Inliners International Forums General Discussion Engines overheating 292

Hello. I have a fresh build 292 that is overheating (on a test stand),i discovered it had a pump from a 250" & purchased a rebuilt 292 pump from Napa.I've acid washed the rad.& flushed it. Run it with & without the t-stat.Also have a 20" box fan up to the rad. & the engine has a fan (flex) installed.50/50 coolant.Timing 8 Deg. I have noted that the crank pulley & the pump pulley are the same dia. 6.75",I've seen some like mine & some with a smaller pump pulley.Any thoughts.Thanks. Bruce..

DID YOU CHECK THE HEAD FOR CRACKS ? DO YOU HAVE THE BYPASS HOSE SETUP FOR A 292 ? IS THERE ANY TIGHT SPOTS HAND TURNNING THE ENGINE ? IS THE BALANCER A NEW REMAN ? ANY WATER IN THE OIL OR VAPOR COMMING OUT THE OIL FILL CAP ? DID YOU MIKE THE PISTONS AND CYLINDER TO CHECK CLEARENCE BEFORE INSTALL ? SAME WITH ROD AND MAIN BEARINGS ? THERES MORE ?

Old Balancer outer rings slip. Need to zero degree your timing marks to be sure. And there are 2 different timing covers with zero at 2 o'clock or 11 o'clock (IIRC).
Temp? RPM?

Thanks for the replies. No cracks,smoke the oil is clean as is the coolant. I'm using the balancer that came with the engine(old). I will check tdc.The timing cover & balancer were original
when i bought it.Engine clearances are ok,turns nicely. Looking forward the timing marks would be at 2 o'clock.
I am questioning this bypas system,i've seen this however this is not what i have. I do have pics.The engine is on a test stand
fast idle & no load.Could you explain this bypas system.I know this pump (bypas) is avaiable from Napa,i've seen pics of it.
Thanks Bruce

YOU NEED A 292 SPECIFIC LOWER THERMO HSG, ITS A GM PART AND NOT AVAILABLE ELSEWHERE EXCEPT USED. THE HOSE IS AVAILABLE. I DONT KNOW HOW YOU HOOKED UP A 292 PUMP WITHOUT IT. AND ANY QUALITY REBUILD ALWAYS INCLUDES A REMAN BALANCER ON ANY ENGINE. JMO

Thank you JMO. The 292 pump i'm using is for a 292,i believe there are 3 different pumps listed for these engines. I have seen pics of 292's w/o this by pass system,so it's a little confusing for me. The pump i'm using has the lower rad hose connection & bolts to the block as normal. only one, maybe 1/2"
female pipe thread opening on the top which i plugged..Stat housing has no provisions for a by pass hose.I'm headed to the bone yard tomorrow maybe i'll get lucky..Bruce.

all 292's had a large bypass hose about 1 1/4" I,D.

My 302 GMC inline has heated up twice. When it gets over 210 the motor stops, probably due to vapor lock. I am running a 700R4 auto with a transmission cooler hooked to the radiator. The system has been flushed and refilled with 50/50 coolant. This only happens when I cruise at low speeds or when I stop at stop lights when the temperature is hot.

Any ideas?

JMO = Just My Opinion. sorry, they have an acronym for everything these days.... =P


mebbe its the trans cooler blocking airflow making a huge dead/hot spot in your radiator. or if you are using a radiator that has a trans cooler built in to it, the tranny is causing too much excess heat for the fan to keep up with it? perhaps an electric fan... or if its a trans cooler literally hooked to the rad mebbe its not getting enough airflow causing your tranny to run hot thereby heating your radiator...

the only other idea is perhaps a hi flow thermostat. i bought one just for fits n giggles and my 292 always ran too cold with it in. a $10 dollar part compared to fussing with trans cooling or rad fans etc...

as for the vapor lock, perhaps the heat flap is stuck open so your carburetor has constant full blast heat from the ehxaust.

and for my final thought... pretty sure a 292 came stock with a 2 core radiator. ive managed just fine with the 4 blade engine driven fan in pretty much all kinds of weather, but i dont have a tranny cooler.

what kinda radiator do you have? 2 core... 4 core? aluminum? copper?

my opinion and a coupla bucks will buy you a cup of coffee at dennys =P

and a pictures worth a thousand words

ran outta edit time =P

is the fan on a clutch? or is it constantly driven by the belt?


what vehicle is this engine in?

what kinna carb are you running?

stock intake exhaust manifolds?

could it be something silly like a stuck choke or a really rich condition....timing.... mincroscopic dirt pieces...montezumas revenge...the list goes on.

you know...opinion...dollars...coffee...

If your trans cooler is attached to the radiator (push through zip tie style or screwed on somehow) without an air space between the two it will transfer heat to whichever is cooler.

I would make sure the advance and jetting is correct as previously mentioned, and make sure the fan is sufficient with a good shroud.

As a trial you could rig a spray bar in front of the radiator and spritz it when it gets hot.

If that gets the temps down enough to keep it from vapor locking you know the engine overheating causes it, as opposed to heat soak in the engine compartment.

Good luck.

See if you can get in touch with Tlowe he just sold me a housing for a 292 with the bypass. He may have another one. Also, FlowKooler makes what is supposedly a high flow pump for a 292. I can't say for certain if is in fact any different then a stock pump because the one I bought is still in the box awaiting my 292's assembly. I think I paid about $100 for the pump if memory serves me correctly. The thing that puzzles me though is when you go on youtube there are videos of 292's running with the correct pump or a 250 pump. Didn't the 292's come with the 250 pumps after 1980 or so?

any progress bruce? im curious if you had resolved your overheating issue.

Thanks to all for your replies.

I put a new 160 degree thermostat in (discovered it didn't even have one in it); new radiator cap; burped system to remove any air that may be in it; put in bottle of "Water Wetter"; turned fans to continuous running; insulated fuel line (to cure vapor lock), ran it 100 miles (2 trips) and I think the problem is solved. I did find the trans cooler was blocking a goodly portion of the radiator; also on the other side my power steering apparatus where I add power steering fluid was blocking also. future plans are to try to install bigger fan behind radiator, I have read they are 30 percent more efficient.
Anyway, wish me luck. To answer some of the questions, the engine is a 302 GMC bored to 320, mild street cam; headers; Edelbrock 4 bbl.

Just a thought: running the fans all the time just wastes wattage over perhaps 40 mph - they can't deliver air as fast as the grill does.
What to do?
I can't think of anything for you (auto trans) but a stick trans can have a switch that interrupts fan power in high gear (breaks the low power signal from the switch to the relay). This way it's always off when you don't need it, and no worries about remembering.

glad to see you got it sorted out!