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Re: the many Mods done to my 3.8 'S'
Posted: Mon Feb 04, 2019 10:03 pm
by NigelW
That's what I'd like to know!
I've also noticed that speeds around 70mph the oil temperature remains stable at 90 degrees C but over 80mph it starts to climb to over 100 degrees, I was wondering if there is some kind of aerodynamic effect on the oil cooler than the fans might mitigate.
Re: the many Mods done to my 3.8 'S'
Posted: Tue Feb 05, 2019 4:11 am
by Glyn Ruck
Nigel ~ A friend in Dallas has a classic car collection that is heading for Jay Leno territory.
He rates the following the best by some margin, & for the fan controller, Derale 16795
https://www.mishimoto.com/automotive/fa ... 3cQAvD_BwE
I postulate as follows: The S Type is the most aerodynamically efficient of S Type, Mk2 & 420. i.e. has the lowest CD. Aerodynamically efficient designs often have issues with adequate cooling. In the case of the S Type if fitted with a decent radiator I don't think the small grill area is the critical/limiting factor. At high speed I think venting air from the engine compartment is the issue. At high speed you can actually see the bonnet trying to rise with built up pressure. The reason some cut vents in the wheel arches.
Don't worry too much about bulk oil temperature as long as pressure is OK. Modern vehicles frequently run bulk oil temperatures > 120 deg C for efficiency & modern lubricants are designed to tolerate this happily.
Re: the many Mods done to my 3.8 'S'
Posted: Tue Feb 05, 2019 9:49 am
by NigelW
Thanks for the info Glyn. I am a bit concerned about the oil temperature as unlike modern engines my S Type uses the original spec 20/50 Castrol Classic oil. I have very good oil pressure as I fitted a Rob Beere uprated racing oil pump when I rebuilt the engine.
Re: the many Mods done to my 3.8 'S'
Posted: Tue Feb 05, 2019 10:54 am
by Glyn Ruck
Hi Nigel.
There is no such thing as "Classic Oil" ~ only obsolete oil & marketing hype. Modern oils will substantially increase XK engine life over what Jaguar had available to them at the time.
Read from Post 16 here to save me repeating myself.
https://www.jaguarforums.com/forum/mki- ... re-212846/
Re: the many Mods done to my 3.8 'S'
Posted: Tue Feb 05, 2019 12:49 pm
by NigelW
We are in danger of straying off topic with this thread - Jose will be after us. Maybe we need a new subject thread for oils as this is a massive subject in it's own right.
Interesting thread about oil though, I tend to agree with you regarding the marketing hype with the "Classic" moniker.
Re: the many Mods done to my 3.8 'S'
Posted: Tue Feb 05, 2019 2:42 pm
by Jose
Nigel, I am assuming this oil cooler is one that you installed, correct? I ask because my car does not have one.
there is a company in the US called JEGS and they sell performance add-ons for all types of cars, classic and modern. I remember Lynn who built his MK2 in Tennessee used many parts from JEGS like an auxiliary radiator, a/c system, etc.. Lynn is an aviation engineer and he invents stuff like the hinge system which lets the bonnet stand up to 90 degrees.
as to the deviation from the orginal thread, we have a habit of doing that. It is a lot of work to move posts to another topic and when doing that, you end up with "orphan" posts. So if it doesn't get too bad, I'm not worried.
www.jegs.com
Re: the many Mods done to my 3.8 'S'
Posted: Tue Feb 05, 2019 3:58 pm
by NigelW
Yes I fitted the cooler myself sometime back, I had it made by Northampton Radiators who also made my double cored radiator. It has an oil stat to only let the oil flow through it when up to temperature, it also has a take off for an oil temperature guage.
Not a very good photo but it'll give you an idea.
Re: the many Mods done to my 3.8 'S'
Posted: Tue Feb 05, 2019 4:06 pm
by Jose
ok, now I understand in full.
and you want to add a fan to this oil radiator, right?
are you wanting a manual switch or a thermal switch for this fan?
did you check JEGS?
Re: the many Mods done to my 3.8 'S'
Posted: Tue Feb 05, 2019 4:31 pm
by NigelW
Yes I need a fan for it, looked at JEGS and the only seem to sell complete coolers with fans but none the same size as mine as it was custom made. A manual switch is just fine
Re: the many Mods done to my 3.8 'S'
Posted: Tue Feb 05, 2019 7:02 pm
by Orlando St.R
Jose - I will post a pic of the stop lights when I next have the garage open and a willing helper around.
Nigel - what difference did the two row core radiator make to your running temperature?