As a part of the Sarah Project B230FT engine, the cylinder head had to be right. What I had thought to be a fairly straightforward and routine part of the engine building project turned out to be considerably more involved.

The first two cylinder heads that I examined for the rebuild were not in the condition that I had expected. The problems I found with those two heads forced me to examine more cylinder heads to find one good enough for the engine. I went through eleven cylinder heads to come up with three candidates. I used the best of the three.

While examining all these cylinder heads, I came to some conclusions as to what the problems were and could be; the causes of those problems; and what I would need to do in order to not have those problems.

The Volvo SOHC [single overhead camshaft] cylinder head is, in my opinion, one of the best, if not THE best, cylinder head designs ever. I was fairly convinced of that before I started this engine project. The examinations, analyses, and determinations of the problems and solutions to those problems did not change my opinion of the SOHC head: it strengthened that opinion.

I consider the volvo SOHC head an excellent design because it is a very efficient package:
...it performs all its tasks with a minimum number of moving parts: the valvetrain is designed to operate smoothly and without rocker arms or followers...fewer moving parts to wear out...less weight for the valve springs to control;
...those parts are configured to operate in the minimum space needed: very compact and tidy;
...the valvetrain components that must endure high pressure loads are well lubricated;
...the tappet design protects the valve stems and guides from any side load: the valves only have to go up and down; any sideload from the cam lobes are absorbed by the well lubricated and well supported bucket type tappets;
...the layout of each cylinder's ports, runners, and combustion chambers is uniform: no mirroring; no reversed configuration;
...swirl is promoted by the inline valve arrangement and the intake ports being tangential to the centerline;
...All of this is done and contained in a single casting....an intricate yet very straightforward design; laid out like a four floor production facility: everything in its place; and a place for every necessary thing.

Are there more "modern" head designs out there? Certainly. And I guess that the general attitude is that 'newer' has to be 'better'. That is not always the case. Excellence and quality are timeless; change for the sake of change is not the correct foundational motivation. Change should be based on the desire for, and with the goal of, improvement.

I have long believed that to remove material from the deck surface in amounts greater than the absolute minimum needed to restore flatness was not wise; whether the head be iron or aluminum. As a result of this forced, but not unwelcomed or regretted, excercise and investigation; my bias against such material removal has only intensified: to "shave a head" to raise compression ratio, especially on an aluminum head, is very ill-advised; and to do that on an aluminum head used in a boosted motor is, as I have come to see things, a very stupid and counterproductive idea....if you are concerned with longevity and durability.

This gallery will follow my search; show some of the problems I found; my conclusions regarding the causes and solutions; and will illustrate some of what I decided to do to address, correct, and avoid them.

UPDATE:
Last year I did a gallery on 'Headbolts', and made it a subgallery here. It seemed to fit in with this gallery. I decided to make 'Headbolts' a separate gallery; to assist those viewing the main page to find that information.

For those arriving here from a link to see the headbolt information, it is the gallery following this one.