SoCal Jet Boats
Tech Talk => Engine Mechanical / Electrical => Topic started by: enginedoctor on May 13, 2010, 08:57:44 PM
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okay..... i don't wanna be a drama queen , ...but:...( Housing Bore I/D )
I had a customer come in today to get a second opinion on some block work that he had done at an unknown shop,
Soooooooo. I do my thing....... I set up my Mic's. @ 2.937 5/10....and inspect the mains.
I find the main housing to be as following:
#1..... 2.938.5 to 2.939.....and tapered. ( .001 .5)
# 2.....2.939. #3. 2.940........ okay anyone see my point........ GT...whatcha think :sly:
Ralph.... ::)
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No Line hone? Or even check for it? Forgive me my ignorance, but is it not first and foremost you make the crank and bores square to the block?
Ray
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No Line hone? Or even check for it? Forgive me my ignorance, but is it not first and foremost you make the crank and bores square to the block?
Ray
My point Ray :).....the main housing was freshly done, yet a two fold problem here...
1. Mics were outa wack when measuring...( and Ralph knows how finickey I am about that/ refer to Brad's build)
2. When using a horizontal hone....you get gravity drag..... In this case ..."operator error/Tooling". :sly:
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So besides being out of round, tapered and oversized to boot? Were 4 and 5 ok or progressively worse?
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So besides being out of round, tapered and oversized to boot? Were 4 and 5 ok or progressively worse?
4 and 5 were worse............and i can tell ya why :)
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4 and 5 were worse............and i can tell ya why :)
Going with a bent, or improperly maintained boring bar or block not properly centered in the tool... :thumbup:
GT
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Going with a bent, or improperly maintained boring bar or block not properly centered in the tool... :thumbup:
GT
Nope!....but close GT :thumbup:
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OK, I dont know sht about machining so excuse the dumb answer (if I'm wrong).
Was the machine somehow collecting material along the way and enlarging each cut ?
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Weak boring bar and the further it got out the worse it loped or took to much in 1 cut and pushed the cutter away
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Or didnt make a spring cut back through it will taper if u make every cut in 1 direction gotta go thru and cut opposite direction too?
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Well ....many of you had great answers....... :thumbup:
Anyhow I observed 2 or 3 problems here.
1. The operator attempted finished size to be at 2.938.0......Operator must not have had bore guage correctly
calibrated as finished size average was 2.939.0 and then some...........
2. mains must have been pretty bad...as at the parting line the block was peened very heavily.
My thoughts...too much material removed off the main caps w/the cap grinder to try to bring back to size.
3. The mains were not " Bored " and then honed to finish size."......Honed only...(Too much material to remove for
honing alone ! )
Finally........It look's as though the stones were worn causing the tapered effect, as well as not rotating the block
during the honing process..... and not enough cool down time....I practice getting sizes close, cool down then go back
the next day, re-calibrate mics. and finish to size.
For those of you who have ever resized connecting rods....the process for main work is very similar........................
Just MHO.... :beer:
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Well ....many of you had great answers....... :thumbup:
Anyhow I observed 2 or 3 problems here.
1. The operator attempted finished size to be at 2.938.0......Operator must not have had bore guage correctly
calibrated as finished size average was 2.939.0 and then some...........
2. mains must have been pretty bad...as at the parting line the block was peened very heavily.
My thoughts...too much material removed off the main caps w/the cap grinder to try to bring back to size.
3. The mains were not " Bored " and then honed to finish size."......Honed only...(Too much material to remove for
honing alone ! )
Finally........It look's as though the stones were worn causing the tapered effect, as well as not rotating the block
during the honing process..... and not enough cool down time....I practice getting sizes close, cool down then go back
the next day, re-calibrate mics. and finish to size.
For those of you who have ever resized connecting rods....the process for main work is very similar........................
Just MHO.... :beer:
ok you lost me!! but i will definitely bring you my motor when its time :thumbup: hope fully not for a long time ;D
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Hey Challenger ;D..........thank's for your reply. :thumbup:
Guess everybody else flaked :beer: :sly: