Serious Overheating

[oilslick]

I've only raced twice this season and both times I've had serious overheating and probably should have pulled off the track. Fortunately I don't think I've damaged anything but I can't take it back out until I fix this.

Both races I've been pushing 260+ degrees. Here's the general setup: I've got a Griffin radiator with an evacuation system. I run a stock water pump with Eslinger pullies on pump and crankshaft. I don't run a thermostat and I run with both water and antifreeze. Have not tried water wetter yet but at the temps I running I don't know if it will do any good. All my hoses and clamps are in good shape. The fan is electric and a run it. I've got the polarity so it pulls rather than pushes, thus it is attached to the back of the radiator. My radiator cap is a 20lb cap. My front has what I believe is enough air flow through it, at least to keep it below 260 degrees. Please help guys, I've haven't a clue what to do next.

Thanks

[car62]

vacuum leak will cause it to run hot,too much ignition timing will cause it to run hot,hoses with no springs in them can collapse and will cause it to run hot, running lean(too small of jets)will cause it to run hot...but in my past experience using griffin radiators...they didnt work for me,the fins are too close together,more for a super speedway car.

[Milford Motorsports]

First: isn't antifreeze illegal at most all tracks,that said.Check your ignition timing first,no more than 36* at 3500rpm.How big is your radiator,we always use a 31 x 19.How big is your fan,was it designed to run as a puller.Not all blade designs work effectivly running backwards.Is the water pump new,if not replace it.Have seen many used pumps fail to circulate water properly.Are you running 108 or higher fuel.Low octane fuel can cause heating problems.Is cam timed properly,is the carburetor jetted correctly.Lastly if everything checks out ok start opening up the nose piece,let more air through.

[let-r-eat]

Take that electric fan off and put a standard fan on. Try it. If it overheats then you can eliminate the fan. From my experience, 99% of the time I see an overheating gauge, its a junk radiator or poor fan.

[Doug_Guilds]

I have had the lower hose collapse when the engine was reved, no spring in it caused me problems.

I use a plastic fan with a shroud, stock pump, esslinger lower pulley, 5/8 restrictor in thermostat housing and a afco aluminum radiator. The car won't get over 160 degrees if I don't block off my nose opening. Block off half the opening and it runs about 185 at the end of the feature. Oh I use distilled water, no additives.

[84Dave]

Are you blowing water into the radiator overflow can with the 20# cap? If so, take the cap to your local parts house and have them check to make sure it's truly 'blowing off' @ 20#. With the radiator full in the shop, and the engine running/cap off, check for 'bubbles' in the water. If bubbles are present, maybe a leaking head gasket? Parts houses also have a little kit to check the radiator water for combustion gas. The tip on wire reenforced radiator hose is valuable. Particularly the lower hose from the radiator to the water pump input. A couple of times in the past, I've revved the engine to 4000-4500 in the shop & watched the lower hose collapse as the water pump 'sucked' the hose partially closed. That lower hose MUST be of a reenforced nature. And borrow a water temp gauge from a buddy to check the temp accuracy against your gauge. Particularly if no major water is being blown into your overflow can. -Dave-

[oilslick]

Thanks guys. Will keep fooling with it and keep you posted.

[dave41]

I have had the lower hose collapse when the engine was reved, no spring in it caused me problems.

I use a plastic fan with a shroud, stock pump, esslinger lower pulley, 5/8 restrictor in thermostat housing and a afco aluminum radiator. The car won't get over 160 degrees if I don't block off my nose opening. Block off half the opening and it runs about 185 at the end of the feature. Oh I use distilled water, no additives.

5/8 restrictor will solve problem, water flowing to fast ,not enough pressure against walls to pull heat.