connecting rod size

Discuss all things Model T related.
Forum rules
If you need help logging in, or have question about how something works, use the Support forum located here Support Forum
Complete set of Forum Rules Forum Rules

Topic author
John bevardos
Posts: 88
Joined: Mon Jan 07, 2019 1:58 am
First Name: John
Last Name: bevardos
Location: Los Angeles

connecting rod size

Post by John bevardos » Fri Feb 07, 2020 7:52 pm

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


Adam
Posts: 613
Joined: Sun Jan 06, 2019 11:57 am
First Name: Adam
Last Name: Doleshal
Location: Wisconsin
MTFCA Number: 23809
MTFCI Number: 1
Board Member Since: 2000

Re: connecting rod size

Post by Adam » Fri Feb 07, 2020 8:38 pm

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.


tman1913
Posts: 20
Joined: Sun Jan 06, 2019 12:30 pm
First Name: Mike
Last Name: Bender
Location: Tulsa OK
MTFCA Number: 21160

Re: connecting rod size

Post by tman1913 » Fri Feb 07, 2020 9:55 pm

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.


Scott_Conger
Posts: 2699
Joined: Sun Jan 06, 2019 11:18 am
First Name: Scott
Last Name: Conger
Location: Clark, WY
Board Member Since: 2005

Re: connecting rod size

Post by Scott_Conger » Fri Feb 07, 2020 11:54 pm

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.
Scott Conger

Full Flow Float Valves - deliver fuel like Henry intended!


Dan McEachern
Posts: 345
Joined: Sun Jan 06, 2019 11:08 am
First Name: DAN
Last Name: MCEACHERN
Location: ALAMEDA,CA,USA

Re: connecting rod size

Post by Dan McEachern » Sat Feb 08, 2020 12:06 am

John- I replied to your other thread regarding rods and never heard from you.
Dan


Topic author
John bevardos
Posts: 88
Joined: Mon Jan 07, 2019 1:58 am
First Name: John
Last Name: bevardos
Location: Los Angeles

Re: connecting rod size

Post by John bevardos » Sat Feb 08, 2020 12:44 pm

Guys, thank you for all the replies. Dan, PM sent. Thank you, John


Gene_French
Posts: 302
Joined: Tue Jan 08, 2019 9:58 am
First Name: Gene
Last Name: French
Location: Nunn, CO
Board Member Since: 2014

Re: connecting rod size

Post by Gene_French » Sat Feb 08, 2020 3:24 pm

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

Post Reply Previous topicNext topic