Been having a strange experience with my new motor! Every so often especially when it is cold, I if stand on it hard my rad cap will lift and spray my engine compartment.(doesn't seam to happen when it is warmed up!) Engine is no where near hot and sometimes the rad is stone cold when this happens. My fear is a head gasket, but there are no signs of that. No antifreeze in the oil or any white smoke out of the tail pipe.  My engine builder calculated my compression at about 10:25 to 1 with the Probe dome pistons.
Car runs great, and pulls REAL strong. I can't take it back to my engine builder as he passed away, shortly after finishing my motor. My thoughts right now are to re-torque the head bolts, unless anyone has any other things I should look at (Ted, John?)

Thanks

I love the smell of burning rubber in the morning!

Make sure the radiator cap is still within spec.  If you or a friend has a cooling system pressure tester, many of those also have  cap tester.



Lawrenceville, GA

Most auto repair places have a dye that indicates if you have an exhaust leak into the cooling system.

  Vic Correnti

Is the wire coil in your bottom radiator hose? could be sucking flat and pressurising the top end of your cooling system. I can get a small amount come out when the revs get higher as the water can't get through the rad fast enough and  pressure increases in the top tank.
If it is spraying over the motor it may be that the rad neck is not flat or the seal on the cap is faulty or maybe the overflow is not able to release the pressure quick enough.
I wouldn't know what mine would do under those circumstances as I never load mine up until it is at running temp.
And as Charlie says, Pressure test your cap. 

I’ll suggest retorqing the head bolts at this point.  Do you have grade eight head bolts?  It does sound like a head gasket pressurizing the cooling system. 

Lorena, Texas (South of Waco)

Ted,
I purchased all new head bolts from John Mummert when I bought the engine kit. What do you recommend retorqing the head bolts to?

I love the smell of burning rubber in the morning!

Thanks for all the other responses, I will have the cap checked out. It is a 13 lbs cap on a new aluminum rad.

I love the smell of burning rubber in the morning!

For head bolt torque, I use 70 lbs. for the short bolts and 75 lbs. for the long bolts.

Lorena, Texas (South of Waco)

Thanks Ted, I hope this works and I caught it in time! I'd hate to have to pull the heads on my new motor and since Rob Burbine has passed, I can't go back to him!

I love the smell of burning rubber in the morning!

Ted,
I tried to re-torque the head bolts to 70 & 75 ft pounds, but didn't even budge the bolts! My head bolts are ARP 12 points supplied by John Mummert. I am going to assume that Rob had torqued my head bolts down a lot more than 75 ft /lbs. I have steel gaskets, not the composite type, do you suppose this may have crushed the gaskets? Motor is perfectly fine if I start it up and let it warm up until the thermostat opens. After that it appears I can stand on it as much as I want! If I do this before the motor completely heats up, I pressurize the rad.  

I love the smell of burning rubber in the morning!