hard filled sbc overheats real bad

Old 09-01-2012, 02:53 PM
  #21  
wazup
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Good luck and as allways be safe.
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Old 09-03-2012, 03:52 PM
  #22  
chevyart
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hey waz ran car with new 16 lb pressure cap and new , bigger jets, and i did not put the 1inch restrictor in as i want to do one thing at a time(like tuning, one at a time). car ran cooler up to takeoff and then at full throttle it went up to 240 and at end of track it came back down to 220 or so and i sat there and cooled it to 180 and drove back to the pits. by time i got back to my spot, it was up to 240(or more). im gonna put in new electridc fan that covers my whole radiator with lots of cfms. the fan in there now is about 3 inches short on each side of the radiator, so i know that fan is inadequate in both cfms and shroud size. still unsure of which way to go with the restrictor. 5/8s or the 1 incher. what is your suggestion. also the oil pressure at end of run, when car is real hot, drops to around 20 lbs until the car cools off and then shoots back up. doers that sound like a problem? i use valvoline 20-50 racing oil. what do you think of that. thanks for help. art
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Old 09-03-2012, 08:24 PM
  #23  
wazup
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Art i wish i was there to help. What did the plugs look like. Im wondering if you might have a vacuum leak. The oil you are using is fine(i use the same) but if you keep running that hot i would change it, as for the oil pressure its only doing that because its to hot. I ran a oil temp gauge in the bottom of my oil pan and the oil temp would get up there(210-230) when driving it on the road. Do you have the trans lines running to the radiator or to a trans cooler. There is alot of thing that can make it run hot so one thing at a time is the best way, if what you change dont help change it back to the way you had it. Let me say this i have a bbc (not filled) that has 28"x17" alum rad i think, with two 10" fans (no shrouds) in front of the radiator pushing,no stat or restrictor with elc water pump (csr) and can drive it stop and go to car show about 5 miles and only runs around 160to170. You might need to move the time around with out killing your power, keep rejetting too, jetting and timing go hand and hand. One more thing try spaying some carb cleaner around the carb and intake gaskets and see if the engine changes. Maybe some of this will help. Sorry your have no luck but its got to be something simple.

You can call me at my shop 321-951-2247 Robert Price (Prices Auto Center)
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Old 09-04-2012, 06:59 AM
  #24  
chevyart
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rob you probably hit the nail on the head about a vacum leak. car wont idle down low and when i put it low it shoots up and down.i have to idle it around 2000 to(maybe a tad lower) to drive it around pits and it definitely bumps hard into gear(powerglide)i never addresed that problem and i should have, right away. how does that make an engine overhear or make it have other bad affects? im putting a newer(bigger carb on. and i will look at the plugs from last sunday.. i iknow they werent quite brown enough last week, but i didnt want to go crazy with the jets. this carb has a new center section from proform. i had it on my old motor,(that blew up) and the car ran good with it, but i was more sure of the old carb for startup of newer motor. i will change the carb gaskets(i have a carb spacer on manifold) and squirt the running engine with (brakeparts cleaner?) or what other liguid would be ok to squirt on thers :rob, what made you think vacum leak in the first place? thanks art
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Old 09-04-2012, 10:23 AM
  #25  
wazup
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Art when you say its still running hot and how fast it runs hot. I have been working on cars for 30 plus years. Its getting hot way to fast so from what your telling me that the plugs were pearl white is a lean condition and can be caused by many different things and a vacuum leak is one of them. Art if you can drive your car down the street as you change things it might help you better. The brake cleaner is fine to use just try and get the idle down as far as you can. Then spray it where the intake mates with the heads to see if there is a change in the engine.
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Old 09-04-2012, 09:32 PM
  #26  
trmnatr
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Originally Posted by chevyart
one thing, now that you mention it is that that in place of a thermostat there should be a restrictor plate. there is none. there was one when i had the 355 in there and it just never made it back in with the engine swap.. it is a drag car only, 13-1 comp and big cam and big alum cylinder heard. what about me only having a 7lb pressure cap. some say it should be up in the 20s lb cap.its a small electric fan running off a relay and it did fine for the 5355(max 200 temp at the track) i have different restrictor. plates. how big of a center should should be on the plate. why the lines from water pump to the heads and not to holes in top(center) of block. why not run all 3 different cooling lines at once. thanks art
Engines filled with Hardblok don't run hot, the water pump can only pump water that's fed into the pump which is the water pump holes. So as you can see the hot water that would normally lay in the bottom of the water jackets that doesn't get cooled down, makes it run warmer.

With Hardblok your engine will take much larger to heat up and cool down much faster. Many people have cooling holes that don't line up with the head gaskets and this needs to be addressed. Bottom line is the Hardblok is not what is making it over heat
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Old 09-04-2012, 09:40 PM
  #27  
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Originally Posted by coloradoracerguy
I would definately put a much higher pressure cap on there, the higher pressure raises the boiling point of the water quite a bit. As to a restrictor, I wouldn't, not really needed. Just make sure you have good flow of coolant. I don't run one at all in my dragster and never have. 600 inch chevy and if I'm at 100-110 at the staging lanes before the run, I'm around 180 by the time I'm back at my pit. One of the issues with yours is the block being filled. It reduces the cooling capacity of your whole system, and it will heat up faster. The best thing you can do at this point is put in the biggest radiator you can fit in the car. You need system capacity, and the block filler just took away about half of it. Additionally, you're making more power which means more heat. The larger the cooling system, the better it's able to deal with the heat.

So my best advice is the biggest and thickest (three or four core aluminum with the 1" wide core tubes) radiator you can get, good shroud and biggest fan you can get. Put either Redline water wetter or Royal Purple Purple Ice in the system as well, it helps. Tap the manifold for four corner cooling as well, and make sure it's only water with the additive that you're running, no antifreeze!!!! Besides being horrible to clean up if spilled, it actually doesn't cool as well as straight water.
Agree except on the Hardblok, we use it in every engine we build. The Hardblok doesn't make it run hotter. Go pull your water pump off, all the water below the water pump holes WON'T come out, the engine can't send this water to the radiator so putting Hardblok to the bottom of the water pump holes changes that problem

Now we have seen LOWER OIL TEMPS with Hardblok, further showing the info above.

Now with NO HARDBLOK IMO, a good design would have a 1/2" NPT on the side of the block where the plugs are to drain the coolant, that way the coolant below the water pump holes can exit the 1/2" NPT connected to the radiator for better cooling

We use A LOT of Hardblok and every engine has shown as I have posted, and about the thermostat. If you run a high volume water pump RUN A RESTRICTOR, if its a standard volume water pump don't run anything
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Old 09-05-2012, 05:21 AM
  #28  
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A serious vacuum leak can (and will) build heat, simply because it's an uncontrollable lean condition. I didn't pay a lot of attention to what heads/intake is being run but one has to be careful anymore, due to the many varied head/intakle combos as well as port placement on the head. In some cases, only one gasket will fit and align correctly.

You also should check for misalignment of the head ports/intake runners. Some heads will only take an intake made specifically for them. Been there done that, too!

And, some gaskets are subject to "Edge soaking" and then leak. We coat just the edges (insides and out) of our intake gaskets with POR15, and seem to have negated this phenomenom.

Another contributor to the heating, if it is a vacuum leak, would be the oil consumption. Oil burns considerably hotter in the combustion chamber than does either gasoline or alcohol, and if your intake is leaking, chances are it's pulling air/oil vapor out of the cam galley. If that's the case, another giveaway (besides the inability to idle smoothly or at all) will be a fine coating of oil and burnt oil smudge inside the headers . . The oil vapor burns so completely that it's nearly impossible to see in daylight, so it's something that most people don't notice . .

On the "Hardblok" . . We ran a 468, and a 496 BBC, both with filled blocks, and then went to a 582 with open water jackets (Dart) and the temp has been the same. 160 out of the water, about 170 at the top light and 185 at the other end. Leave the pump and fan run while towing back and it'll be about 100 at the thermostat housing when we get to the trailer . . .

Just some things that crossed my mind on the subject.
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Old 09-05-2012, 01:10 PM
  #29  
chevyart
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thanks trmnatr and roadkill 2. this problem is making me sick and i dont want to hurt my new engine. wazup has really been helpful along the way with his explanations and i am concerned with the whole hard blocked thing. you explained that the water does not move at all below the bottom of the water pump holes. above that line does the water circulate around the sides of the block, or is there no water movement in sides of the block. at all? my engine has holes drilled and tapped to accept a #6an fitting on each side in aprox center of engine , right above the hard block material. (its a 400 block). i guess the holes were drilled either to drain water or possibly circulate water to this area by tapping the sides of the waterpump and pumping cool water over to the area above the hard block all along the sides of the block.. my manifold does not have bungs in the rear to send lines from front to rear of intake, and there are no tapped holes in the heads to accept lines from either waterpump or lines from thermostat housing area i am.thinking strongly about running the lines from waterpump to holes tapped in block as i explained above. is this a waste of time? also, how do i know if my waterpump is performing.. PS biggest thing i dont understand is the car shoots up to 240 during pass and as soon as i let off the gas it goes back pretty quickly to the 200-210 range. cools down to 180 in 5 minutes(i stop and run waterpump and fan) and is back up to 240-250 by the time i arrive in the pits. does this sound like a radiator problem or waterpump problem thanks art
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Old 09-05-2012, 02:03 PM
  #30  
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fill the radiator up, then pull the top hose off at the radiator, then put a bucket under the hose anf turn the pump on. it will pump until the water gets below the water pump. This should tell you if the water is moving pretty good or the pump is weak.

JMO

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