1st Situation: GM crate motor (from Summit Racing) with 10 - 15K miles T-350 automatic trans factory thermostat must be 185° because that's what it consistently runs at in Clarence; 3,500# panel truck was running poorly so changed plugs these plugs came in the engine when new old and new plugs are ACDelco R45TS plugs were fouled; a couple horribly A friend looked at the plugs and said he thinks that those plugs were meant for fuel injected engines running much hotter (230° or so) and not a cooler carbureted engine. This is a new concept to me. Question: Should a carbureted SBC 350 use a different spark plug? also see next situation. 2nd Situation: When sitting in traffic at SK-500 a couple of months ago engine pegged the temp gauge needle, which reads to 245°. Engine never boiled over. After cool-down coolant level in top radiator tank remained right where it always is. Radiator is aluminum built by Portell Radiator (using the original 1948 Ford radiator as a pattern/template). Question: Should I change thermostat so engine runs hotter?
Like Jim said 45 ts , maybe switch to a NGK , Been over 20 year since I use ACs I felt quality no longer there, Maybe air in system . Witch crate, The reason I ask Vortec , uses a double spring thermostat & if using with Non reverse W P A by pass or heater hose's needed
190 (195 ???) hp engine; pretty much Summit's base engine when I purchased it in 2015. Most of the intervening time was spent in various shops getting body mods. When the engine was new I drove it for a couple of summers and then last year I put 8K miles on it. It was pretty much parked for 6-7 years. I don't know what Vortec means, although I've heard the term, but I doubt that this engine is such an animal. Clarence has heat/air so yes, there is a heater hose.
I'm getting the feeling that you're thinking the spark plug heat range will have a direct effect on coolant temperatures. I think you're going to find that this is not the case. The first thing I'd check is if your engine has reverse flow cooling or not. And then make sure you're rotating the correct water pump in the right direction to ensure proper coolant flow.
@atch Vortec has ""8 bolt intake"" , bolts are vertical with 4 center bolt Vavle covers , Main identification the 8 bolts . The other sbc heads 86-94 with 12 bolt intake & 4 center Bolt vavle cover also But Not a Vortec, In OEM set up the Vortec has reverse rotation water pump , with double spring thermostat. In Hot Rod use most put / use a Standard rotation water pump , with carb intake , Then you still need the double spring thermostat & a bypass or heater hoses needed , with out , if temp gauge reads correct Temp will be 240- plus with out Double thermostat & No bypass / heater hoses ... ""Timing "" No matter witch year from 60s - 98 ish Gen 1 sbc 's "" None SB2 engine"" with carb Stock to slight Mods , it will like Run better with 12ish to 17ish deg's of initial timing BTDC . Over factory spec thats Like 8 deg's BTDC ,, Also not enough initial timing BTDC plays a part cooling temps @ idle & low cruse speeds . So verify witch year / style engine if Vortec 8 bolt intake .. Then No Air in cooling system all Gen 1 sbc. Thermostat working correctly & Initial Timing BTDC
I doubt you have the wrong direction water pump, you would have had trouble right from the start. If it only gets hot while stuck in low/no speed traffic, then it's an airflow through the radiator issue. You haven't talked about your fan/shroud set up, but 245 is too hot. I chicken out and shut down at 230. I like 180. Running up at 210 like a modern car gives you very little leeway if something goes wrong. Your rings start to lose tension up much higher than 240. I'm with Eddy on plugs, NGK has a tech line that can give a recommendation for plugs. If the plugs are fouling, your carb may be too rich, or choke not open, or other reasons.
Chevy used different plug gaps over the years. 0.035 with points, then 0.060 with HEI, then they dropped it back to 0.045 because folks let them go too long without replacing them. So if you have a "low energy" ignition system with a can type coil, 0.035 is good, if you have an HEI with the square coil, then 0.045 will work. But 0.035 will still work either way. The carb could be causing the problem, but there might be something else? if you have PCV and aftermarket valve covers without good oil separators, it could be drawing in oil? like was mentioned, pictures of the fouled plugs will help us help you figure it out
Jim [squirrel ] is always pretty much on the head. I would clean the plugs, re gap to a middle of the road .030, install and go for a 20 or 30 mile drive, beating on it as much as practical . Check the plugs again. Remembering which cylinder was fouled. Ben
What distributor and ignition system are you using to fire the engine? And what plug gap? If it's a newer electronic ignition I'd gap those plugs about .040", but if it's got an MSD or high voltage coil I'd go more like .050" gap.
Actually just the opposite. I was wondering if running the engine hotter would help keep the plugs cleaner. And I'm not worried about the water pump. Engine has "old fashioned" 4 perimeter valve cover bolts. I'm not worried about overheating. I only mentioned the "stuck in traffic" comment to show that the cooling system is holding pressure well and probably wouldn't be adversely affected if I installed a higher temp thermostat. Distributor is original GM single point from way back and has ballast resistor installed. I'm very aware that if temp goes up at low speed that a shroud is needed. Clarence had a shroud when the original radiator was there but I need to make a shroud to fit the new aluminum radiator. The carb being the source of fouled plugs never occurred to me. I'll be checking into that. SO; in answer/response to my original questions: I'll keep on using ACDelco R45TS for now but might also call the NKG tech line. I'll keep the 185° thermostat. Thank you all for your input and wisdom. Case now closed.
Even though you only have 10 to 15K miles on the engine I would do a leak down test to determine if the rings, valves, valve guides and seals are not the problem. Just a suggestion as it may save you time confirming that the engine is mechanically functioning correctively.
Fuel has changed a lot in the last 5 years - to aid modern fuel injected cars that run higher compression, finer screens in the injectors, etc... It has nothing to do with ethanol. To make up for it, 16-18 BTDC at idle is needed to prevent engine temps from climbing in your average SBC. Most of the new GM Goodwrench SBCs run 98-99% on a leakdown when new. I'd double check mixture and maybe add a bit more fuel - remember fuel acts as a combustion chamber coolant!!! Make sure your vac unit is holding a vacuum and not creating a vacuum leak.
Id first make sure its not running so rich or flooding its not fuel fouling the plugs . would have black smoke and smell like gasoline bad . What carb and is the choke on ? If its oil fouling the plugs it would be burning a shit ton of oil and you would have blue smoke. you would know you have a issue and there would be all kinds of build up on the plugs I highly doubt those plugs are fouling to running to cool or have anything to do with engine temp. check the timing is not to retarded , check the carb is not running to rich at idle and going down the road . really look at the plug and see what is burning . Id also check the compression and stuff as if its got a deas or weak cylinder its going to show a fouled looking plug as well This is the stuff if your going to be a hot rodder you need to learn how to diagnose .
His heads (being newer than 1969) will take tapered seat "peanut" plugs, so the R46 won't work in them.
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