Started assy. of my block, ready to degree cam, installed #1 piston w/no rings to find TDC, timing set (Rollmaster 9 key) set to "0" dial indicator, etc., I SLOOOOOOWLY rotate crank, sure enough, it stops, rod hitting lobe on cam. I found out where its hitting and slowly grind away, test fit 8 or more times, I was test fitting WITHOUT the rod cap for ease of removal and re-install to check, I'd follow the piston down and up with my hand, finally it cleared. Bolted rod cap on, it rubs the lobe, DAMN I look at the rod cap with the bolts, the one bolt protrudes just a hair enough to rub the cam lobe, I ground a taper onto the threaded end of the bolt, FINALLY My question, being I had the rotating assy balanced, now Im grinding/sanding a bit of a few rods (haven't checked the rest yet) am I going to have to rebalance, or no?
I bet yes, but weigh the rod and find out the difference then call the place that balanced it and ask them
Depending on how many grams was remove you may or may not need to have it re balanced. If it was over 2 grams I would have it re balanced, if under 2 grams I would run it.
I'm sure the rods were geared more towards fitting a lesser cam. Roller with wide profiles and larger lifts can eat up cleanable at these points, is this a stk stroke setup
That's what I was thinking, with the rollers lobes being larger (longer, being able to hold the valve open longer) they do take up what little room there is, and BANG
Good to know! I think the biggest issue is us 350 guys aren't used to real performance parts for our 350's, this is new territory for us, but for 455 guys and other makes of engines, they're used to modifying aftermarket performance parts to make stuff work, part of hot rodding. Us 350 guys are used to stock type parts that fit with no thought to "will it work ok" Its actually fun
No the amount removed to make clearance does not effect the strength. I do suggest that people degree in the can when they do the mock up and not only make sure the rods clear where the cam will be set but also at a few degrees advanced and retarded. That way if you ever get a worn timing set and or change the degree setting on your cam it will still clear.
I agree! This is new territory for us 350 guys taking a different path. Its old school for 455 guys and Chevy, Mopar, Ford, etc guys. I even asked my machinist if it normally takes this long to mock up, check, disassemble, repeat, he smiled and said, yes. I wasn't used to it, Im used to using factory parts that fit without issue. This path requires a whole new mindset
A lot of people don't realize what actually goes into building a motor b4 you get to the point of finial assembly. On our last bbb motor we had to add billet main caps. After all the fit, sent out to be line bored, we honed the mains to spec, went in ate lunch to everything a chance to cool, still in spec......sent the block through the wash tank, then spend a long time hand washing the block with soup and water outside........it was Feb mid michigan.......got ready to assemble, left for the night, come back the next morning, start to assemble found main spec to have settle and was .005 smaller than we wanted. Had to repeat the whole days work again. But it got me thinking about engine specs ,we spend a lot of time getting specs set, but by the time the motor warms up or cycles a few times I'm sure those number change and go right out the window
Yep, its a lot of checking for sure for sure! I only spend a few hours at a time in the garage, when I feel Im loosing my concentration, I wrap it up for the day, I don't wanna cut corners or get sloppy. I have thought of the parts getting hot also, and clearance getting tighter.
2 grams is = to .070 oz so you will not need to grind any amount to make a need to go back and rebalance.
Just remember a few grams can still cause a ton of extra damage to the bearings... https://www.perpetualbalance.com/precision-vs.-street-balancing.html
8 grams removed from each rod I would have the crank re balanced... it’s enough to cause a lot of un due stress on the engine...
