Long story, but I'll try to outline some good trouble shooting steps for cooling issues.
I have a restomod with a 383 stroker. I've dumped waaaaaayyyyyyy too much money in it and for the last y ear it's been running hot. The saga started when I charged the AC at a friends shop and it overheated on the way home. Another guy told me the AC was overcharged and that I was sitting on a bomb
. I had another shop discharge it and refill and they said if anything, it was a little light on freon. I asked what pressure it was running at and they said a good pressure, but it was climbing since the fan didn't turn on. Ok, I guess I needed a trinany switch to toggle on my electric fan. So, another discharge and I installed the switch. Since it was getting warming, I decided to make sure it was running cool before I charged the AC again.
The best advice I had at that time was to change to a mechanical fan, but I wanted to stay electric.
I designated a 3 mile "course" by my house, pretty good hill. I'd drive it aggressively to the top. The temp would hit 204. And then it would detonate.
Now I have some pretty good components in my newly rebuilt rig. Sanderson block huggers to keep the heat flowing out, billet true track with Edelbrook 8882 high flow water pump and a Ron Davis radiator with a high output spal fan. The fact that these components wouldn't cool my rig was depressing. All desire to keep working on other parts of my cruiser was put on hold indefinitely. I was seriously depressed.
In a last ditch effort, I decided to call Ron Davis and see if my I had a bad radiator. To my surprise, Ron actually called me back and we worked together for the next 3 weeks trying different things.
Once again, the baseline test was hammering up the course to read 204 degrees at the top.
1. Pulled off the hood to determine if the engine compartment was not passing air. Result was 203. No guarantee that the radiator and fan are not the problem.
2. IR temp gun check on the top of the radiator and the bottom. You have to make sure you're not temping anything shiney. You can add black electrical tape. I temped a 20 degree difference between the top and bottom. Ron said that's a little high and would like to see 10-15 degrees. At this point, we're pretty sure the radiator is cooling, just the coolant is not moving fast enough.
3. Hogged out an old themostat for the spacer but essentially ran with no thermostat. 202 degrees on the run. Little better, but not good enough.
4. Neighbor had an IR camera and we filmed the whole setup. He thought my super expensive stainless steel radiator hose with AN fittings were slowing the coolant. I tried a $100 experiment and bought a stock standard thermostat housing, radiator hose and Mr Gasket high flow thermostat. No difference, still hitting 202.
4. Did some investigation on the water pump pulley. Billet Specialties said the pulley is 70% the size of the crank pulley so is over driven very close to OEM. Edelbrok says the pump can run at 6800 RPM so I have some headroom. I still may experiment with a smaller pulley, although Ron wasn't excited about this option.
5. I talked to my engine builder and he recommend more fuel and timing. I was at 14.2 AFR so I kept making passes on the hill increasing the fuel .2 each run until I hit 13, I saw no difference to went back to 13.2. Same thing on timing. Timing made the biggest difference, and I was at 38 degrees advanced. I was now just below 200 at 199. Pretty good.
6. On a short trip on the freeway, I was creeping up to 205 and pulled over. I remembered that I set the Dakota Digital fan control to cut out at 50 mph. I turned that option off and now run with the fan on all of the time, if its over 180. Since it was also knocking, I back the timing back to 36 degrees.
7. I was about to go 4x4 camping and I was over heating again. The fan wasn't turning on. After inspection, I noticed that the cheap 60 amp breaker was turning off and on. If I pushed the breaker closed, it would stay on. So bad breaker, who knows if it had been cutting out the entire time. Replaced it with a 60 amp inline fuse and ran it that weekend. Ran fairly cool, but still knocked at 192+ when I was on the throttle.
8. Replaced the spark plugs with one step cool heat range. Went with Nkg UR6 plugs. Ran the hill again, with AC charged and blowing cold, 198. I'm also getting no detonation.
I think I'm pretty close. Close enough that I started working on other parts.
The neighbor had a great idea on verifying that my fan relay (and my fuel relay) are working. Old phone lan line stripped and folded over the spade connections on the relay. Then run the wire up the windshield and wire up LEDs. Obviously you'll need power on the ground spade LED, but all 4 lights should light if the relay is working.
Sorry for the long post, but I feel for anyone with a SBC who can't cool it. Hit me up with any suggestions or questions.
I have a restomod with a 383 stroker. I've dumped waaaaaayyyyyyy too much money in it and for the last y ear it's been running hot. The saga started when I charged the AC at a friends shop and it overheated on the way home. Another guy told me the AC was overcharged and that I was sitting on a bomb
. I had another shop discharge it and refill and they said if anything, it was a little light on freon. I asked what pressure it was running at and they said a good pressure, but it was climbing since the fan didn't turn on. Ok, I guess I needed a trinany switch to toggle on my electric fan. So, another discharge and I installed the switch. Since it was getting warming, I decided to make sure it was running cool before I charged the AC again.The best advice I had at that time was to change to a mechanical fan, but I wanted to stay electric.
I designated a 3 mile "course" by my house, pretty good hill. I'd drive it aggressively to the top. The temp would hit 204. And then it would detonate.
Now I have some pretty good components in my newly rebuilt rig. Sanderson block huggers to keep the heat flowing out, billet true track with Edelbrook 8882 high flow water pump and a Ron Davis radiator with a high output spal fan. The fact that these components wouldn't cool my rig was depressing. All desire to keep working on other parts of my cruiser was put on hold indefinitely. I was seriously depressed.
In a last ditch effort, I decided to call Ron Davis and see if my I had a bad radiator. To my surprise, Ron actually called me back and we worked together for the next 3 weeks trying different things.
Once again, the baseline test was hammering up the course to read 204 degrees at the top.
1. Pulled off the hood to determine if the engine compartment was not passing air. Result was 203. No guarantee that the radiator and fan are not the problem.
2. IR temp gun check on the top of the radiator and the bottom. You have to make sure you're not temping anything shiney. You can add black electrical tape. I temped a 20 degree difference between the top and bottom. Ron said that's a little high and would like to see 10-15 degrees. At this point, we're pretty sure the radiator is cooling, just the coolant is not moving fast enough.
3. Hogged out an old themostat for the spacer but essentially ran with no thermostat. 202 degrees on the run. Little better, but not good enough.
4. Neighbor had an IR camera and we filmed the whole setup. He thought my super expensive stainless steel radiator hose with AN fittings were slowing the coolant. I tried a $100 experiment and bought a stock standard thermostat housing, radiator hose and Mr Gasket high flow thermostat. No difference, still hitting 202.
4. Did some investigation on the water pump pulley. Billet Specialties said the pulley is 70% the size of the crank pulley so is over driven very close to OEM. Edelbrok says the pump can run at 6800 RPM so I have some headroom. I still may experiment with a smaller pulley, although Ron wasn't excited about this option.
5. I talked to my engine builder and he recommend more fuel and timing. I was at 14.2 AFR so I kept making passes on the hill increasing the fuel .2 each run until I hit 13, I saw no difference to went back to 13.2. Same thing on timing. Timing made the biggest difference, and I was at 38 degrees advanced. I was now just below 200 at 199. Pretty good.
6. On a short trip on the freeway, I was creeping up to 205 and pulled over. I remembered that I set the Dakota Digital fan control to cut out at 50 mph. I turned that option off and now run with the fan on all of the time, if its over 180. Since it was also knocking, I back the timing back to 36 degrees.
7. I was about to go 4x4 camping and I was over heating again. The fan wasn't turning on. After inspection, I noticed that the cheap 60 amp breaker was turning off and on. If I pushed the breaker closed, it would stay on. So bad breaker, who knows if it had been cutting out the entire time. Replaced it with a 60 amp inline fuse and ran it that weekend. Ran fairly cool, but still knocked at 192+ when I was on the throttle.
8. Replaced the spark plugs with one step cool heat range. Went with Nkg UR6 plugs. Ran the hill again, with AC charged and blowing cold, 198. I'm also getting no detonation.
I think I'm pretty close. Close enough that I started working on other parts.
The neighbor had a great idea on verifying that my fan relay (and my fuel relay) are working. Old phone lan line stripped and folded over the spade connections on the relay. Then run the wire up the windshield and wire up LEDs. Obviously you'll need power on the ground spade LED, but all 4 lights should light if the relay is working.
Sorry for the long post, but I feel for anyone with a SBC who can't cool it. Hit me up with any suggestions or questions.
