I have a 71 Cutlass with a 455cu (all cast iron - 30 over - C cast heads) that was rebuilt several years ago. Since the rebuild I have had overheating issues. My question, is there an easy way to tell if the head gaskets were put in incorrectly?
The issues are:
1) when starting the engine in 60 deg weather when chock is set on high idle (1200 rpm) and not moving the engine will heat up quickly to 220 deg and spit out coolant into overflow. The electric fans are set to start about 190 deg.
2) when driving on expressway at 65 - 70 mph (2800 - 3000 rpm) the engine will start climbing above 220 deg until I slow down to 60 mph when the temp will come down. I have not run it long enough to find the high temp, I have seen it go over 230 deg. This same thing happened even with a 180 deg thermostat or restrictors so it's not flowing thru the radiator too quickly.
Things I have tried to rectify - different clutch fan, high volume pump, 4 core radiator, different thermostats and restrictors. The block and heads was heat cleaned to break up and remove all debris and all passages checked, then machined.
I now have the 4 core radiator that is used in 442's w/455, Flow Cooler high volume pump, no thermostat or restrictor and Derale dual electric fans.
I believe that one or both head gaskets were installed upside down leaving a front passage open allowing the water to flow thru the front part of the head and not the rest thus creating excessive heat in the back of the block. There is no visible difference in the block paint showing excessive heat and the plugs all look the same so the heat difference is not visible but something is causing these issues.
If there is an easy way to find out if a head gasket was installed incorrectly (visible tabs etc.) it would be good to know, I would hate to pull off the heads.
Thanks, Ted

 

May be able to use an infrared point and shoot thermometer on the intake cooling runners to determine which is hotter/cooler. I'm ASSUMING that the rear ports should be a little cooler than the front but I'm not certain. Anyone know for sure?

 

Do you know how tight the pistons were installed? To tight will cause heating problem. Do you have the timing correct?

 

1st, make sure your radiator cap is holding pressure

2nd Replace your thermostat

 

bingo

 

Your question was about head gaskets. I have never seen head gaskets for the Oldsmobile tall deck series motors marked for "correct orientation" installation. Therefore I don't believe that they could be the culprit.

 

 

I am not sure this will give any helpful info.

 

I spoke to the engine builder and he is certain they are not too tight.

 

The radiator and thermostat are not the issue but the radiator cap is 18psi and seals and if you read the full post you would know I am not running a thermostat currently. I have tried several different thermostats (160,175,180 & 185) and several different size restrictor plates (5/8", 3/4", 1") and there was negligible difference.

 

I read your post, and I would remove the water pump to check the impeller, getting way too hot at idle. My 455 runs around 180* at idle with 1 fan running, stock Olds pw., and 180* in motion.

 

Nice ride and i like the color and wheels.
I have used a stock water pump and even tried a second new water pump from Rock Auto thinking the first may have been a cheap chinese knock off. Currently I have a Flow Cooler water pump with higher flow rates, pressure and 30% cooling and I still have issues.
My motor is all cast iron, "C" heads and the block is 30 over so a total of 465ci. I have seen and heard of many 455's 30 over that had heat issues and everyone had tried different things with very little results.
The inital cooling where is spikes on warm up I can reslove and it will idle at 185 - 190 with no issues after. The rising temp at 2800 to 3000rpm continuous driving (open road or expressway) is the major concern because it will go over 230 and that is where I back off to let it cool down.
How do you like the Legend 5 speed? I was thinging of going with a Tremec 5 speed.

 

The issues are:
1) when starting the engine in 60 deg weather when chock is set on high idle (1200 rpm) and not moving the engine will heat up quickly to 220 deg and spit out coolant into overflow.

1. Did you personally install the water pump after inspecting the impeller? Was wp gasket installed properly?
2. Aftermarket radiator?
3. Temp gauge accuracy verified?

 

1) Yes and yes
2) No, but the 4 core radiator that is used in 442's
3) Yes with multiple different gauges.

 

Just looking at your pics, it looks like you have 2 temperature sensors in your intake, mechanical and electrical? Please correct me if I am wrong. I would check to see if that is causing coolant flow issues in the area you are sensing the temp?? May want to try going down to 1, and jusmake sure coolant flow is not being disturbed. Just a thought.

 

I have the same scenario as you but didn't create a thread. For 1), how quickly? Maybe we are used to modern engines or small 4 cylinders compared to big cast iron V8s get up to temp "quickly" compared to other engines. For 2), curious what is your axle ratio? If your car was originally designed for say a 2.73 ratio, it would turn less rpms at that speed and run cooler. Mine has a 3.73 and bet it would run cooler with OD. Service manual considers 250+ "overheating" if you read the temperature light section also.

1) when starting the engine in 60 deg weather when chock is set on high idle (1200 rpm) and not moving the engine will heat up quickly to 220 deg and spit out coolant into overflow. The electric fans are set to start about 190 deg.2) when driving on expressway at 65 - 70 mph (2800 - 3000 rpm) the engine will start climbing above 220 deg until I slow down to 60 mph when the temp will come down. I have not run it long enough to find the high temp, I have seen it go over 230 deg. This same thing happened even with a 180 deg thermostat or restrictors so it's not flowing thru the radiator too quickly.