i'm putting together my flathead piece by piece. i'm pretty sure i want to box weld the rods to strengthen them, and i noticed two things. one, the studs are cast with the rod and i can't see a way of getting them out. I know it would be a little overkill, but i would like to put some ARP hardware on the inside. Also i noticed that I have a 78 pound crankshaft which i sent out to get stroked. that seventy eight pound crank is held into the engine by three two bolt mains. i do know where i can get an engine girdle to keep everything together, but that too seems overkill for the amount of power a flattie will put out. should i go with the girdle or should i just use main bearing caps? Any input would be nice
Things I've heard and seen: 1) Boxing flathead rods is a waste of resources. The stock rods are capable of withstanding all but the most vicious applications. 2) Some pretty strong running engines have been built with no girdle - just main caps. Some even with nothing more than a strap accross the center main. True? I wouldn't know first hand...yet. I guess I'm not really following your logic at this point. You want boxed rods and a girdle - then in the next breath say it's overkill as the flathead wouln't be putting out much power? I think you are seriously underestimating what these motors are capable of. What else are you planning for this motor? Cam? Induction? Type and extent of port work? Just curious here. I don't think there is any way to rework the rods for other hardware unless you're talking about just using ARP nuts. For the time involved with boxing etc. I would think you would be bucks ahead to buy some high zoot H-beam rods? That said I understand wanting to do things a certain way to feel good about the build. Good luck - maybe give up a little more about you're build. There are some seriously skilled and seasoned people here. I'm sure they'll be around.
Like he said. The rods look dainty by SBC standards, but they are quality pieces and are not going to let you down unless you do something really harsh.
Boxing rods can mess them up more then it makes them stronger, the welding adds stress and can give them a shape you can not fix,like twist of pin to crank and lossit alinemint. I have been able to fix only a few sets to useible of all the ones that have showed up at RPM of Miami Engine Balancing(now retired) Some old tips; don't box rods=cost more to fix then getting race rods,never mix caps or put them on wrong side around,always get new high Q nuts/or if you must use old nuts-then never put them on upside down from how they came off(means don't bend load nut threads back the other way,that kills them) I have 40 years of running a race car shop.
maybe i should rephrase. should i box weld my rods and put them back in or should i sacrifice a few hundred bucks and get some h-beams and an ARP hardware kit? i know that if i boxed the stock rods, they would be lighter than getting h-beams. i know that flatheads are more torquemonsters than powerhouses. the most hp you can get from a flattie non ardun ohv conversion but with a supercharger you can make a little over 300 hp. but don't get me wrong that's damn good for an engine that came with 60-100hp. i guess my question is what would be the best route to take?
I wouldn't box the rods. Is this a blown nitro engine? If so, just go for serious rods. Several companies make them. If this is a street engine or even a mild race engine, just have your rods straightened, the ends reworked, and the rods shot peened. Maybe a light polishing is called for if you want to, but there isn't much metal on them, so you shouldn't take too much off. The studs are part of the rod forging and can't be replaced, but you can use new rod nuts on them if you want to. The stock rods are amazingly durable. If you are building a street engine or a mild race engine, the stock bottom end should be fine. Get everything balanced. Blown nitro does call for a girdle or something a bit stouter than stock. I do know one racer that runs a stock bottom end in an unblown nitromethane fueled flathead dragster and has for years.
I finally got the last two pistons out of my 59AB. I will use stock rods, but I'm considering the girdle. How much are they?
Errr... I guess you have to spend ten bucks just to find out? Flathead Jack Homeboy needs an online catalog.
Flathead Jacks prices have always been on the high side.... $10 bucks for a pretty catalogue?? Now that's Vanity and hiway robbery... D/load Tatoms catalogue for free with out the high prices attached. . . JMHO. . .
Blueprint those rods and replace the stock nuts with ARP's. Then the single best thing to reduce stress on the rods while upping the performance level of the engine is to use the lightest piston you can, preferably with a set of the new style low friction metric ringsets.
Unless you're going to be running a blower and nitro, you don't need to box the rods. My Father had a blown Ardun that put out almost 400 HP and ran stock rods. They are much stronger than you'd think. A modified street flathead will never damage an original ford rod. Matt
I've seen a pic where Ford twisted a stock rod about 6 or 7 times & it didn't break - it just twisted up like a pretzel. They're durable. Boxing is a waste of time - you'd have more time & money in them than a new set of **** rods. Same with a girdle. Unless you're going blow all-out race engine, a girdle is probably a waste of time & money. If you're going street blown, I might consider a center main strap, but not much more... A blown 276 is going to put out 300 or less, so the stock rods & mains are pretty safe. Send your crank to Mike Bishop for some carving & polishing - that'll reduce the weight of that near 80-pound monstrosity. Looks like a piece of art when he's done...
I broke my center main with my 15.0 284 carb motor.It had a good strap on it .Did not know it was broken till motor swap.Brad knows story.Rand you got bit by the flatmotor bug too?
Rods were boxed at a time when stronger rods weren't available. There are a couple of very tough fuel-cabable rods available for flatheads today, but they are not cheap. Stock Ford rods are plenty strong for most applications. Just make sure they p*** mag inspection, then have them rebushed and resized. Or, step up to a set of new French rods -- rather like a flathead version of "blueprinted" Chevy Pink rods. They benefit from improvements in metalurgy and forging and machining technology since the last 8BA rods were manufactured in the early '50s. And, the weight-difference range for a set is usually within 3 grams. Vern Tardel has them for $125.00/set plus S&H. The m***ive Doug King style girdle is overkill for anything short of a blown nitro motor running lots of pop. Dave Tatom's four-bolt center cap addresses most of the concerns about putting lots of pressure in the motor. This bottom end was torn down after a full day on Flowmaster's ch***is dyno followed by six runs at Bonneville (with a new record in hand!), and it looked as fresh as it did when it was first ***embled. The rods, forged Olivers, have already been removed so the journals could be inspected, but the Tatom center main cap is still in place. The crank is a French 4-incher whittled down to about 54 pounds, knife edged and fully polished. As a measure of what the bottom end is capable of handling with no more added strenght than a Tatom center-main cap, this motor developed 440-plus hp at the rear wheels of the TarMac roadster, on the ch***is dyno at Flowmaster. Boost is about 15 pounds, and the motor runs on alcohol. Upgrades for this roadster for '07 include replacing the Ford 9-inch diff with a QC and a "standard" trans taking the place of the C4 -- all in the interest of freeing up some horsepower currently ****ed away by the high parasitic drag of the driveline. Unless you plan to build a motor to similar specs and needs, you'll do fine with a set of freshly prepped stock rods, and if you need some extra ***urance for your own peace of mind, the French rods from VT Enterprises are a huge bargain. Mike
Mike; so you guys did it!! What's the NEW record?? Hmmm .. that crank treatment looks familiar!! Dave
Mike I also run the Tatom cap.I had speed merchant Brad get one for their rail.I have not pulled motor to see how well it helded up.Thanks for good news about use of his cap.It did look like a good soluion to a apearant problem to me.I own two of them.
I looking for a 1 1/8th crank. I've got the rest of the rotating ***y. Then I build mine similar to Brads. Thanks for the advice Flatdog.
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