Yikes!!! Hot motor!!!

T

twbowhunter

Active member
fired up the new 200 and the temp went to 210 (with a 195 thermo) my son drove it maybe 5 miles came back steaming, said it never got over 220 ,wtf? new everything water pump ect ,please dont tell me its because i went 60 over on the bore ill shoot myself !!!!! i live in califorina and its cold ! :cry: :cry: :cry:
 
Remember a few details.

First up - are you sure the thermostat is in right?

Next - did you fit the oil pump hex shaft, and does it have good oil pressure? Oil takes away a lot of heat.

Did you break in the cam before driving it, and set the base timing to about 10-12° advanced?

Is fuel pressure good?

How was the block cleaned internally, and was the radiator flushed? Did you bleed the cooling system while filling, and top up the radiator after a few minutes' operation?

Finally, remember a new motor with tight clearances will run a little hot for the first 1500 miles or so.
 
Addo asks many good questions.

Dont trust any one single gauge. Get one of those IR gun things to confirm gauge readings.

220 should not boil unless it was only water and not under pressure. If you had pressure or a proper antifreeze mix that should have been fine. With both you should have had maybe even another 30* before anything would blow.

An engine I rebuild this summer seems to like to run around 220 on typical warm days. It started out closer to 200 but after all the break in stuff on its first long drive it peaked a couple times over 230 but then fell back down to around 200. I could not think of any reasons for the peaks, the terrain and ambient temps were all the same. Must have been some sort of break in thing happening or perhaps a air bubble in the system somewhere that suddenly moved.
 
TW,

Yea, when I started my motor after its rebuild (with mild ported 250 head, 260 cam, total seal rings, etc) it ran hot too. It has a 165 t/stat and it ran in the 205 range. I would turn it off when it got to 220 as well. I did put in a larger "desert" radiator and that seemed to lower the temp to the 185-195 range. My only guess is that the engine is moving more air/fuel and the cooling system isn't designed to handle all that heat.

Personally I think the water temp should should be controlled by the t/stat and not the heat transfer area of the radiator. The larger 3 core radiator helped, but didn't totally solve the problem in my opinion. I'm still trying to get the temps down. The initial timing is 12*, and the balancer is deadnuts on. So I guess I don't have any suggestions to help (besides a larger radiator) but to let you know that others have the same issue. Keep us updated if you find a fix.

tanx,
Mugsy 8)
 
Did you replace the radiator?
The radiator cap? A leaking cap (one that will not hold its rated pressure) would explain the boiling over at relatively low temps.
Ignition timing: Make sure the distributor is functioning, both the centrifugal advance and the vacuum advance. Insufficient advance will cause high temps.
Doug
 
Usually more advance makes them run a bit cooler but I would imagine to the point of detonation could make it worse. Detonation on any motor is a bad thing, even worse on a new one. I have had old motors that didnt seem to care. I was helping a guy with a fresh motor and it didnt sound that bad to me but he ended up loosing compression. Turned out to be a hole in one piston and cracked rings in the rest. Rod bearings also didnt do so well.
 
Thats what mine seems to do. Seems like I read some race guys say that also so they run the vac while in line to keep temps down then unhook it for the run. I think thats also why most of the emissions cars run off a ported source because it raises temps and lowers (or raises?) one of the gases they are trying to reduce.
 
When you first start a new engine, you want to make sure the coolant level is completely full & the cylinder head has coolant in it.

One sure method is to take 2 aspirn pills & place them under the thermostat poppet valve to make sure the valve is open to bleed air out of the top of the engine. This will prevent waiting till the thermostat opens to burp the system. The pills will dissolve when hot coolant hits them, but by that time the system is void of air pockets.

Your engine will not suffer from the pain of overheating since the system is fully topped off. It works, Bill
 
I second that, Ive always read too much timing will make it run more hot
Click to expand...

I recently asked an mechanical engineer who did his Masters in internal combustion whether advanced timing made it run hotter. I asked him whether it would run appreciably hotter before you noticed any pinging. He said that it would start pinging before you noted a temperature problem. If you are detonating due to excessive heat, I suppose it could sound like pinging. But the root cause is typically something other than advanced timing.
Doug
 
I had to back my timing off because I was heating up and pinging on the hot days. Going back 2 degrees helped. What plugs are you using btw??
 
i hope i found it, my son drained the coolent today and when he looked into the radiator most of the tubes were pluged,i had it redone when i put the first motor in and just thought it was good :oops: now i just hope i didnt screw anything up running the new motor at 215 :(
 
old moter had a lot of bars leek and other crap put in it by previous owner i figured when he freshend it up (ha ha ) it was cleaned out ! :lol:
 
I would buy a back-flush kit and flush the block and heater core before you put the new / rebuilt radiator back in service. Make sure you remove the drain plugs on the block and you may have to poke up in the holes with wire in order to get the stuff to start coming out.
And 215 degrees is nothing to worry about.
Doug
 
In addition to the other tips, I would do the following:

1) Remove all of the heater hoses and either plug the ports on the engine or loop the hose. If you have not cleaned out the heater tank, do not connect until you have done so. The amount of crud in there will just contaminate your system again.

2) Make sure all of your hose clamps are very tight and close to the raised nipple portion of your inlets and outlets. This is critical to keep the system pressurized. If you do not have reinforced hoses, change them out now. Check your radiator for possible leaks around the overflow tube. They are notorious for solder leaks. I would personally go with a new radiator after you flush your block.
 
big thanks to all of you for your imput, had the radiator redone and followed your advise the new motor now runs at 170 and has a lot more power than the old one :banana:, thanks again
 
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