Dealing with high temperatures

[Shad]

Last night at Brands was by far the hottest track day I've done in the Caterham and it's the first time I felt uncomfortable with the water and oil temperatures. Admittedly I couldn't tell exactly what the oil temp was (no gauge, just mechanical pressure) but given it was dropping to just 20psi hot idle when I don't normally see below 35psi hot idle, I'm assuming it was very hot and very thin. I also saw less than 35psi through Graham Hill which I haven't done before. Oil level was spot on for a K series with Apollo tank, Caterham/Comma motorsport oil.

 

It was worse when following cars and trying to get past so I think a triple pass rad upgrade could be a good move. What do people do for an oil cooler? Something small in front of the rad or does a laminova serve much the same purpose if the water temp is under control?

 

Cheers

[Graham King]

Shad, I was at Brands last night and it was hot, I saw similar oil pressure figures as you (I assume you have a K-Series). I run a standard Radtec with a QED remote stat and my water temp was fine. I'm not sure the triple pass rad is best for trackdays, I always thought this was designed to work in the restricted airflow when trailing cars during racing rather than at trackdays where this isn't such an issue.

 

Laminova's are a good answer for oil temp, I don't have one as I haven't yet managed to fit one with the QED, but my brother, who was also there last night, does run a laminova. My oil temps reached about 100 last night, whereas his stayed below 90. How much difference this would make to your oil pressure issues I am not sure to be honest, but if I will fit a Laminova if I can find a way to make it fit. I prefer this to an oil cooler to be honest as it also warms the oil in cold weather.

 

Which car were you in by the way, it was a very enjoyable evening.

 

Graham.

[Paul McKenzie]

If you decide to go the oil cooler route, I have a complete kit available here if you want to make me an offer

 

Paul

[SLR No.77]

Shad, you need to just work through things in a structured order ..... you mention you "felt uncomfortable with the water and oil temperatures" - is the coolant temperature definitely an issue or just the oil?

First thing is to fit a second temperature sender, into the side of the Apollo tank, and add a switch between the water and oil gauges to enable the temperature gauge to be used for both. Only then will you really know what's happening.

Secondly, are you running an 88ºC stat? Swap it to 82ºC which should bring the coolant temperature down a little, and in turn this will benefit the oil temp.

Afterwards you can consider bigger spend items such as a new rad and Laminova but start with the basics first - it may be all you need for 99.9% of your car's use.

 

Stu.

[Shad]

Graham: the water temp was highest after a few laps stuck in fast queue of cars so the air flow was definitely restricted which was why my mind went to the triple pass rad. Good to hear about the laminova though. I was in a yellow car with cage, big Caterham vinyl on the back, garage 8 Which one were you? Apologies if we spoke, I think I met a couple of Grahams last night!!

 

Paul: Will take a look, cheers

 

Stu: Appreciate what you're saying. Water was hot, over between 90 and 100 degrees on track. I have the temp sender in the Apollo tank but not hooked up to the gauge, so I am making an assumption there. Experience tells me that hot oil flows at lower pressure (I normally see 35psi hot idle) so to my mind when I see 20psi hot idle it must be running much hotter than usual? I've never seen my oil warning lamp come on around Graham Hill before. I'm running the 82 degree stat already too. And yes it was probably a rare case last night but I'd like to be prepared for all eventualities without going too mad

 

Cheers!

[Paul Deslandes]

if you're losing pressure on the bends then its because oil isn't finding its way to the pick up pipe and you're seeing oil starvation. The only long term solution is drysump unless you can increase the amount of oil in the engine or stop it sloshing around. 20psi at idle, whilst lower than normal, isn't going to harm your engine provided its been run in properly.

If the track was really hot, were you cornering faster with the tyres being stickier than usual? The extra lateral 'g' would throw the oil further up the side of the engine, robbing the pick up pipe in the corners. Keeping temperatures down will help but not really solve the underlying problem.

Years ago I had the same problem with my, then, wet sump Vx, particularly at Goodwood. Believing it to be temperature, I fitted a cooler which helped. I subsequently realised that the cooler had simply added a bit more oil capacity, as does an Apollo tank, but the cooling benefit was minimal.

With drysump all such problems went away.

I'm sure you've done all the mods to improve oil pickup and circulation.

[Shad]

Good point Paul, I hadn't factored in the extra grip last night. I agree that anything short of a dry sump is going to mask the problem, and I *do* want to go dry sump eventually. Maybe now is the time...

 

I'm sure you've done all the mods to improve oil pickup and circulation.

I have no sump foam and have the two/three holes in the gasket. Is there anything else I should be doing?

[Paul Deslandes]

I have little or no knowledge of the K series engine so others would have to advise what else you might do. The mods you've done sound familiar though from earlier posts that I've read.

Dry sump is well worth the money and is reckoned to free up quite a few bhp due to reduced crank oil thrash. Its also cheaper than a trashed engine 😳 😬

[Mankee]

Since you've ditched the foam and done the gasket mod, the only other thing you could try is DVA's oil pump back plate mods: here

 

But this isn't easly practical as you have to remove the cam belt, crank pulley, remove oil pump etc. etc., do the mod and then reassemble and retime the cams.

[Myles]

Not that I run one, but a Laminova has attractions if your rad is up to the job. One of my sevens has an oil-cooler sitting in front of the rad. It's rather over-specified for my usage - keeps the oil nice and cool (helped a bit by the large DS tank) when charging hard - but over-cools the oil when pottering or during cool weather.

 

I do blank it off in the late-summer/Autumn - but it's a faff on this particular car!

[Tony Wright]

Myles, you have a bike engine in your Westie yes?? Reason I ask is I had similar problems today (outside temp over 32c) with my Cat Busa.

 

Pressure seemed fine when driving but dropped to 11psi when stopped at the lights and my oil temp was at 78c. I recently did an oil change (a couple of months ago) and have not driven the car much since, so wondering if there was an need to bleed the dry sump after emptying it? Also had an issue with the oil cooler as I couldn't remember which way I had taken it off and if it was possible to put it on the wrong way around By the way the drive was only about 50 km and never went over half rev's. Do you think there could be an issue there and if so any thoughts on what to check?

 

Sorry, edited to apologise for the thread highjack

 

Edited by - Tony Wright on 27 Jul 2012 16:11:54