Hi guys
I was doing some back reading for fun and need to add some stuff.
The gear drives for SOHCs were made at Holman Moody Stroppe by my first boss, master machinist Noel Timney. It was one of the first SOHC prototype parts from the 60's that we made more of, for boat racing too, and we had the prototype and plans, mounted on a board, with the way to hob the gears, and what the material and heat treat was. Hard finished product, like a current style drive. I thought Pete brought the idea to us and we made it in this huge machine shop we had. It went on and on, and we had gear hobbing locally by batch. You just call out the root, pitch, etc.. This was what the shop said, so I recall it clearly.
Pete was a great man, and Ford loved him, we lost him too young, testing down force in a fueler, at Pomona. He did want what the Dodges ran, and we did a bunch of Drag Team cars, most all of them visited too, when out West.
The thin backing plate was replaced by hard, ground steel, and there were other tricks. Noel also made gear drive for Ford McCullough and Paxton style blowers, and other Ford race cars
I just loved the guy, so his name is worth remembering for some of us. He helped Ford win a lot. He made it into the Garlits Hall of fame too, round 1, for building the first Drag Car to go 150 MPH at the original NHRA Nationals in Topeka Kansas, Lloyd Scott drove it. It had 2 engines, and he made the differential, with one ring gear, and 2 pinions. A friend from Lion's Drag Strip, saw that pass, and we talked about it recently. He is older than me,,,,ha ha. Check out The Bustle Bomb some day.
But Noel claimed this, he actually made these gear drives, I made parts for some too. So did the big bosses, so i wanted to add this to be more accurate. The gear drive, it was one of many Ford Racing special parts, because the goal was winning and the budget was big. The consensus was though, the SOHC gear drive was great, but very expensive, and had to be fit, and matched in, had a lot of parts, and a lot of gears, in a daisy chain. For the era, it didn't really catch on, since so many were winning, in Dragsters, with chains. Also, gear drive stub cams, and chains upstairs. I have one of the first good gear drives for the stub cam, thus magneto, if blown.
The next step was a belt drive, that was tested then, then done a lot later.
Like current Pro Stocks spinning way high, on carbs, retarding the cam can help
So way back when, guys were on to this on gas.
OK, we tested cam retard and advance in many ways, sensors, strobes, sure, we also had crank sensors to measure crank flex at the rod journals, in minutes away from perfect 90 degree indexing, and so on. The tension on the chain plays a big part of the graphs you derive.
I would say 2 things, having done a whole lot of blown fuel too, Dyno Don, who I raced with, and helped, and miss, and knew well, actually changed his cam timing, to suit the track, or, between rounds, based on the bite, opposition, air and so on. That was state of the art on carbs back then. So his Crew Chief in the Maverick Pro Stock years, was another boss back when, and he is still a close friend.
Just tweaking the tensioner between rounds can be a wise move.
Somebody here said Dyno ran the Nitro 640s, that is way off. We had a long list of secret in house grinds, and 'special' stuff from Crane, Holman and others, The trick was sometimes, getting the raw blanks, or turning billet to do special stuff.
I am writing to try to help the guys not mix apples and oranges.
In the era of the SOHC on fuel, and later in Pro Stock, they are different beasts
The SOHC came to the drags, on fuel, to run against the 392 and 354 Dodge Hemi, on fuel. These guys, we spin them over 10,000 today, at about 250 MPH. They always had a gear drive, since the late 50s.
Why? To drive a fuel pump and a mag, and take a lot of valve spring and heavy rockers, steel, and big chromoly pushrods
So, one reason Pete and others wanted a comlex gear drive, was to reliably drive a big magneto, off of the stub cam, and a fuel pump, off of the fixed idler. These loads, requires a bigger hex drive too
Blown on fuel, precise valve timing does bang a lot less blowers, sure, and the pumps and mag, just follow the leader
Cam retard is not a big enough benefit. You have to just imagine, you are staring at the blower, in a front motor Dragster, going over 200 MPH, sitting on the rear end. Everybody had a 8 3/4 Chrysler 3rd member, and Hig Tuff Henry's axles. Those alone nearly killed Jack Chrisman, poor guy.
So blower banged all of the time back then, they wer not stripped, but carefully set closer, with tricks, and the mags were tiny,so...would you like to have less flames in your face? Less rotors hitting your open face helmet? Most that we knew said yes...ha ha, so the gears were for safety in large measure. Pete was known to design in speed and safety ingenuity, with Fords help, and the help of many.
Back to carbs,,,
With a lot of compression, big cams, a high launch RPM, and a 4 speed, the way to split the cams, and which one to lead, and by how much, was worked and worked and worked on, on the same combo, to squeak out hundreths in ET. Over and over, pass after pass. So that was the deal way back when, squezing every last drop, out of a rules mandated combo.
Now Ed Pink is super smart and had a big budget, not like FORD racing did then, but he is top shelf. He did do special chains, with chromoly bushings and pins, and they were better, but expensive. Kieth Black ran them, many did. They look different from some distance. So they were and are trick.
Then, the sponsored racers got free parts like water, so the stock chains got changed out a lot, if the slot on the tensioner showed stretch, or pin wear. Adios. Hand to this or that team
We should remember, the sponsored teams, had stacks and rows of spare free parts. Chrisman place was close to were I grew up. He had a wide bench, and below it, was a tall stack of sohc heads, in various state of use, or injury
Point is, many many good cars, ran fast nitro or gas cars, with hand me down SOHC parts. Blown fuel parts, got passed to injected fuel SOHCs, the blown gas, injected, then carbs.
The gear drives were great, but complex and expensive, and milling the stock heads or block a lot required adjustments sometimes.
I think Noel deserves credit for his part here, everybody said he made what PEte asked for, and fast. He also did the first super tough main cap girdles, I made some for him. They really added strength blown, and also on fast gas with a bunch of RPM. The are 1'' thick. I have one left. You got a lot more passes on a 'H' , or SOHC block or sideoiler, this way, by fitting them perfectly, then remachining. It took time, so, one size did not fit all. We often refined the pan rail dimensions, and we added a surface grond flat on the caps. The botom end of a Y block, ends up more like a Indy engine this way, for example, the entire bottom end gets tied in, and stressed simultaneously,in essence.
On the sleeves leaking, I know that you figured out how important a snug fit on bottom is. The bottom register helps a lot as heat sinks into the sleeve, and contact on bottom, transfers up to the compression seal, and provides a lot less rock, better heat transfer, and it won't leak.
This was a R&D effort I would guess, right ? Sounds fun.
I just remember, we did 351 C Pro Stock blocks, by furnace welding in thick sleeves, in large heat treat ovens. Seeing the braze, make a complete seal on bottom, and top, was critical. Same deal adding bigger, thicker sleeves to a Side Oiler. Lots of special machine work, and time, and furnace work, and in the end, you need a huge budget, like we had, to throw such stuff at a design, to try to win this or that event.
I bet that you could restore the actual seal down there a few ways, and add epoxy to stablize it, down low, but you have a bunch of spares, so race a solid block maybe, and use this guy for street FE or something.
I buy the Shelby Big bore blocks for some guys, and they have a bigger sleeve too, but no holes in the block so that the pressure test and seal.
The big bore block is 4.400, and really, that is so close, you just service the sleeve if it hones much beyond that size, they start at 4.375. For the guys if they wonder.
I bet you run them too, my wonder was, how big were these bores ?
I will read more, nice job, this is a fun thread, and thanks for sticking with SOHC's and pushing the envelope.
Also,
I read on the these SOHC theads, that testing kind of re determined, that the stock rocker, non adjustable, which there are tricks for, with the range of lash caps, which we had a roll away dedicated too,,,,lol plus custom ones, do live well in certain racing conditons. They are better than some people think , with light valves.
Spring tricks are also a big deal, running the stock spring cup was improved on some. A lot actually. We made our own, hardened and ground, heat treated
People rail against sodium races without remembering something, they won a bunch of races. The Lemans rods got new cap screws every rebuild, like the manual suggested, but we had the trick stretch stuff way back then.
And on the sodium valves, they get maligned. Guys need to know, they were free, buy the box, so they got changed out after enough use to stretch, or move, show any wear, and on a real safe change out interval. Ford knew how far to stretch that string, so use, versus abuse seems fair to note.
We had boxes of them in used conditon. We tossed them at each other, across a huge series of shops, to say Hey, the lunch truck is here, and so on. They got thrown out a lot, often.
They grind, new, with a unique sound, and bounce with this high pitch ping. We checked it all to blueprint tighter, sure, but I would say, what I was taught. They did a lot of good work, when new ? They won, a lot. We did not have titanium valves, we did have Donovan stainless.
The problem was, they were so pretty, the ones headed to the trash got taken home, sold, given away, and those used valves got beat until failure I think. Just run to death. That reputation for popping heads, and for separation, was probably due to use way beyond the designed in fatique point, we figured. Old valves, even NOS new, today, do corrode from inside, so beware, sure. I have a bunch for momentos. Brand new. For a museum maybe...ha ha.
But again, on these same Ford valves, we shortened them, and won a lot of Trans Am races with them too, in Boss 302's. Ask Doug Nash and others. There is a oil quenching trick for these.
This was a fun thread, thanks.
It is fun to back read some of these builds and failure analysis.
This is just me, I would probably scale back the bore a bit, to stabilze the sleeve and block, and give the entire bottom end more passes and life maybe. It is hard to trust sealer, and then find water in the oil at a race
Nice work and thanks again
When I have more time, I look forward to seeing the rest of this analysis
OH, we often dynoed and dialed, raced, pulled the engine, re dynoed to see the loss, or GAIN in power. If possible, or to refine a new part. It does reveal things too, as you guys know
Now I look forward to reading all of the rest here, I posted after about 10 comments, I have another wonder, the steam cleaned cylinder, clearly saw coolant and steamed the color and carbon away. See it from 20 feet kind of issue, now I am trying to figure, how didn't this show up on the plugs, between rounds, or as the car got serviced. You see this fast when you rack the plugs between rounds, so I wondered why this big issue was showed up way late, or on tear down? Then I say, we got lucky because this kind of trauma, can kick a rod when it hydraulics, seen it in the pits on carb cars, seen it the second a blown car fires, if it did not get backed down for example, or when a lot of fueler ran a water block or heads. Many still do in nostalgia, so I figured, the plugs looked even, then the drive home sprung the leak, or? Glad it didn't leak, sit, then get fired and say ouch. But I also wondered, didn't the puke can, show coolant loss too? To give you a warning and heads up maybe,,,I just wondered there
I'll read more
Oh, I read some guy kind of making fun of Dyno Dons 'sextant' they called it. That was one of several devices he used to win. You gotta remember, race airplanes from prior eras, and war birds, had advance retard mechanical devices, like a Model T, to trim the engine out for performance. Don played and played with how and were to add or lose total advance, while driving the car,,,,that takes one hell of a driver if you ask me. He did it by feel, then confirmed it with the time slips. He was a great tuner/driver, and his advance/retard device, was a quiet, but winning trick from then, being able to move the distributor, by a scale, or with the shifter cane, or rods. I thought it was super cool, pre solid state chip style retarders and so on, programmable maps. Seat of the pants, and make 1000 passes works good too if you ask me....
Very fun
Thanks a bunch
