Pulled Engine ... Need Dimensional Specs
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Instructor
Joined: Jan 2002
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From: Wixom Mi
Pulled Engine ... Need Dimensional Specs
I'd like to compare my engine "as is" to the original specs before I start working on it. It's a std. bore '81. Could someone tell me the tolerance on the bore size and the size & tolerances of the crank rod & main diameters?? Thanks.
Le Mans Master
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From: Unreconstructed, South Carolina
Re: Pulled Engine ... Need Dimensional Specs (Motorcity81)
I’d written this down after plagarizing from an old chilton manual for a 71 model
crank journals:
mains #1-4: 2.4484-2.4493
main # 5: 2.4478-2.4488
rods: 2.0990-2.1000
block’s std deck height (centerline of crank to top of bore): 9.025”
Don’t have a spec on bore but a NEW std 350 bore should measure 4.000 +/- 0.005 ... a worn std bore could measure as much as 4.015 ... maybe a bit more. If you have oversize pistons, they'll almost certainly be marked somewhere with the oversize ... probably faintly stamped into pistons' tops underneath the carbon buildup. Same goes for the crank bearings ... oversize stamped into backside of bearing halves. If you haven't already done so, your best bet is to establish a relationship with a good local auto machine shop ... start by taking your crank there & have them mike it ... probably won't charge a dime. Even if you have your own gages ... it'll pay off in spades to know a reliable auto machinist.
crank journals:
mains #1-4: 2.4484-2.4493
main # 5: 2.4478-2.4488
rods: 2.0990-2.1000
block’s std deck height (centerline of crank to top of bore): 9.025”
Don’t have a spec on bore but a NEW std 350 bore should measure 4.000 +/- 0.005 ... a worn std bore could measure as much as 4.015 ... maybe a bit more. If you have oversize pistons, they'll almost certainly be marked somewhere with the oversize ... probably faintly stamped into pistons' tops underneath the carbon buildup. Same goes for the crank bearings ... oversize stamped into backside of bearing halves. If you haven't already done so, your best bet is to establish a relationship with a good local auto machine shop ... start by taking your crank there & have them mike it ... probably won't charge a dime. Even if you have your own gages ... it'll pay off in spades to know a reliable auto machinist.
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Instructor
Joined: Jan 2002
Posts: 124
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From: Wixom Mi
Re: Pulled Engine ... Need Dimensional Specs (jackson)
Thanks for the input. Machinist I use to use is out of business, or at least I can't find him (been a few years). I'll have to take my chances on someone else. Regards, and thanks again.
