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connecting rod size

Posted: Fri Feb 07, 2020 7:52 pm
by John bevardos
Hi guys ,
my basic math has left me ----- I have a crank that was ground .005 undersize and my connecting rod choices are either std or .010.
Should I use the std size rods and take shims away or should I scrape the .010 down? Btw--its to replace existing rods in the engine already .

Thank you

John

Re: connecting rod size

Posted: Fri Feb 07, 2020 8:38 pm
by Adam
Scrape the .010” rods is your best bet for a tight clearance.

Standards will be your easiest option, but will end up with wider side clearances. If you go with standards and remove shims, you will have your target clearance top and bottom, but .005” over that on the sides.

Re: connecting rod size

Posted: Fri Feb 07, 2020 9:55 pm
by tman1913
Why not have a set of rods poured and cut to your size. They are a number of companies that can provide you that service for the same price as a standard or .010" under rod.

Re: connecting rod size

Posted: Fri Feb 07, 2020 11:54 pm
by Scott_Conger
Mike gives good advice. This is exactly what I did and am happy I did. Don't fool with trying to tell THEM what you need by calculating the size...just measure your journals, and if they are round and straight, tell them the size and they will bore them to be the correct fit from the get-go. Like Mike says, there are several folks to go to and if you'd like a recommendation, email me.

Re: connecting rod size

Posted: Sat Feb 08, 2020 12:06 am
by Dan McEachern
John- I replied to your other thread regarding rods and never heard from you.
Dan

Re: connecting rod size

Posted: Sat Feb 08, 2020 12:44 pm
by John bevardos
Guys, thank you for all the replies. Dan, PM sent. Thank you, John

Re: connecting rod size

Posted: Sat Feb 08, 2020 3:24 pm
by Gene_French
John:
if you start with the minus .010 rods (1.240" diameter ) you can scrape or bore to the 1.245" diameter needed … can make a smaller bore bigger but not so easy to make a too big bore smaller … always an optimist ...Gene French