Overheating new 360 help

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mechanic190

mechanic190

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I am pulling my hair out with this motor. I built this about a year ago and one thing led to another so now I'm just getting it running. The cam was not broken in when out together. Block is I believe an 80 and ran decent before getting rebuilt. Pulled it down and re ringed and new bearings new cam. Slapped her in a 1981 w150 and purchased a brand new radiator from Napa, bypassed the heater hoses and filled with just water to brake in the cam. First found the distributor had a bent shaft. Pulled drive gear out and checked it. Seamed like the distributor was dropped at one point causing this issue. Only had a Mallory unilite on hand unfortunately so I pulled the dizzy and swapped to the unilite. Wire it up and tried to get her running. Couldn't get fuel to carb. Blew down fuel tank to clear whatever in the tank. Fuel pump wasn't pumping. Swapped to a used fuel pump on hand and was able to get fuel. Started and bumped up to 2k 2500 rpm immediately. Engine ran for about 10 min varying rpm between 2k and 2500. checked timing at 2k and was at 22 degree advanced. Engine started to over heat and had to shut her down. Let it cool down and was not able to start again.

Did I just screw up my cam break in? Possible to save? It is a comp cam 275DEH with their lifter and their valve springs.

I'm pretty sure my problem right now is the POS Mallory on it currently.
 
Can should be fine. Just be sure to run the rpm's back up to 2K+ to finish the breakin.
 
Distributor is fine.

Not enough timing during break in. The exhaust gas temps were probably VERY high. Hopefully you didn't stick an exhaust valve.
 
Ok that's good news that I can just re start lol. Can't get the engine to start again. Won't flash the timing light and it has full voltage to it while cranking. Only fired off one cylinder every so often. How much timing should I have at 2k rpm? Exhaust was running too hot. Could that be a cause to over heating? Or should I also be looking else where?
 
Well so here is my story continuation. Pulled truck out last weekend and didn't push it in till Thursday. Didn't drain the water from the right side of the engine so ended up pushing 2 right side freeze plugs out and the rear right side. So out came the tranny. Buttoned the tranny up after installing new freeze plugs. Swapped to factory electronic distributor. Set timing at 16 degrees before top dead. Started cranking. No spark. Found pick up coil in brand new reman was open. Pulled dizzy again and traded pick ups with a big block dizzy and reinstalled. Started engine and had 38 degrees advance with no vacuum advance at 2500. Ran good for about 20 min then overheated again. Shut down and cooled. Since cam brake in time was done after this 20 min and the last time, started her back up and was trying to adjust timing to vacuum gauge. Turned out the edlebrock on top started leaking gas from the throttle shafts on both sides. So there's another issue that needs addressed. Go to start the truck up again after sitting for awhile and starter failed, just clicks. Would have been nice to have failed when the header was already off today. Had to push it outside (with 50/50 coolant this time) with the skid steer. Gonna be another week before I can order a mini starter and carb rebuild kit. Any ideas on the over heating? When filling it is very slow to drain down in the radiator. Checked both upper and lower hoses for a rag or something blocking it. Thermostat is new but sat in the engine for a year. Fan seams to be spinning fast enough when warm. Radiator is new last week from Napa.

I'm about getting fed up and just go back to diesels.
 
The excessive cranking with no start may or may not have hurt the breakin. As said X3 you need more timing & that was making it run hot. the rad is new so you have good flow assuming the stat is opening & likely it is. I would want the stat out & a fan in front & ~40 deg or more timing (see what is up with the dist advance) .
 
Hopefully you don't have of those Abercrombie & Fitch 160 degree thermostats. Keep it 195.
 
Since this overheats after some period of time, that seem to indicate low coolant flow or low airflow, or a combustion leak into the water jacket. I.e., the cooling system just is not pulling enough heat out. IMO, chasing a few degrees of advance above 38 degrees at 2500 RPM is fruitless. But see note 8.

1. Is this a standard mechanical fan? How many blades?
2. Is there a shroud installed? If not, then this could be the issue as it is needed at idle to make the air go through the rad.
3. What are the rad dimensions, including depth?
4. Pull water pump and make sure the impeller is not loose.
5. Get an old t'stat and gut out the moving parts and use that for another test. No, don't run with nothing in that spot; you need a flow restriction there to keep pressure up in the heads. Watch the flow in the top of the rad while doing this.
6. Watch for the lower hose to be collapsing on itself; make sure there is a spring in there.
7. Get/borrow a cooling system pressure tester to look for elevated pressures and for pressure pulsations. This would indicate a block crack or a head crack or a poor head gasket seal.
8. Find true #1 TDC and check the timing mark on the damper to be accurate. If it is off, then you could think the engine is at 38 degrees advance but actually be a lot less.

And with the 2 freeze/core plugs being pushed out.... that is bad news. Keep an eye on the oil for water.

And I would not consider the slow draindown in the rad while filling to be abnormal. A very small hole drilled in the flat flange of the t'stat will help this.
 
I would pull the thermostat out and run it. I bet its stuck. New doesn't mean its good.
 
mechanic190 said:
Well so here is my story continuation. Pulled truck out last weekend and didn't push it in till Thursday. Didn't drain the water from the right side of the engine so ended up pushing 2 right side freeze plugs out and the rear right side. So out came the tranny. Buttoned the tranny up after installing new freeze plugs. Swapped to factory electronic distributor. Set timing at 16 degrees before top dead. Started cranking. No spark. Found pick up coil in brand new reman was open. Pulled dizzy again and traded pick ups with a big block dizzy and reinstalled. Started engine and had 38 degrees advance with no vacuum advance at 2500. Ran good for about 20 min then overheated again. Shut down and cooled. Since cam brake in time was done after this 20 min and the last time, started her back up and was trying to adjust timing to vacuum gauge. Turned out the edlebrock on top started leaking gas from the throttle shafts on both sides. So there's another issue that needs addressed. Go to start the truck up again after sitting for awhile and starter failed, just clicks. Would have been nice to have failed when the header was already off today. Had to push it outside (with 50/50 coolant this time) with the skid steer. Gonna be another week before I can order a mini starter and carb rebuild kit. Any ideas on the over heating? When filling it is very slow to drain down in the radiator. Checked both upper and lower hoses for a rag or something blocking it. Thermostat is new but sat in the engine for a year. Fan seams to be spinning fast enough when warm. Radiator is new last week from Napa.

I'm about getting fed up and just go back to diesels.
Click to expand...
So you let it freeze? Good luck. Hope you did not crack anything. Might have.
 
no water transfer into oil yet. Timing set to around 38 last time I had it running. Pressured up cooking system before starting. Radiator is from Napa as listed for an 81 w150 with a.c. no shroud just don't have one. Water pump is a known good Used one. Have not worked on it since due to carb needing a adjustment and having to buy a mini starter to properly fit with headers
 
And as far as letting it freeze. The freeze plugs did their job as it seams. I only left water in one side of the block and I'd guess the cylinder head didn't have water that high up just had water in the passenger side block
 
Sounds like it's scrap metal now.
 
Update. Put the motor in a different truck and got running tonight. Overheating issue was from bad fan or combination of timing. Found my timing light took a **** and is reading way too much timing at the moment. But had her running and no issues in the new truck.
 
mechanic190 said:
And as far as letting it freeze. The freeze plugs did their job as it seams. I only left water in one side of the block and I'd guess the cylinder head didn't have water that high up just had water in the passenger side block
Click to expand...

"Freeze plugs" are not for freezing. They have NOTHING to do with freezing or freeze protection. The name is an old wives tale just like removing a battery cable on a running engine to test the charging system.

"Freeze" plugs had one purpose and one purpose only.......to allow the factory to cast the block.!!!! The proper name is "core plugs."

Your light won't flash? Is it inductive? Try flipping the pickup around and moving it on the wire. Otherwise, it might just be a bad light.
 
No it's reading at 38 degrees when I set the timing at 20 degrees when I put back in the distributor on a stock rebuild 360 with vac advance unplugged and idling
 
mechanic190 said:
No it's reading at 38 degrees when I set the timing at 20 degrees when I put back in the distributor on a stock rebuild 360 with vac advance unplugged and idling
Click to expand...



PM me if you still have the Unilite. I'd be interested in it, as long as it does NOT have vacuum advance.

Thanks.
 
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