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51 GMC 4.2 turbo Can't solved today's problems using the same technology/thinking that created them
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Hey,that was pretty cool seeing that old tape.
Drew Mid-Atlantic Chapter
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That was one cool video! Thanks really enjoyed it. Tom
Inliner Member 1716 65 Chevelle Wagon and 41 Hudson Pickup Information and parts www.12bolt.com
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That was cool!
I would have thought the MPH would have been a little faster though?
MBHD
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"I wonder if God created man because he was disappointed in the monkey?" Mark Twain
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That was cool!
I would have thought the MPH would have been a little faster though?
MBHD Hank, that was in the days when he and Headrick were running the Webers. They later changed to the (3)Holley 2bbls. and ran a best of 10.39@128 at 3160 lbs. using a 301 cubic inch engine.
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Hank, that was in the days when he and Headrick were running the Webers. They later changed to the (3)Holley 2bbls. and ran a best of 10.39@128 at 3160 lbs. using a 301 cubic inch engine. Thanks CNC dude, do you remember what size Webers he used? 45 MM? Are there anymore recent videos when running the 3 two barrels? Also ,what were his 60 ft times? Took off really good! MBHD
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The size of the Webers were (3)58MM. Remember, that Cotton lauched his car between 10,500-11,200 RPM, and they needed some huge carbs to feed that many inches at that high RPM. I don't know of any other videos, but his final race was against the first car in this video, Larry Kopp@ The US National at Indy, and that was also his fastest pass of 10.39@128. His average 60' times were 1.28, but had a few 1.25's. I do have some pics of his engine with the 3 x 2 setup in his Chevy 11, and also in the Comp dragster he drove after NHRA did away with the Modified production class. I'll see if I can find them if your interested.
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Damm, & I thought my 48 mm's were big.
I have seen 3 50 MM Webers before in person & those looked huge.
Just how long would the cranks last in Cottons Nova spinning 10,500 - 11,200?
MBHD
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Once the power got to the 575-600 HP level, we broke one at 20 passes. So after that we changed the cranks at the 20 pass mark whether they were broke or not. If they weren't in 2 pieces by then, they were cracked really bad. The Rpm's in the dragster were much lower, but crank breakage was still at the 20 pass mark even in that car.
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which crank were you running?
51 GMC 4.2 turbo Can't solved today's problems using the same technology/thinking that created them
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It was a stock cast "N" crank. But it was heavily modified by lightening and knife-edged and nitrided.
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CNC-dude,
did they ever run a 250,230 ci engine?
If so,any times they ran? Just curious.
MBHD
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I think that they always ran 292's. The Pocket Rocket car in the video was their 3rd and last Chevy 11 that they raced(most famous also). Back in the early 70's when Cotton and Jim partnered up, Cotton was a route salseman(truck driver) for a local bread company, and he and Jim were able to get the engines and rear ends out of the trucks that they took out of service(292 engines and Dana 60 rear ends). So I think their choice for the 292's was a convenience issue more than anything.
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10k~11k RPM?????????????? In a 104mm 292 crank??? Man... that´s crazy!!! CNC DUDE: do you know what Cam and Cylindear head combination Cotton Perry was running to REV like that??
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Yes, I can duplicate his engine combo.
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20 quarter-mile passes = five miles per crankshaft!
That's racing. It's a beautiful thing to see, in performance. What we don't see are the many hours of thought and labor . . . and finding the money . . . in the preparation.
One has to want to win, enough to do whatever one has to do.
Marshall, how many hours of machine work and tender care -- by someone who knows what he's doing -- go into each one of those crankshafts?
God's Peace to you.
d Inliner #1450
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Don, its not as long and drawn out as it sounds if you have a well equipt shop. We had a Bridgeport mill and a V-block fixture to place the crank in to begin removing material from the rod cheek area first. Then we could also use the same fixture to knife-edge the counter weights. Once that was done, the crank was put in a big lathe or our crankgrinder to start removing the counterweights to offset the mass that was taken off by knife-edging and material removed from the crank cheek area. Once you got it close enough balance-wise, where you could spin it on the balance machine, you either took the rest of the material off in the lathe, or was just finished with a hand grinder. Also, all the remaining factory drilled balance holes in the counter weights were also welded up to reduce windage, so you had a smooth counterweight OD, with no holes in it. So, all in all it took about 2 full days to lighten and balance the crank. Then the rod and main journals were reground and it was sent out to be nitrided.
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The investment in equipment would, one might hope, be paid for by the customers . . . so the work on the race car gets done "betimes" -- unless the race car is the main focus of the shop, and then the customer work, if there be any, is done betimes and, probably, begrudgingly. Either way, competing at a high level and winning races with a 292 six-cylinder engine would be an expensive proposition. Having to launch at 11,000 rpm would not make it less expensive.
If you were to set out today to replicate the success of Perry and Headrick with a six-cylinder inline engine -- assuming that you think that could be done -- what engine would you choose? How much money would someone have to spend to make that happen?
God's Peace to you.
d Inliner #1450
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Well Don, the technology has changed so much. Some things could be done easier and faster because of that, or just out right better. But there is a lot of things that still have advanced to the point of being unobtainable to the average guy without a good # of sponsors and/or deep pockets. Jim and Cotton raced out of their own pockets, and each had a wife and kids also. Today, to field a competitive 6 cylinder Comp car, you have to match or equal the pocketbook of Rob Harrison's Igor all billet block and cylinder head, or the AJ billet headed Ford of Steve Ambrose. Simply duplicating Cotton's old powerplant today probably wouldn't even get you into the 4th or 5th alternate spot in qualifying. Its kinda' like comparing an 8 track tape to a CD by comparisons sake. Today, the engine of choice a lot of racers are using is the Atlas 4200 engine, which several racers are claiming an easy 3 HP/CID in N/A trim. The cost of maintenance and upkeep to get this kind of power #'s out of them, compared to the older 292 style engines is hands down the way to go. You have an engine that can make over 100 more HP with 50 less cubic inch, and in classes that have lb./cubic inch rules, you just cant compete or be competitve against that kind of handicap. The main expense in Cotton's engines was always the head, everything else was pretty simple to get off the shelf. Many people might not know, but Cotton was just one of several dozens of well known racers that Headrick's race shop did engines for, for over 20 years, and the many others were all equally famous or successful in their own respective fields, whether it was drag racing or dirt or asphalt round track, or off-shore boat racing. Cotton was probably by far the most profilic and winningest that there was or still is as far as 6 cylinders go. As far as cost to do it today on a competitive level, I couldn't even guess. I know for some of the V8 Comp guys, the cost is well over $100 grand a year. The 250/292 style engines still have a huge potential for the Inliner events that the club puts on, and is a pretty economical street/strip engine even for bracket racers also.
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