I ran that same setup before.. really liked that setup ..I did however crack the crank in the rod radius ..6500rpm was the happy place 7000 was it's breaking point. It never showed any problems but the magnaflux showed the damage ... aluminum rods would of helped
I like stuff the lighter the better. This same reason why I just get a billet crank and be done. By the time you do all the work to a factory crank and make it as best you can,you are over halfway to the price of a billet,but you still have a heavy and weaker crank. I understand a billet isn’t for everyone,but yes,a lighter crank will help in more ways than one. As Gary mentioned,a Moldex isn’t much of an improvement. I have one myself. I’ve done what I can with it,but still not what I call satisfactory,compared to my other cranks,but that’s what it’s priced where it is. Adding Mallory to a stock crank brings up a good point. You could end up with a crank that is heavier than when it started,so be careful. Definitely an aluminum rod. I prefer a GRP pro-material. Very good rod. CP is still one of the best pistons out there as well with strength and lightweight,and a nice thin ring stack.
Make sure all that Mallory is welded in place.. seen more than a few "pressed" in pieces get loose, and make a hell of a mess. I keep Iron block race motors simple.. as they are a expendable commodity.. don't believe in spending a ton of money on them, so you will never catch me internal balancing one, or trying to get cute with the crank to get 5 HP.. Both those mods are supposedly beneficial for what the stock block does not want to do.. and that is turn big rpm. External or internal balance is not going to make enough difference here, to keep one alive, vs not. Shortcomings of the iron block run much deeper than those specific areas, where the internal balancing will help.. do believe in Alum rods.. although they complicate any balance job.. Keep your iron motor budget reasonable, don't spend to much.. Not when there is a much better alternative available.. The only exception to that is when your building a NHRA Stock eliminator motor.. then you just throw all reason and sanity out the window... but that's how you get a 3652 lbs GS with iron heads, intake and Q-jet in the 10's... Anyway.. good luck JW
I myself can't consider a now $8k bare block a viable option Jim,..not many of us can,...I myself see more guys going back to the old ways unfortunately,....$20k in a short block is nothing new for the other guys but from my perspective there is A LOT more money out there in those guys pockets,....if that wasn't the case Rod wouldn't be the only guy going 200mph Believe you me if I had the resources I would have set the Buick world on it's ass wayyy b4 now,...but copious amounts of green I'll never have
I polished my crank couple builds ago, it was fun and sort of dirty way to spend several hours out in the shop. It didnt need any weight added or major balance issues. Also it didnt seem to make a noticeable improvement
I understand Ethan, and I am right there with you.. there is no 8K block in the future for any of my race cars.. I would have to get a different job to be able to afford that expensive an engine and I am bracket racing mainly, so what's the point? The only way I will ever own one of those deals is to acquire it second hand.. and I suspect that is true for a lot of us. But that does not mean I am going to lose my mind for a bracket engine and throw a bunch of good money after bad.. There is no need to be spending hundreds of dollars on crank prep for an engine like this, is my point. Keep it simple, and relatively inexpensive. Understanding the limits of the stock block and working with them is the key to a long lasting bracket engine, that will serve you for many years. 700 HP NA is about the reasonable max for an iron motor, any more than that typically requires more rpm than the block can survive long term.. even if it does not blow up, believe you me, it's hurt after a season of twisting to 7K thru the traps. Having built a number of 800-900 HP BBB based on iron blocks, trust me, you don't want nothing to do with that circus. If that is your goal, shortcut all the sorrow and work, and buy that 8K block now. Been there, done that. The iron block simply does not have enough structural rigidity to turn the rpm required to make big HP naturally.. to give it any chance at all, you need to girdle it, and fill the water jackets to the top with grout.. which has it's own side effects.. A light rotating assembly helps, I am encouraged to see you using aluminum rods, that will help reduce the stress on the much too thin cylinder walls. A 750-800 HP low boost boosted motor, is possible, they don't require the block twisting rpm that the NA motors do, but do need the grout and girdles.. and short of a jungle of braided stainless and oil coolers, that relegates it to a drag race only motor, as the oil gets hot in that type of engine very quickly. If going that way, I encourage you to build a 430 or even a 400 with a 4.1X bore in it.. Tons more cylinder wall in those engines. I am building a couple of boosted motors right now, a 430 that should be in the 750 HP range with a pro charger, and then a 464 with an 8-71 and and Enderlie Bug catcher/EFI setup that is basically a show motor, and will have a rpm limit of 5500.. JW
I have 2 400 blocks I'm holding on to for just that purpose,...alot of power can be made below 6500rpm with 400inches even with a so so head,...I'll see where the power lands hope it lives but I'll be the first to say if it does expire prematurely a single large frame 88 with a 400 cement block will be the route to go there after
All very good points Jim. I have a general rule for my Junk that I beat on . Aluminum rods Generous oil clearance Internal balance Grooved main saddles Rear grooved TA cam bearings. Is this the best way to go ? Who knows but it has worked for me I am I little bit of a RPM junkie lol. Like said keep the iron engine simple cause one day they will fail .that's why I would never bother putting a 4000$ crank in a junk block .
You will possibly like David Vizard crank mods he did in his last vid. on you tube. It is a stock entry level race crank, as he puts it check it out hugger.
