Engine Cooling

[Campbell]

This is my first season with the .40 over engine and a lower final drive gear in my tranny.. it seems the engine temp on the stock gauge is almost at the top during the race (ambient temp 85 to 92, been hot this summer). I don't remember the stock bore running that hot, I have a stock Scirocco radiator and am running a thermostat. Anything I can do to run cooler? thanks

[67ITB]

You want to make sure that all the air entering the front of the car is going through the radiator. You can build shrouds (SP?) out of just about anything. Aluminum, plastic, old Rubbermaid containers, roofing flashing… and of course secure it all with zip ties and 100 MPH tape.
Also many VW’s came with a stock cardboard type material that may also work in your application.

Good luck and I hope this helps
And I guess I should have asked the standard IT.com question “what kind of car”
Matt Bal

[Bill Miller]

Couple things. As Matt pointed out, make sure you get as much of the air through the radiator as you can. Second, are you sure you got it purged out well, when you reinstalled the motor? VW motors are notorious for being a PITA to get filled. I always drill a small (1/8") hole in the T-stat plate.

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MARRS #25 ITB Rabbit GTI (sold) | MARRS #25 HProd Rabbit
SCCA 279608

[Campbell]

Thanks, I will see about fashioning a shroud. The car is an ITB 1.8L Scirocco.

[JamesB]

Are you still running the VW oil heater or have you gone with an external cooler? With a .40 over motor you will carry more engine temps and higher cyl head temps thats a given. Running a shroud to grab as much air as possible will help, but getting a better oil cooler will add relief to the stock cooling system.

Another trick used by street modified 16v guys is to drille 2-4 3mm holes in the Tstat to increase cooling flow in this situation.

[Bildon]

Also check the sender. VWs usually have no problems with cooling after the A/C crap is removed... even in extreme heat. So I'd check the sender and to make sure it's accurate.

I'd throw a set of aux. temp guages on the car for peace of mind.

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Bill Sulouff - Bildon Motorsport
Volkswagen Racing Equipment

[racer14itc]

I use a Griffin drag race style aluminum radiator in my GP Scirocco. The stock radiator is marginal in terms of heat rejection for a race motor. The Griffin radiator is good for up to 250HP or there about. My water temp is usually 170-180F in the middle of the summer, in the draft it MIGHT go up to 190F. And that's OUT of the motor. In the cooler months I have to tape off quite a bit to get the temps up.

http://www.griffinrad.com/drag.php

Much easier to deal with having too much cooling capacity vs. not enough. The only drawback is that it holds another 2 quarts or so of water, so that adds 4 lbs or so on the nose of the car.

MC

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Mark Coffin
#14 GP BSI Racing/Action Digital/Airborn Coatings/Krispy Kreme VW Scirocco

[Campbell]

Thanks for the suggestions. I know my radiator is a stock non a/c unit - I was thinking about seeing if the a/c cars had a bigger one.. After shrouding if it is still an issue I will look at Griffin rads and/or oil coolers (I do have the piping for an external oil cooler but not the cooler itself).

[racer14itc]

An external oil cooler will help the water temp and vice versa. A really big oil cooler will help the engine run cooler overall. I have a 19 row Mocal oil cooler in conjunction with the Griffin rad.

In 90F+ ambient temps, my oil temp is 180-190F back to the engine and water temp is usually 180-190F out of the head.

Even though in theory running the oil and water temps warmer will make a little bit more power, running the engine cooler seems to make the engine (and the driver/owner) happier!



MC



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Mark Coffin
#14 GP BSI Racing/Action Digital/Airborn Coatings/Krispy Kreme VW Scirocco

[Dick Elliott]

AC Diesel VWs have the biggest radiators I've been told.

[Bildon]

>> is good for up to 250HP

Woo hoo! What is the Prod motor making?

Hey Mark, long time no "talk"
Glad to see you are still a regular here even though your are Prod now.
Question: Do you guys have a good place to discuss Prod issues and collaborate via a forum or anything? I know a couple of Prod sites have come and gone and I haven't found a place like IT.com for talking about Prod car building etc. I need to get moving on my GProd Golf again.

- Bill

[racer14itc]

Originally posted by Bildon:
>> is good for up to 250HP

Woo hoo! What is the Prod motor making?

Hey Mark, long time no "talk"
Glad to see you are still a regular here even though your are Prod now.
Question: Do you guys have a good place to discuss Prod issues and collaborate via a forum or anything? I know a couple of Prod sites have come and gone and I haven't found a place like IT.com for talking about Prod car building etc. I need to get moving on my GProd Golf again.

- Bill

http://www.coloradoscca.org/prodcar is where we hang out.

I'll let you know what the 1.6 GP motor is making after this weekend. 1st weekend ever with a 1.6, I've been using 1.5's up to this point. Best was 115 whp according to the DL1 data logger. The 1.6 should make more hp with the extra displacement and the dual sidedrafts instead of the CIS injection. I'm shooting for 125-130 whp, which would be around 150 horsepower at the crank.

Yes, you need to get going on the GP Golf!

MC




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Mark Coffin
#14 GP BSI Racing/Action Digital/Airborn Coatings/Krispy Kreme VW Scirocco

[theenico]

Originally posted by Campbell@Aug 2 2005, 08:00 AM
Thanks for the suggestions. I know my radiator is a stock non a/c unit - I was thinking about seeing if the a/c cars had a bigger one.. After shrouding if it is still an issue I will look at Griffin rads and/or oil coolers (I do have the piping for an external oil cooler but not the cooler itself).

[snapback]37509[/snapback]

The biggest radiator that came in an A1 chassis is the one in 16V Sciroccos. The A/C version has the top outlet pointed at the pass. side fender. The non A/C version is the same as a Golf rad with the inlet & outlet in the normal spots. These rads are wider than the one you have now and are a lot cheaper than the Griffin unit (lighter too if I remember correctly). I have nothing against the Griffins. I bought a used one for my old ITB Scirocco because it was cheap.



You can see the black plastic piece I made to close up the area to the right of the radiator.

[racer_tim]

Also, are you using a thermostat or a restrictor? I know that if you remove the thermostat you will have over heating problems. You need to have a restrictor if you plan on running without a thermostat.

I just took a standard thermostat, and cut the spring and guts out of it, and used the "base" as the restrictor.

Haven't had any overheating problems with my LP 1.8 motor in by LP GP Wabbit

[Campbell]

I use a thermostat that I did drill a couple 1/8" holes in.. I have removed the rubber flaps on the back of the radiator to make sure there is as much air flow thru it as possible. I am also going to drop my timing, it is now at 38 to 33 or 34 (from past posts everyone seems to run in that range best) and see if that helps bring the temp down. I am racing next weekend and will see how it goes. thanks

[John McFarland]

One thing that Mark didn't mention about the Griffin radiator is that the off the shelf unit has a 1 1/2" inlet and a 1 3/4" outlet. These do not match the stock sizes. He had a custom one built that has 1 1/4" outlets, just like stock.

I just picked up an off the shelf unit from Summit and I think I found the hoses needed to make it work without a custom order. I will have mine in by the weekend. If all goes well, I will save a lot of time and money using the off the shelf unit.

If you want to go this route, I can give you the hose part numbers so you can make it work.

I also have a new spare radiator from BSI that is about 2 inches longer than the stock unit if you may want to purchase that from me.

I have been fighting the hot engine for the last couple of weekends out. I am sure this will fix my problem...