Rod knockin'

AA Ford Discussion Group relating to the repair and restoration of your AA Ford.
Post Reply
User avatar
Chris Haynes
Posts: 2062
Joined: September 7th, 2003, 5:18 pm
Body Type: 82A
Model Year: 1930
Location: North Hills, CA/ Pine Grove, CA

Rod knockin'

Post by Chris Haynes » March 12th, 2018, 9:21 pm

I have developed a rod knock. Time to pull the pan and see whats happening. Hopefully the crank isn't damaged. That would open a big can of worms. I guess that answered my question whether my engine had poured or inserted bearings.

birdacre
Posts: 425
Joined: October 8th, 2013, 2:37 pm
Body Type: AA express
Model Year: 1928

Re: Rod knockin'

Post by birdacre » March 13th, 2018, 1:25 pm

i had the same thing. engine nice for a month and then a knock started. the pin bearings or connecting rod journals were tapered one end to the other. some of the babbit even looked like it had been patched. i was lucky to find a good used engine, yeah right, he warranted it, said to drive it for a few weeks before paying him 200 dollars. to this day it is great. very lucky. my first engine came with the truck and no history and was a crap shoot. hope yours is ok, post updates. kevin

User avatar
Chris Haynes
Posts: 2062
Joined: September 7th, 2003, 5:18 pm
Body Type: 82A
Model Year: 1930
Location: North Hills, CA/ Pine Grove, CA

Re: Rod knockin'

Post by Chris Haynes » March 14th, 2018, 10:19 am

It may not be a rod bearing. My engine is still running smooth at idle and low speed.When I accelerate to mid range or higher it has a ferocious hard rattle.

birdacre
Posts: 425
Joined: October 8th, 2013, 2:37 pm
Body Type: AA express
Model Year: 1928

Re: Rod knockin'

Post by birdacre » March 14th, 2018, 5:26 pm

i also grounded each spark plug one at a time to hear where noise was coming from. an old man showed me to also listen through a 30inch section of garden hose as well to ascertain the noise. hope all is well. kevin

Stakebed
Posts: 1187
Joined: June 14th, 2007, 7:29 pm
Body Type: Grainbox
Model Year: 1929
Location: Illinois

Re: Rod knockin'

Post by Stakebed » March 14th, 2018, 7:29 pm

And your SURE its from inside the engine? Could be flywheel/clutch related. Does it do it in neutral when your stopped and revving the engine? Clutch depressed and revving VS released?

Is it only under a load? What about when in reverse? driveshaft can transmit sounds to many places...

MrBill
Posts: 6
Joined: February 14th, 2018, 3:11 pm
Body Type: CCPU
Model Year: 1929

Re: Rod knockin'

Post by MrBill » March 16th, 2018, 3:55 pm

mine recently started knocking too...when I shorted out the plugs number 3 cyl was the one and it made a double knock then...pulled pan and found piston pin loose in piston and others had loose pin bushings

Cschaff63
Posts: 60
Joined: September 14th, 2017, 5:57 pm
Body Type: Dump
Model Year: 1928
Location: Pa

Re: Rod knockin'

Post by Cschaff63 » August 2nd, 2019, 5:52 pm

Chris Haynes wrote:
March 14th, 2018, 10:19 am
It may not be a rod bearing. My engine is still running smooth at idle and low speed.When I accelerate to mid range or higher it has a ferocious hard rattle.
Did you ever find that rattle? mine just started doing the same thing. My engine is a fresh rebuild by Antique Engines

User avatar
Chris Haynes
Posts: 2062
Joined: September 7th, 2003, 5:18 pm
Body Type: 82A
Model Year: 1930
Location: North Hills, CA/ Pine Grove, CA

Re: Rod knockin'

Post by Chris Haynes » August 2nd, 2019, 11:19 pm

It was all of my bearings.

KimVanOrder
Posts: 523
Joined: August 11th, 2013, 4:25 pm
Body Type: 82-A Platform
Model Year: 1928
Location: Hamilton, Mich.

Re: Rod knockin'

Post by KimVanOrder » August 6th, 2019, 3:56 pm

Chris Haynes wrote:
August 2nd, 2019, 11:19 pm
It was all of my bearings.
But what about the truck bearings? :lol:
KVO
Dec. '28 AA

Cschaff63
Posts: 60
Joined: September 14th, 2017, 5:57 pm
Body Type: Dump
Model Year: 1928
Location: Pa

Re: Rod knockin'

Post by Cschaff63 » August 8th, 2019, 2:20 pm

I lucked out on this one, turns out my timing was too far advanced. Retarded the time, and the rattle stopped!

Cschaff63
Posts: 60
Joined: September 14th, 2017, 5:57 pm
Body Type: Dump
Model Year: 1928
Location: Pa

Re: Rod knockin'

Post by Cschaff63 » August 11th, 2019, 1:30 pm

Cschaff63 wrote:
August 8th, 2019, 2:20 pm
I lucked out on this one, turns out my timing was too far advanced. Retarded the time, and the rattle stopped!
Well, maybe spoke too soon, when I retarded the timing, the rattle or clatter sound went away. Now it is back at a different rpm and under load mostly, I’m running a Zipper centrifugal distributor, is it possible it is not functioning as it is supposed to? Sure seems like it is timing related somehow!

User avatar
1crosscut
Posts: 791
Joined: December 25th, 2010, 7:22 pm
Body Type: 82-A
Model Year: 1929
Location: Lincoln, NE

Re: Rod knockin'

Post by 1crosscut » August 11th, 2019, 2:10 pm

Go back to the stock distributor set up and see if that helps. That way you will know if that is the problem.
You don't want to be running it if it is so advanced it's causing it to knock. Engines don't like that.
------------
Dave

Post Reply