..stupid quick question, but when machining your crank for a 494 stroker, does the reduced rod journal size of 2.00" make for significant reduction in strength of the journal? ...assuming all other components were done correctly.
That's a good question Bob, I always wondered about that. Maybe JW can answer that for us. My guess is it isn't as much of a problem as you would think. I bet using the lightest pistons and rods is advisable. If I was building an engine today, I'd want the 482. JW says we should have drop in rods for that combo very soon.
Yes, The vast majority of broken 455 cranks I have seen over the years, have been 494 strokers. They tend to crack in the rod journal radius, even under normal use, above 750 HP. That's been my experience. Seen 3 or 4 do that, was worried about the 494 I am freshening for a local racer right now, but that crank passed the mag check. I prefer a 2.200 rod journal for serious use, don't mind a 2.100 under tightly controlled circumstances (race motor) but that small journal SBC size always made me a bit queezy. I, and many others built them successfully over the years, but it would not be my first choice today.
I've done several 494's without an issue. currently running one in Scat and over 400 passes. Lately I've been recommending 482's and have built 9 of them for customers. They run as well as the 494's for some reason, and provide more strength in the journal and are easier to machine a good radius which is critical. I've seen a couple 494 failures sent to me for redoing and it appeared the radius' were carelessly machined.
It sounds like the question should be "what is the most you can stroke a factory 455 crank without weakening it?" Where are the oiling holes,or where do they end up,when you offset grind the crank?
1/4" stroke (494) is the most you can safely stroke it, never tried more to use a Honda rod but it would be a time bomb.
Trick stroke it to a 482. My 482 runs great that Gary built. My 470 Gary built I like better. Revs faster and pulls to 6400 all day. There's over 400 passes on it and crank didn't need polished. Checked the 482 bearings and they were perfect also. What are you doing? Trying to build an engine? Sell you my aluminum Heads and rod 482. Keeping the 470 in this bad boy.
I was planning on the TA Stage 2 TE heads. Still deciding on the rest. White GSX Stage 2,but with modern updates,as if it were built today.
had 2 494 cranks first one cracked after too many 7000rpm blasts, had a second one done never took it above 6500 and it passed the mag before I sold it off the machinist said "trust me it will be cracked" he was shocked when it was "good" so if you keep the rpm in a normal range it should be just fine
Sounds like I'll just get a billet. More coin now,but if you scatter everything,look at how much you just wasted.
Where does the difference in cubes come from with the 482 and 470? Just wondering how the 470 revs faster. Tommy
Trick, Have brand new Stage 2 TE heads in the box and headers. Unless you plan on a new block. Don't waste your time buying a billet crank. Block let's go before cranks done right. People with argue both points. The extra crank weight about 22 lbs flying around verses light weight parts? Hmm see what Gary Paine thinks or Jim Weise. Getting ready to sell the heads and headers soon. Just love looking at them in the new box.
One thing I've learned is lightweight lightweight lightweight,when it comes to these big dinosaurs. Less weight is more power,and less stress. The billet crank weighs less and won't do the wet-noodle-whip inside the block. It can only help. I also have a my complete 70 455 that I will keep a little more tame,and just use a girdle. I'll get a TA block for the business engine.
