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Nascar con. rod bolt torque spec.
Hey guys, I bought a set of vintage oem peaned and polished nascar connecting rods w/ 7/16th 12 point original thick shanked SPS cap screw bolts. I took them up to my engine builder who has worked w/ FE blocks/engines, lemans rod and after market rods etc,etc,etc. He hasn't touched a set of nascar rods,,,,, ever. He wants the specs. to mag and die ck. under oem torq. spec. I have numerous Ford FE books, but can't find torque specs. Can I get some help pls. The person I bought them from was and is quite the buff on fe stuff, But no info on tightness. Thanx in advance!!!
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tork readings
55 lbs is the blue print spec for a 427 wedge motor, SOHC motor is 58-62 lbs with oil on the threads. A 7/16 bolt grade 8 spec is 50-65 lbs for rod bolts. You need your machinist to get a micrometer to measure rod bolt stretch. Blueprint rod clearance is still.0025"-.0030" in all the old books. This is for all FE motors I have found specs for. Plastic gauge is going to tell you the clearance anyway. These numbers don't say what crank is being used. Hope this helps. Rick Lake Ps You may want to try call Rich Kirk 19183724537. He owns alot of old FE stuff and may have a different answer.
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Torque To Yield....
It could be that there isn't any "torque" specification for that rod setup. The
fasteners could be "torque to yield" style where you use a con rod bolt stretch gauge instead of a torque wrench. In any event, you probably shouldn't reuse the fasteners, get some new ones from ARP and they can supply the TTY specs for them. But to start out, you might want to make sure you can actually use those rods in your engine. Since you are building a stroker FE, are you using a custom crank? Most, if not all of the aftermarket stroker cranks have 2.2" journals for BBC rods. BBC rods are used in practically all stroker FE's because they are available in a 6.7" length (compared to 6.488" for an FE rod) and this improves the R/S ratio and pistons are readily available for BBC rod setup. 3.98" cranks are readily available with FE rod journal size, but beyond that, 2.2" journals are pretty much the rule. You would need a custom crank (not cheap) or perhaps you could have a 2.2" crank welded up to 2.438" FE journal size. (probably more trouble than its worth to use those old rods) Then you'll need pistons for that setup and they won't be off the shelf. You would probably be better off to use those old NASCAR rods as paperweights and build your stroker FE around proven ingredients that have good longevity in the street environment. A lot of "race" stuff is not appropriate for a street engine because racing equipment is designed to last the length of a single race and is discarded afterwards, consequently fatigue resistance is usually not an important design criteria. Since rod failure often causes the block to be ruined, it probably doesn't make sense to risk a valuble FE block to an unknown quantity. ....Fred |
65 foot-pounds
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Nascar rods
1nce bitten You know that nascar rods need a different crank because the rods are wider on the bottom to help with those high rpm races. The ID # isC9AZ-6303D , the rods are C7OE-6200A. The crank and rods are .080" wider. These rods are also 1000 grams each. Hang them on a wall and go with a BBC crank, rod and piston. You will need a wider bearing which is made for these rods. You are pretty limited here too. No body sees your rods in the bottom end. Just a thought. Rick L.
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Thanx guys for the valuable input, I need to update my profile, I'm not going the stroker route now that I found a standard bore virgin 66 nos x block. Thanx Rick, FFlindling, & Professor Fate!
Rick Lake, The guy I bought them off of thought he was getting a set of untouched rods when he bought them, He got jipped when he mic'd them and found out that they (the rods) were shaved .040" each side to run on a lemans crank the original owner stated. Because the nascar crank is hard to find and a pretty dime to pocket at that. So I'll either go w/ a lemans or most likely a scat 4340! Also Rick, The rods were balanced, peaned & polished. They (the rods) are down closer to lemans weight due to diet of balancing and so forth. Thanx again!:) |
cranks.....
Since you decided not to go with a stroker setup, just get a standard Ford
2.438" journal crank if you want to use those rods. You can go with either a 3.78" or 3.98" crank and put together a reasonably priced rotating assembly. With 6.488" rods, going much beyond 428 stroke (3.98") gets you into a situation where the R/S ratio becomes marginal. Have those rods thoroughly checked by someone knowledgable before using them, you don't want to risk that nice NOS block, aren't many of those left. ....Fred |
1nce bitten
A first name would be nice. Anyway I have a set of c9zz6200a rods in the boxes in my basement. I was going to use them in my first Shelby motor with a 428 crank, 10-10. RPM limit 6250. Eagle had just came out with there new rods and on sale. The eagle rods where 100 grams lighter and for a 2705 lbs ERA cobra and low rpm limit, it was a no brainer for me. I also got the ARP rod bolts for these rods. When Charlie balanced the whole assembly no wieght was needed. I would not spin these eagle rods to 7000 rpm or take a chance with a NOS 427 block. I would go with the 3.98 crank. Barry R. sell a nice kit that drops in. Just get it balanced and tell him the flywheel wieght and balancer wieght. I run a 20 lb flywheel not the 40 lbs that came stock. I am building #2 motor and have gone the bigger path with a shelby motor, a 496 but small bore and long stroke. I am going with a set of Howard BBC rods that are 796 grams each, a balanced set, was told they are good for 1k hp. I am looking for 600 hp and 650 tork when done. RPM limit 6500. 3.31 gears may be too much for the car. may drop to 3.07s. Try and stay light and strong with parts, match the intake,heads and camshaft to work together. Look at the drivability for cruising. Big cams are a pain and need more maintainance than smaller ones. Talk to the Smith boys about engines sizes and max controlable power for your car. I don't have the biggest motor or strongest and after 6 years of R&G I broke a rocker shaft finally. The clutch is the only problem I have had. Maintainance basic, Fun and down time little, time with car priceless. I help others fix there cars. Rick Lake
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