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Author Topic: Conrod  (Read 804 times)

Barry T

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Conrod
« on: April 13, 2020, 11:28:03 PM »
Hi
Has anyone straightened a conrod,
 I have a 9hp cs47020 9-1-35 which I bought a few years ago and with the lock down i pulled it out to get it running but it has very low compression, After pulling the head off the liner was dragged but honed out and I cleaned the piston with emery cloth, I have Re ground the valves but need either a conrod or straighten this one if possible.
Thanks
Barry

sirpedrosa

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Re: Conrod
« Reply #1 on: April 14, 2020, 12:57:19 AM »
Hi Barry

A CS bent conrod? Piston is alu?

BR
VP
Bernard 18A - 1968 (mama's water pump - year of my birth)
Petter PAZ1 - Jun 1967, 3HP, sn 416xxxx
Petter PAZ1 - Nov 1979, 3HP, sn 425xxxx
Lister 12/2 - 12651227, the pearl!

Barry T

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Re: Conrod
« Reply #2 on: April 14, 2020, 04:06:30 PM »
Yes Aluminum piston,
I donít know the history on it but when I went to get it running I drained the oil, when cleaning the sump I found the lug belonging to the liner, When I turn the engine over the conrod is only clearing the liner,
Thanks
Barry

sirpedrosa

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Re: Conrod
« Reply #3 on: April 15, 2020, 08:17:35 PM »
Hi Barry

Please put rant in english, so I can compreend. Or better post some pics.

But, bent a conrod with alu piston, I think piston will crack first. Just my thoughts!

Stay safe
VP
Bernard 18A - 1968 (mama's water pump - year of my birth)
Petter PAZ1 - Jun 1967, 3HP, sn 416xxxx
Petter PAZ1 - Nov 1979, 3HP, sn 425xxxx
Lister 12/2 - 12651227, the pearl!

listard-jp2

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Re: Conrod
« Reply #4 on: April 15, 2020, 08:50:26 PM »
Hi Barry

A CS bent conrod? Piston is alu?

Not a CS like you are thinking, but a Lister JP1 AKA 9-1.

Surprised you have bent one of those conrods, as they are massive in comparison to a CS6/1 con rod.
Also they have 4 big end bolts.


Barry T

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Re: Conrod
« Reply #5 on: April 16, 2020, 09:53:13 AM »
lister photos

dieselspanner

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Re: Conrod
« Reply #6 on: April 16, 2020, 01:01:26 PM »
That's certainly taken a beating!

For what my six eggs is worth, assuming you don't want the machine to run at the max 24/7....

I'd get an infra red thermometer and warm the rod with a propane torch up to somewhere around 650 degrees c and hold it there for half an hour or so then wrap it in an old fire blanket and let it cool slowly.

Make up a couple of dummy shafts, for the big and small ends and then take it down to the local fabrication shop on a Saturday morning and slip the boss a tenner to push it about in a brake press until the dummy shafts are as close to parallel in all aspects as you can get.

Clean it up, give it a good thick coat of inspection and if you have access to the kit, crack test it. The guy in the fab shop will probably let you have a couple of squirts, to save buying the whole kit.

https://www.ebay.co.uk/itm/Flawtek-Weld-Metal-Crack-Flaw-Detection-Complete-3-Part-Kit/141181661281?hash=item20df153061:g:KIQAAOSwHfxdlzbk

As an side, you don't half get a lot of interesting stuff when you check eBay for 'Crack testing kit'!!

Based on a good outcome I'd be tempted to run the machine at half then two thirds power and if the rod doesn't let go then I'd live with half power from then on.

That would give you a cheaper start up and if you are happy with the machine and want more from it you can swap the rod out at your leisure.

Cheers
Stef







Tighten 'til it strips, weld nut to chassis, peen stud, adjust with angle grinder.

sirpedrosa

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Re: Conrod
« Reply #7 on: April 16, 2020, 08:09:17 PM »
Hi Barry

This is a serious damage! cylinder skirt broken changes the picture.

Has this engine swallowed water? or other liquid?

IMMO this cylinder is scraped, because piston protrude almost 1" bellow skirt edge when working.

Try to get new, old stock, or reazonable condition, conrod and cylinder. But....

Cheers
VP
Bernard 18A - 1968 (mama's water pump - year of my birth)
Petter PAZ1 - Jun 1967, 3HP, sn 416xxxx
Petter PAZ1 - Nov 1979, 3HP, sn 425xxxx
Lister 12/2 - 12651227, the pearl!

listard-jp2

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Re: Conrod
« Reply #8 on: April 16, 2020, 09:46:14 PM »

As an side, you don't half get a lot of interesting stuff when you check eBay for 'Crack testing kit'!!


Ohhh yes, I've done a fair bit of 'Crack' testing in my youth  ;) ;) ;) usually not long after pub closing time on a Friday night




IMMO this cylinder is scraped, because piston protrude almost 1" bellow skirt edge when working.


As this is a wet liner engine, it may well be recoverable with a replacement cylinder liner.

OP I am assuming your UK based? If you send me a PM I have contact details of someone who has broke up a JP4 for parts. He may still have all the parts you need to put this right.

Only slight fly in the ointment, is that his JP4 was an early version with parallel sided top ring groove instead of the more usual keystone wedge top ring style found on JP engines.

Willw

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Re: Conrod
« Reply #9 on: April 17, 2020, 03:40:13 PM »
+1 with listard-jp2.
Daily driver '97 GMC W4 tipper on WVO/Kerosene mix.
6/1 clone standby generator.
Too many projects.

listard-jp2

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Re: Conrod
« Reply #10 on: April 18, 2020, 08:19:20 AM »
Barry,

I have sent a detailed response to your Yahoo email account, let me know via email if you need any further information.

All the best,

Listard-JP2

George A

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Re: Conrod
« Reply #11 on: April 18, 2020, 11:31:06 AM »
From the Ford Model T service manual.........

To check the connecting rods for twist and straightness, machine two pieces of bar stock to a snug fit in both upper and lower bearings. Lay the entire assembly on the ways of an engine lathe. This will reveal any twist or misalignment.

To check for sideways twist, carefully measure the center to center distance of the bar stock, on each side of the connecting rod.

The above is paraphrased from an original manual, and it works. It provides a quick and accurate method of checking progress when straightening a bent rod.
I've joined "the dark side"....if it has a spark plug, it's obsolete technology.

dax021

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Re: Conrod
« Reply #12 on: April 18, 2020, 02:07:23 PM »
clever

dieselspanner

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Re: Conrod
« Reply #13 on: April 19, 2020, 10:33:31 PM »
See?

I told you all I'm 'Old School'!!

Cheers
Stef
Tighten 'til it strips, weld nut to chassis, peen stud, adjust with angle grinder.

snowman18

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Re: Conrod
« Reply #14 on: April 20, 2020, 03:49:51 AM »
Ford's 'Model T used, Vanadium alloy steels for crankshaft, camshaft, connecting rods which could stand up to reworking.