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Post by sc397 on Oct 12, 2021 8:36:22 GMT -8
Stock was a Motocrap unit. He is cheating so I wonder if I can cheat a little better. There is a listing out there of Holley AMC replacement carbs for the Motocraft carb. If he used a Edelbrock I could probably use a Carter AFB. Or, I can just have n2ojoe supertune the original In the end, the rules are more of a guideline which is fine.
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Post by sc397 on Oct 12, 2021 14:19:33 GMT -8
This would be the engine plan. It will be interesting to find out what kind of power this combination of parts will make. 360 block and crank - I have a couple of those Wiseco flat top pistons w/ 8.60cc valve reliefs - In stock Molnar Conn Rods - On order 58cc heads would make 10.27:1 compression ratio. 51cc heads would make 11.15:1 compression ratio. - I will probably go this rout. Cam - has to have a stockish idle. I should use something like what Joe has. I am thinking I should go with internal balancing on this one - because I have the parts. BHS Balancer = 11.2# - In Stock Stock 360 Balancer = 9.4# Flywheel- Is the big question... I have a few to choose from and here are the weights. 360 stock cast iron = 29.4# - could be neutral balanced easily enough 258 stock cast iron = 26.8# - all ready neutral balanced 401 Steel = 44# - The car has to run on E-70-14 bias-plys. Not sure if a heavier flywheel will help or hurt. Comments?
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Post by spud on Oct 21, 2021 12:50:53 GMT -8
Do the rules allow and mods to the manifold or carb spacer? Look into the mods they do to limited nascar engines. You know the 390 holley restricter plate motors. They have done years of reasesrch and work tricking those tiny holleys into making power. A lot of it is in the manifold, but you might get some good ideas. I would not try a heavier wheel. Its only good to launch a heavy car or tall gear and will hurt after that. The idea is only as much flywheel as you need, with that combo stock 30 # is a good start. The lighter 258 wheel would be my first choice. It might launch ok with even LESS given its got a decent size 360 engine in a fairly light chassis. Heavy wheels are outstanding for shocking everything behind them into atoms. In that respect consider keeping everything as light as pratical in the drivetrain, and only as heavy as the job requires. A lighter wheel is easier on everything, same thing goes with overbuilt driveshafts, too big or heavy a clutch and disc, a heavy damper, etc. think light. Make the most out of what little power you have. I would even consider lightening the rotating assembly if practical.that kind of depends on how light you are with the molnar wiseco combo. Not a lot you should try to remove from them.
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Post by landbarge on Oct 21, 2021 14:07:03 GMT -8
I'd also vote for the lighter of the bunch flywheel. Being tire size restricted, no need to toss a grenade at them.
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Post by n2ojoe on Oct 22, 2021 6:52:21 GMT -8
I've been thinking about a 360 combo lately. Since we are allowed up to .070" over bore max (372"), another possible route is a 390 crank in a standard bore 360 block (374"). In the very rare chance that an actual tech inspection happens, they "pump" (P&G) test the engine to check cubic inches. The tester has a +/- .5% error window (so +1.86" on a 372" engine) so you're good. I guess the stock stroke route/max bore has the advantage of unshrouding the valves a bit though, and less torque for traction. Another note on the P&G tester, I have heard of someone drilling a tiny hole under the spark plug's flat gasket, into the combustion chamber, which is only exposed with the plug removed. When the tester's hose is threaded into the plug hole, it seals with an o-ring and allows the added hole to bleed off air when turning over the engine, and a smaller cubic inch reading. π Since the rules state production connecting rods only, why not use production titanium rods from an LS7 with 2.1" rod journals and just over 6" length, on a turned down 390 crank internally balanced. Crank scraper, windage tray, etc. ( crank-scrapers.com/ ) The later oil pans with the relief for the Jeep front axle are more deep in the front half of the pan than the early rear drain pans, and have more room for a welded in screen. We are also allowed 1.5 points more compression than stock, so definitely claim an early 1971 engine at 9:1, and max it out at 10.5:1. No port/polishing, but 11/32" valves and a "big port" 3195532 intake manifold. Maybe mill the plenum into a "Machine" intake clone. The cam will need at least a 112 lobe separation, maybe the small Summit cam or Lunati Voodoo with the 113/120 duration, retarded 4 degrees to work with the free flow exhaust manifolds. 2.25" exhaust with x pipe. 2.43 ratio T10 with aluminum flywheel, and maybe 3.73-4.10 gear. Good starting point IMO. Or just use the stuff that you already have, it's fine too and a whole lot cheaper lol... I'd go with the 291c's, and the 258 flywheel.
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Post by stickshifter on Oct 23, 2021 3:14:11 GMT -8
DO NOT USE A CAST IRON FLYWHEEL. That is my official opinion. You are already on the short side, no need to take off anymore height.
An aluminum wheel would be a great idea for the application. And a true race clutch if allowed. That way you can adjust the clutch to launch without destroying the tires. That is my plan for the RWB Gremlin too.
My son's car uses a 360 block and a 390 crank. The crank was "junk" and bought it for $50. Then I had it ground for a 2.0" pin at the stroke that I wanted to use the cheap Scat SBC rods. Used SBC 400 pistons with the valve reliefs cut at the proper angle. With flat tops and the 502 heads it yields about 12:1.
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Post by n2ojoe on Oct 23, 2021 3:54:43 GMT -8
Yeah, I have to agree on the steel flywheel too. If you're gonna race it, you're gonna have to slip the clutch ALOT and turn the flywheel blue. I run an SFI steel flywheel with Centerforce dual friction clutch in my AMX and forget about how much punishment it takes. I'd like to switch to an aluminum wheel myself.
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Post by spud on Oct 23, 2021 6:34:15 GMT -8
Ahh the complexities a faking a stock car. π
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Post by n2ojoe on Oct 23, 2021 7:14:52 GMT -8
I know, right?! I too was appalled to find out that all these other classes with "stock" right there in the name are not what they say they are either!! STOCK eliminator, super STOCK, factory STOCK, pro STOCK! Who do they think they are fooling? NO WAY NO HOW does a new Camaro run in the 6's from the factory. CHEATERS LOL!! π
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Post by spud on Oct 23, 2021 8:41:11 GMT -8
It always starts as a good idea and is fun for a lot of folks but by next season its always a cheatfest. Stock for a season then katy bar the door. That truly is racing (no matter what the rules are). Oh well anyways have fun with all that. Interesting subject though. Looks like another class of racing has gone the way of big bux big tech and big cheats.
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Post by Captain Awesome on Oct 23, 2021 9:09:08 GMT -8
It always turns into something a lot can't afford. Like the Lawn Tractor pulls. Several 1000 dollar engine on a little Cub Cadet to come in 20th place.
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Post by n2ojoe on Oct 23, 2021 9:32:10 GMT -8
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Post by 69Rebel on Oct 23, 2021 10:38:44 GMT -8
Cheatin' is racin', ain't it?
I remember when the show "Pinks" was a thing and some good ol' boys were cleaning house with a Javelin. Everyone was whining that team Jav were sandbagging hard core. My though was "well, sandbagging is racing."
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Post by Captain Awesome on Oct 23, 2021 10:41:40 GMT -8
Yep, I always loved all Uncle Randy's stories of what guys did, till they got caught. Some cases had Tower people involved and even I got burned by a tower person, so their buddy could keep going rounds.
Also some stories of record setting car with 3 dif pistons and two dif heads. Not BS stories, well documented big local names. They were better with a hammer than Uncle Baloney.
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Post by spud on Oct 23, 2021 11:49:31 GMT -8
Hey iβm not against cheating at all. I might be a hypocrite, but βstockβ racing was tailor made for liars cheaters and hypocrites. π this aint exactly a good thread for me, iβm not a stock racer, its not my baileywhig. Racing has always been about getting an advantage to win, rules have always been about keeping the playing field even. They are always at odds with each other and extremes of the same conversation. My comments were not intended to distract or detract from the topic.
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