On Wednesday 26 November 2014 03:55:18 Gregg Eshelman did opine And Gene did reply: > >> I am sure we've both seen some pretty "square" camshafts but > >> everytime I think about the roller tappet stuff, I recall the cam > >> and tappets in the Nash Ambassador big 6 engine used from '49 to > >> the end of Nash. > >> > >> and despite the single barreled carb > >> and that covered ditch in the head casting capable of being > >> uncovered and suitably polished, > > My folks had a 1952 Golden Anniversary edition Nash Ambassador with the > special metallic gold and dark red paint. The single side draft carb > was a PITA. If the car was parked anywhere with any tilt toward the > left, it was very hard to start because the gasoline would run out of > the carb instead of into the intake. > > I'd like to take one of those engines, CNC mill out the intake channel, > just enough to smooth it. Polish the ports too.
I did that, with a drill and sandpaper. Worked well. > > Then mill a new cover plate with injector bungs and convert the carb to > a dry throttle body. > > No more problems with fuel going the wrong way before it fires up. I never had that problem that I noticed. > > Was there ever a dual carb version of the big overhead valve Nash > straight 6? Those engines are insanely heavy, much more massive than > any common American 1960's and later V8. Not to my knowledge Gregg. Heavy, and taller by 6" than anything else since. > Much of the fuel efficiency came from the optional overdrive on the > manual 3-speed transmission. True, but there was another effect there. Dead flattop pistons and about 40% of the top of the combustion chamber was milled flat, so it had more turbulance from the mix being sqwished as it approached TDC than most engines of its day. And, once started and the cable pulled to advance the timing about 35-40 degrees, the combination made for very efficient burning. But if it was killed, shove that cable in before stepping on the clutch to restart it, else that amount of advance would bend the starter shaft everytime. I found that out quickly and expensively. :( The ideal situation would have been much heavier advance weights that swung all the way out by 500 revs, with just enough springs to pull it back to TDC below 150 revs, but while I considered it, I wasn't able to locate the heavier weights. Spin it would though, fast enough to make 1/4" long pieces out of its rings. 4.375 strokers should never be pushed beyond about 6 grand even if they were pulling strongly yet. I got tired of listing to one of the guys in my crowd at the time, bragging about all the 11/1 HC heads and dual carbs on his 50 ford, and invited him to lay the title on the counter alongside mine & we'd go check out favorite 2 block dragway to see how well we actually faired. He knew the low gear only rule, but didn't know I had a switch on the gear shift that controlled my overdrive. I also knew his block had not been relieved so it could breath. We started out, with me in low+od, and he pulled ahead about a length right away, but he was out of free breathing revs at the end of the first block, and at the end of the 2nd block I was about 3 lengths ahead. But that turned that big six up around 7500 revs & made grapenuts out of its rings. I didn't pick up his title, didn't want it, but went looking for something else. But I did get what I wanted, which was for Tom to shut the hell up bragging about his hot rod ford. I guess he was suitably embarrassed to have a Nash clean his clock. He couldn't play black jack either. ;-) > There's a thing I'd like to figure out how to rebuild, the planet gear > carrier in that Borg Warner overdrive. Either the needle bearings wear > or the gear bores do. Things get sloppy and pressure on the gears > increases. That causes heating, making the ring gear expand until it > seizes in the overdrive housing. *BANG* Car comes to a quick halt! Never had that happen Gregg. Ever. > > The problem with fixing those is the pins the planet gears spin on are > welded into the carrier, then an oil pickup/distribution ring is > crimped on. That's there to use centrifugal force to push gear oil > into the planet gear needle bearings. Of course the welds are under > that crimped on ring. The ring would pretty much have to be destroyed > to get it off so the welds could be milled through. > > Sooo, design and machine new dies to stamp new oil rings, and more dies > to crim the new rings on. Also design and build a fixture to hold the > planet carrier to mill out the welds on the pins. > > Then there's the wear problems. If the gears and pins are OK, drop in > new pins of stock diameter. If the pins are worn, replace with new ones > hard enough for high pressure roller bearing use. If the gear bores are > worn, grind or hone straight and concentric to a suitable diameter for > use with a larger stock diameter of needle bearing rollers. > > Then there's accommodating all the slightly different output shafts and > other variances the various vehicle manufacturers had Borg Warner make > on that part. > > There would be good money in it for someone who can do all that to > rebuild those overdrive planet gears. Nobody is making any more new > ones. I'm not going to do it, I don't have a need for a rebuilt one. > > When my folks' Nash overdrive did that we happened to have a Nash > transmission someone had attempted to rebuild (probably back in the > 60's) but couldn't get put back together. In the box of parts was a > brand new planet gear assembly. Swapped that into the 52 and it was a > new overdrive. > > That failed transmission rebuild yielded up another useful part when I > was fixing a transmission in a 1984 Ford 1/2 ton pickup. It needed a > brass syncro ring and the old 1950's syncro rings were the exact same > part. Instead of a week waiting on a new part, I had it done in a > couple of days. Ya gotta luv it when a plan comes together and you've beat "The Man" at his own game. :) Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> US V Castleman, SCOTUS, Mar 2014 is grounds for Impeaching SCOTUS ------------------------------------------------------------------------------ Download BIRT iHub F-Type - The Free Enterprise-Grade BIRT Server from Actuate! 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