New engine instantly gets hot

[aahsac]

I'm hoping someone has senn this exact thing before. I had a new long block built using my core. The head had already been done, a D3 head on a C9 engine, the head was milled .075. I had driven the car a few hundred miles with this head so I assume there was no problem there. Turns out the camshaft ws bad, hence the rebuild. The new engine has a new cam and timing chain set from Classic Inlines. I'm not home so I can't say which cam I have but it is a mild one.

The engine will get hot to boiling over in 3-4 minutes. The mechanic went ahead and knocked the center out of the thermostat, no change. The ignition timing is spot on. The engine seems to run correctly in every way except it gets hot and fast. Both upper and lower radiator hoses get hot so I have to assume there is water flow. The engine doesn't act tight and there are no unusual noises.

I always considered the engine to run a little warm but it never boiled over even in the summer.

I am going to call the company the built the engine tomorrow, Blaines Motor Supply, to see what they say but I'm posting this in hopes someone has seen the exact same thing. The car is about 200 miles away from where I am right now so I can't check anything myself right now and report back to the forum. I have very limited internet access until Tuesday but if someone sends me a PM I can send and receive those.

Is there a water pump that fits and was meant to turn in another direction (like I have the wrong pump), or can you flip the head gasket front to back and it would bolt up but block a water passage? just grasping at straws....

I'm hoping someone has seen the exact same thing before..

Thanks.

Stephen
Plano, Tx

 

[Asa]

you can fit the gasket backwards, but i think it should pour out coolant, not make it boil over
no reverse drive water pumps, so if the pump is good it shouldn't be a concern

knocking out the thermostat is actually a negative as it will no longer be able to regulate the temperature, just install the housing without it next time so that you can reinstall it later when you determine if that's it or not


change your cap, and get your radiator flushed out/cleaned
i'd be willing to go with radiator

 

[gtm1086]

Try bumping your timing up to around 12 degrees. and richen up you carb mixture. You may also if you haven't done so already is to have the radiator cleaned and install a 14 lb cap.

 

[BUZZ]

I had a truck with a blown head gasket that would do that. After just a few minutes of running it would jump to 220* other than the overheating the motor seemed fine no water in the oil or steam out the tailpipe. I think it was just leaking combustion gas into the water jackets.The only other thing that comes to mind is timing.

 

[rbohm]

8) there is alsi the distinct possibility that when the short block was rebuilt and the core plugs knocked out, that the old ones were left in the water jacket and are blocking flow to the point where you have little.

 

[grocery getter]

the head was shaved .075. was it cc'd ?

air trapped in the coolant system will cause this.

if the mechanic does smog checks. he can put the wand on an open radiator and check for a head gasket leak.

 

[rickwrench]

It's most likely a timing issue.
If your balancer has slipped (a common issue on a 35-45 y.o. balancer) the TDC mark will be very retarded. Severely retarded engines run very hot.
Check to make sure TDC is really TDC.
Another possibility is the cam was installed a tooth off.
Check the balancer first though.
Rick(wrench)

 

[ludwig]

What he means is find TDC manually. Disconnect the battery. Then remove all the plugs. Then rotate the engine with a wrench on the damper while you have your finger stuck in the first sparkplug hole. When you feel the pressure max out, that is TDC. Alternately, you can use a probe of some kind in the same hole and watch it rise until it stops. That is TDC. Now make a white mark on the damper at true TCD across from the pointer.

 

[powerband]

A note from under the shade tree:

"The engine will get hot to boiling over in 3-4 minutes"

That's real fast ... Any chance it's the guage/sensor, get a cheap mechanical guage if any doubts.

If you have no thermostat ( or center removed), with the radiator mostly filled and cap off, you should be able to see the coolant flow rather strongly when you rev it up a little . Also the coolant should rapidly become warm in the radiator if it's circulating and overheating.



The performance built 250 engine overheated immediately on initial startup to break in cam. I was using the same radiator that worked fine with the stock 170. I flooded the radiator with a water hose which cooled it right down and confirmed my overheating problem to be the radiator.


PB

 

[l3n]

3-4 minutes sounds awful quick, but like someone else already said, if the carb is running lean that can kick up the heat something fierce, I just went through that one as part of a HW 5200 swap. I'd definitely look at the timing too.

 

[MustangSix]

There is also a remote possibility that the pump impeller has come loose.

 

[powerband]

There is also a remote possibility that the pump impeller has come loose.

I have seen an impeller eroded or slurry ground enough to be ineffective.

PB

 

[CobraSix]

I doubt the carb or timing issues. I've had carbs running crazy lean and some seriously retarded timing before, and never had my car overheat that fast.

1) pull and check your Waterpump.
2) Flush your system while you are at it.

Heck, I could probably disengage my water pump belt and still wouldn't head up that fast.

I think it's either a water pump, radiator, or something is stuck in a cooling port. I did have that happen on my old truck once...something got stuck in the cooling port around #6 cylinder and the block ended up cracking around the #6 cylinder. Real bitch of it was I never saw the temp gauge overheat because it was still flowing around 80% of the engine and thus was cool. Only since was when all of a sudden the engine died going down the highway at 8pm at night. This was before cell phones and I didn't have AAA so finding a tow company was fun...

Slade

 

[BUZZ]

You could run a motor with out a water pump belt any where from 5 to 10 minutes while moving before it gets hot, sitting I'd say at least 7 minutes. He said both hoses get hot which makes me believe that he has water flow of some sort. This is a very strange problem

 

[CobraSix]

I'm starting to think you have a combo of problems that are factoring in on this.

 

[Bort62]

I will throw in that you can run a motor w/o a functioning water pump for quite a while before it exhibits any signs of overheating. It takes a LOT of energy to heat up water.

4.21kJ/Kg * C to be exact

I would suspect some sort of internal engine problem

 

[addo]

Yes, or dry-torqued head bolts leading to an undertightened head.

 

[mugsy]

I have a similar problem with my D7 head on a C6 block. Prior to the rebuild the original '65 engine's coolant ran at the temp of the t/stat. When I started it up AFTER the rebuild, the coolant ran about 205F (with a 165F t/stat fromthe old engine). Timing was set at 12*. The damper was rebuilt so no slipping there and I also verified TDC with a degree wheel. I put in a "desert" radiator (three row vs. two row I think) and the temp went down to 185 while driving above 30 mph. She would heat back up into the 200-215 range in stop-n-go driving. I also installed an A/F meter, and if anything the A/F was slightly rich. I have yet to figure this out, so come on guys help us BOTH out ! Anything we haven't thought of?

 

[aahsac]

Since I knew the condition of the motor (new) and the fact that this car sat for 20 years in a garage because of a busted head and the fact that I have thought all along the the busted head was from severe over heating i pulled the radiator. You really can't tell much about the radiator from the top as mine has the baffle in the top but when I pulled the radiator the bottom end was completely gunked up. Dallas Radiator Exchange will build me a three row which I need anyway since I'm moving to Az in April.

Once I get that back and installed I'll report back with the results. Thanks to all for your input and thoughts.


Stephen
Plano, Tx

 

[wallaka]

Since I knew the condition of the motor (new) and the fact that this car sat for 20 years in a garage because of a busted head and the fact that I have thought all along the the busted head was from severe over heating i pulled the radiator. You really can't tell much about the radiator from the top as mine has the baffle in the top but when I pulled the radiator the bottom end was completely gunked up. Dallas Radiator Exchange will build me a three row which I need anyway since I'm moving to Az in April.

Once I get that back and installed I'll report back with the results. Thanks to all for your input and thoughts.


Stephen
Plano, Tx

Well, I like an easy solution.