The 24 Hours of Lemons Forums → Lemons Tech → Small Block Chevy Overheating Problems?
From what I have been reading SBC has a bad habit of running hot? Is that right? Has anyone figured out why? Or is it just a matter of badly prepared cars with small block for the first few years creating a self perpetuating myth?
Haven't even started with a car, but I have been avoiding Novas, Camaros, and such because of the overheating.
Woody
I think there are some cheap tricks you can try for all that. Run manual transmission and send the actual oil through the condenser (oil-cooled SB!). I think Vortec blocks had very nice stock pan lids to keep oil from sloshing around. Finally, don't rev the snot out of it and provide plenty of air to the engine, not just the radiator.
But then again, why bother? Find me a nice Vortec longblock and I'll exchange it for my Camaro's 250ci L6, complete with a 4-barrel Quadrajet and shortened truck headers 
most of the camaros and firebirds suffer from an enclosed nose that relies on a radiator fed from underneath the car. The design works in open air. as my team learned in deep traffic the draft so to speak takes away a significant portion of the cooling ability of the car. to the point that i could watch the temp needle climb while being behind someone and watch it fall pull around them into clean air. a massive rhinoplasty can help things significantly.
The failures of the SBC at Lemons has to do with excessive revs and taxed cooling systems, coupled with typical i can make this faster with these heads that ive been using as tarp weights and this carb off my daddys race car from 40 year ago.
In my experience (not related to Lemons) - the SBC suffers from frothing oil that itself overheats and then fails to lube. So you would be cruising along and slowly you are introducing more and more friction into the engine, losing power and getting more heat. You slowly overheat, overpressure, and boil off your coolant. Until finally you run out of cooant and then your temp needle pegs or you pull into the pits and your cooling system boils over when you are no longer getting air through the radiator.
The matchbox malibu (car #350) has run at least 2 races w/ the same engine. the only problems I recall were carb/fuel issue at Summit, and a broken rocker at Gman.
I think if you've got a decent engine and don't over rev (stay under 5000, 4500 is better) you'd be fine. this is understanding that good cooling is extremely important, as is w/ all Lemons cars. Electric fans help w/ the boiling in the pits, except when refueling.
So instead of spending time on a cheater cam and milled heads, a road racing SBC team should drop the pan and add a windage tray and an oil scraper. Maybe weld a trap door into the oil pan?
FireGremlin - Are you suggesting the stovebolt six would run cooler than the small block?
The solution to any reliability problem is forced induction.
FireGremlin - Are you suggesting the stovebolt six would run cooler than the small block?
Mine runs pretty cool even in the middle of summer, stock 4-blade unshrouded fan and all. They just don't seem to make enough power to create any significant amount of heat. Half-empty engine bay helps, too.
They also survive overheating nicely. I once blew the alternator belt which caused the PS belt to slip off, leaving me with no fan belts. I was doing doughnuts in snow on top of a parking garage at the time. Didn't notice the loss of power steering much until I saw smoke coming out. Boiled the snot out of it. 10 minutes of throwing snow at the engine, reinstalled the PS belt, and the car ran perfectly fine afterward.
The solution to any reliability problem is forced induction.
LOL. Got a near-spit take out of that one.
a road racing SBC team should drop the pan and add a windage tray and an oil scraper
Windage tray, yes. I wouldn't think a crank scraper would help much unless you're spinning over 5000rpm. An oil accumulator would be another good idea.
The solution to any reliability problem is forced induction.
^^this.
We do pretty well with ours. Lots of junkyard coolers to cool every fluid, a big aluminum piece of sheetmetal made into an air dam, cutting holes in the front bumper to add airflow, plug the vent hole in the water pump to reduce bypass, etc
There are lots of little/free things that can be done, but most people don't seem to do all that. We run an auto tranny and can keep it plenty cool.
How about not revving the living shit out of it?
How about not revving the living shit out of it?
Winner!
How about not revving the living shit out of it?
but but...then it's not COOL and Lemons is waaaaay more about style than coming in first!
The heroic fix guys at Capitol Offense (small block ford), when asked "where are you shifting?" calmly answered "about 6400." On a 200k mile jy engine.
Brilliant!!!!
It did make for great theater.
How about not revving the living shit out of it?
We ran our 160k mile motor with the auto tranny and let it shift at 4k with no issues. Then, the second day of the second race, one driver decided to hold it in gear and rev it to 5k for a stint. The motor let go with about 40 minutes left in the race.
I second the comment about not trying to rev the shit out of it.
Look, reving the motor higher is fine. The oil and water pump turns just that much faster so that isn't the issue making them blowed up. I played high school footbal so I know what the hell I'm talking about.
Our CA20E doesn't cut fuel until you're way north of 7000RPM, but I think we're gonna stick to factory recommendation of "Not operating the engine above 5000RPM for extended periods of time". It's gutless up there anyway, so might as well save some fuel and wear.
Yet another reason to boost the snot out of your small block, btw.
I always thought that a 10psi, twin-charged twin-turbo Cadillac 500 (that's one supercharger and two turbos) that holds "peak" torque from idle to a ~4500RPM redline would be a swell little motor for a daily driver. Must be way more reliable than those all-motor stroked 500's that can barely crest 5500rpm before running out of air.
Look, reving the motor higher is fine.
+1
As long as your engine is reving, you're racing.
It's only when the revs stop that you're screwed.
I always thought that a 10psi, twin-charged twin-turbo Cadillac 500 (that's one supercharger and two turbos) that holds "peak" torque from idle to a ~4500RPM redline would be a swell little motor for a daily driver.
Spend $400 on a rocker shaft conversion, $400 on a set of forged rods, and $200 on a hotter cam and you can spin it to 6000rpm while making over 500 horsepower.
The # 350 chevy malibu had to have its engine replaced last season. One of our drivers over-revved it on an offcamber downhill turn. It revved to (i'm guessing here) about 7500 rpm. It was very loud and then BANG! hole in side of block.
We have since kept our motor to 5200 rpm with no problems. It still makes good power and we don't worry about it.
We run a 6 blade non-flex fan in a hodgepodge shroud. We got it from a swap meet. We traded a flex fan for it. Stock radiator, stock hoses. We never see above 200 to 215 on the track.
We run an auto tranny with a small cooler. Tranny runs fine and motor stays cool. We also run about a half quart of oil over full and run Rotella T oil (it has more zinc and other stuff old V8's like).
Once we got rid of our flex fan (that was on the car) we have not had any issues with overheating.
As long as you don't over rev it and keep track of your temp and oil pressure, you should be fine!
RobL: Would the frothy oil change the oil pressure? Is there a solution to the frothy oil?
Thanks,
RobR.
Our CA20E doesn't cut fuel until you're way north of 7000RPM, but I think we're gonna stick to factory recommendation of "Not operating the engine above 5000RPM for extended periods of time". It's gutless up there anyway, so might as well save some fuel and wear.
Scratch that. We ran it all the way to 7K rpm all weekend, since shifting into 4th proved too troublesome. Our best driver told us to keep it in 3rd all the time and just not shift, period. Nothing exploded.
So yeah. Rev it up, it'll be ok.
Oh, wait, we're talking about a SBC
First, I'd like to apologize for making the assumption that the matchbox car ran for multiple races on the same engine.
Second, what the fuck is a ca20e? or a 1gtze20bca? Can't people say Toyota 2.0 or I6?
I guess I should also apologize for not knowing all the engine codes too, but please dumb the converstaion down for me.
It's a 2-liter single-overhead-cam Nissan 4-cylinder motor, 8 valves, with a funny 8-spark-plug setup, that was used in the 80's in their midsize passenger cars, mostly. Later evolved to have dual overhead camshafts (CA18DE) and finally a turbocharged variant that Japanese Silvias (our 240SX) had - CA18DET. Has a bunch of other variants as well, but those three are the most well-known. The 2-liter variant that I have is most famous for being a gutless POS that Nissan stuffed into base 200SX, making that car hopelessly slow for its looks.
The reason why I use engine codes: people who know what I'm talking about don't have a problem with it, and all the others would probably not appreciate the stupidity/futility of revving that particular mill 1K beyond tachometer-marked redline, so to them it's just like saying "my motor".
Think of having to say "Chevrolet 5.7 V8 iron-block pushrod engine" every time you just want to call it a 350 or a SBC 
Nissan codes are easy, though. First two letters for engine family (CA, GA, VG, etc), second two indicate displacement (20 for 2.0, 16 for 1.6, and so on), and then you get S for carbed, E for EFI, D for dual overhead cam, and T for turbo. Still doesn't tell you much, but it's a start.
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