Oil And Water Temperatures Running Twin Carbs

[mos 1]

Hi,

a new member to the forum, although i have used this site for years for info etc...

i have a skip brown 1.9s conversion running twin 45 dellorto carbs. the car is for road use and is my everyday transport

i have the 13 row mocal oil cooler fitted to my car but i never seem to register any oil temp on my journey to work, it is solely city traffic and some fast road work, nothing above 50mph. the journey is about 20 miles and takes 45mins to a hour usually. i take this route in the mornings so i can drop my girlfriend at work but in the evenings i go the more direct route home which is a bout 15miles motorways and two miles road. on the return journey i always get an oil temperature reading around the second thick line (if that makes sense) so obviously the guage/sensor are working.

i am worried that unless i go on the motorway the oil in my engine never gets up to proper working temperature and i am worried about the damage/premature wear this may be causing

my question is would i

a) be better fitting the standard water type oil cooler if i can find one and the pipework or

replacing the sandwich plate around the oil filter with a mocal one incorporating a themostat that only opens above 80 degrees C so the oil cooler only comes into play above this temperature.

i definately think the oil being colder makes a difference because when i come off a run on the motorway with a warm oil temp the engine idles slightly faster (less oil drag as the oil is thinner when warm) or

c) am i worrying about nothing

 

then theres the water i am running a standard gti rad lowered to allow cold air to the carbs but, particularly at this time of year the car gets hot quick and stays hot around town/roads near the third thick line on the guage, not too hot i know but enough to make the car feel lumpy and boggy. On a run on a fast A road or the motorway the temperature drops back to the second thick guage and the car feels much better.

so my question is would it be worth me fitting a Turbo Diesel Radiator and would it also be a good idea to run spark plugs a couple of grades colder than the standard NGK ones i currently use.

 

any advice gratefully accepted

 

thanks in advance

 

mark

[pug_ham 244 3 Cars]

What does your water temp get up to on these runs?

 

I'd try the thermo controlled plate first but I think you should definately get some oil temp showing on a 50 minute drive no matter how sedate.

 

I wouldn't fit the TD radiator, especially not if you go for the oil water exchanger as this will keep the oil at a similar temp to the water which with a larger rad would be lower imo.

 

It depends on whether you can find the water oil exchanger complete & which is cheaper in the end but I have the oil water on mine & its fine. Only gets oil temps that high on a trackday & thats with an 82' thermostat.

 

Graham.

[mos 1]

sorry i do not have a the facility to actually read the water and oil temperatures so i have to go off the guage

water temp never increases beyond the second thick line on the guage on the motorway no matter how long or hard i drive.

excessive heat definately seems to be an around town driving problem where the temp rises very quickly to the third thick bar and the fan is on and off all the time.

my thinking behind the TD rad was that the thermostat in the cylinder head would prevent over cooling, i.e trapping the water in the engine and preventing circulation into the Rad unless the temp requires it, so the engine would not overcool if that makes sense. i though the extra capicity of the TD rad would help by providing a much larger surface area for the water to flow and cool through (even though there will not be too much air flow at the radiator as the car only really gets hot when in stop start traffic and general around town driving)

the other thing i thought was to fit a second fan but this was scuppered by the fact that the mocal oil cooler is located in the cowling where the second fan would go just in front of the radiator.

 

thanks

[pug_ham 244 3 Cars]

I only mean't what do the dash guages show your water temp at when the oil is that high.

 

Every thing you suggest is purely to keep your water cool which from your description isn't getting high enough to really need anything doing except for in traffic when the cooling fan is doing its job OK.

 

Its just your oil thats getting hot from the sound of things.

 

Have you checked the condition of the wire for the oil tempguage? The insulation can become melted through & damaged so the wire occasionally touches the block & gives spurious readings on the guage. It could be something that simple.

 

Graham.

[mos 1]

the water temp stays at the second thick line on the motorway/fast roads, infact both the oil and water are at the same point, the second thick line on there respective guages.

 

i have probably not explained myself very well what i want to do is

A) change something that gets my oil up to operating temperature around town as at the moment it reads as if its too cold and only warms up on a motorway.

change something else to keep my water temperature cooler around town as on the motorway its fine and when you leave a motorway with both warm oil and water reading the same (second thick line)the car runs a little quicker (less oil drag i think) but the car runs a dream, feels at its most response and it is only when you have been driving around town for a while that the water temp increases to the third thick line and the oil temp actually drops back to nearly nothing on the guage.

once the oil temp is low and the water temp is at this higher position the car feels boggy and not nice to drive at all.

so i guess what i am trying to achieve is to have the temperatures for both water and oil i get on the motorway on the around town drivingwhich i think will involve changing a couple of things, something on the oil system and something on the water side.

i hope this is a bit clearer sorry its a ramble!

any ideas?

 

thanks

Edited July 20, 2006 by mos

[Daz_C 8 1 Cars]

the water temp stays at the second thick line on the motorway/fast roads, infact both the oil and water are at the same point, the second thick line on there respective guages.

 

i have probably not explained myself very well what i want to do is

A) change something that gets my oil up to operating temperature around town as at the moment it reads as if its too cold and only warms up on a motorway.

change something else to keep my water temperature cooler around town as on the motorway its fine and when you leave a motorway with both warm oil and water reading the same (second thick line)the car runs a little quicker (less oil drag i think) but the car runs a dream, feels at its most response and it is only when you have been driving around town for a while that the water temp increases to the third thick line and the oil temp actually drops back to nearly nothing on the guage.

once the oil temp is low and the water temp is at this higher position the car feels boggy and not nice to drive at all.

so i guess what i am trying to achieve is to have the temperatures for both water and oil i get on the motorway on the around town drivingwhich i think will involve changing a couple of things, something on the oil system and something on the water side.

i hope this is a bit clearer sorry its a ramble!

any ideas?

 

thanks

I think you will find that the reason the car feels so boggy is cus of the engine bay temperatures being very high due to the weather at the moment and lack of wind to blow through to lower the air temp in the engine bay. As you have said after a run on the motorway it seems fine until your stuck in traffic and then it runs a tad s*ite until your on a decent run again. I have the same symptoms on my 16v which is also running carbs. I also have a 1.9s with the same cooling set up as yours as do many other people on here (13 row mocal/standard rad) and I personaly don't have any probs with this and my gauges work around the same peramiters as yours.

My personal opinion would be that its your Engine Bay Air temps thats the problem for your car running Boggy around town not the oil or water temp.

[ada205 2]

I think you will find that the reason the car feels so boggy is cus of the engine bay temperatures being very high due to the weather at the moment and lack of wind to blow through to lower the air temp in the engine bay. As you have said after a run on the motorway it seems fine until your stuck in traffic and then it runs a tad s*ite until your on a decent run again. I have the same symptoms on my 16v which is also running carbs. I also have a 1.9s with the same cooling set up as yours as do many other people on here (13 row mocal/standard rad) and I personaly don't have any probs with this and my gauges work around the same peramiters as yours.

My personal opinion would be that its your Engine Bay Air temps thats the problem for your car running Boggy around town not the oil or water temp.

Agree with Daz_C. I also run carbs on an Mi, but with no oil cooler, and under bonnet temp definately has a noticable effect, especially at this time off year. In the weather we're having now, mine feels like a completely different car when drivin in the late evening compared to mid afternoon, when the car feels more sluggish in the mid-day heat.

 

As for your low oil temp, as long as like Graham says, your gauge/wire/sensor are ok, then i'd personally like to see some oil temp after your morning trip. Unless a cars trashed all the time or tracked, i dont see the point of a cooler on an n/a 205, and some people reckon the standard items dont make much difference to temps any way. Anyone tried a before and after to say if this is true or not?

 

For the record, my oil temp takes around 10mins to work it's way to the 2nd White bar when driving steady at this time of year. Sits between 3rd & 4th bar when drivin hard. The water temp sits on the 3rd bar whilst moving, and only goes higher when in traffic.

Edited July 20, 2006 by ada205

[mos 1]

thanks

 

so you guys recon it might be worth trying the car with no oil cooler at all? i suppose it may be worth a shot after all it is solely a road vehicle and as hard as i drive at times its not going to get the constant hammer that a track/rally car must take and ambient temp not likely to get much hotter than the heatwave we are current having so it would be the ideal time to try this.

removing the oil cooler will allow more air to flow at the rad as well as it sits in front of the rad in the second fan housing and must block a good portion of the rad from getting air straight to it. may aid water cooling

 

as for the water cooling side do you guys not think the TD rad will help keep the temp down and the car in the desired temp zone for longer where the car performs better without bogging.

then when it turns colder wont the thermostat in the cylinder head prevent the larger TD rad from overcooling the engine?

 

thanks

Edited July 20, 2006 by mos

[pug_ham 244 3 Cars]

Where do you mean by the second thick white line on the guage? The fdirst mark is a thick line but thats at the bottom of the guage & of no use as the needle rests above this even when disconnected, the second one is where the thermostat opens approximately on mine & then the next is to the right of the guage & just below where my cooling fan cuts in.

 

Personally before removing the oil cooler I'd want to findout why its getting so high on the motorway. With it showing that high on a motorway run having no oil cooler might be a bad thing long term.

 

Alternativelty, I'd get a water oil heat exchanger as fitted to the PAS model GTi's later in their production & you should get evenly matched oil & water temps. I have one on mine & its fine even on trackdays.

 

Try that first & if you are still getting high oil & water temps then have another think about a TD radiator or easier a lower temp thermostat.

 

Might be worth lowerring the radiator also to get a better cold air flow into the carbs rather than through the rad.

 

Graham.

[mos 1]

sorry to be confusing

 

i was including the first thick line on the guage in my calculation, the one that is literally useless as it is actually under the needle when cold and the ignition is off, i see what you mean if you were not including that line in your thinking, the second thick line would then be running quite hot, hotter than i would normally be happy with.

what i am referring to as the second thick line is the line where the thermostats seem to open on gti's and

what i am calling the third thick line is indeed where the fan seems to cut in, sorry about confusing people.

 

i am planning on tackling the water and oil one at a time as i dont want to confuse myself or trip myself up.

oil will be first, i am thinking of bypassing the oil cooler all together by removing the sandwich plate that runs to the mocal oil cooler as an experiment to see if this cures my oil temp issues,

question, will i need to replace this with another sandwich plate from a non oil cooler model such as a 1.6 gti or will the filter screw straight to the block, hence no sandwich plate required at all

 

the plan is to see if this works, i.e gets the oil up to temperature even driving around town, but also i will need to ensure that the oil temperature does not get excessive on a motorway etc.

 

if this works then great

but if it works in terms of getting the oil up to temp around town but the oil now gets too hot on a fast road/motorway i will either have to source and fit a water oil cooler and all the associated fittings or buy a new sandwich plate from mocal that incorporates a themostat that only opens once the oil has reach 80 degrees C, not sure which method would be best to be honest.

 

graham i think your implying the water based system would be best, rather than the mocal air oil cooler and thermostat sandwich plate, am i right in thinking that?

 

i do have the rad lowered by about 10cm at present this did make a considerable difference when i first fitted carbs a long time ago, i ran the car for about six months in the normal position then lowered it and the car certainly felt better for it, definately a mod i would reccommend to anyone running either carbs or throttle bodies

 

 

any ideas or thoughs anyone?

 

thanks

 

mark