Super-kewl PTP Evo 220 K 1800 engine...is it too Kewl?
Discussion
I simply can't believe what my oil temp gauge is trying to tell me. It claims my max oil temperature, in SW France, in June, when it's like 30 something °C, is no more than around 80°C.
b
ks it is. I think it's got to be a problem with the sender, or possibly the (new) Smiths manual temp gauge. It has a long aeroquip hose running from the sender, which is fitted in a Mocal sender block, probably with brass thread adapter, and the Mocal block is in the hose returning oil from the sump scavange pump to the top of the Brise kidney tank, sitting in front of the motor.
I'm going to take it for a few quick hillclimb sections and then remove the bonnet and check the tank itself with a thermometer gun.
How the hell could it be bloody 80°C? It's crazy...it's so hot today, when I took my Grinnall Scorpion 3 on a 14km round trip for fuel, the red light for overheat was showing....it didn't even do that in August 2003 in the Sahara!
But the Kewl Cateringvan stays....at 80°C.
I do not believe it.
Scorp in the North Sahara, Aug 2003 (the heatwave)
b
ks it is. I think it's got to be a problem with the sender, or possibly the (new) Smiths manual temp gauge. It has a long aeroquip hose running from the sender, which is fitted in a Mocal sender block, probably with brass thread adapter, and the Mocal block is in the hose returning oil from the sump scavange pump to the top of the Brise kidney tank, sitting in front of the motor.I'm going to take it for a few quick hillclimb sections and then remove the bonnet and check the tank itself with a thermometer gun.
How the hell could it be bloody 80°C? It's crazy...it's so hot today, when I took my Grinnall Scorpion 3 on a 14km round trip for fuel, the red light for overheat was showing....it didn't even do that in August 2003 in the Sahara!
But the Kewl Cateringvan stays....at 80°C.
I do not believe it.
Scorp in the North Sahara, Aug 2003 (the heatwave)
Edited by unclefester on Tuesday 13th June 18:19
Since the last post I've tested it by doing several local hillclimb courses and the temperatures on the gauge are right. I'll keep an eye open for a smaller oil tank, but what I can do now is simply insulate it.
Also fit a couple of Wolverine preheat pads.
Anyone know the best source for insulating jackets for dry sump kidney tanks? I'll check with Brise tomorrow, I need to sort this urgently.
edit I ordered some alu reflective twinwall sheet with bubble cells. A few layers should sort it's problem I think, and a couple of Wolverine pre-heater pads will help.
Also fit a couple of Wolverine preheat pads.
Anyone know the best source for insulating jackets for dry sump kidney tanks? I'll check with Brise tomorrow, I need to sort this urgently.
edit I ordered some alu reflective twinwall sheet with bubble cells. A few layers should sort it's problem I think, and a couple of Wolverine pre-heater pads will help.
Edited by unclefester on Wednesday 14th June 08:54
In my experience, oil pre-heat pads have almost zero effect. You run them for ages heating up the DS tank oil, then start the engine and run the slightly warm oil through the cold engine and it comes out cold!
Out of interest, I didn't trust the oil temp read from from a laser tyre temp gun - I had the other problem - overheating oil and the laser gun showed a very much lower temp.
Bert
Out of interest, I didn't trust the oil temp read from from a laser tyre temp gun - I had the other problem - overheating oil and the laser gun showed a very much lower temp.
Bert
By the way, I don't think you need to be running oil at 100 degrees to get the water out. I think it will 'evaporate' at lower temps. Having said that, I think I would want to have my oil hotter than 80. I would want it in the range 90-110. So I think you are right to get it running hotter.
Bert
Bert
BB, I've read that while the Wolverine pre-heat pads will heat the contents of a DS tank up to 50°C....it didn't state what volume, or how long it took, as you say the heat is quickly used up in heating the engine components once started. It helps, but probably the main difference is it heats the oil enough to get decent flow in the first few seconds.
I agree that 100°C all the time the engine is running is equally not necessary....after all, as you say, water is going to be evaporating at well under 100°. The other thing to remember is that while a kg of fuel being burned will produce a kg of water, the vast majority is ejected in the exhaust.
I don't know what percentage goes into the oil, it must be minuscule.
My 'oil conditioner' has a deep cellulose long fibre matrix which removes some water, as well as keeping particles out of the oil, so I have less of a worry with the oil turning acidic.
Also, it's an Amsoil synthetic with a high base composition expressly designed to keep acid formation under control.
I've looked and I do have room for two or three layers of thinwall insulation.
I'll see how it responds to this, before blowing money on pads.
If it fails, I will sell the engine and DS system to someone who wants to race it, and reinstall my tuned 1600K on Jenveys....
I agree that 100°C all the time the engine is running is equally not necessary....after all, as you say, water is going to be evaporating at well under 100°. The other thing to remember is that while a kg of fuel being burned will produce a kg of water, the vast majority is ejected in the exhaust.
I don't know what percentage goes into the oil, it must be minuscule.
My 'oil conditioner' has a deep cellulose long fibre matrix which removes some water, as well as keeping particles out of the oil, so I have less of a worry with the oil turning acidic.
Also, it's an Amsoil synthetic with a high base composition expressly designed to keep acid formation under control.
I've looked and I do have room for two or three layers of thinwall insulation.
I'll see how it responds to this, before blowing money on pads.
If it fails, I will sell the engine and DS system to someone who wants to race it, and reinstall my tuned 1600K on Jenveys....
My insulation still hasn't arrived so I improvised with a sheet of foam camping met. Not the best in terms of insulation I think but at least I now have a pattern to work to.
Tested last night, it seems to help as the oil got warmer quicker, but it still wasn't showing over 80°C.
I'm off to see someone who has a Caterham with full race/DS Vauxhall engine to see how he copes, and as I'll be on my own I'll try and get the thing a bit hotter than last night when my wife was acting as a verbal braking system.....
Later...
That made very little difference. I think it warmed up quicker but I did half an hour at 80mph on the autoroute and temp was just over 80°C.
My buddy, who I went to see, has a 260bhp VX engine in his Caterham, and he told me he doesn't see over around 80°C on the road, but this seems to be oil temperature just before it goes into the engine...that's about 40°C more than I think mine enters at.
However, his DS tank is half the size of mine and is near the un insulated exhaust headers at the back of the engine bay.
I'm going to try sucking 4 litres out now.
I removed 2.5 litres.
It runs a bit hotter....I'll drop the rest of the oil tomorrow and see how much is really in there, then replace 6.5 litres.
Tested last night, it seems to help as the oil got warmer quicker, but it still wasn't showing over 80°C.
I'm off to see someone who has a Caterham with full race/DS Vauxhall engine to see how he copes, and as I'll be on my own I'll try and get the thing a bit hotter than last night when my wife was acting as a verbal braking system.....
Later...
That made very little difference. I think it warmed up quicker but I did half an hour at 80mph on the autoroute and temp was just over 80°C.
My buddy, who I went to see, has a 260bhp VX engine in his Caterham, and he told me he doesn't see over around 80°C on the road, but this seems to be oil temperature just before it goes into the engine...that's about 40°C more than I think mine enters at.
However, his DS tank is half the size of mine and is near the un insulated exhaust headers at the back of the engine bay.
I'm going to try sucking 4 litres out now.
I removed 2.5 litres.
It runs a bit hotter....I'll drop the rest of the oil tomorrow and see how much is really in there, then replace 6.5 litres.
Edited by unclefester on Saturday 17th June 18:27
It seems I was wildly out when I said the system holds 12 litres. Checked yesterday and tank plus sump is only 5.5 litres, with more in the pipes and the oil conditioner holds about another litre.
I put the oil in 3 years back in someone else's garage, there were a lot of interruptions, people wandering around, could be someone swiped 6 litres out of my 12 litre box of Amsoil?
I also had a response from an engine builder buddy who has vast K engine experience and has designed a K engine DS system, and he says it's impossible that my IR gun gradient readings are right....it can't have a temp drop of more than 10°C with no oil cooler involved.
My oil conditioner will have only minimal cooling effect as there's no airflow through it....it's not a heat exchanger.
So I'm less concerned than I was, I'll check using thermo-strips on the tank to see what's really going on.
I put the oil in 3 years back in someone else's garage, there were a lot of interruptions, people wandering around, could be someone swiped 6 litres out of my 12 litre box of Amsoil?
I also had a response from an engine builder buddy who has vast K engine experience and has designed a K engine DS system, and he says it's impossible that my IR gun gradient readings are right....it can't have a temp drop of more than 10°C with no oil cooler involved.
My oil conditioner will have only minimal cooling effect as there's no airflow through it....it's not a heat exchanger.
So I'm less concerned than I was, I'll check using thermo-strips on the tank to see what's really going on.
Running at a steady 80mph is going to generate the square root of not much heat in comparison with running WoT properly on track, so I'm not surprised the oil doesn't get hotter than 80.
Also IR thermometers don't work too well on shiny surfaces so won't measure the tank temp well. I've even found that temp strips stuck on the DS tank read much lower than the bulk temp from the oil temp gauge.
Bert
Also IR thermometers don't work too well on shiny surfaces so won't measure the tank temp well. I've even found that temp strips stuck on the DS tank read much lower than the bulk temp from the oil temp gauge.
Bert
I didn't know that about IR guns, but was thinking that the angle at which the beam hits the polished surface of the ali tank makes a difference.
When I took the gradient readings down the side of the tank, the highest was from about 4" below the top, ie 1" below the baffle, where the oil surface is.
As I took the lower readings the angle dropped from near 90° to a lot less...as did the temperature reading!
When I took the gradient readings down the side of the tank, the highest was from about 4" below the top, ie 1" below the baffle, where the oil surface is.
As I took the lower readings the angle dropped from near 90° to a lot less...as did the temperature reading!
unclefester said:
I didn't know that about IR guns, but was thinking that the angle at which the beam hits the polished surface of the ali tank makes a difference.
When I took the gradient readings down the side of the tank, the highest was from about 4" below the top, ie 1" below the baffle, where the oil surface is.
As I took the lower readings the angle dropped from near 90° to a lot less...as did the temperature reading!
There's no beam from the pyrometer. The laser is just to help you aim. When I took the gradient readings down the side of the tank, the highest was from about 4" below the top, ie 1" below the baffle, where the oil surface is.
As I took the lower readings the angle dropped from near 90° to a lot less...as did the temperature reading!
The pyrometer picks up the level of IR radiation emitted from whatever it's aimed at.
The colour and finish of the surface changes the accuracy though, so an alloy/stainless tank will be less accurate than a black body.
Also the pyrometers only tell you the temperature at the surface, though this will be related to the contents, of course.
REALIST123 said:
There's no beam from the pyrometer. The laser is just to help you aim.
The pyrometer picks up the level of IR radiation emitted from whatever it's aimed at.
The colour and finish of the surface changes the accuracy though, so an alloy/stainless tank will be less accurate than a black body.
Also the pyrometers only tell you the temperature at the surface, though this will be related to the contents, of course.
I'm aware the laser is so you can tell exactly where you're taking the reading, as on a hunting rifle...but the fact I was getting a 30°C difference as the angle changed tends to indicate that a less directly perpendicular angle from the target surface results in a lower reading.The pyrometer picks up the level of IR radiation emitted from whatever it's aimed at.
The colour and finish of the surface changes the accuracy though, so an alloy/stainless tank will be less accurate than a black body.
Also the pyrometers only tell you the temperature at the surface, though this will be related to the contents, of course.
The other explanation would require a near 40°C drop in temperature from the oil returning from the sump to the tank, and the oil leaving to the engine from the bottom of the tank.
I'm assured this is impossible by people who should know, having done experiments with oil circulation in tuned K series engines while designing one of the K series dry-sump systems. They reckon a max drop of 10°C, assuming no oil cooler involvement.
unclefester said:
REALIST123 said:
There's no beam from the pyrometer. The laser is just to help you aim.
The pyrometer picks up the level of IR radiation emitted from whatever it's aimed at.
The colour and finish of the surface changes the accuracy though, so an alloy/stainless tank will be less accurate than a black body.
Also the pyrometers only tell you the temperature at the surface, though this will be related to the contents, of course.
I'm aware the laser is so you can tell exactly where you're taking the reading, as on a hunting rifle...but the fact I was getting a 30°C difference as the angle changed tends to indicate that a less directly perpendicular angle from the target surface results in a lower reading.The pyrometer picks up the level of IR radiation emitted from whatever it's aimed at.
The colour and finish of the surface changes the accuracy though, so an alloy/stainless tank will be less accurate than a black body.
Also the pyrometers only tell you the temperature at the surface, though this will be related to the contents, of course.
The other explanation would require a near 40°C drop in temperature from the oil returning from the sump to the tank, and the oil leaving to the engine from the bottom of the tank.
I'm assured this is impossible by people who should know, having done experiments with oil circulation in tuned K series engines while designing one of the K series dry-sump systems. They reckon a max drop of 10°C, assuming no oil cooler involvement.
I'm sorry, must have been misled by you saying:
"Was thinking that the angle at which the beam hits the polished surface of the ali tank makes a difference."
I'll leave you to it.
Edited by anonymous-user on Thursday 22 June 08:12
Surely the point of having a laser is to show you at what point you are measuring the temperature?
Are you suggesting that a reading taken at 90° from a surface of polished alu will be identical to one taken at an obtuse angle?
If the angle is in fact not a factor, then the temperature gradient is indeed around 40°C in this tank and the car clearly operates under different thermodynamic laws than any other Caterham on the planet.
Unless there are others out there with the new Brise refrigerated DS tanks fitted!
Are you suggesting that a reading taken at 90° from a surface of polished alu will be identical to one taken at an obtuse angle?
If the angle is in fact not a factor, then the temperature gradient is indeed around 40°C in this tank and the car clearly operates under different thermodynamic laws than any other Caterham on the planet.
Unless there are others out there with the new Brise refrigerated DS tanks fitted!
Edited by unclefester on Thursday 22 June 09:07
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