Looking at the same head from a slightly different angle and with some fade correction to emphasize the contrasts.

The deck surface was lightly and slowly stoned. Think of it as a light sanding, but with a rigid and flat stone versus a flexible piece of sandpaper. The purpose of the stoning was to bring out the high and low spots. The head is not warped; but it does have some problems.

One problem that this head did not suffer from was a lack of headbolt clamping force. Look closely at the ten headbolt hole areas. They are all "high" spots. The headbolts provided plenty of clamping force: more than enough to actually pull the aluminum around each bolt towards the block. I bring this up because there are some that think the new style headbolts aren't strong enough to hold the head down and keep the head gasket in place and prevent a head gasket failure. This image shows otherwise. A supposed lack of head bolt strength and clamping force IS NOT the problem; nor is it the cause of the problems I found on most of the cylinder heads I examined. The much touted notion that finding the old style head bolts, and overtorque-ing them by about 10 lbs-ft being the trick way to go is a myth...and will result in the very problem that that misguided notion seeks to prevent. Overtorque-ing a bolt is EXACTLY that: OVER-torque-ing.

The new style head bolts are more than sufficient to do the job, IF everything else is right. The high spots around the head bolt holes shows that the new style headbolts have enough clamping force to distort the aluminum of the head casting over a period of time. To apply more clamping force than this a good idea??? I don't think so. You just end up distorting the aluminum more faster: ie a greater amount of metal movement in a shorter time frame.

**** UPDATE 8-22-2004 ****

I have editied the text to change the nomenclature of the head bolts. I had referred to them as TTY head bolts; the TTY standing for "Torque To Yield". I have done some research that leads me to conclude that the later style head bolts that Volvo changed over to in the early '80s are NOT really TTY bolts. They look like TTY bolts commonly seen and used automotively: they have a center section that has a reduced diameter. But they are not installed in the same exact manner as TTY bolts. Rather, they are installed using a procedure known as "angle tightening". I will put up a picture in the gallery to show the old vs later bolts; and get into the discussion with that image.

**** UPDATE 8-27-2004 ****

I have changed the name from TTY to "new style" in this text. I have added a subgallery entitled "headbolts" to explain the reasons for the name change; and to clarify my arguments on the subject.