BDR+408= overheating at low speeds?

Gatorac · #1 (**permalink**) 03-27-2005, 01:24 PM

I can't seem to stay cool at speeds lower then 25mph. It runs about 85c when cruising. It heats up pretty quick at a light,(100-105+). This leads me to believe that the fans are not pulling enough air.

Anyone else have an issue like this? Are there more powerful fans available to put in place of the stock ones?

oncebitten · #2 (**permalink**) 03-27-2005, 06:32 PM

Are you sure the fans are turning on at all. They typically will turn on aroung 95c. If you are reaching 105 you have a coolant. What engine are running? I recently had a car delivered and had to replace the rediator due to shipping. I had concerns as well but after testing and verification from REg and frank al seems fine. When I reach the temp for fan turn on the temp gauge does drop. Does this happen with your car.

CobraDan · #3 (**permalink**) 03-27-2005, 07:30 PM

Spal fans move some serious air! If you want to keep your ride running cool at low driving speeds these ultra high performance fans are your answer. Spal fans are regarded as the best in the market. not only do many of the worlds finest automakers, including Ferrari and Lamborghini, rely on Spal Products, but a vast majority of professional race teams, including the Nextel Cup, SCCA, Busch, IMCA, IHRA, and NHRA depend on Spal to keep their engines cool and running at peak performance all day long.

11" dual fans CFM 2780
16" Extreme CFM 3000

Gatorac · #4 (**permalink**) 03-27-2005, 08:20 PM

Once,

My fans are coming on. They come on at 85c. Once they kick on the don't go off. The temperature only changes with speed.

Dan,

The BDR fan set up is not just a fan tie-banded to the radiator. It has a really slick shroud that 2 fans mount into. It would be nice to have a couple of fans that would mount in the factory shroud that could pull more air.

oncebitten · #5 (**permalink**) 03-27-2005, 08:31 PM

what engine are you running? Is it from Backdraft

Trueoo7 · #6 (**permalink**) 03-27-2005, 08:34 PM

Have you checked to see if both fans are working also look at these as well.
Coolant level
Coolant mixture (too much water?)
Was the system properly filled and purged of all air, you could have an air gap.
Do you have any type of screening in front of radiator.
The bottom of the stainless steel tank has a rubber hose that makes a 90 deg turn, I've seen this hose come from the factory with a kink in it. Mine did and I replaced it with a better more sweeping 90deg hose.

Just somethings to check
Trueoo7

oncebitten · #7 (**permalink**) 03-27-2005, 08:38 PM

Also to true007's reply. The bottom hose can have a kink as well. I guess we should ask? is this a new car that has had this problem or something just developed?

xlr8or · #8 (**permalink**) 03-27-2005, 09:41 PM

Make sure if your talking about a puller fan that it is actually pulling. Blowing hot air from the engine over the radiator isn't too efficient. If this is a new install it may be wired backward and trying to blow air back out the front and you have to drive over 25 to over come it.

Secret Squirrel · #9 (**permalink**) 03-27-2005, 09:43 PM

Gatorac,

Check to make sure that the fans are pulling air from the front to the rear of the radiator. I was doing a cooling systems check on my BDR before I started the engine for the first time back in December and found that my fans were wired in reverse and blowing air from the rear of the radiator towards the front. Who ever wired the fan plugs at the factory had them reversed. I corrected them and cooling is not a problem. Easy way to check is put a sheet of paper in front of the radiator with the fans on and see if the paper gets sucked into the radiator surface.

Hope this Helps.

Cashburn · #10 (**permalink**) 03-27-2005, 11:26 PM

All great suggestions... burping the cooling system is a great step after you verify the fans are heading the right way.

CobraDan · #11 (**permalink**) 03-28-2005, 02:40 AM

Quote:

Originally posted by Gatorac

Dan,

The BDR fan set up is not just a fan tie-banded to the radiator. It has a really slick shroud that 2 fans mount into. It would be nice to have a couple of fans that would mount in the factory shroud that could pull more air.

If there 11" duel fans are they pulling 2780 CFM because you could just buy the 11" fans and install them in the BDR shroud. I just resently installed a 16" single Spal fan and I no longer have an over heating problem it pulls twice the air as the first fan I installed. In fact with the high gas prices I just let the fan pull me down the street without the engine running.

Dan

tryce · #12 (**permalink**) 03-28-2005, 08:50 AM

Check your timing. You may be supprised

Gatorac · #13 (**permalink**) 03-28-2005, 04:05 PM

The fans are both running in the correct direction. I am using a restrictor in place of the t-stat. The problem is the same as when I had the t-stat in. There is no kink in the hose. There is no screen in front of the raditor.

408 windsor from SA. I Just double checked the timing @ 28 total.
<<<<<<<<<<

Am I missing something regarding "burping" the cooling system? There is an expansion tank right on top to bleed out the air. There is no thermostat for the air to get trapped at.

I believe the problem is air flow related. It does not change with engine RPM. Only with speed.

xlr8or · #14 (**permalink**) 03-28-2005, 04:29 PM

Ok so the fans are pulling air from the front of the car through the radiator toward the engine. Now are the fan blades oriented correctly for this? The reason I bring this up is a fan blade will move air either direction based on rotation but will always be more efficient and move more air when spinning the intended direction. ie: This is a puller fan correct?

ezplans · #15 (**permalink**) 03-28-2005, 04:49 PM

Wow, have any of you looked at the oil temp thread? I have a sideoiler and can't get to what I feel are proper temps, especially oil. 90C oil highest I've ever seen, water is usually 10 degrees under the oil. Could this be a BDR issue?

MDP727 · #16 (**permalink**) 03-30-2005, 09:35 AM

I have car 211. It has the bdr 408 in it. It has heating up just like yours until 500 miles. Then Reg and the gang got the car for a check up. They changed the timing and jets and the car never heats up now and is a lot more powerful. I sat in traffic 2 weeks ago for the gator nationals. It was about a good hour and the car never heated up.

The biggest improvement was the power. Listen to this---just last night I lined up next to 2 rice rockets at a red light. They started revvin up looking for a race. Normally I wouldn't mess with a jap bike but this time I said what the hell. When the light turned green we left the light and one bike was left standing, he must of fallen asleep. I was dead even with the other bike until I shifted into second and he creeped a couple feet in front of me. Then I hit second---pulled up to him and passed him. The whole time I thought his little jap motor was going to explode in my ear. I even had a passenger!

Cashburn · #17 (**permalink**) 03-30-2005, 12:11 PM

It's not a BDR issue ... something is up with the motor. You can burp the system easily like this: http://www.ehow.com/how_7369_burp-cars-cooling.html

After we are sure that is done we can start playing with timing and jets.

Have you spoken with SA for any ideas?

Gatorac · #18 (**permalink**) 03-30-2005, 05:27 PM

I tried a different temp gauge today to make sure that was not the problem. It wasn't.

I'll give the "burp" a try next.

Thanks for the help. I was hoping that someone with the same engine combo would chime in and say they either had a similar problem or not. I can see myself getting in the middle of the blame game since the engine and car were purchased from different vendors. With the issues I've had with the engine, I suspect that's where the problem lies.

tryce · #19 (**permalink**) 03-30-2005, 05:35 PM

As I sugested befor and as MDP727 has said Check the Timing.
Hope it is an easy fix.
Pete

Engineer Ed · #20 (**permalink**) 03-30-2005, 06:02 PM

I know how to fix your problem.....
Stop driving slow you sissy!

Ed
DSCC President
Backdraft #223.
Arriving in Tampa 4/1/05