few cars and wonder if the pots should be raised even higher – especially on the CanAm where they have sometimes appeared to be lower than the top of the engine.
With the above precautions there was a marked improvement in water temperature when I was again stuck in traffic on the way home from LeMans. I was able to keep temp down to about 95C if I switched the Air Con off, and it took considerably longer to get to this temp. Still not satisfied (I wanted the Air Con back on) I opened the rear canopy and crawled along in the mostly stationary traffic. Temp almost immediately dropped to mid 80’s and that was with the Air Con switched back on.
This all points back to the fact it needs more ventilation to let the heat dissipate.
I now intend to swap all mesh on the engine cover with something else.
The sidepod scoops are the part I am unsure of as they will be ineffective at the low speed the overheating occurs at, but I was wondering whether they could be fitted with just the outer skin with just a wire grill on the front instead of the fancy pipe work which I have seen in pictures. Or maybe I should just swap the side Mesh for wire, which will allow the air to move more freely.
At the other end of the spectrum when pushing the car hard or cruising at high speed (about 150mph) the water remains at reasonable temp but the oil temp soars to well over 100 degrees C. Now this is where the scoop may come in useful. – I’m open to ideas and would appreciate any suggestions.
On the subject of scoops, my thoughts are:
1) I want to fit the Riviera type side scoops, as Andy's Canam's take on them was very positive. The negative point is that I have no intention of paying Riviera what they are asking as its daylight robbery, so I am awaiting the mk2 version from our friend in the US.
2) Its all well and good bringing in a fresh supply of air from the sides, but the air needs a proper flow path with entry point and exit path from the rear clip, otherwise turbulence will be introduced under the hood, which in turn could cancel the cooling effect completely. I have noticed similar to this when being involved in the cooling design of expensive servers in a server room - must have dedicated entry and exit points.
3) I like the rear grille and do not want to remove it so I was wondering how a mould could be made to duct the air out another route - bottom of wheel arches may be? But I don't want to end up creating positive pressure between the car and the road surface. Alternatively how about a grill which is electrically operated to open or tilt at low speeds like a Porsche spoiler?
4) I have been thinking along the lines of a small scoop under the front of the engine compartment floor which draws air up from the road and pushes air flow from the floor and up over the engine and out the back somehow. Has anyone else had these thoughts and what impact will this have on the overal drag of the car ?
5) Some people here have boxed in the air supply to the carb/efi, utilising the top scoop. This is a great idea as it keeps the intake air much cooler. I have also noticed that after a good run
the idle goes lower with the hood closed and can only guess that it is due to the underbonnet air being so hot that it effects the carburration and fueling. I want to do this mod, but only after I have found an alternative fresh air supply for the rear compartment.
6) While at the Kit Car show last Saturday, Clive and I came across an old but beautiful Ultima Sport. A total garage queen, with more pollished bits than a Harley
but under the rear clip the guy had fitted two large diameter electric fans - radiator sized. One at the bottom of the chassis and one at the top where the oil catch pot goes. He claimed that his temperature never goes above 80 degrees in traffic or whatever with the air con on. His motor is good for 400hp allegedly, so it would appear that his mod works. Clive has the details of the car as its well known by its last owner. I'm pretty sure I don't have the room for two fans as my dry sump tank is in the factory recommended position.
So I think the underbody scoop could be the way to go, but I am not a qualified engineer in 'air dynamics and the co-efficient of drag'.
1) I want to fit the Riviera type side scoops, as Andy's Canam's take on them was very positive. The negative point is that I have no intention of paying Riviera what they are asking as its daylight robbery, so I am awaiting the mk2 version from our friend in the US.
2) Its all well and good bringing in a fresh supply of air from the sides, but the air needs a proper flow path with entry point and exit path from the rear clip, otherwise turbulence will be introduced under the hood, which in turn could cancel the cooling effect completely. I have noticed similar to this when being involved in the cooling design of expensive servers in a server room - must have dedicated entry and exit points.
3) I like the rear grille and do not want to remove it so I was wondering how a mould could be made to duct the air out another route - bottom of wheel arches may be? But I don't want to end up creating positive pressure between the car and the road surface. Alternatively how about a grill which is electrically operated to open or tilt at low speeds like a Porsche spoiler?
4) I have been thinking along the lines of a small scoop under the front of the engine compartment floor which draws air up from the road and pushes air flow from the floor and up over the engine and out the back somehow. Has anyone else had these thoughts and what impact will this have on the overal drag of the car ?
5) Some people here have boxed in the air supply to the carb/efi, utilising the top scoop. This is a great idea as it keeps the intake air much cooler. I have also noticed that after a good run
the idle goes lower with the hood closed and can only guess that it is due to the underbonnet air being so hot that it effects the carburration and fueling. I want to do this mod, but only after I have found an alternative fresh air supply for the rear compartment. 6) While at the Kit Car show last Saturday, Clive and I came across an old but beautiful Ultima Sport. A total garage queen, with more pollished bits than a Harley
but under the rear clip the guy had fitted two large diameter electric fans - radiator sized. One at the bottom of the chassis and one at the top where the oil catch pot goes. He claimed that his temperature never goes above 80 degrees in traffic or whatever with the air con on. His motor is good for 400hp allegedly, so it would appear that his mod works. Clive has the details of the car as its well known by its last owner. I'm pretty sure I don't have the room for two fans as my dry sump tank is in the factory recommended position. So I think the underbody scoop could be the way to go, but I am not a qualified engineer in 'air dynamics and the co-efficient of drag'.
If you are going to tackle the problem throughly I think you need to work out why the current system isn't working. You need three ingredients: adequate water flow through the radiator, adequate cold air flow through the radiator, and a radiator capable of connecting the two together. If you measure the water temperature before and after the radiator, and the air temperature before and after the radiator, this will enable you to work out whether the problem is with the air flow, water flow or radiator.
Chewy - regarding having the clip open, I noticed that this solved the problem, that's what led me to getting the exhausts cermakromed. I looked into putting additional vents into the canopy but didn't want to mess about with the bodywork too much.
Anyway, mine's good as gold now and seeing as it's got a big lump of radiating metalwork on top of the typical engine, you should be ok
Anyway, mine's good as gold now and seeing as it's got a big lump of radiating metalwork on top of the typical engine, you should be ok
The most effective thing I did to reduce water temp was fitting the oil cooler..... after fitting this I never had a problem with overheating....
BUT
I did see a drop in water temp from fitting the side scoops (but not in trafic).
Also I had an air temp sensor in the engine bay and found that the side scoop reduced under clip temperatures massivelly on the move and I ALSO saw a significant reduction after wrapping the headers (I'd say the coating would be even more effective).
Andy
BUT
I did see a drop in water temp from fitting the side scoops (but not in trafic).
Also I had an air temp sensor in the engine bay and found that the side scoop reduced under clip temperatures massivelly on the move and I ALSO saw a significant reduction after wrapping the headers (I'd say the coating would be even more effective).
Andy
cooling is also a issue on our can-am 2mins in traffic and its pushing 100 ,where did all you guys get your uprated fans from and what did you order size ect,only been on road for 3weeks still trying to get all these noggles sorted, know what you mean about tool kit garage is empty !!!would like to go for run on sunday anybody going any where?
The problem of overheating in traffic has been a perennial problem with Ultimas (and most other mid-engine cars) from the beginning. The early "Sports" was very prone to overheat and the factory put a lot of effort into making its successor, the GTR, more traffic friendly which it undoubtedly is. Unfortunately, people keep putting bigger and bigger engines in these cars which means more and more heat to dissipate.
When I built my "Sports" in the late 90's, I made a number of changes to the design of the cooling system which have been described and illustrated in the first few additions of "Ultimatum" (anybody remember that?) so I won't go over them again except to say that putting in an extra radiator and two engine bay extraction fans were probably the most effective mods in preventing my car from overheating in the 5 years that it has been on the road. On one memorable run down to Le Mans, which included an absolute crawl through Rouen on a very hot day, the highest temperature I saw on my Stack readout during the whole trip was 87C. My pal, travelling behind in another "Sports" also Stack equiped, saw 115C: yes 115. He couldn't stop because he didn't know the way and didn't have a map but that's another story. 87C is fine but my "Sports" has a more or less standard 350 Chevvy HO engine which was dyno'd at 332 bhp (ie about half the power that some of you guys are running).
I'm building a GTR at the moment and have just taken delivery of the engine, a 427 sbc with efi from AS. I now have to cool something over 500 bhp. To do this, I again intend to install a second radiator (in the n/s side pod). This will be fed via a motorised 3 way valve situated on the output side of the swirl pot. During normal running, this radiator will not be used and the coolant will take the normal route but if the temperature begins to exceed say 85/90C, I can open this valve from the cockpit and bring in the second radiator. Some sort of valve is necessary so as to isolate this second radiator and prevent the engine from running too cool when the ambient temperature is low. I shall again be fitting the 2 engine bay extraction fans as in the "Sports" and, if I can find somewhere to put it, an oil cooler with thermostatic control.
Belt and braces? For sure but I don't want nightmares about getting caught in one of those monumental bank holiday traffic jams on my local by-pass, the M25.
>> Edited by Alan 2 on Wednesday 23 June 21:17
When I built my "Sports" in the late 90's, I made a number of changes to the design of the cooling system which have been described and illustrated in the first few additions of "Ultimatum" (anybody remember that?) so I won't go over them again except to say that putting in an extra radiator and two engine bay extraction fans were probably the most effective mods in preventing my car from overheating in the 5 years that it has been on the road. On one memorable run down to Le Mans, which included an absolute crawl through Rouen on a very hot day, the highest temperature I saw on my Stack readout during the whole trip was 87C. My pal, travelling behind in another "Sports" also Stack equiped, saw 115C: yes 115. He couldn't stop because he didn't know the way and didn't have a map but that's another story. 87C is fine but my "Sports" has a more or less standard 350 Chevvy HO engine which was dyno'd at 332 bhp (ie about half the power that some of you guys are running).
I'm building a GTR at the moment and have just taken delivery of the engine, a 427 sbc with efi from AS. I now have to cool something over 500 bhp. To do this, I again intend to install a second radiator (in the n/s side pod). This will be fed via a motorised 3 way valve situated on the output side of the swirl pot. During normal running, this radiator will not be used and the coolant will take the normal route but if the temperature begins to exceed say 85/90C, I can open this valve from the cockpit and bring in the second radiator. Some sort of valve is necessary so as to isolate this second radiator and prevent the engine from running too cool when the ambient temperature is low. I shall again be fitting the 2 engine bay extraction fans as in the "Sports" and, if I can find somewhere to put it, an oil cooler with thermostatic control.
Belt and braces? For sure but I don't want nightmares about getting caught in one of those monumental bank holiday traffic jams on my local by-pass, the M25.
>> Edited by Alan 2 on Wednesday 23 June 21:17
Glad to see the factory responding to some of the experiences of other builders. Just a couple of things to add. Many of us with the older Sports and Spyders are probably using 4 row radiators not 5 row as the factory now supply. Also a lot of people have a misconception about the operating coolant temp of a smallblock chevy. Install a 180 deg. F stat and most freak when it doesn't run near 180 deg. F(82 c). If the factory is getting 90 deg. c in traffic with their demonstrators, with your UK ambient temps, then I feel pretty fortunate to see cooling temps in this same neighborhood with my Texas temps and smaller 4 row radiator. Lets see, Yahoo Weather, says you should see a high of about 15 deg. C at the factory with light rain, and here in South Texas we also have light rain (not a common summer phenomena) and a high temp of 30 today.
Humidity for you guys is 77% and for me today its 97%. Up until now, I haven't really had any cooling issues. I would be a little concerned if the temp rose and never stopped rising while in traffic or at speed. At idle, with aircon running, with a temp of 30 deg., my water temp at idle stays at 90 deg c. The first day of summer just began for us this week. The real test for me will come in August in traffic, but then again Death Valley is seeing around 45 deg. C today without rain. So if you didn't have troubles in Death Valley, I probably shouldn't have them here in traffic. South Texas is no death valley, but their avg. yearly hi temp is 32 C and mine is 27 C for the year. Their summers are hotter, my winters don't fall off as much. I'll let you know how I fair through August, but it sounds like I'm running my car (in some of the higher ambient air temps of most owners without problems. A couple of things that may have helped, is that I did flush my radiator after the first hundred miles (lots of rust in the cooling passages of some of these older blocks that aren't cleaned properly) and I also run water from all 4 water jackets on my intake manifold to the thermostat. The only trouble I've had lately is a hot start issue, but I am about to test a new battery and if that doesn't work I may try running two of the Odyssey PC680s instead of one.
Cheers!
-Mack
Humidity for you guys is 77% and for me today its 97%. Up until now, I haven't really had any cooling issues. I would be a little concerned if the temp rose and never stopped rising while in traffic or at speed. At idle, with aircon running, with a temp of 30 deg., my water temp at idle stays at 90 deg c. The first day of summer just began for us this week. The real test for me will come in August in traffic, but then again Death Valley is seeing around 45 deg. C today without rain. So if you didn't have troubles in Death Valley, I probably shouldn't have them here in traffic. South Texas is no death valley, but their avg. yearly hi temp is 32 C and mine is 27 C for the year. Their summers are hotter, my winters don't fall off as much. I'll let you know how I fair through August, but it sounds like I'm running my car (in some of the higher ambient air temps of most owners without problems. A couple of things that may have helped, is that I did flush my radiator after the first hundred miles (lots of rust in the cooling passages of some of these older blocks that aren't cleaned properly) and I also run water from all 4 water jackets on my intake manifold to the thermostat. The only trouble I've had lately is a hot start issue, but I am about to test a new battery and if that doesn't work I may try running two of the Odyssey PC680s instead of one.
Cheers!
-Mack
Overheating - owner response
No doubt that all of the points the factory lists are correct and important and if not respected the cooling system can´t work properly and the motor will overheat.
There is also no doubt that the Ultima cooling system is very effective WHEN THE CAR MOVES. I have no doubt that it behaves very well even in the Death Valley if it does not sit in a traffic jam, but these are probably not very frequent there. When I was driving last year at highway speeds, even on the hottest days the water temp. was not rising higher than 60-70 degrees which is even too low for my taste but shows that the cooling system is more than adequately designed.
Problems occur once the cars are stationary and it is hot outside. Most scaring is that the temperature continues to rise well above 100 or 110 degrees, and is still rising, until you panic and switch the motor off. When opening then the rear canopy it is obvious that the reason for this situation is that the hot air is sitting there. You can even feel on your back that something is really getting hot behind you.
Our 4 cars in the Czech Republic are all factory build with AS engines and - as far as I know - had exactly the same problem from new. And I believe that at this point none of the problems as listed by the factory have been an issue on these cars.
What I would recommend to the factory:
Why not offer the ceramic coating as a factory option, it is really worth the money IMO. Maybe you could also offer some effective fan solution for slow traffic situations, at least a fan for the oil cooler. My personal wish would be also a factory option for a more efficient oil cooler solution (i.e. directly in the air stream), but I would agree that a big part of the need for that can be attributed to the fact that the engines in the Ultimas get bigger and bigger, whereas for the std. 400 HP engines the current solution is most probably sufficient.
Just my opinion,
Peter
No doubt that all of the points the factory lists are correct and important and if not respected the cooling system can´t work properly and the motor will overheat.
There is also no doubt that the Ultima cooling system is very effective WHEN THE CAR MOVES. I have no doubt that it behaves very well even in the Death Valley if it does not sit in a traffic jam, but these are probably not very frequent there. When I was driving last year at highway speeds, even on the hottest days the water temp. was not rising higher than 60-70 degrees which is even too low for my taste but shows that the cooling system is more than adequately designed.
Problems occur once the cars are stationary and it is hot outside. Most scaring is that the temperature continues to rise well above 100 or 110 degrees, and is still rising, until you panic and switch the motor off. When opening then the rear canopy it is obvious that the reason for this situation is that the hot air is sitting there. You can even feel on your back that something is really getting hot behind you.
Our 4 cars in the Czech Republic are all factory build with AS engines and - as far as I know - had exactly the same problem from new. And I believe that at this point none of the problems as listed by the factory have been an issue on these cars.
What I would recommend to the factory:
Why not offer the ceramic coating as a factory option, it is really worth the money IMO. Maybe you could also offer some effective fan solution for slow traffic situations, at least a fan for the oil cooler. My personal wish would be also a factory option for a more efficient oil cooler solution (i.e. directly in the air stream), but I would agree that a big part of the need for that can be attributed to the fact that the engines in the Ultimas get bigger and bigger, whereas for the std. 400 HP engines the current solution is most probably sufficient.
Just my opinion,
Peter
Have you thought about water spraying under the rear bonnet?
Or under carburateur instead of richening mixture?
<a href="http://www.aquamist.co.uk">www.aquamist.co.uk</a>
I will.
Because my 600+HP AS engine is pig rich on idle.
>> Edited by Igor+ on Thursday 24th June 18:45
Or under carburateur instead of richening mixture?
<a href="http://www.aquamist.co.uk">www.aquamist.co.uk</a>
I will.
Because my 600+HP AS engine is pig rich on idle.
>> Edited by Igor+ on Thursday 24th June 18:45
I have cooling problems in traffic, and I can tick off most of the factory list as not being a problem. I do not have a five row radiator though, but then neither did the car that crossed Death Valley, but this picture from the Ultima Sports website might explain why they didn't have a problem (speedo seems slightly north of 100mph )
What is the procedure for lowering the idle rpm / adjusting the idle mixture? Do you just adjust the idle speed screw to the lowest stable RPM then richen up the idle screws till your eyes water? Or do you richen, reduce speed, etc until you get to the lowest RPM? I'm concerned that with my Edelbrock carb (does anyone else have one?) richening the idle will upset the light throttle, low revs situation, where the idle circuit has more affect on the total fuelling. Don't know if the Holley carbs work the same way.
When I'm travelling in convoy with other cars, I already get complaints that my idle emmisions are noxious
, shame none of them can get past to get out of my hydrocarbons. One caterham driver even suggested his car could idle with just the unburnt fuel in my exhaust.
) What is the procedure for lowering the idle rpm / adjusting the idle mixture? Do you just adjust the idle speed screw to the lowest stable RPM then richen up the idle screws till your eyes water? Or do you richen, reduce speed, etc until you get to the lowest RPM? I'm concerned that with my Edelbrock carb (does anyone else have one?) richening the idle will upset the light throttle, low revs situation, where the idle circuit has more affect on the total fuelling. Don't know if the Holley carbs work the same way.
When I'm travelling in convoy with other cars, I already get complaints that my idle emmisions are noxious
, shame none of them can get past to get out of my hydrocarbons. One caterham driver even suggested his car could idle with just the unburnt fuel in my exhaust.Ultima Factory said:I had overheating problems in traffic in the hot weather in Le Mans. I spoke to Ted and Richard in the circuit on Sunday afternoon who suggested the above, and decided that rather than risk the traffic jams on the way out of the circuit on what was a hot afternoon I'd have a fiddle in the car park. So after warming her up I just slowed the idle down, adjusted the idle mixture screw to the optimal position then richened it up till I found the spot where it started to deteriorate. I then set it to the mid-point between the two, and repeated on the other side. Then reset the idle speed.
We are confident that a lower idle speed and richer idle mixture will cure this high temperature rise in heavy traffic.
This seemingly tiny adjustment to settings does have a significant influence on the temperature at idle.
As expected the traffic was heavy on the way into town, but the water temp didn't reach 90, whereas it was going up above 100 before.
It was still like sitting in a greenhouse in the cockpit, but I was happy
The problem remaining is getting a compromise on the idle speed so the engine doesn't die with the aircon on. I didn't really appreciate how much power an aircon compressor takes until I experienced how much it pulls the idle down on a seriously grunty 6.3 Chevy. Much of this I suppose depends on the cams in the individual engine. I suspect trying to maintain a 750rpm idle speed on my 383 450bhp As engine is a bit optimistic.
While the car is moving I've never experienced any problems, even when it gets hot the temp comes down very quickly as soon as you get above 30mph.
I have a persistent problem with air build up in system. Been better since I bypassed heater circuit, but still under duress (prolonged traffic or hard track use) it has a tendency to eventually displace water from expansion tank, leaving air in circulating system until result is rapid fluctuations in temp (80-100 deg) as pockets of air get into pump.
Basic cooling I think is fine, even in traffic with air con on, if only I could bleed the system properly and keep it that way. Tried all the usual tricks, jacking rear, running engine while filling etc, but every time if temp rises much over 80 deg, too much fluid ends up getting displaced into expansion tank voiding the circulating system. I think my plumbing is exactly as per build CD. Definitely not head gasket leak. I intend to raise the swirl pot a few inches to see if this helps. Any ideas?
Basic cooling I think is fine, even in traffic with air con on, if only I could bleed the system properly and keep it that way. Tried all the usual tricks, jacking rear, running engine while filling etc, but every time if temp rises much over 80 deg, too much fluid ends up getting displaced into expansion tank voiding the circulating system. I think my plumbing is exactly as per build CD. Definitely not head gasket leak. I intend to raise the swirl pot a few inches to see if this helps. Any ideas?
GDR,
Sort of dumb, but have you flushed your radiator lately? I'm wondering if the system is backing up at the radiator some and forcing more coolant than it should into the reservoir. When I flushed my radiator recently all kinds of crap came out. I took it out of the car to do this and set it standing where the coolant intake side was on the ground and a hose going into radiator outlet on the top. This is an area to watch for those of us who've installed older engines. AS should be hot tank dipping their blocks to clean out the cooling passages, but you just never know with other engine builders.
Cheers!
-Mack
Sort of dumb, but have you flushed your radiator lately? I'm wondering if the system is backing up at the radiator some and forcing more coolant than it should into the reservoir. When I flushed my radiator recently all kinds of crap came out. I took it out of the car to do this and set it standing where the coolant intake side was on the ground and a hose going into radiator outlet on the top. This is an area to watch for those of us who've installed older engines. AS should be hot tank dipping their blocks to clean out the cooling passages, but you just never know with other engine builders.
Cheers!
-Mack
Thanks for ideas guys. Certainly the restriction to flow may be an issue either due to crap in radiator or thermostat. I noticed that when revved hard, my upper silicon hose was getting sucked in a bit, since replaced with ally pipe plus short bits of silicon. Might actually be sucking air in via expansion tank. Will investigate and keep you posted.
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