Detonation

[87GNSteve]

Did your compression ratio go up?
Maybe the new heads had smaller chambers/CC's from the milling of the deck and larger/heavier valves add to it too. What HG? steel shim? Felpro composite?
I understand on these engines it doesnt take much to raise the CR.

 

[tmsbuic]

I found my problem, atleast I hope I did. I used a bore scope and I found #'s 1,4,6 cylinders have coolant drops on top of the pistons. Either the RJC head gaskets didn't seal good or these new Champion heads have a defect in them. Once I get them off, I'm going to have them pressure check to see if the machining done to them might have got into a coolant passage. This is a starting point and needs to be fixed first. I'll post again if this solves everything or not. Thanks for everyones input on this issue.

 

[VadersV6]

Find a shop with a pressure testing jig for cylinder heads. You could have a little pinhole somewhere or even a crack. Hopefully they didnt spray some sort of silicone on the headgaskets.
Do the valve guides run through the coolant passages on champion heads? Sometimes you can get some leaking through there if the aluminum was galled or damaged when the old guides were being driven out, or the new ones driven in.
Were the heads milled? Dont remember if you mentioned that.
So was it coolant on the pistons for sure, or drops of condensation? Condensation from the exhaust can find its way into the cylinders via EGR.
Perhaps you're getting a little cross talk from the coolant passages on the intake into the ports. Hopefully you dont have any cracked cylinders.

 

[tmsbuic]

These are new Champion Iron heads. They did all the machining and the egr passages are filled with alum. Its coolant, the sparks plugs had it on them also. I hope there CNC machine didn't make a mistake, if so, I hope the company I bought them through will work with me since they only have no more than a couple hundred miles on them. It might just be the headgaskets from RJC. I followed there instructions on applying the sealent and stuff, but they might not have taken a good seal. Anyways, I will get the machine shop here to pressure check them and go from there. It they turn out good, I might just go back with fel-pro headgaskets.

 

[tmsbuic]

There shouldn't be any cracked cylinders, everything worked fine until I did the head swap and then the problem started. The actual bottom end of the engine only has 7000 to 8000 miles on it since rebuild. I also noticed since I put these heads on is when the car sits and idles for over ten minutes, I start seeing and smelling oil smoke slowly coming out of the exhaust. That also makes me think there is a problem with these heads with the valve guides/seal area. Never had any type of smoking problem UNTIL these heads were put on especially with only 7 to 8 k miles on shortblock.

 

[tmsbuic]

One area I'm going to really look at before I tear the heads off is the intake sealing. Its possible that its not sealing correctly and allowing coolant and oil to seep into the intake runners. I'll pull the dog house off and use the bore scope to see if there is any coolant/oil going down the intake track first.

 

[iamjeff]

i had a simular problem with my car when i accidentally cracked the porcelin on the #6 spark plug. the car would idle fine, but whenever it was put under load it would cut out. cracks can be difficult to see and mine just looked like a hair on the side of the spark plug. just something to check.

-Jeff

 

[Jerryl]

...... My cars always ran worse on winter gas, which sucks cause thats when the cold weather is there.

Saw something on discovery channel ...... there are different gas formulas for each state and possibly each region. That may be one difference in the gas results noted earlier.

I also think that wintergas has something else in it (duhhhh ) to ensure vaporization in colder weather. If it is something like ethanol, this would lean out the motor on winter gas and cause KR. Would be interesting to see a comparison between winter and summer gas with a WB.