I know it's been asked a million times before, but I would appreciate your help/advice with making the right choices the first time. I've got two purchases to make and could use your experience... My 455 struggles with overheating while idling. It does not have AC. It started as a 1972 GS350, but the prior owner installed a 1973 Electra 455 with 500HP/600 lb. ft. torque. It was used for 1/4 mile runs exclusively and saw very little traffic. Now I own it and drive it on the street. 100 °F outside and it's 220 °F and climbing in 10 minutes of idling, 40 °F outside and I might get 20 minutes of idle until I get worried. Though, at any ambient temp it will stay a wonderful 160 °F - 180 °F for hours so long as it's cruising 25mph - highway speed (70mph/2,400 rpm). Flushed radiator & tried everything else to increase air flow across radiator (except electric fans). Will check temp difference from radiator outlet to inlet this weekend. I currently have an original 3 core copper/brass radiator, 7 blade fan, HD fan clutch, properly fitted shroud, original type water pump, heater core, etc. (basically a stock cooling system). Pulley geometry is correct. I'm not a fan of aluminum radiators and it seemed petty straightforward until I began to read the fine print and options. Now I'm a bit confused at what to buy and just want a 4 core replacement original as much as possible. 1. Would this be a good option? https://usradiator.com/product/buick-skylark-1972-73-v8-350-455-factory-4-row-radiator Another concern is mpg. The last owner swapped the original 20 gallon tank for a lighter 13 gallon tank. I'd like to reinstall a 20 gallon tank to reduce my fill ups. 2. Would this be a good option? https://www.rockauto.com/en/moreinfo.php?pk=9108256&cc=1379785&pt=6268&jsn=422 It also has terrible vapor lock and heat soak, but I am going to use a shielded fuel line from the high flow pump and reroute it away from the header & up by the distributor instead, add a check valve, a glass fuel filter and pressure gauge (it's already split to the separate bowls with AN lines). The headers are already ceramic coated, but I will also wrap them as best I can. I appreciate your feedback...
No glass gas filter! You can get the radiator "rod'ed", basically the shop takes the tanks off, cleans the core and reassembles it. Does the fuel system have a return line to the tank? That keeps the fuel cool.
Do you have a fan shroud in the car? I would think that that 4 row unit would do a nice job. A two row aluminum with 1" tubes would also do well. I have read many reviews where a two row aluminum radiator keeps things cool - even in Phoenix, AZ with A/C on. You might also consider removing the thermostat if not driving the car in cold weather. With today's fuels you probably would not be disappointed with the stainless fuel tank.
I've used the stainless tanks before. They fit like stock tanks. A bit shinier than stock, but they look nice.
Yeah, maybe ditch the glass filter, seems like a hazard when you think about it. In line gauge does the same thing. The radiator I have is 51 years old, time for a new one. Besides, I'd rather not rebuild when I can get new. Return fuel line; it has a stock return vapor line, but the fuel system I run is almost stock at 6 - 10 psi max and doesn't need a return line to bleed off pressure. They just snaked the line right next to the driver side header, up the block & across the intake to the carb and it picks up too much ambient heat. The reason I wanted to reroute the line and blanket it to control heat absorption.
Let me agree, NEVER a glass fuel filter. Find another way to deal with the problem. Look into a fuel return line to the tank. Helping to keep cool fuel supply can reduce vapor lock. Other things are blocking any "exhaust" based heat to carb, air cleaner, intake heating by exhaust crossover or carb heat by blocking or isolation of heat. I use USRadiator brass/copper "optima" units in both of my Buicks. A bit pricy, but I cry once and can't hear all the naysayers as I jam down the highway or sit in near 100 degree stop and go traffic for several hours. I'm too old and cannot tolerate anything that results in sitting on the side of the road waiting for Triple A to bale me out. I'll spend now, cry now and then run for years than deal with the alternative trying to save a few bucks. YMMV...
Yes. I'll get a diagram tomorrow. But, basically, return fuel back to the tank from the fuel pump (mechanical) that keeps fuel flowing from the tank to pump that is cooler, rather than slowly supplying fuel that may be heat soaked to the carb. Older cars can be "upgraded" to later year pumps with a return, the line can be low pressure rubber, to return fuel to the tank. A lot of tanks have the ability to accept return fuel line to a specific port, and if not, you can facilitate a return line using a tank vent line port with a fitting and a check valve. This allows fuel not used by the carb, to tow back to the tank from the fuel pump and cooler fuel to supply the carb from the fuel pump from the tank.
Should you decide to go that route, make absolute sure the radiator shop uses the high efficiency cores Maine Auto Radiator sells. My local radiator guy uses their products and has done my original heater core - and a few for other board members - as well as my OEM Harrison 3 core. He's also redone a few radiators for board members as well. I have all the factory cooling components in my car and even on the warmest days, it runs nice and cool. Of course, if you're not a ridiculous OCD purist like me, there's obviously other options.
If your ignition timing at idle is relatively retarded, that alone will heat the engine up. Do you have vacuum advance? Also, looks like aluminum heads (Edelbrock?) and intake. Aluminum heads don't have a crossover, and aluminum intakes dissipate heat much faster than cast iron.
All the ancillary idle overheating possibilities have been checked thoroughly. Either can't get enough air across the radiator or need to reduce the coolant temp by adding surface area. Timing is fine, was a racer so no vacuum advance, just mechanical. Yep, heads are Edelbrock RPM Performer and intake is Edelbrock B4B.
Do you know if the fan clutch is operating correctly? Also, are you using a thermostat? What temp? And is it working correctly?
I'd say kind of in the middle ish. '73 block .030 over align bored 10.1 forged pistons Eagle forged rods Crank cut .010 under Flywheel cut Rotating assembly balanced ARP bolts Main bearings modified for oiling 5/8 pick up tube TA front cover/oil pump TA 413 cam - degreed Double grooved cam bearings Romac harmonic balancer 1786 Stage 1 heads ported by TSP TA HD rocker shafts w/hold down clamps/studs Lectric Limited ignition; distributor recurved/rebuilt by Dave Knutsen with 32° total, all in by 2,500 RPM Early B4B intake MT Super Scavengers '73 800 cfm Rob Ross Q-Jet It rarely hits 190° during the dog days of these Southeastern MA summers.
Well that leaves your 51 year old radiator The original radiators were marginal to begin with IMHO. A 51 year old radiator has to be at least partially clogged with solder bloom. Not sure you can effectively clean that out no matter what you do to it. Nothing will cool your engine like a 2 row aluminum radiator with 1 1/4" tubes. In your first post, you say that the engine will stay cool as long as the car is moving at 25-70 MPH. If the radiator was clogged, that would not be the case. It would heat up at speed. Your problem is at idle. Temperature creep at idle is classic retarded timing. You say timing is fine. Can you tell me what the timing is at idle?
New HD clutch fan, new thermostat (currently 160 °F, but replaced a 180 °F). Can feel upper hose go from luke warm to hot. I have an IR thermometer gun coming tomorrow, will check in/out temps...
Will recheck timing...I wouldn't call it temp "creep", I'd call it temp "run" from 170 °F to 220+ °F in just minutes (on a warm day, 80+ °F)...
HP as in high performance or horsepower? Not sure what the horsepower is, so, yeah - it's high performance.
