blown radiator - ZR-1 Net Registry Forums

Bill · 10-24-2005

About 2 months ago put in a new radiator, while I had it apart I replaced the thermostat. I put in a Stant 14068 thermostat and a DeWitt A90M radiator. After about 500 miles the radiator started leaking. I pulled it out and sent it back to DeWittsâ€™s. Tom checked it out and said it had been overpressure. 90% of the tubes were ballooned out the end caps were also expanded. These end caps are made of .060 inch thick aluminum, that took a serious pressure excursion. I had reinstalled the stock radiator to keep the car running. After about 500 miles the same things happened to the stock radiator. Before replacing the radiator again I checked out the whole system. The only questionable part was the Stant 14068 thermostat. Evidently the pressure relief function of the thermostat was not functioning properly. After several conversations with Tom DeWitt I put the stock thermostat back in with another new A90M. The radiator in ALL of the C4â€™s are the same. The LT5 engine was designed with a much higher water flow than the other C4 engines. The radiator was designed for the standard engine. This means that the by-pass feature on our ZR-1â€™s must work or the radiator (weak point) will break! From what Iâ€™ve learned pressures inside my radiator exceeded 50psi to cause the damage that it suffered. I am attaching pictures of the stock & Stant thermostats and the housing. BTW I donâ€™t see how the thermostat can be put in backwards. It simply will not fit.
Stock thermostat

STANT 14068

housing

Thanks for reading

WB9MCW · 10-24-2005

gud post bill...who would of thought that a bogus bypass could lead to all the problems...glad u got a handle on it!!!

Bill · 10-24-2005

Hey, We learn something new every day.

tomtom72 · 10-25-2005

Jez'us Bill, sorry to hear that this happened to you!! I suppose that the real answer is stay with the stock GM T-stat??? Does Mr. DeWitt think that the stant could have been defective?

I hope the trouble for your car is over!

Tom

cuisinartvette · 10-25-2005

That's one heck of an expensive lesson, thanks for sharing that withus.

Kevin · 10-25-2005

I've had to replace 4 rads. It was not a very fun summer that year

Bill · 10-25-2005

I listed the same post on 2 other boards, The thread on corvetteforum was very informative
http://forums.corvetteforum.com/show...79&forum_id=50

It looks like the Stant part number is good, but the wrong part was in the box. I will be talking to Kragen where I bought it. Lets see what they have to say.

sledutah · 10-25-2005

Thanks for the heads up. Doesn't look like much fun figuring this one out

I saw the thread on CF last night. Glad to hear you've got it figured out now

Craig

10-24-2005	#1
Bill Join Date: Mar 2004 Location: Sacramento, CA. Posts: 141	blown radiator About 2 months ago put in a new radiator, while I had it apart I replaced the thermostat. I put in a Stant 14068 thermostat and a DeWitt A90M radiator. After about 500 miles the radiator started leaking. I pulled it out and sent it back to DeWittsâ€™s. Tom checked it out and said it had been overpressure. 90% of the tubes were ballooned out the end caps were also expanded. These end caps are made of .060 inch thick aluminum, that took a serious pressure excursion. I had reinstalled the stock radiator to keep the car running. After about 500 miles the same things happened to the stock radiator. Before replacing the radiator again I checked out the whole system. The only questionable part was the Stant 14068 thermostat. Evidently the pressure relief function of the thermostat was not functioning properly. After several conversations with Tom DeWitt I put the stock thermostat back in with another new A90M. The radiator in ALL of the C4â€™s are the same. The LT5 engine was designed with a much higher water flow than the other C4 engines. The radiator was designed for the standard engine. This means that the by-pass feature on our ZR-1â€™s must work or the radiator (weak point) will break! From what Iâ€™ve learned pressures inside my radiator exceeded 50psi to cause the damage that it suffered. I am attaching pictures of the stock & Stant thermostats and the housing. BTW I donâ€™t see how the thermostat can be put in backwards. It simply will not fit. Stock thermostat STANT 14068 housing Thanks for reading __________________ [img]http://home.comcast.net/%7Ebsoomann/srsig.jpg[/img]

10-24-2005	#2
WB9MCW Join Date: Dec 2003 Location: McHenry, Il. Posts: 6,607	Re: blown radiator gud post bill...who would of thought that a bogus bypass could lead to all the problems...glad u got a handle on it!!! __________________ http://i119.photobucket.com/albums/o...9mcw/SIG-2.jpg http://i119.photobucket.com/albums/o128/wb9mcw/vcm.gif "The Budget should be balanced, the Treasury should be refilled, public debt should be reduced, the arrogance of officialdom should be tempered and controlled, and the assistance to foreign lands should be curtailed, lest Rome will become bankrupt. People must again learn to work instead of living on public assistance." - Cicero, 55 BC " We the people are the rightful masters of both Congress and the courts, not to overthrow the Constitution but to overthrow the men who pervert the Constitution." - Abraham Lincoln

10-24-2005	#3
Bill Join Date: Mar 2004 Location: Sacramento, CA. Posts: 141	Re: blown radiator Hey, We learn something new every day. __________________ [img]http://home.comcast.net/%7Ebsoomann/srsig.jpg[/img]

10-25-2005	#4
tomtom72 Join Date: Dec 2004 Location: Jacksonville, FL USA Posts: 4,645	Re: blown radiator Jez'us Bill, sorry to hear that this happened to you!! I suppose that the real answer is stay with the stock GM T-stat??? Does Mr. DeWitt think that the stant could have been defective? I hope the trouble for your car is over! Tom __________________ 1990 ZR-1, Black/grey, #2233, stock. ZR-1 Net Reg Founding Member #316 & NCM member

10-25-2005	#5
cuisinartvette Join Date: Aug 2005 Location: San Fernando Valley, CA. Posts: 896	Re: blown radiator That's one heck of an expensive lesson, thanks for sharing that withus. __________________ 1990 ZR1, 142,000 miles-Black on black 4.09's Haibeck chip, 3"exh, K&N, meth inj.

10-25-2005	#6
Kevin Join Date: Jun 2005 Location: pittsburgh Posts: 4,633	Re: blown radiator I've had to replace 4 rads. It was not a very fun summer that year __________________ It's not the car, it's the people - Doug Johnson 90 r/r "KEYS ON" nick named "T.L.B"

10-25-2005	#7
Bill Join Date: Mar 2004 Location: Sacramento, CA. Posts: 141	Re: blown radiator I listed the same post on 2 other boards, The thread on corvetteforum was very informative http://forums.corvetteforum.com/show...79&forum_id=50 It looks like the Stant part number is good, but the wrong part was in the box. I will be talking to Kragen where I bought it. Lets see what they have to say. __________________ [img]http://home.comcast.net/%7Ebsoomann/srsig.jpg[/img]

10-25-2005	#8
sledutah Join Date: Sep 2005 Location: Centerville, Utah Posts: 134	Re: blown radiator Thanks for the heads up. Doesn't look like much fun figuring this one out I saw the thread on CF last night. Glad to hear you've got it figured out now Craig __________________ I feel sorry for people who don't drink, because when they wake up, that's best they feel all day -- Frank Sinatra Beer is proof that God loves us and wants us to be happy. -- Author Unknown, it is NOT Benjamin Franklin