Overheating and Blown Head Gaskets

Long post, please bear with me...

I over heated twice and blew two headgaskets this weekend at Barber.

The first occurred Friday during the final practice session.
The car ran cool (180+/-) and well until the cool-down lap.
From the cool down lap to the paddock, the temp went to 240-260.
(I lost an alternator belt earlier in the day and thought the fan probably quit.)
Replaced the belt.

Cranked up Saturday morning to go to qualifying grid to discover the distinct sound of a leaking head gasket.
Pulled the head and #2 and #3 had water in them.
Dried cylinders and replaced the head gasket. Oil and plugs looked very good.

Car ran very well during a 15 lap race on Saturday
Temps on the straights would drop to 160+/-.
(This makes me think the water pump was working and the system had plenty of water.)
On the cool-down lap, same as before, temps shot up to the 240-260 range and it dies when I got back to paddock.
It would not start up.
I ran compression check on the motor:
1-120 lbs
2-30 lbs
3-30-lbs
4-121 lbs
I now supect a warped head.

On a side note, the upper timing cover melted around its bolts to the point where the plastic dripped.

Finally (If I haven't bored you) my question is:

What could be causing the overheating?
Especially the heat around the timing cover???

Thanks,

Todd

Oh yeah...

It's an ITC... CVCC and Carb.

bad water pump? only flows at rpm...

no experience with those cars, just doing the math


what do you have for a thermostat?

Yes I agree it seems like a bad water pump, I would also think about flushing the radiator and blowing the bugs out of the fins.

The head is warped for sure, and I think you might want to double check the cyl. bores to make sure the overheating didn't score them.

Tom Blaney

O and: eng fan? or electric?

Thanks Guys,

I've been "coached" I'm probably running too much advance, which I am.
That explains why the car ran so well.

I pulled the head this morning. It is warped.
I'll plan to replace the water pump (just in case) and put back together.

Todd

I would say that the rings lost there tension also if it got hot enough to melt the plastic cover. Is the block straight? I would get the head pressure test to make sure it is not cracked.

I would take a serious look at the radiator and either have it professionally cleaned or just replace it.

Quote:

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Originally Posted by toddgreene

Long post, please bear with me...

I over heated twice and blew two headgaskets this weekend at Barber.

The first occurred Friday during the final practice session.
The car ran cool (180+/-) and well until the cool-down lap.
From the cool down lap to the paddock, the temp went to 240-260.
(I lost an alternator belt earlier in the day and thought the fan probably quit.)
Replaced the belt.

Cranked up Saturday morning to go to qualifying grid to discover the distinct sound of a leaking head gasket.
Pulled the head and #2 and #3 had water in them.
Dried cylinders and replaced the head gasket. Oil and plugs looked very good.

Car ran very well during a 15 lap race on Saturday
Temps on the straights would drop to 160+/-.
(This makes me think the water pump was working and the system had plenty of water.)
On the cool-down lap, same as before, temps shot up to the 240-260 range and it dies when I got back to paddock.
It would not start up.
I ran compression check on the motor:
1-120 lbs
2-30 lbs
3-30-lbs
4-121 lbs
I now supect a warped head.

On a side note, the upper timing cover melted around its bolts to the point where the plastic dripped.

Finally (If I haven't bored you) my question is:

What could be causing the overheating?
Especially the heat around the timing cover???

Thanks,

Todd

---

Check the block with a good straight edge. I had the same problem with and went through several head gaskets came to find out the cylinders were actually lower than the block deck. Blocks are easy to find.

I too had an overheating Honda motor for a season. Although I have not completely inspected the block, it was the culprit. The temp fluctuations you are seeing is when water is present (160F) and then steam (240-260F) as the cooling system has air in it after blowing the head gasket. The block may have had a cracked sleeve or as Rick says the sleeve could be lower in the block. Either way you get a cylinder compression into the coolant system. A coolant overflow coolant tank cap blowing off is a good sign. I put in a new Blaney engine and have not had a problem since.