OVERHEATING/ with supercharger
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Joined: Feb 2006
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From: Mississippi
OVERHEATING/ with supercharger
Have 69 427 w/trw pistons .30 over 8.5 comp,lunati 049Roller, Hooker 4" sidepipes,174 B&M Blower 4 pds boost,eldebrock wtr pump,March serpintine belt drive,4 speed, Radiator is Ron Davis 31193 (2 - 1" row 31" x 19.2") with permacool 16" fan 3200 cfm(homemade shroud) 160 deg thermostat, no vac adv. 16 deg initail timing 34 total. over heats if sitting for more than 3- 4 mins. and slowly begins to try to overheat on highway. FAn is turning right direction(puller) and is always on. ANY ADVICE? maybe bigger fan ,if so what would fit? or larger Radiator(if so whta and from who? Have checked themostat(160 deg) /or add oil cooler and fan for it?
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From: Waterloo ontario Canada
Originally Posted by Russ57
Have 69 427 w/trw pistons .30 over 8.5 comp,lunati 049Roller, Hooker 4" sidepipes,174 B&M Blower 4 pds boost,eldebrock wtr pump,March serpintine belt drive,4 speed, Radiator is Ron Davis 31193 (2 - 1" row 31" x 19.2") with permacool 16" fan 3200 cfm(homemade shroud) 160 deg thermostat, no vac adv. 16 deg initail timing 34 total. over heats if sitting for more than 3- 4 mins. and slowly begins to try to overheat on highway. FAn is turning right direction(puller) and is always on. ANY ADVICE? maybe bigger fan ,if so what would fit? or larger Radiator(if so whta and from who? Have checked themostat(160 deg) /or add oil cooler and fan for it?Try running without a thermostat. It is almost impossible to speed up the water pump with that pulley setup so that is out.
I did end up running twin fans but without a shroud. I mount one 16 inch fan behind and off to one side and another out front and off to the other side with seperate switches for each.
In hot stop traffic I have to use both but on the expressways turn off both and run no fan.
Between my aluminum rad, two fans, I do run the water pump 30% over engine speed and no thermostat I have trouble getting the motor hot enough. If I install any thermostat I need to run ONE fan all the time even at highway cruising speeds to keep from overheating.
Seems even the 160 degree thermostat causes me to require one fan all the time and the second in case of stop and go.
I do run a bigger 1 1/2 inch tubed rad.
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From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Originally Posted by Russ57
Have 69 427 w/trw pistons .30 over 8.5 comp,lunati 049Roller, Hooker 4" sidepipes,174 B&M Blower 4 pds boost,eldebrock wtr pump,March serpintine belt drive,4 speed, Radiator is Ron Davis 31193 (2 - 1" row 31" x 19.2") with permacool 16" fan 3200 cfm(homemade shroud) 160 deg thermostat, no vac adv. 16 deg initail timing 34 total. over heats if sitting for more than 3- 4 mins. and slowly begins to try to overheat on highway. FAn is turning right direction(puller) and is always on. ANY ADVICE? maybe bigger fan ,if so what would fit? or larger Radiator(if so whta and from who? Have checked themostat(160 deg) /or add oil cooler and fan for it?
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From: Waterloo ontario Canada
Originally Posted by 69427
I'd try to hook up a vacuum advance to your distributor. With 8.5 compression and no VA, your thermal efficiency at non WOT conditions is not enviable. The overheating while sitting for 3-4 minutes makes perfect sense to me, and the highway overheating seems expected too. Increase your thermal efficiency. It ought to help. I don't see anything fancy in your basic engine setup that any of us big block owners aren't already successfully dealing with.
I worry about drawing the vacuum off the intake since that same intake suddenly moves from vacuum to boost and I wonder what would happen to the vacuum diaphram under 12 pounds of boost? It could rupture or would it actually push the advance into extra retart?
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From: Waterloo ontario Canada
Originally Posted by Ironcross
500-1 will say that it`s ok to remove the thermostat. Sure if you really want it to boil. Put a 180 stat in the sucker band go from there. 
I have done extensive testing on my setup with and without a thermostat and taking it out means alot cooler engine.
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From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Originally Posted by norvalwilhelm
Mine will sit all day in traffic and not overheat and I do not run vacuum advance but it is something I have thought about doing.
I worry about drawing the vacuum off the intake since that same intake suddenly moves from vacuum to boost and I wonder what would happen to the vacuum diaphram under 12 pounds of boost? It could rupture or would it actually push the advance into extra retart?
I worry about drawing the vacuum off the intake since that same intake suddenly moves from vacuum to boost and I wonder what would happen to the vacuum diaphram under 12 pounds of boost? It could rupture or would it actually push the advance into extra retart?
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Le Mans Master
Joined: Apr 2000
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From: cincinnati ohio
St. Jude Donor '09
Get some more timing in it at idle and cruise...made a huge difference in mine. I have 35* at idle with the vacuum advance to the manifold and it will idle at 180* all day. Temps will drop 10-15* at cruise speed.
I run a Robert Shaw 160* high flow stat.
I don't think pressure to the advance can will push the plate the other way, but I'm gunna' try it
I run a Robert Shaw 160* high flow stat.
I don't think pressure to the advance can will push the plate the other way, but I'm gunna' try it
Race Director
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From: Waterloo ontario Canada
Originally Posted by Artsvette73
Norval
how about a check valve for the vacuum advance?
how about a check valve for the vacuum advance?
Race Director
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From: Florida
Originally Posted by norvalwilhelm
Mine will sit all day in traffic and not overheat and I do not run vacuum advance but it is something I have thought about doing.
I worry about drawing the vacuum off the intake since that same intake suddenly moves from vacuum to boost and I wonder what would happen to the vacuum diaphram under 12 pounds of boost? It could rupture or would it actually push the advance into extra retart?
I worry about drawing the vacuum off the intake since that same intake suddenly moves from vacuum to boost and I wonder what would happen to the vacuum diaphram under 12 pounds of boost? It could rupture or would it actually push the advance into extra retart?
Then you just have to ponder over ported or manifold LOL
Instructor
Joined: Jan 2003
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From: Thomson Illinois
Originally Posted by yellow 72
Get some more timing in it at idle and cruise...made a huge difference in mine. I have 35* at idle with the vacuum advance to the manifold and it will idle at 180* all day. Temps will drop 10-15* at cruise speed.
I run a Robert Shaw 160* high flow stat.
I don't think pressure to the advance can will push the plate the other way, but I'm gunna' try it
I run a Robert Shaw 160* high flow stat.
I don't think pressure to the advance can will push the plate the other way, but I'm gunna' try it
I know I am comparing apples to oranges since I am running a small block, but I have an overheating issue as well. I am running 18* initial timing, 30* total and it runs like a scolded slug before boost. From what I have been reading on here, I have been afraid of bringing the world to an end if I got above 36*. Depending on the outside temp, it is common for mine to run 200*-220* in warm weather. Warmer in stop and go traffic. I am not running any vacuum advance, my distributor doesnt have one. Maybe I need to rethink my timing...
KC
Last edited by kdcollins; Oct 22, 2006 at 06:56 PM.
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From: Waterloo ontario Canada
Originally Posted by noonie
Why don't you take vacumn as normally from a carb or the carb baseplate, should be no boost up there.
Then you just have to ponder over ported or manifold LOL
Then you just have to ponder over ported or manifold LOL
Even when to set on it the vacuum under the carbs stay good. The blower is sucking from under the carbs and that pressure even when I am showing slight boost is good.
So we would end up with the vacuum advance still recieving a descent vacuum signal and yet the intake is seeing positive boost pressure.'
Running dual gages you can really see what is happening and I often wondered where I would get the vacuum for a realistic signal.
The intake responds instantly to vacuum boost but again I am afraid the boost would destroy the diaghram.
12 pounds of boost spread over a couple of square inches could do damage.
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From: Waterloo ontario Canada
Originally Posted by kdcollins
This is interesting Mike.
I know I am comparing apples to oranges since I am running a small block, but I have an overheating issue as well. I am running 30* initial timing, 36* total and it runs like a scolded slug before boost. From what I have been reading on here, I have been afraid of bringing the world to an end if I got above 36*. Depending on the outside temp, it is common for mine to run 200*-220* in warm weather. Warmer in stop and go traffic. I am not running any vacuum advance, my distributor doesnt have one. Maybe I need to rethink my timing...
KC
I know I am comparing apples to oranges since I am running a small block, but I have an overheating issue as well. I am running 30* initial timing, 36* total and it runs like a scolded slug before boost. From what I have been reading on here, I have been afraid of bringing the world to an end if I got above 36*. Depending on the outside temp, it is common for mine to run 200*-220* in warm weather. Warmer in stop and go traffic. I am not running any vacuum advance, my distributor doesnt have one. Maybe I need to rethink my timing...
KC
Again I have NO problem maintaing 170 - 180 on warm days in stop and go. I do run dual 16 inch toronado fans.
Le Mans Master
Joined: Apr 2000
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From: cincinnati ohio
St. Jude Donor '09
Originally Posted by kdcollins
This is interesting Mike.
I know I am comparing apples to oranges since I am running a small block, but I have an overheating issue as well. I am running 30* initial timing, 36* total and it runs like a scolded slug before boost. From what I have been reading on here, I have been afraid of bringing the world to an end if I got above 36*. Depending on the outside temp, it is common for mine to run 200*-220* in warm weather. Warmer in stop and go traffic. I am not running any vacuum advance, my distributor doesnt have one. Maybe I need to rethink my timing...
KC
I know I am comparing apples to oranges since I am running a small block, but I have an overheating issue as well. I am running 30* initial timing, 36* total and it runs like a scolded slug before boost. From what I have been reading on here, I have been afraid of bringing the world to an end if I got above 36*. Depending on the outside temp, it is common for mine to run 200*-220* in warm weather. Warmer in stop and go traffic. I am not running any vacuum advance, my distributor doesnt have one. Maybe I need to rethink my timing...
KC
A few degrees of timing can make a big difference.
The vacuum advance at idle made mine more responsive and cleaned up the idle. And everyone I have talked with always stress that blower motors love a lot of initial.
I don't have a lot of miles on mine since the blower, and really haven't hammered it a lot but from idle to 5000, I'm very satisfied.
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From: Mississippi
Ok Maybe Fan Isn"t Big Enough?what And From Who
I am running a permacool 16" 3200cfm fan with homemade shroud,if I am hearing correctly I need approx.5000cfm for big block of my approx horsepower. again 174 blower,msd box,dui Hei NO vac advance,roller rockers and lunati 049 cam if I remember it is 232/242/594/605 w/ 112 lobe sep. that's close anyway.8.5 comp. .030 over forged....4spd. Davis Rad is 2 1" row 31X19" need fans have looked at flex-a-lite,permacool, and derale / alt is 100amp .I also just got a derale 16pass oil cooler w/950cfm fan will set it up with dual remoate fltr.So what recommendation on fans that will fit,not kill alt,and not kill budget....impossible I know...also have edelbrock water pump with march serpintine belt drive....may need a newer/better water pump any ideas....also centerforce clutch is slippin now do to blower....
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Joined: Apr 1999
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Is that a higher flow water pump? I've had heating issues on my 427. Even though I went with the BeKool aluminum made for 1000 hp, racing water pump and twin spal 15 amp each fans.
Norval - made me a pump pulley to drive the race pump 30% faster. I have not yet reinstalled my rebuild 427 to test it yet. But my smaller motor works fine even with my 192 thermistat right now. My motor really purrs when up to temp. My chokeless hot rod motor is kind of ruff running up till them.
IMO - get bigger fans and a pump that flows lots of GPM at lower rpm. The lack of thermostat would of coarse increase pump flow for right now and see if it works for you.
Norval - made me a pump pulley to drive the race pump 30% faster. I have not yet reinstalled my rebuild 427 to test it yet. But my smaller motor works fine even with my 192 thermistat right now. My motor really purrs when up to temp. My chokeless hot rod motor is kind of ruff running up till them.
IMO - get bigger fans and a pump that flows lots of GPM at lower rpm. The lack of thermostat would of coarse increase pump flow for right now and see if it works for you.
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From: Taylor Michigan
Note, retarded engines run hot. Put some timing in the sucker and also run a 180 thermostat. Superchargers are no different than normally asperated except they make more HP. Your running racing gas arn`t you? You do not need a vc can, thats 
just run the timing up to 36-38 total all in at 3000. Then if the engine runs up on idle turn the carbs back to 850-900. 
just run the timing up to 36-38 total all in at 3000. Then if the engine runs up on idle turn the carbs back to 850-900.
