Lonnie, Post #36 has a link to Automotive Machine and Performance's site. There are pictures of the balance line. I'll link the larger ones for you. http://automachperf.com/images/aux_line1.JPG http://automachperf.com/images/aux_line2.JPG http://automachperf.com/images/aux_line3.JPG
I believe he did Sean, but it was some type of fault or deformity that magnafluxing could not pick up. Still, it would go out of round on the final torque increment, and JW's crank guy confirmed it, but couldn't explain why. I believe that is what Jim told me. I'm just happy that Jim is so thorough, and I didn't have to find that out the hard way. I know this motor will be worth the wait.
The way I read that is it went out of round after the dyno. And then the block will be set aside because the issue isnt going away.
sorry if this is a dumb question, but is that hole always there above the starter? that looks simple enough to achieve. think i will add that to my arsenel when i go to put it together. love the advice i get on here. thanks guys
The deal went down like this.. Built motor the first time, very happy with how things measured up, and it's performance on the dyno.. obviously after this, this thread was started. Thought we could coax a little better idle quality out of it, with a straight pattern cam, with little to no loss in HP. So took it down, to the shortblock again, it was spotless clean and as good as a motor can look with around 30 dyno pulls on it.. I did not pull a main cap, or a rod cap.. saw no reason to, great oil pressure, nothing in the filters or oil pan, and it kept gaining HP thru out the session. Re-assembled with the new cam.. back on the dyno, and it's off in power. Second pull, still down.. unstrap it, and back to the stand. Pulled the pan, still clean, and no obvious heat marks on any rods from any type of oiling issue.. Pulled number 4 main (always the first one that gets hurt, as it has the highest stress on it) and was very surprised to see it just starting to scuff the bearing hard enough to show a little copper. Suspected 2 things then.. either cracked block, or broken crank.. Magged the crank.. no problem Cleaned the block all up, and started torquing on the mains.. notice right away that the last step on number 4 "felt funny".. hard to describe, but pull that last step on a couple hundred 455 main bolts like I have, and you notice the difference.. Looked hard at the cap, bolts, and block threaded holes, as well as the main web on the block.. swap bolts around, ect ect ect... and after 6 or 7 different times torquing up that cap, and measuring, it varies well over a thousandth, and never repeats exactly. Took the block over to one of my machinist buddies, just for a quick second opinion, he torqued the first three caps... ok... but got a look on his face like he was sucking on a lemon when he hit the last step on number 4.. I did not tell him ahead of time about it, just asked him to torque the mains up. We looked at it carefully, and ya, maybe that's a crack, maybe a parting line.. you know the conversation.. but bottom line, let's quit wasting time here. This one is a paperweight... naked 600 HP Buick thin wall block.. anyone that says you can't hurt them at this level, simply has not built enough examples or tested them hard enough, to find out the limitations.. Queued up a nice "fattie" cylinder block that I had set aside for a healthy motor a while ago, and got going on the machine work again, but knowing full well it would be getting toward spring to get it back together, with the move and all.. Larry is ok with all that, and here we are.. Remember, the average dyno session is 5-9 pulls, and had I stopped then, and put it in a box, and sent it to Larry, it would be in his car today, and just fine...he will never stress it like I do on the dyno. But this is what prototyping is all about, find the combo, and find the durability limits. Buick did it when they first built the motor, and in a sense, that needs to be done again now. With the advent of the hyd roller cam, we now can built what is truely a "street motor", with 13-15 inchs of vacuum at 750-800 rpm, and make 600 HP. Never before have I, or anyone I know of, built that kind of power, in a motor this "tame".. So now we have a whole new dynamic for cylinder pressures at lower rpm levels, as well as a whole new set of stress parameters, with the reciprocating assembly, than we have seen in the past with the more race oriented stuff. Let's not forget, those motors typically got the block filler and or the girdles/ along with more race oriented clearances in the past, typically because they were more strip oriented. Was I happy with the block failure?.. no, but we learn a lot more from dyno flogging and from failed stuff, than from motors that go sit between the frame rails of some guy's car, and get driven once a month, and raced twice a year.. Those motors tend to bring that "Hey, my buddy has a 650 HP 455, with stock rods, and it lives just fine".. I am sure it does.. for now...uzzled: JW
I like putting the hole behind the intake for a couple of reasons. 1. Heat from the headers adding to the oil. 2. I think it may weaken the block by putting the hole by the starter (no sure data ).
ya i was curious about the heat from the headers. and with a half fill i dont want an oil cooler and that might aggravate things.
I had a balance line on my engine when I was racing. I don't think it weakened the block or over heated the oil. I took it off when I put the engine in my 53. The line went on the engine in the late 70s. Not really a new idea by any means. Bob H.
that said what clearances would you think i would need with 12-1 compression 308s and ported alum stg 1s spx and 4000 plus stall speed and 373s with 28 or 29 tire?
Lonnie I would shoot for .025 on the mains and rods. But everyone will have a different tolerance opinion.
thats what i was thinking, but horror stories of bad line honing on the huge main kinda scare me. i dont want low idle oil pressure but i dont want to spit out the crank.
Exactly, I thought the same thing and talked myself into getting a brand new T/A timing cover already set up from them with the oil pump and regulater. It sure is a lot of pennies to drop, but good piece of mind.
Lonnie, Iron block, no girdle, cast crank... at around 600 HP I would give it some space, around .003 on the mains.. Now a fully filled block, with a TA girdle, and a forged or Billet crank... I ran that setup sucessfully for years, at .0025, in a motor that turned 7000 rpm, and made 870 HP.. the key was, with all that fill, girdles and hardware, along with a rigid crank, flex is limited, and you can run the parts tighter. JE
