Extensive BB water temp testing.......(Mr. Dewitt, please step in..)
Thread Starter
Le Mans Master
Joined: May 2006
Posts: 9,993
Likes: 1,136
From: League City Tx
I drove it around some more yesterday. It was 92* and the car still ran 170* or less on the highway. In town with the AC on it runs around 180-185* as long as I'm barely moving. At a dead idle with the AC for about 10 mins(like a couple LONG stop lights) it was at 190* but cools back down at speed. So it looks like it will be ok unless I get stuck in a bad traffic jam, like 20-30 mins or something...and even then it would likely just creep on up. Hopefully not though. Probably would have cooled better in town with the electric fans but the simplicity and reliability of the clutch fan can't be beat.
I look forward to a lot of cruising this summer! If I can afford the gas....my last tank measured at 9mpgs and that had a lot of highway miles...
I look forward to a lot of cruising this summer! If I can afford the gas....my last tank measured at 9mpgs and that had a lot of highway miles...
Burning Brakes
Joined: Sep 2008
Posts: 753
Likes: 0
glad that you are happy with the Alu radiator
when i received my l88 replica a couple years ago , she had all kinds of cooling issues due to the copper radiator ( that was in bad conditions too). I went immediately for a Dewitts and everything was fine. Also I'm more concerned than you in weight reduction on the front. you had both the copper and the Alu rads in your hand. do you see how nicely lightweight is the Dewitts?Go for nice Aluminum heads. i removed also the power steering to get rid of that sloppy steering feel and save other 24lbs on the front
Aldo
when i received my l88 replica a couple years ago , she had all kinds of cooling issues due to the copper radiator ( that was in bad conditions too). I went immediately for a Dewitts and everything was fine. Also I'm more concerned than you in weight reduction on the front. you had both the copper and the Alu rads in your hand. do you see how nicely lightweight is the Dewitts?Go for nice Aluminum heads. i removed also the power steering to get rid of that sloppy steering feel and save other 24lbs on the front
Aldo
Drifting
Joined: Jul 2009
Posts: 1,534
Likes: 14
From: Dallas-Fort Worth TX
Good Job Alan, glad to hear it worked out. 
160* T stat,, if you ran a 180 t stat, do you think your temps would end up higher? Meaning would it run at 170 on the highway or would it run up to temp to 180 for the different t stat? I am a bit confused on what T-Stat I should use. 160 or 180.
If it gets hotter provide another report.
Weather calls for 99* for a high hear all week long.... and its technically not even Summer yet.....
160* T stat,, if you ran a 180 t stat, do you think your temps would end up higher? Meaning would it run at 170 on the highway or would it run up to temp to 180 for the different t stat? I am a bit confused on what T-Stat I should use. 160 or 180.If it gets hotter provide another report.
Weather calls for 99* for a high hear all week long.... and its technically not even Summer yet.....
Thread Starter
Le Mans Master
Joined: May 2006
Posts: 9,993
Likes: 1,136
From: League City Tx
Good Job Alan, glad to hear it worked out. 160* T stat,, if you ran a 180 t stat, do you think your temps would end up higher? Meaning would it run at 170 on the highway or would it run up to temp to 180 for the different t stat? I am a bit confused on what T-Stat I should use. 160 or 180.
If it gets hotter provide another report.
Weather calls for 99* for a high hear all week long.... and its technically not even Summer yet.....
160* T stat,, if you ran a 180 t stat, do you think your temps would end up higher? Meaning would it run at 170 on the highway or would it run up to temp to 180 for the different t stat? I am a bit confused on what T-Stat I should use. 160 or 180.If it gets hotter provide another report.
Weather calls for 99* for a high hear all week long.... and its technically not even Summer yet.....
Well obviously...a 180* stat will have it running hotter. If a cooling system is capable of cooling an engine down to 160* consistantly and you go to a thermostat that is hotter then that, then it will stay shut until the temp climbs up to it's opening temp setting....ie 180*.
As for yours, it really just depends on what water temp you want it to run. I am sure a 180* stat will be fine. I really wanted mine a tad cooler then that to help ward off detonation and dieseling, not to mention make more power.....I like mine running at 165-170*, especially when I am beating on it. This is the water temp the engine builder recommends....he builds and sells about 8-10 of these 10 Sec big blocks a month so I trust what he says.
Racer
Joined: Oct 2005
Posts: 273
Likes: 1
From: Fabens TX
I am reading this thread with alot of interest as I am also having cooling problems. My deal is that I am close to swapping in a 498 with iron heads (for now) and worried about cooling as I stated . Currently the small block has 305 heads that the previous owner installed on a 350 short block. I know , it was a bad move. I 'm thinking if maybe that raised cpr to high and that's what 's contributing to my overheating problems. My problem was that I was cool at idle and at highway speeds I start overheating. Well I swapped out the 4 core rad for a 2 core alum rad . It cooled my engine real nice at idle but still would creep up to 220-230 at highway speeds. I put a closer to the ground air dam and that helped a bit . It cooled the engine about 10 degrees. I think I need to have the dam closer to the ground to scoop up more air. That is where I am currently. This bbc that I am swapping in is supposed to be about 450-480rwhp and maybe hit the 500rwhp mark when I go aluminum heads.
Pro
Joined: Nov 2008
Posts: 680
Likes: 5
From: Denham Springs LA
Is it normal for all big blocks to run hot in traffic?
I have a stock 71BB (365hp) with 59,000 miles I bought this winter. The original radiator had a leak so I replaced it with the DeWitts Aluminum and new seals. Car runs about 190F on highway and while moving around town. But sitting in traffic more than 10 minutes it creeps up, getting hotter and hotter, above 220F, I don't know how hot it will get, but I am worried. I don't have AC hooked up yet so I expect it to run even hotter when I get that fixed.
This car sat for about 6 years (before I bought it) with very little driving/running. I replaced all the heater hoses and radiator hoses. I found the heater hose nipples/fittings on the engine to be very corroded. I flushed the engine with typical off the shelf prestone engine flush. I didn't remove the plugs from the side of the engine. Does flushing the engine by removing the threaded plug on the side of the engine make a big difference in engine temperature?
Roger
I have a stock 71BB (365hp) with 59,000 miles I bought this winter. The original radiator had a leak so I replaced it with the DeWitts Aluminum and new seals. Car runs about 190F on highway and while moving around town. But sitting in traffic more than 10 minutes it creeps up, getting hotter and hotter, above 220F, I don't know how hot it will get, but I am worried. I don't have AC hooked up yet so I expect it to run even hotter when I get that fixed.
This car sat for about 6 years (before I bought it) with very little driving/running. I replaced all the heater hoses and radiator hoses. I found the heater hose nipples/fittings on the engine to be very corroded. I flushed the engine with typical off the shelf prestone engine flush. I didn't remove the plugs from the side of the engine. Does flushing the engine by removing the threaded plug on the side of the engine make a big difference in engine temperature?
Roger
Race Director
Joined: Mar 2006
Posts: 14,112
Likes: 28
From: Florida
Is it normal for all big blocks to run hot in traffic?
I have a stock 71BB (365hp) with 59,000 miles I bought this winter. The original radiator had a leak so I replaced it with the DeWitts Aluminum and new seals. Car runs about 190F on highway and while moving around town. But sitting in traffic more than 10 minutes it creeps up, getting hotter and hotter, above 220F, I don't know how hot it will get, but I am worried. I don't have AC hooked up yet so I expect it to run even hotter when I get that fixed.
This car sat for about 6 years (before I bought it) with very little driving/running. I replaced all the heater hoses and radiator hoses. I found the heater hose nipples/fittings on the engine to be very corroded. I flushed the engine with typical off the shelf prestone engine flush. I didn't remove the plugs from the side of the engine. Does flushing the engine by removing the threaded plug on the side of the engine make a big difference in engine temperature?
Roger
I have a stock 71BB (365hp) with 59,000 miles I bought this winter. The original radiator had a leak so I replaced it with the DeWitts Aluminum and new seals. Car runs about 190F on highway and while moving around town. But sitting in traffic more than 10 minutes it creeps up, getting hotter and hotter, above 220F, I don't know how hot it will get, but I am worried. I don't have AC hooked up yet so I expect it to run even hotter when I get that fixed.
This car sat for about 6 years (before I bought it) with very little driving/running. I replaced all the heater hoses and radiator hoses. I found the heater hose nipples/fittings on the engine to be very corroded. I flushed the engine with typical off the shelf prestone engine flush. I didn't remove the plugs from the side of the engine. Does flushing the engine by removing the threaded plug on the side of the engine make a big difference in engine temperature?
Roger
Thread Starter
Le Mans Master
Joined: May 2006
Posts: 9,993
Likes: 1,136
From: League City Tx
Roger I am not sure that flushing your block out will make THAT much difference...odds are, most of the scale, corrosion etc in the block would have to be hot tanked/grinder out....not just rinsed out with a hose. I suppose it is worth a try.
First thing I would do if I was you would be to get a Hayden #2799 Severe duty fan clutch. It knocked 5* off of my highway temps and I can idle for 15-20 mins with AC on and it stays under 200* in 90* air temp. It's only $60 from Oreilys or autozone.
Next thing I would do is double check your timing both at idle and at 3000rpms, also check it with the vac advance hooked up to see the total timing at 3000.
Lastly flush the coolant, remove the threaded plugs in the block and flush it out as best you can....I wouldn't expect much from that. Then refill with 60/40 water/antifreeze. Or even 70/30....unless you are in an area that freezes in winter.
First thing I would do if I was you would be to get a Hayden #2799 Severe duty fan clutch. It knocked 5* off of my highway temps and I can idle for 15-20 mins with AC on and it stays under 200* in 90* air temp. It's only $60 from Oreilys or autozone.
Next thing I would do is double check your timing both at idle and at 3000rpms, also check it with the vac advance hooked up to see the total timing at 3000.
Lastly flush the coolant, remove the threaded plugs in the block and flush it out as best you can....I wouldn't expect much from that. Then refill with 60/40 water/antifreeze. Or even 70/30....unless you are in an area that freezes in winter.
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Michael S. Palmer
Race Director
Joined: Mar 2006
Posts: 14,112
Likes: 28
From: Florida
When clean change the coolant once a year.
Use your best judgement.
That's a good example of why you should do a very good job of it if you decide to tackle it at all.
Most cleaners and flushes are designed to dissolve the scale and rust into small particles, suspend it in solution and carry it out when drained. If a system is severely scaled and corroded, then the scale and mostly rust is just loosened and not drained completely. The first thing that will happen is that these particles will plug up a radiator (especially a new tech small tube aluminum ones) and the heater core.
Done right, it takes me a full day easily, with hundreds and hundreds of gallon of water and you will end up with your driveway srained.
It's an absolute must to use the block drains.
When I bought it
A 5 gallon bucket, still coming out after several hours of flushing
Comparison of the size of the particles
When finished, can't be any cleaner.
Both the 77 and 75 were like this and that's why this is about the first thing I do when I get a car.
You can't beat the results even down here in S Florida where it is always really hot.
The 77 has a chin spoiler, old brass radiator, NO foam anywhere around the rad and runs at tsat temp all the time 195°
The 75 has NO chin spoiler, NO foam, Stewart stage 2 pump, and old brass radiator. Runs at a little less than tstat temp under all conditions. Will probably downgrade to a good stock GM pump since it runs a little too cold.
Most cleaners and flushes are designed to dissolve the scale and rust into small particles, suspend it in solution and carry it out when drained. If a system is severely scaled and corroded, then the scale and mostly rust is just loosened and not drained completely. The first thing that will happen is that these particles will plug up a radiator (especially a new tech small tube aluminum ones) and the heater core.
Done right, it takes me a full day easily, with hundreds and hundreds of gallon of water and you will end up with your driveway srained.
It's an absolute must to use the block drains.
When I bought it
A 5 gallon bucket, still coming out after several hours of flushing
Comparison of the size of the particles
When finished, can't be any cleaner.
Both the 77 and 75 were like this and that's why this is about the first thing I do when I get a car.
You can't beat the results even down here in S Florida where it is always really hot.
The 77 has a chin spoiler, old brass radiator, NO foam anywhere around the rad and runs at tsat temp all the time 195°
The 75 has NO chin spoiler, NO foam, Stewart stage 2 pump, and old brass radiator. Runs at a little less than tstat temp under all conditions. Will probably downgrade to a good stock GM pump since it runs a little too cold.
Pro
Joined: Nov 2008
Posts: 680
Likes: 5
From: Denham Springs LA
Yes, I flushed it with the old radiator and flushed it again with the new radiator.
My timing is 36deg BTDC at 3000rpm. I am running the stock solenoid setup which prevents vacuum to distributor unless I am in 3rd gear, reverse, or the engine is running hot. I am going to bypass this solenoid and let the vacuum advance do it's job. Currently the port that feeds vaccum to the solenoid is a port that only has vacuum above idle so I will switch it to another port that always has manifold vacuum.
Why does the super duty fan clutch help so much? Not doubting you, just want to understand what's going on.
Thanks,
Roger
My timing is 36deg BTDC at 3000rpm. I am running the stock solenoid setup which prevents vacuum to distributor unless I am in 3rd gear, reverse, or the engine is running hot. I am going to bypass this solenoid and let the vacuum advance do it's job. Currently the port that feeds vaccum to the solenoid is a port that only has vacuum above idle so I will switch it to another port that always has manifold vacuum.
Why does the super duty fan clutch help so much? Not doubting you, just want to understand what's going on.
Thanks,
Roger
Pro
Joined: Nov 2008
Posts: 680
Likes: 5
From: Denham Springs LA
Noonie,
I do not want to be in the group of knuckle heads trying to "**** up a rope". I will remove the engine plugs and flush it. That's pretty funny.
ARe you flushing with the engine running, or using a hose. Can you give me some details of what you do?
Roger
I do not want to be in the group of knuckle heads trying to "**** up a rope". I will remove the engine plugs and flush it. That's pretty funny.
ARe you flushing with the engine running, or using a hose. Can you give me some details of what you do?
Roger
Burning Brakes
Joined: May 2009
Posts: 850
Likes: 36
From: Providence RI
Usually, a super-duty or severe-duty clutch for a given application locks up at a lower temp, and requires a higher rpm before it freewheels. They are usually distinguished by a bimetallic coil on the front face of the clutch, and a larger cast-aluminum body with larger fins.
But a design that might be considered "severe duty" for one application such as a Chevette might count as a "regular duty" fan clutch for a 1-ton truck, so make sure you are getting a severe-duty clutch for your application.
Race Director
Joined: Mar 2006
Posts: 14,112
Likes: 28
From: Florida
Do NOT do it with the new DeWitt rad connected.
The inside of the newer tubes of the alum rads are getting smaller all the time and you don't want to risk plugging up a new rad with a corroded system. Don't know whose tubes he is using, maybe he can report the id size, but I wouldn't risk it.
I'll look up the good proceedure this evening for you.
Pro
Joined: Jul 2005
Posts: 517
Likes: 7
From: Peoria IL
It's pretty involved to do it properly, but well worth it.
Do NOT do it with the new DeWitt rad connected.
The inside of the newer tubes of the alum rads are getting smaller all the time and you don't want to risk plugging up a new rad with a corroded system. Don't know whose tubes he is using, maybe he can report the id size, but I wouldn't risk it.
I'll look up the good proceedure this evening for you.
Do NOT do it with the new DeWitt rad connected.
The inside of the newer tubes of the alum rads are getting smaller all the time and you don't want to risk plugging up a new rad with a corroded system. Don't know whose tubes he is using, maybe he can report the id size, but I wouldn't risk it.
I'll look up the good proceedure this evening for you.
Race Director
Joined: Mar 2006
Posts: 14,112
Likes: 28
From: Florida
I forgot all about this, but here is a link that you can download the pdf.
There's another method I use to, but it's not for the faint of heart. Let me know if you need it and I'll try and find it.
http://www.filesend.net/download.php...7ef2a57b183b38
There's another method I use to, but it's not for the faint of heart. Let me know if you need it and I'll try and find it.
http://www.filesend.net/download.php...7ef2a57b183b38
Pro
Joined: Jul 2005
Posts: 517
Likes: 7
From: Peoria IL
Thank you, noonie. I am interested in the more extensive process.
The C3 I'm working on now has a freshly rebuilt engine (18 months ago), new (brass) radiator, new hoses, no heater core, and a new aluminum GM water pump. Hopefully there's no need to go through the intensive scouring processes, but the annual flush is likely overdue now.
Is the annual flush process safe for the modern aluminum (DeWitts) radiators?
Thanks again sir, I'm going to be sharing this with a friend of mine that's a chemical engineer to see if he has any suggestions for improving the process.
The C3 I'm working on now has a freshly rebuilt engine (18 months ago), new (brass) radiator, new hoses, no heater core, and a new aluminum GM water pump. Hopefully there's no need to go through the intensive scouring processes, but the annual flush is likely overdue now.
Is the annual flush process safe for the modern aluminum (DeWitts) radiators?
Thanks again sir, I'm going to be sharing this with a friend of mine that's a chemical engineer to see if he has any suggestions for improving the process.
Race Director
Joined: Mar 2006
Posts: 14,112
Likes: 28
From: Florida
Thank you, noonie. I am interested in the more extensive process.
The C3 I'm working on now has a freshly rebuilt engine (18 months ago), new (brass) radiator, new hoses, no heater core, and a new aluminum GM water pump. Hopefully there's no need to go through the intensive scouring processes, but the annual flush is likely overdue now.
Is the annual flush process safe for the modern aluminum (DeWitts) radiators?
Thanks again sir, I'm going to be sharing this with a friend of mine that's a chemical engineer to see if he has any suggestions for improving the process.
The C3 I'm working on now has a freshly rebuilt engine (18 months ago), new (brass) radiator, new hoses, no heater core, and a new aluminum GM water pump. Hopefully there's no need to go through the intensive scouring processes, but the annual flush is likely overdue now.
Is the annual flush process safe for the modern aluminum (DeWitts) radiators?
Thanks again sir, I'm going to be sharing this with a friend of mine that's a chemical engineer to see if he has any suggestions for improving the process.
I doubt you even need to go with the pdf I posted with all newer parts. Just a mild flush and refill should be adequate. Just use the block plugs to empty it all.
I'd be interested in hearing what the chemist has to say.
I know one here and asked him about phosphoric acid, he'd never heard of it before. Showed him what it does etching and now he uses it.
