Uh Oh

[smittytx]

I went down to Texas World Speedway last weekend, on Saturday I was having a great run and then got in a small train and my temps started creeping up. I didn't really think anything about it because they settled down as soon as I got past the train. So I stomped on the pedal as hard as I could and about one lap latter my temps start shooting up. At 250 CHT I'm off the power and coasting at about 70 mph and they still keep climbing. I cut the motor and turn the ignition back to on to monitor the temps and it's still climbing. I started just to see if some water circulation will stop the rising temps, no luck. I stopped the motor and could only watch while my temps (ECT and CHT) went up to the low 290s. I get towed in and water the reservoir is bone dry and I have fluid all over the side of my car. I am bummed! I added water to the system and the car started right up and idled normally, I feel one percent better. Nobody had a hose so I went to Lowes and pieced together my own repair kit. So I fix my radiator and hose and wait for Sunday, I had SOME hope since it started up and sounded fine.
On Sunday I went out and babied it for half of the session and temps were good so I got on it and everything was fine. I put some new 295s R6s on and went out and bested Saturday’s time by just over 5 seconds. So it ran great for four sessions yesterday. I don’t know what to think, it ran fine, but I had to have taken some of the life out of it.

Guess I’ll find out.

Thoughts?

 

[2012YellowBoss]

Hard to say, sounds like you did not hurt it too bad. It is amazing how much abuse these Road Runners can take and still keep going strong.

However, I'm no expert so better ask Mark

 

[steveespo]

Mark
I think you may be OK if you got off it before it went in limp mode. The CHT spiked because steam formed in the heads as air replaced coolant and pressure was lost due to the hose breaking. The oil will help cool the engine somewhat, but you should change that too before running the car. Biggest potential problems are head gasket, warped valve seats or valve heads. Combustion heat is transferred from the valve heads to the seat and taken away by the coolant in the heads around the combustion chambers. When this coolant goes to steam circulation stops and things start bending. Change the oil, make sure the coolant system is vacuum filled so there are no air pockets in the heads and then run the car moderately. If there is any sign of power loss shut it down. At that point damage to the heads is likely but the short block is probably OK, a head rebuild or new heads, gaskets and head bolts would be in order probably $5000, if the bottom end goes too you will have to plug in a new crate Boss for $12000. Hopefully no real damage occurred
Good luck with it.
Steve

 

[ArizonaBOSS]

Eek. Did you blow a hose or what?

 

[Jimmy Pribble]

All of the 302Rs that I saw this weekend used hard rad lines and silicone hose to join the hard pieces. Some used the Canton overflow. I didn't see anyone using stock hoses or plastic overflow. These things won't help the overheating problems, but they could mean the difference between a bad and catastrophic event.



Can you remind us what cooling mods you have already? TWS is my "home" track and I will be trying to get the Boss out there this year. I thought we were in better shape than some of the guys on this forum, since we are closer to sea level. Apparently, that might not be the case.

 

[gremlinsteve]

warped head and or dropped valve seats are your main concerns with high temps.
cht temps will read higher than coolant temps as you know. do you know what the ect was at? not that it was accurate as stated due to the steam

 

[Sesshomurai]

No engine codes or sloppy idle? Good sign.

Is there a hose upgrade path on the market or is it all fab Jimmy.

 

[PeteInCT]

I agree with Steve, if you didn't go limp I'd think you didn't do much damage.

 

[smittytx]

The hole in the hose happened because the lower right rubber bushing that supports the radiator was gone. This caused the radiator to drop about 1/2 inch, it didn't drop any further because the hose was resting on a nice sharp object which rubbed a hole into it.

I think I may have hit limp mode, if I did it was only for a few seconds before I shut it down. My ECT and CHT temps were both at 295. My oil temp never got above 235.

I ran fine the next day. Should I pull the heads and have them checked?

 

[Jimmy Pribble]

Is there a hose upgrade path on the market or is it all fab Jimmy.

It looked different for each team, so I'm guessing it was just fabbed-up. Too many variables on radiators, overflows, etc.

 

[ArizonaBOSS]

The hole in the hose happened because the lower right rubber bushing that supports the radiator was gone.

I'm assuming this was a result of your Mid-Ohio trip? You guys just forget to replace the bushing or something during the rebuild?

 

[Roadhouse]

Sounds like somewhat of a scary situation. Glad you were able to get back out there Sunday though and sounds like everything may be OK.

 

[steveespo]

The hole in the hose happened because the lower right rubber bushing that supports the radiator was gone. This caused the radiator to drop about 1/2 inch, it didn't drop any further because the hose was resting on a nice sharp object which rubbed a hole into it.

I think I may have hit limp mode, if I did it was only for a few seconds before I shut it down. My ECT and CHT temps were both at 295. My oil temp never got above 235.

I ran fine the next day. Should I pull the heads and have them checked?

If it runs OK I wouldn't mess with it. The money to have it torn down to inspect could be used towards replacing parts you know are bad. Drive it to see how it feels, if it seem on power then you are probably good. I once had a built supercharged 302 that I lost all the oil from a ruptured oil cooler hose clutched it when I felt the rear slip in 3rd on a drag pass. Saw oil pressure at 0 and thought I threw a rod out of the pan. Removed oil cooler adapter, put the filter back on, filled her up and that engine is still running 23 years later. It's probably all good.
Steve

 

[gremlinsteve]

the first and prolly only thing i would worry about is the valve seats falling out of the heads.
once that happens your done. it will eat itself.
sounds like you dodged the bullet though as it should have already happened.
mopars hemi is well known for doing just that at around the 250-260 degree area.

steve