WIX Archives
Jack Roush Packard-Merlins
Posted by bdk on Wed Mar 20, 2002 04:01:45 PM
In reply top Re: Is anyone manufacturing DB-series spares? posted by Jim H on Wed Mar 20, 2002 03:06:39 PM
I believe he was marketing a roller rocker arm kit for the Merlin. The cam follower is one of the weak points of the Merlin design.
And I quote:
"And John led me to a corner filled with giant engine parts. Ah yes, of
course, Jack owns a P-51 Mustang! And so here is the corner of the shop
where some of his many (MANY) P-51 cylinder heads get the full treatment:
http://members.aol.com/mikeldrew/mustangheads.jpg
John told me that original valves just aren?t available anymore, so John had
to build new ones from scratch. The originals were sodium-filled and Roush
reached out to various manufacturers to have them so-equipped, but due to the
high performance and liability, none were willing to undertake the operation.
So, feeling peeved, Roush instructed John to simply buy all the machinery
and tooling needed to fill hollow valves with sodium. One million dollars
later, they were in the sodium valve business! The valve stems are machined,
then filled with sodium (which is apparently rather explosive!), then capped,
then the caps are welded onto the stems, then machined back, then the heads
are welded to the other end, and re-machined.
Of course, all sorts of various valve sizes and shapes were being
experimented with....
The Rolls-Royce Merlin is an extremely advanced design for the 1930?s, with
all-aluminum construction, four valves per cylinder, and overhead cams.
Roush has engineered a custom roller-rocker setup, very trick indeed.
Scattered throughout the various buildings were more Mustang engine parts
than I figured existed in the world--shelf after shelf of engine blocks,
heads, intakes, superchargers, plus a whole small building filled with
miscellaneous bits and pieces--just amazing. He even had a shelf filled with
NOS heads, blocks etc. still in their original boxes."
Also look here:
http://www.pylon1.com/news/reno2000/reno2k_update/reno2k_update_04.htm
"When asking Bob about the current state of his program he wasn't too shy to place credit where credit was due - "That Jack Hovey is the best thing that's happened to us. Now that we have our own deal (engine program) he's taught us so much and is an incredible machinist, a stickler for precision, exactness and close tolerances, and just flat knows how to make those engines work. He's truly the shining light in our program. I don't think we are going to have any gremlins - I feel very comfortable and confident about saying that we'll be in the top three or top four this year. Things are going real good. We're going to - as Jackson puts it - Whip it tomorrow with the transport cams and then we are going to install the Roush roller rocker-arms in and the Whip it again to see if there is any horsepower advantage there. After that, we'll drain the race fuel out and put av-gas in it - drive it around for another hour and then put it in the hangar for a week.""
: I maybe pipedreaming here but I recall reading somewhere t
: hat engine guru Jack Roush was making some merlin componen
: ts...anyone have insight?