Vintage V-12: Restoring Merlins

Gary Aldrich

Originally published June 1997

A small but, valiant band of PPTAF raiders tackled a journey of Homeric proportion last month when they traveled to a hidden location in the Tehachapi valley to visit Vintage V-12's. Following cryptic instructions such as "turn in by the red truck", our heroes discovered an engine overhaul shop....Ah, but not just any engine! Vintage V-12's specializes in, you guessed it, overhauling aircraft engines from the golden era of internal combustion development.

The shop and warehouse were stacked floor to ceiling, literally, with Merlin, Allison, Griffin, and Daimler-Benz V-12's as well as the odd-looking Bristol Centaurus radial engine. Owner Mike Nixon and his lovely wife Kim started their unique business (one of only a half dozen or so in the U.S.) in 1974 after Mike discovered his love of the old engines. They've been located in Tehachapi since 1986.

Kim was our hostess for the tour and provided fascinating insight into the history of some of the motors while lead mechanic Jose Flores provided the technical commentary on the overhaul process. We learned that when a "core" comes in from a customer a teardown and inspection takes place to determine the tasks required to bring it back to spec performance. Kim said that most of the engines are removed from flying aircraft but some--like the Daimler-Benz Me-109 engine currently in work--come from wrecks or storage in the fabled "barn full of airplanes". Some have famous owners. Examples are the Allison belonging to former Astronaut Frank Borman and the Merlin out of Bob Hoover's famous P-51.

An interesting difference in basic design between these V-12's and the engines we typically find in our cars (other than the obvious difference in number of cylinders) is that the pistons do not ride directly in the block, but are in separate, removable cylinder liners. Not only would this reduce the required accuracy in casting the blocks and the requisite honing, but it probably made it much easier to overhaul the cylinders (easy fix for cylinders worn past oversize limits).

Jose told us that after one of their overhauls, an owner using careful maintenance should expect up to 800 hours of faithful service. This is significantly greater than the "factory" wartime TBO of 500 hours...and especially good, considering that most cores are pushing 50 years old and were only intended to last the short span of the War. Interestingly, it also takes 800 hours of labor to overhaul the engines...sort of a 1-to-1 thing going here.

When we asked about the availability of parts for these old war-horses, both Kim and Jose indicated that it's really no problem. Some parts, like pistons, are now back in limited production. Others, if not available, can be specially cast or machined by some shops. That is the method Mike will use to resurrect the Daimler-Benz. This engine suffered massive corrosion damage to the large number of magnesium parts. New parts will be cast, using parts from similar engines as molds. In a year or so, it should be flying in the only original Me-109 in the world...and we got to touch it!

For their more common parts needs, they only need to stroll out the back door to the warehouse which contains a veritable treasure trove of complete engines, cores, and miscellaneous parts. We saw complete Allisons, covered in the original cosmolene and stacked on shelves. There were several cores for the massive sleeve-valve Bristol Centaurus engine that powers the Hawker Sea Fury. We even found out what a "sleeve-valve" is! All present agreed that the Centaurus would be the perfect engine for a Berkut, once the cowling, prop clearance, weight and balance, and fuel capacity problems were addressed.

So, if you are ready to have that ol' Merlin redone, how much do you make out the check for? Kim said that the price is really reasonable, considering that the general aviation industry rule of thumb is that the engine overhaul should cost about 25% of the total cost of the airplane. For only $50,000 or so, you can make your core engine pump out it's original 1650 horsepower. Considering that your typical flying P-51 goes for far more than $200,000, it really is a bargain (if anything costing $50,000 can be called a "bargain").

Mike was once asked if they sell overhaul "kits". He said, "Yes, of course, the price is the same...$50,000." Judging by the number of engines crammed into the shop, there is no shortage of customers with the "scratch" to have the job done right--by the professionals at Vintage V-12's.

After prying Ron Applegate away from Jose and the warehouse (Ron's thinking of swapping the 140's Continental for one Mike's Allisons), we found our way to Domingo's Mexican Restaurant. We persuaded Kim to join us...which was a clever ruse, since none of us could find it ourselves. Domingo's has, to quote Ron, "some dishes I haven't seen since I left Mexico." (I, at least, was surprised to learn of Ron's Hispanic heritage--Applegate must be his married name.) At any rate, lively conversation (aviation and otherwise) continued as we consumed mass quantities of chips and salsa while waiting (interminably) to be served our delicious meals. This place may earn honorable mention in the PPTAF High-Fructose Reconnaissance Manual; if you aren't on a tight schedule. The "meeting" adjourned after a moment of silent contemplation of our stricken comrades who were forced to miss the event.

For Mike Pelletier's sake...No, we didn't read the minutes (the Secretary was among the missing), and no, we didn't cover the business items (because the crowd was virtually the same as at the board meeting),...Sorry.

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Revised -- 20 December 1997