240 degree coolant temps on a cool day

[RussMcB]

Can I assume that 244 degree coolant temperatures are abnormally high for my car while racing at Road Atlanta last weekend in 60 degree weather?

Details:
Oil temps were roughly the same.

Coolant was pushed into the catch can.

Prior to the weekend I flushed the system with tap water and refilled with one bottle of Valvoline VV858 additive, topped off with distilled water.

My rad cap is 22 lb. It pressures tests good, as does the entire system. The engine has 4 race weekends on it, so I'd like to assume the pump and general engine condition is okay.

I'm not sure what the condition of the radiator internals are. It may need to come out for a cleaning.

I do not have a pressure warning sensor in the car but plan to have one.

For those of you who can set alarms to go off at certain degrees, what temps to you use to set off alarms for water and oil?

Thanks for any comments.

On edit: Aha! I just looked at Pi data and see that the water temps went from around 220 max to 240 around the same time as the fuel pressure started to fluctuate and drop. I was probably running lean and creating extra temps. What do you think?

[Jack Crone]

Russ, unfortunatly there is a good chance that you are starting to loose a head gasket or possibly a crack in your cylinder head. I would suggest adding a tube of alumiseal in your coolant header tank and see if it slows down the water being pushed out of the cooling system. It would also be wise to check you radiator and make sure there is nothing restricting the flow thru it. Also verify that your water pump pulley is not sliping on the shaft. Make sure that if you have any bleed lines coming off the top of your radiator or out of your thermostat housing or cylinder head they have no restrictions in them and they flow water into the header tank when the car is reved up to 4000 or 5000 rpm. I have had alumiseal work on several occations. Jack Crone

[D.T. Benner]

The Alumaseal has worked for me also. Just don't dump powder in as one lump as the results arn't pretty!

[Paul LeCain]

I'd bet on the head gasket and the bleed lines.

These cars notoriously overcool when things are right. We rarely saw 70 deg C unless there was a problem.

[RussMcB]

Thanks for the responses.

I'd like to think that I can rule out a head gasket or crack problem because my cooling system will hold 20 lb. for quite a while without dropping pressure. Would you agree?

It is a little unsettling that coolant was pushed out, but I was hoping that was caused by, 1) topping off, 2) high temps resulting in expansion and possibly boiling*, and 3) a radiator cap that is releasing pressure when it should.

I'm not sure how much coolant was pushed out. I'll check that tonight. Maybe I'll put the pressure tester on it again and see if it holds overnight.

* I'm not sure what my boiling point is. The Valvoline product is rated at 232 degrees by itself. I'm not sure what my mixture ratio is or what the resulting boiling point would be at 20 lb. That would be good to know so that I could set my Pi alarm value appropriately.

[ZEKESPEED]

Sounds as if you might have air trapped in your system. I would try the re-bleeding process again. Also for most racing/extreme conditions use a 28 to 31 Lbs radiator cap. Every lbs of presure increases the boiling point by 4 degrees. Good Luck

[Tom Sprecher]

I am no engine expert but I did stay at a Holiday Inn Express. Top it off and run the overflow where you can see it. Start up stone cold, watch the temp and see when the overflow occurs. I would guess if it occurs rather soon it may be the head gasket. If it does it once everything gets hot that it may be the topped off / high temps / cap opening like you described.

Also, when you start up cold leave the pressure gage on the cap and see if the pressure builds up immediately possibly indicating a head gasket leak. Compression pressures and 20 psi are no match.

BTW - tonight about 7-7:30 would be great. Mark and two of my neighors will be there as well. I see a Dr. today at 5 and thank you, Russ, I mean it, thanks bud.

[bob darcey]

Boiling point of water is 259F at 20 PSIG, 262F at 22 PSIG and 274F at 30 PSIG.

Cracks or even leaky gaskets might only show up at metal operating temp, and not during a pressure test.

[Jack Crone]

Unfortunatly, minor cracks in cylinder heads and minor head gasget leaks usually do not appear until the engine is at full tempature and under extreame load. I have seen this problem several times. Jack Crone

[RussMcB]

Unfortunatly, minor cracks in cylinder heads and minor head gasget leaks usually do not appear until the engine is at full tempature and under extreame load. I have seen this problem several times. Jack Crone

Yes, I suppose that could be the case. :-(

I purchased this car a few months ago and was told it had 3 events on the engine. I'd like to believe that's true, but I haven't been able to confirm it with paperwork.

Here's my tentative plan: Do as much as I can without taking the engine out (check bleed lines, fix erratic fuel pressure, maybe add alumaseal*, etc.), then do a test day where I'll slowly work up to speed while watching the temps closely. Maybe I'll be lucky and the temps will be low. If not, I'll park the car and take the engine out to be checked & freshened.

Thanks again for all of the opinions and suggestions. Please let me know if you see any potential gotchas with my plan.

* I'm not sure if I'm completely comfortable with adding alumaseal to the system. Are there drawbacks? For instance, does the entire system get an inner coating, even where it may not be needed? I'm getting a mental picture of clogged arteries ...

[Dave Welsh]

Russ

How is your battery voltage during your session? Low voltage could have an effect on your fuel pressure.

Our DB4 had sat for several prior to us getting the car. When we first tried to start we had fuel pump issues. Our setup has 2 pumps in the cell. A GM style pump sits at the bottom of the large aluminum tube, it feeds a sump in the tube, and a TRD pump draws from the sump and pressurizes the fuel system. We have had to replace both pumps. We found out when the bottom pump failed we could not draw fuel when the was 7 gallons or less in the cell.

We tend to run very cool. We had half of the left side pod intake covered at Kershaw, Left the grid showing 172, and ran 152 during the race.

We are chasing voltage problems, not sure if the generator or regulator is failing. Our voltage is running fro 12v at the start, dropping to 11.3v at the finish.

[RussMcB]

How is your battery voltage during your session? Low voltage could have an effect on your fuel pressure.

Hmm. You might be on to something there.

11.8-12.0 volts at the start of the race (seems low considering the car battery was on the charger over night and jump battery used each start). Dropped to 11.3-11.5 by mid race, then down to 11.2-11.4 by the end of the race.

AFAIK, my car does not have an alternator. I've looked for one but have not found anything that I thought was an alternator. Only thing close is what I believe to be the crank sensor, not alternator. I could be mistaken. I'm planning to order a new Odyssey PC645 battery before the next outing.

Our DB4 had sat for several prior to us getting the car. When we first tried to start we had fuel pump issues. Our setup has 2 pumps in the cell. A GM style pump sits at the bottom of the large aluminum tube, it feeds a sump in the tube, and a TRD pump draws from the sump and pressurizes the fuel system. We have had to replace both pumps. We found out when the bottom pump failed we could not draw fuel when the was 7 gallons or less in the cell.

We tend to run very cool. We had half of the left side pod intake covered at Kershaw, Left the grid showing 172, and ran 152 during the race.

We are chasing voltage problems, not sure if the generator or regulator is failing. Our voltage is running fro 12v at the start, dropping to 11.3v at the finish.

Sounds familiar. My car's last race was in 1998. :-)

Can you tell me about replacing the pumps? I see two wires going down into the top of the cell, but it's been a mystery to me what's in there or how I would go about replacing the pump(s).

Thanks.

[Charles Warner]

Russ,


I think we are mixing our Swifts. I assume you have a carbed version in the DB4 and there should be no alternator. The only way to change the pumps is to go into the cell. Not a fun job. The Reynard actully had a dual pump setup in the bottom of the cell as redundancy while only one pump was needed to run the car. You could switch between the pumps if need be. Should be standard GM style non-FI fuel pumps costing about $75 a piece. If the car sat that long it would be a good idea to pull the cell and have the cell pressure checked and the foam replaced. Replace the pump while you are in there.

The battery voltage should be fine as that car only requires around 4-5 psi fuel pressure, IIRC. You do have a pressure regulator, right? And it is for the proper range? If you are experiencing a pressure fluctuation I would suspect the pump or the regulator. Of course, with old race cars, everything is suspect. It's possible a line is collapsing or there is a leak somewhere in the lines in the cell itself.

[RussMcB]

Sorry to lead you down the wrong path, Charles. I have fuel injection. Fuel pressure seems to be around 63-64 lb. when normal, but has become erratic after a few laps, dropping down into the 50's, 40's and even 30's. I'm still wondering if the low pressures = lean mixtures = higher temperatures. I'm crossing my fingers that if I fix the FP problems and make sure the cooling system is bled, maybe my water temps will drop to normal.

[Charles Warner]

Russ,

I'd buy your logic. I don't know enough about those FI systems but I would think there should be an alternator of some sort. It should also be very obvious. Mine runs off the left half shaft with a special grooved pulley. I'm pretty sure my car won't run a whole race on the battery.

[Paul LeCain]

Charlie is right about the battery. The PC 645 won't run a fuel-injected car reliably for a National race. It might for a (presumably shorter) regional. A Varley 30 will work.

There are two pumps, as Dave describes above. The bottom one just pumps fuel up into the large aluminum tube where the high pressure one feeds the FI.

It's not too bad to get the whole thing out. It comes out as one piece attached to the top plate.

[Mark Ishikawa]

We've had lots of electrical problems with our Swift 008 before we started running alternators. Fuel pressure would bounce all oveer the place and sensors would start giving us strange readings as the voltage dropped. I've seen problems with the battery dropping below 11.5v under load.

Mark

[Purple Frog]

Russ,

Just reading your thread. A couple of things...

1. Could be a radiator cap that fails hot. Had that happen at RRR two years ago. It "blew by" lots of fluid also, ran hot. I was sweating bullets thinking we had bad head gasket, went to Tim @Safequip, bought a new cap, proceeded on.

2. Kevin @ Comprent told me about some miracle stuff he uses on Atlantics/Champ Cars with leaks. (even head gasket leaks) Brand name "Dike", manufactured by Conklin. Works fantastic. I might have got mine from Kevin. Call him! i discovered pinhole leaks in the Tatuus radiator a week before the Runoffs, put in the Dike, the rest is history. (But even during and after the crash, they never leaked.)

3. In 2000 at the Sprints my car went to real hot. We could not find anything wrong. Changed water pumps, etc. ) Only after I pulled the radiators and had them cleaned out did we solve the problem. The cause was an engine block that had been sitting a while. The water jackets around the cylinders had rusted. When we fired it up, and it got hot, the rust flaked off and clogged the radiators. They would flow fine, but were only flowing in 1/4 of the available tubes.

[Triallyr]

I don't mean to hijack the thread but could someone provide me with a wiring diagram to hookup the alternator (generator I think on my car,) and regulator? (Swift 008)



Any would be greatly appreciated

Steven

[RussMcB]

I don't mean to hijack the thread but could someone provide me with a wiring diagram to hookup the alternator (generator I think on my car,) and regulator? (Swift 008)

Steven, I would be interested in that discussion, too. Let's start a new thread for that topic, okay? Shall I or would you like to?

Edit:

NEW THREAD STARTED HERE --> http://www.apexspeed.com/forums/showthread.php?t=16391

[Dave Welsh]

Russ

As Paul said, Pulling the pumps out is not too hard. Just pull the top plate off the fuel cell, the aluminum pipe is attached to that plate. The whole works pulls out in one unit.

At the bottom of the inside of the tube is a Fram fuel filter element (for their external filter). Screwed to a fitting at the top of tis element is the pressure pump. It ma show a strange 5 digit part number. This is a TRD part number, and they want well over $200 for this pump. Not to worry. We went to our local CarQuest store, where the parts people know how to read parts books, think on their feet, and not rely on punching buttons on the parts computer to tell them what to do. When we entered the store, a parts man said, I have seen that pump, pulled a catalog off the shelf, turned to the proper page, and there it was. Cost $125, and is exactly the same as the TRD pump.

External to, and below the pipe is a GM style in tank pump with the sock style filter on it. This feeds fuel into the pipe (sump) which supplies fuel to the pressure pump when the fuel level drop below the pressure pump (The pressure pump sits about 5 inches above the bottom of the cell.. Both pumps are wired to the same circuit and both run at the same time.

To remove the fuel cell is a bitch. One has to remove the engine, remove about 80 rivets on the back plate to get to it, and then reverse the process.

ope this helps

Dave

[RussMcB]

Dave, two things:

1) "Hope this helps." Are you kidding? This is fantastic information. I'm amazed at the great assistance I'm getting here.

2) I think I may move and live near you. I haven't worked with a good auto parts guy in years. They don't have "1991 Swift DB-4 no A/C" on their computer screen as a choice, so that's usually the end of the discussion, followed by a diatribe by me about the way things use to be. :-).

[John Robinson II]

Dave,

Is the GM fuel pump a low pressure pump similar to the ones ATL sells? Is there a specific car model and year or can I just get a generic one. THe parts guys around here have no books, even the NAPA guys...lol

John

[TimW]

Not sure if this will help you or not John, but I use a KEM Parts EFP95 fuel pump in the cell of my DB6 and has worked great so far. Its 5-7 psi thus you need a dump valve or regulator, but otherwise is a sanitary way to remove yet another part from the engine bay.

[Dave Welsh]

Russ

2 photos are looking into the fuel cell. You can see the top of the pressure pump, and the aluminum tube is from the bottom, feeder pump.

John

Here is a photo of a GM pump similar to the bottom, feeder pump in our DB4. I believe it is a full size pickup truck pump.

Dave

[Mark H]

Hey Russ,

I use Carquest 10 times a day and they have very good guys that will cross part #'s with no problem.

Carquest has a kit called Block Test, we use it to find a compression leak into the cooling system. It comes with a rubber plug that pushs into the rad cap neck and a small tube above it that holds test fluid. You put this on and run the engine, if the fluid turns yellow there are HC's leaking into your cooling system.

The ceramic seal stuff is a stop gap fix that in my opinion (not worth much ) ,your situation dosen't warrent? Ive tried it and it won't seal a head gasket, it's more for sealing a crack or rad hole that isen't seeing high pressure like found in a cylinder. Plus it leaves a white paste thruout the cooling system.
I saw Junior Johnson put some in Bill's car during the last pit stop at the '94 Southern 500 while leading, because of 250 deg temps and water loss. They won the race but the engine locked down on the victory lap! Kinda not your situation huhh?

The lean problem could cause high water temps too? An engine with pop-up pistons don't like lean!