John Beyl wrote:
[quote=
"Jim, I understand that a Mr. Rousch in Michigan is manufacturing new heads and blocks for MERLINS".
Inspector,
Roush Aviation (RA) is
not manufacturing new castings for the Merlin, at least any of the major castings. Jack estimates there are approximately 3-4 sets of castings, in various states of serviceability, for every flying application that uses them. In fact, it's his contention that there are plenty of castings as long as we're careful with those we have left.
He and his engineers have developed welding processes that can repair cracked heads which not long ago, were deemed unserviceable. RA also has the technology to repair large areas of missing casting by weld process and then re-machine them to spec. I've seen repaired examples...it's beautiful work and is as structural as the base metal around it.
RA has already re-engineered to modern standards (Not reverse engineered) and is currently producing many of the parts that we were once scrambling to find or were already down to using the best of the used. At this point, if a customer brings two bear, cracked head castings and water jackets to them, RA can recondition the heads, water jackets to better than new condition and build up the balance with new parts...not NOS parts...
NEW parts (Including new pistons, rings and wrist pins!
They are also working on the long standing issues with the Northeast magnetos because there are simply not enough Rotax Magnetos to go around and the Northeast’s are good pieces! To date they've determined the issue and are working on a fix for it.
RA is also producing a litany of other parts for the Merlin that are either suffering the ravages of age or it simply make sense from a safety standpoint to build new. That includes everything from new oil lines to larger, stronger transport style main bearing caps to steel head nuts. Currently on the board is a new set of connecting rods that marries the size required for the Merlin to the better, stronger design of the Allison without having to outhouse engineer a set of Allison rods to make them fit in the Merlin as has been done in the past. Good -7 and -9 rods are getting as scarce as hens teeth.
In the end, if it wasn't for Jack Roush's love of aviation and his passion for the Mustang, the Merlin would be getting close to flat line right now. If any of you enthusiasts ever get a chance to meet Jack in person, don't ask him for his autograph, put your hand out to shake his and tell him thanks!
Don't feel bad about burning up a bunch of "Junque" 40 or 50 years ago. Back then nobody would have ever dreamed this stuff would be worth more than a bucket of a slop water.
Regards,
John
After receiving a PM last night regarding my post I felt it necessary to make one correction and a point of clarification:
Regarding the Northeast magneto modifications, apparently Dwight Thorn and Mike Barrow determined what the issue was with them and created a suitable fix for them. Roush Aviation has been using these modified magnetos with great success.
My comment “Outhouse Engineering” regarding the modified Allison rods used in the Merlin was understandably taken out of context. Certainly it is understood that a great deal of true engineering work had to be undertaken by Dwight Thorn to make this mod work as successfully as it has proven to be over the last three decades. My point was that Roush Aviation was going to take that innovation one step further by creating a rod based on the proven positive design elements of both rods and incorporating them into one rod assembly that requires no modification for strength and durability.
My apologies to Miike Barrow for the misinformation and misunderstood comment posted above.
Regards,
John