i put on a JG stage 3 race head, this thing is hogged out. Due to the excessive porting the head has lost its thermal absorbtion. Under pressure the coolant will be resistant to boiling so obviously when I open the cap (not sealed anymore) there are bubbles. At first I thought it was the head gasket. So the question is, will there be steam pockets and should I worry? Is this a track only head, I wouldn't no I only put on 100 miles with it but it makes serious power.

 

i have no data to back this comment up, but: that cannot be good. sounds to me like another head destroyed...

 

have u done a leakdown test?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BokChoy &raquo;</TD></TR><TR><TD CLASS="quote">i put on a JG stage 3 race head, this thing is hogged out. </TD></TR></TABLE>

D'oh! See my sig for what it is like to deal with Javier.....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BokChoy &raquo;</TD></TR><TR><TD CLASS="quote"> Due to the excessive porting the head has lost its thermal absorbtion. </TD></TR></TABLE>

How did you decide this?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BokChoy &raquo;</TD></TR><TR><TD CLASS="quote"> Due to the excessive porting the head has lost its thermal absorbtion..</TD></TR></TABLE>
Yea id like to know as well..and umm yea ususally your coolant will bubble if you take the rad. cap off while the car is at operating temp...It will also blow super hot water and steam in ur face..Is the car overheating or losing coolant? If not then whats the problem?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BokChoy &raquo;</TD></TR><TR><TD CLASS="quote"> Due to the excessive porting the head has lost its thermal absorbtion. </TD></TR></TABLE>

o god thats gold. new sig.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tony1 &raquo;</TD></TR><TR><TD CLASS="quote">

How did you decide this?</TD></TR></TABLE>

not really a concrete decision, I've just noticed that on an excessivly ported heads the coolant boils and I can't think of any other explanation. Its tough to explain but we yanked the old head and put the new one on and it started doing this, the stock head didn't. Can u think of any other explanation? I don't see the problem with it but I've been told to worry/sell the head. I like it and don't want to get rid of it so I'm trying to find someone who can identify the problem or lack there of, to more or less say don't worry about it its all good. The head wan't cheap and I'd like to keep it.

Coolant levels stay fine and it runs a little hot, still with in safe operating temps.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by shortyz21 &raquo;</TD></TR><TR><TD CLASS="quote">

o god thats gold. new sig. </TD></TR></TABLE>

why is this gold is it not logical to believe that more material equals beter heat dispersal? I fail to see the technical merit to your reply maybe you could elaborate. Are you suggesting I build a golden head, cause I can't afford that. Thanks for your input though you truly are an asset to the honda community.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RedEj8 &raquo;</TD></TR><TR><TD CLASS="quote">
Yea id like to know as well..and umm yea ususally your coolant will bubble if you take the rad. cap off while the car is at operating temp...It will also blow super hot water and steam in ur face..Is the car overheating or losing coolant? If not then whats the problem?</TD></TR></TABLE>


Couldn't agree more... Everything has a boiling point... Considering that the head itself is hotter than the coolant (since the coolant is extracting the heat from it) all of the thermal energy in the head is either dissapated into the coolant or into the surrounding air. You might argue that since there is less material in the head to contain the heat (or slow down the transfer of energy) that it might be passed into the coolant at a faster rate, causing the coolants temperature to rise faster than if the heads extra material was still there. One might also argue that since the material is removed, the surface area inside of the ports has been increased, having a double effect. Cool intake air will extract heat from the head on the intake stroke faster that normal, and hot air on the exhaust stroke will be transferred into the head faster than normal. However, if your were to relate the ability of head to slow the transfer of heat from the combustion chamber to the coolant passages throught the materials mass, you would be able to create a ratio of preported mass to postported mass and determine that the (just an estimate) 1% change in mass really doesn't hold that much "weight" in an argument. The next aspect to look at would be the cooling system itself. since average coolant temperature is over the boiling point of water, the coolant has to be modified so that it resists boiling until higher temperatures. This is done in two ways, pressurizing the system, and changing the chemical properties of the coolant. Judging by the topic, if you've noticed that the coolant is boiling, you have the cap off and the system is not designed to function properly at atmospheric pressures. If you noticed an extreme change in the amount of airflow through the coolant, I would be leading towards combustion leaks. Just my two cents....


Modified by tmac007 at 9:09 PM 12/18/2006

 

Well, what it comes down to is that your car is running hotter than it was, right? You can't base anything off of the water boiling w/o the cap on. The cap raises the pressure, which raises the boiling point. What engine temps are you seeing as it is? What gauge are you basing this off of?

There's not that much material removed from porting. In the big picture, as far as heat dissipation, how much of the head was removed, material wise? .5% maybe?