Title: Motor Engineer
Accomplishment: The Father of the Pontiac V-8
Of all the people who contributed to the design and development of the Pontiac V-8 engine, Mark Frank is at the top of the list. Mark started at Pontiac during the ’30s when Pontiac sold Flat-Head Straight-6s and Straight-8s. He became the motor engineer in 1942, and held that title during the Pontiac V-8’s inception through to production.
Assistant Engine Engineer Clayton Leach examines a set of 8-Lug wheels, which he designed.
When I started at Pontiac in 1957, Mark was the engine boss. He was very smart and capable, but didn’t make a lot of noise. Perhaps that’s why he didn’t get much publicity outside of the corporation. I was fearful of him when I started as a junior draftsman because he would come by every day to see what I was doing, but never said anything or made eye contact. One time when there was a design drawing of mine that he thought was incorrect, he didn’t say anything to me, but discussed it with the chief draftsman, who relayed Mark’s dissatisfaction with the drawing to me. I had to advance within Pontiac’s ranks before Mark started to speak to me directly.
Mark Frank’s 7,000-rpm camshaft
My next encounter with Mark was in 1965 when I was assigned to run the Pontiac Test Group at the GM Proving Grounds. The GTO was rapidly growing in popularity, and I built the first functional hoodscoop in the Proving Grounds shop. (The styling department knew how to make the hoodscoop look good, but I had to figure out how to actually make it work!) Our team was looking for ways to improve GTO engine performance, but with a usable rpm limit of about 5,500, we were limited.
One of my duties was to attend the monthly engine meetings. (About 50 engineers were at these meetings, even though the Pontiac V-8 engine was fully developed and in production for 10 years.) At one of the meetings I mentioned that we could improve the GTO’s performance if we could get a camshaft and valvetrain that would give us more than 5,500 rpm.
By then (April 1965 or shortly thereafter), Mark had been placed on “special assignment” (that’s General Motors-speak for “We want you to retire!”) by John DeLorean, and was replaced by Malcolm McKellar. Later, I found out why. Mark objected to putting the 389 engine in the Tempest, so DeLorean purposefully pushed him out of the way to prevent him from hindering Pontiac from ushering in the musclecar era.
You can view Clayton Leach’s patent (and other patents submitted on the behalf of Pontiac
As I exited the meeting, Mark came by and quietly told me that he would get me the high-performance camshaft we needed. About a month later it showed up in my office. We put it in our GTO test car and it immediately ran up to 7,000 rpm just like he promised.
It’s not hard to guess what happened next. Mark’s 7,000-rpm camshaft pushed a connecting rod past its metallurgical limits. In other words, it blew a rod. No one in the Engineering Group was interested in further work on it. I would have pursued it, but I was then assigned to Advanced Engineering.
If it had made it into production, would it have changed the course of Pontiac performance history? If so, Pontiac would have been forced to raise the durability of its V-8’s reciprocating assembly, which was only rated to 4,500 rpm for 100 hours non-stop at wide-open throttle. (Published redlines are higher because they are designed to allow the engine higher-rpm for short bursts of time—not 100 hours!) It was a cost the Division was unwilling to undertake to keep the GTO’s manufacturing expense under the bean counters’ radar.