Tech: When Ford Adapter or Block Plates Go Bad and How To Fix ‘Em
September 2020 • Tony Thacker
I’d never heard of this situation before until I stopped by Rick ‘Speed’ Lefever’s shop in Pomona, CA, to photograph his son Rayce’s Model A coupe and saw him working on this Ford engine and Tremec five-speed transmission for Carl Akin’s Deuce 3-window. The power train components were assembled elsewhere and said to be ready to be installed and delivered to the customer when Rick decided to perform a fit check just to make sure that everything was correctly installed. Unfortunately, it was far from correct.
Just to be clear, this is not a typical situation; companies such as Holley sell block plates all day long without a problem. However, in this case there were reasons for correcting the existing plate rather than just throwing it away and buying a new one. Here’s how the fix was put in.
The block plate, also known as a separator or spacer plate, is a steel plate that goes between the engine and the bellhousing and is there to ensure perfect alignment between the starter Bendix drive and the flywheel ring gear and the transmission input shaft, the bellhousing and the crank. Perfect alignment ensures that you have the input shaft of the trans aligned with the crank and therefore minimal chance of problems or even an explosion due to misalignment. Most racing organizations require a block plate and they should therefore meet S.F.I. safety requirements if you intend to go racing.
Unfortunately, in this instance none of the components were in alignment consequently Rick had to disassemble the assembly separating the trans from the bellhousing and the bellhousing from the block plate. He was then able to measure the boss, also known as the register, on the trans and the hole in the bellhousing. There’s supposed to be a .005 clearance but in this instance it was .400 or almost ½-inch. Also, the locating hole in the block plate for the starter had been hogged out—why we don’t know—and was no longer locating the starter, as it should. To be blunt, it was a mess and required a complete rebuild.
You might think this operation was way over the top, and you’d be right, but if you’re serious about your build, especially if you are using a Ford engine, and intend to do any racing you’d best be aware of the right way to do it.