In a nutshell Crank offset grind, throws widened, indexed, magged, mains ground .010.. $319 (price increased from my vendor 1-11)-- from your core. Eagle 6.8 Rods- $449.00- pin fit small end- $49.00 My Diamond piston that makes it all work out- $749.00 That builds a zero deck motor, with just a .020 cleanup cut off the deck, this is often the minimum cut to fully clean the deck. This much cut will not adversely affect the fit of the heads/intake. The TA combo typically requires a .050 deck cut, which adds cost (most machine shops charge double to cut this much off) and then you will need to cut the intake faces of the heads, or the intake, to get everything to match up. I did a comparision between my 470 and a TRW Forged/Stock rod motor here last fall for a customer who wanted a Level 1 Iron motor.. all things considered, the 470 was only like $150 more.. Because of this, all my Iron performance motors are build off that 470 combo, it's a very good value for what your getting, which is a rod good to 800 HP. And a very good set of pistons, which would cost you 900- $1000 for the same piston with the features mine has if you custom ordered them. I can sell them for that price due to the volume I do.. Diamond assigned them an exclusive part number for me. I had to pony up and buy 5 sets of them all at once to make that happen, but it was a good investment. All those are long sold, and I am thru my second order of 40 pieces now. I also can make one custom change for just $8 per piston.. which I just did with Larry's motor, because his heads were cut .040 for his previous combo, we ran a bigger dish in his set. This gives me much greater flexiblity, in compression distance, dish volume ect.. JW
Jim, are these iron 470 engines on the shelf now or made to order. also are they available in a short block ?
Done to order, and yes, they are available as a shortblock. Shortblock (assembled rotating assembly in machined block, with flat tappet cam/lifters and rollmaster timing chain w/sfi flexplate and reman stock damper), from your cores, is $5295.00 Plenty of options for oil pans and timing covers to complete the lower end. Thanks JW
Scott, Yup, if you go with a .150 stroker, it does stack up right, but what you end up dealing with is the piston pin issue. LS Rods are .927 vs the 1" Buick pin. By the time you deal with that, (if even possible in that forging) it is cheaper to by the 470 deal, if you compare apples to apples (good quality forged pistons like JE, Diamond, CP ect) Gary, Due to issues of piston rock and ring stability, I like to keep the short skirt pistons on the racetrack, and I do believe you are talking about a street motor. Not saying you can't do it, but I will say that you won't find any magic bullet there, and spend a lot of money finding that out. JW
LS and sbc use the same bearings and have the same rod thickness @ the big end of .940" is .012" thicker than a BBB rod. The pin bore would have to be opened up and re-bushed for your pistons from the sbc size of .927" to what your pistons have. Here are the dimensions from the ad; Dimensions: length: 6.560 in. rod journal: 2.100 in. housing bore: 2.2250 in. pin size: 0.927 in. big end width: 0.9400 in. pin end width: 0.0000 in. thickness above pin: 0.200 in. typical weight: 650g Notes: Uses 0.927 piston pin, on center The pin end width looks like a misprint, probably is suppose to be 1.000". The big end would need to be narrowed .012" and the sbc bearings can be used, no problem to work in a BBB.(of coarse the crank's rod journals would need turned down to 2.100") Let us know if you use this option. Derek
Some of the ls rods I've had are .945 with a bushing. so .974"(?) w/o. If you are into re-machining things to make work. I wouldn't suggest that, but...
I called Eagle to ask about the small end. Apparently they are bushed for a floating pin. I have pressed pins. I called to ask about weakening the small end of the rod by opening it up to the Buick 1.00" pin dimension. Tech support stated that the OD of the bushing is 0.995" so I would only be taking 0.005" metal out of the rod. His opinion was that that was not enough to make a difference.
It sounds very doable, so are you going to go with the Eagle rods? What did your machine shop say about opening the wristpin hole up? Shouldn't be to hard to get the bushings out, then all they would need to do is hone them .004" to get to .9985" so you have .0015" press fit. Sounds like a good deal. GL Derek
Yes, I've decided to go with those. Haven't asked the machine shop but I can't imagine it's not doable. One advantage of the LS rod is that at .940" BE width, I only have to take 0.013" off each crank rod journal side to fit them as opposed to widening them 0.063 each for the BBC rod (0.126 total). Plus, the 6.56 length and my 1.975 CH pistons will leave me only 0.010 to cut off the deck
I had some concerns about crank strength with cutting 0.150" off the rod journal vs 0.050. But with the piston, pin and rod totaling 1625 gm, which is the same as the BBC 6.8 rod and diamond piston, plus taking less off the rod journal sides, I feel that's a wash...but I could be wrong
At 2.100" rod journal size it should still be strong enough to handle that weight. A lighter piston is always a good idea, but as long as you keep the RPM below 6,000 I would think this would be ok with a mild build good for more low end torque. The 494 BBB stroker builds have the rod journal cut down to a 2.00" journal size, I think with your intentions to build your engine as a street cruiser with a few track runs a year you should be good to go, plus you'll be able to say you have a 482 BBB! Derek
It would be easier to have the .013" cut off of the non-chamfered side of the rods than to ask the crank grinder to grind the journals wider. Most crank grinders don't like to widen the journals unless you have it done in MN where JW has his cranks done, it would seem they're the only ones that I have heard of that doesn't mind widening the journals for some reason. The .013" off of the width of the rod isn't anything to worry about because the sbc bearings will still be much more narrow than the new rod thickness. The sbc performance rod bearings are only .842" wide so go with the machining process that will cost less. If widening the crank's rod journals cost less to have done go with that one, or if making the rods a bit more narrow costs less go that way. GL Derek