A fragged Offy piston, autographed by Parnelli Jones
Offies Suffer Expensive Toll In Trials
Magnaflux Tells All
By Rick Johnson, Indianapolis Star, May 27, 1964
The huffing and puffing that the old reliable Meyer-Drake engine did this month, while trying to catch those flying Fords at the Indianapolis Motor Speedway, has taken an expensive toll.
According to the Magnaflux Corp., a division of Champion Spark Plug Co., stationed at the track, five crankshafts from the old Offy, along with a bushel basket of pistons and connecting rods, several main bearing webs, valves, valve springs and clutch springs have failed to pass due to cracks and flaws detected under Magnaflux scrutiny.
No total cost was available on the parts, but crankshafts cost $1,000 each, pistons sell for $50 apiece, connecting rods cost a minimum of $183, while the crankcase bearing support webs range in cost from $45 to $75.
(Rick Johnson Photo)
United States Auto Club rules stipulate that before a race car is allowed to go on the track to practice, it must first be submitted for Magnaflux inspection of vital engine parts, steering assembly and torsion bar apparatus, as well as the front hubs and wing nuts.
Magnaflux inspection also covers the differential, hubs, torsion bars, and adjustment arms. And only after the car has passed inspection by replacing defective parts, is it allowed on the track.
To prevent a part with a flaw in it from being installed in a racecar, the part is red-tagged by car number and kept in the Magnaflux office until after the race, when it is returned to the owner.
But this first inspection is not the last by a long shot. According to the test station manager Ed Oclon, each time a car spins, come in contact with the wall or anything else while running at high speeds, the wheels and steering apparatus are checked again to determine if cracks developed in the slide or accident.
And again, all defective parts are kept and red-tagged to prevent them from being used.
To further insure the safety of the 500-Mile Race, USAC also insists that the cars qualified for the race undergo a second Magnaflux inspection that is as intensive as the first.
If the car does not submit to the second inspection, it will not receive permission to run in the race from USAC.
Oclon explained that, while all vital parts must be inspected, not all are inspected by Magnaflux at the Speedway. A few car owners want their equipment examined elsewhere, which is within the rules as long as the owners are able to produce proof to USAC that the parts have been examined.
For example, the steering apparatus and some pieces of the steering assembly from the Lotus-Ford machines, to be driven by Jim Clark and Dan Gurney, have been examined by Magnaflux at the track. But the engines and their parts are examined at the Ford factory after teardown and measurement at the track by USAC technical committee members.
In commenting on the unusually high number of defective engine parts found this year, Oclon said, “This year has been the worst I can remember for several years for finding bad crankshafts and connection rods. But we have found several bad steering parts and gears that have failed to pass inspection, too.”
“And to go along with this pile, we have more than a dozen racing wheels in here that didn’t make the grade,” he added.
The wheels are worth an average of $90 each.
In the Magnaflux process, an engine part is magnetized, and a solution containing iron filings is poured over the part. Under black light, the filings concentrate around a crack or flaw and bring the area out more clearly to the human eye.
(Photo Courtesy Thurston Engineering)
Another process called Zyglow is used to detect flaws in magnesium parts and other non-magnetic pieces.
In this process, the part is first degreased and then dipped into a chemical solution that penetrates the metal entirely. When the solution is rinsed off with water, it comes off completely except in an area that is cracked or has a flaw. This area is discolored by the chemical and clearly shows the flaw.
As Oclon and his assistant looked over the vast table of bad parts, they shook their heads. Oclon said, “And this isn’t all of them,” as he surveyed the rash of red tags.
“A lot of the boys lost complete engines out here this month. They didn’t even bother to bring in the pieces.”
Most of the mechanics in the garage area agreed that the old Offy has had its tail twisted just about as tight as it ever can be without coming apart…at least in one of the conventional speedway roadsters.
(Rick Johnson Photo)