I read a recent post about cooling for a big 914. I believe the post that said that the stock system is probably adequate however I am still paranoid about my engine over-heating. My 914 is around 2.4l. I am trying to find out if there are any cheap cooling upgrades that anybody is aware of? The only thing that I have been able to find for 914's is the 914 DTM kit however it is a bit too expensive for me.
Any advice?
Thanks,
Steve
914 Cooling Options
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Dave_Darling
- Posts: 2534
- Joined: Thu Apr 27, 2000 12:01 am
Step 1: Instrumentation. Four CHT senders, one under each spark plug. A four-way CHT gauge, or a pair of two-way ones. (Westach is highly regarded, IIRC.) One oil temp sender and gauge.
That should help you figure out if your engine really is overheating or not. If so, there are things you can do, depending on exactly what you find.
High oil temps can be controlled by using a good synthetic oil, or by adding an external oil cooler, or both.
High head temps require more work. First, make sure the stock system is in excellent working condition, with all the fan blades present on the impeller, and no leaks in the engine tin, and either a working thermostat and flaps, or just the flaps. (They're needed to get air to where it needs to be!) Make sure the rubber flaps under the car at the front of the engine bay are there. Ditch the rear valance. If that doesn't help enough, you can duct cool air into the engine bay. Cool air will help your engine cool more effectively than warm air.
If that doesn't help, you may be able to use a water mister if you only need help on the CHTs for short periods (e.g., pulling up a hill or running WOT on the track).
Or you can go with a different cooling system. A race car can use the "sewer pipe" approach, where cooling air is ducted in from the headlight buckets directly to the inlet of the cooling fan. Those fans usually have a number of blades removed, mostly to cut down on the HP loss from pushing the air around. The "ram air" effect of the ducted cooling air helps to move the air through the engine.
DTM is, as noted, another option. So is the FAT 911 fan conversion. I know that it is not as well regarded as the DTM, but it is supposed to help larger engines cool better than the stock setup.
And finally, if your 2.4 uses very large cast-iron cylinders, you may find it diffcult to keep cool no matter what you do. The 103s and 105s seem to make engines run hot. Switching over to "Nickies" can help significantly, from my readings on this BBS. But those aren't cheap either....
--DD
That should help you figure out if your engine really is overheating or not. If so, there are things you can do, depending on exactly what you find.
High oil temps can be controlled by using a good synthetic oil, or by adding an external oil cooler, or both.
High head temps require more work. First, make sure the stock system is in excellent working condition, with all the fan blades present on the impeller, and no leaks in the engine tin, and either a working thermostat and flaps, or just the flaps. (They're needed to get air to where it needs to be!) Make sure the rubber flaps under the car at the front of the engine bay are there. Ditch the rear valance. If that doesn't help enough, you can duct cool air into the engine bay. Cool air will help your engine cool more effectively than warm air.
If that doesn't help, you may be able to use a water mister if you only need help on the CHTs for short periods (e.g., pulling up a hill or running WOT on the track).
Or you can go with a different cooling system. A race car can use the "sewer pipe" approach, where cooling air is ducted in from the headlight buckets directly to the inlet of the cooling fan. Those fans usually have a number of blades removed, mostly to cut down on the HP loss from pushing the air around. The "ram air" effect of the ducted cooling air helps to move the air through the engine.
DTM is, as noted, another option. So is the FAT 911 fan conversion. I know that it is not as well regarded as the DTM, but it is supposed to help larger engines cool better than the stock setup.
And finally, if your 2.4 uses very large cast-iron cylinders, you may find it diffcult to keep cool no matter what you do. The 103s and 105s seem to make engines run hot. Switching over to "Nickies" can help significantly, from my readings on this BBS. But those aren't cheap either....
--DD
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tornik550
- Posts: 83
- Joined: Wed Dec 13, 2006 1:48 pm
Thanks for the advice. I will try some of the options. I am pretty sure that the real problem is in my own head because of a bad experience in the past with an unrelated car. It seems that it is my nerves overheating and not the engine.
With the ram air option, where do they run the ducting? Do they run the ducting thru the center tunnel or do they make their own holes thru the firewall?
With the ram air option, where do they run the ducting? Do they run the ducting thru the center tunnel or do they make their own holes thru the firewall?
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Twystd1
- Posts: 323
- Joined: Sat Nov 13, 2004 8:42 pm
I understand your concerns.
Since you have a stroker motor of some configuration.
A couple of things occur to me.
1) If the engine is configured correctly. The stock cooling may very well be adequate for the cylinder head cooling. And the stock oil cooler may be adequate for your configuration.
And it may not.....!!!!!!!!!!!
The only way you can tell what is REALLY going on with your engine is to do what Dave Darling suggested.
Quad head temp gauges.
(or a dual with a toggle to check the other 2 cylinders)
And a proper oil temp gauge.
Then the facts/data will dictate any further changes.
There are SOooo many things that can effect these temps.
From what kind of exhaust you have, cam config, timing, compression ratios, engine coatings, oil brand and viscosity, induction, cooling flaps, etc...... And on and on......
Since all of these are an unknown combination to us.
I would (and do) have gauges to make sure I don't cook my 2.5 stroker engine.
My engine (10:1 compression) runs fine with a stock cooler and stock oil cooler...
Until I run it hard. Then a remote oil cooler solves the oil temp issues.
(Also have a 3 qt. accusump)
Head temps can be mitigated with differant fan shrouds and differant engine combos. Read what DD said above...!!!!!!!!
Cheers,
C
Since you have a stroker motor of some configuration.
A couple of things occur to me.
1) If the engine is configured correctly. The stock cooling may very well be adequate for the cylinder head cooling. And the stock oil cooler may be adequate for your configuration.
And it may not.....!!!!!!!!!!!
The only way you can tell what is REALLY going on with your engine is to do what Dave Darling suggested.
Quad head temp gauges.
(or a dual with a toggle to check the other 2 cylinders)
And a proper oil temp gauge.
Then the facts/data will dictate any further changes.
There are SOooo many things that can effect these temps.
From what kind of exhaust you have, cam config, timing, compression ratios, engine coatings, oil brand and viscosity, induction, cooling flaps, etc...... And on and on......
Since all of these are an unknown combination to us.
I would (and do) have gauges to make sure I don't cook my 2.5 stroker engine.
My engine (10:1 compression) runs fine with a stock cooler and stock oil cooler...
Until I run it hard. Then a remote oil cooler solves the oil temp issues.
(Also have a 3 qt. accusump)
Head temps can be mitigated with differant fan shrouds and differant engine combos. Read what DD said above...!!!!!!!!
Cheers,
C
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Dave_Darling
- Posts: 2534
- Joined: Thu Apr 27, 2000 12:01 am
When I said "sewer pipe", I wasn't really exaggerating! We're talking a very large piece of air conduit, probably 18" in diameter! It doesn't exactly "fit" nicely anywhere... It runs from the front trunk into the passenger compartment by way of the fuel tank compartment. Great big holes in everything, including the firewall!!tornik550 wrote:With the ram air option, where do they run the ducting? Do they run the ducting thru the center tunnel or do they make their own holes thru the firewall?
Did I mention that this was only for race cars that don't see the street? Ones with zero interior, a nice fire suppression system, fire suit for the driver, no provision for any passenger at all, and just about zero time spent sitting still idling? Not exactly good for a street car. (You didn't mention your application...)
--DD