Jump to content

Gardner 2LW Crankshaft crank pins - offset? Not 180 degrees.


TheCoot
 Share

Featured Posts

I have been looking on the Internet for information on the Gardner crankshaft but cannot find the info I am looking for.

Does anyone on here know the angle in degrees between the crank pins on the 2LW crankshaft?

 

The Gardner 2LW, like many twin cylinder engines, doesn't have the crank pins set at 180 degrees - otherwise you wouldn't hear the distinctive "po-TA-to, po-TA-to" beat from the exhaust.

I have already emailed gardnermarine and had no response yet.  I will try Tangent Engineering at some point, but I thought I'd ask the community on here first.

 

Looking  forward to replies.

Richard

Link to comment
Share on other sites

Great photo - thank you very much - and to the other reply above this one.

Odd, though, how the beat doesn't sound 180 apart at idle. Maybe something to do with the inertia not being sufficient to keep an even note?

 

Thank you!

Link to comment
Share on other sites

The crank pins are almost certainly at 180 to balance the engine (one piston going up, one coming down). The distinctive exhaust note of a twin is because the firing is uneven:....

 bang bang gap gap

This is percieved as one "complicated" bang per cycle which gives the distinctive and slow revving sound.

Link to comment
Share on other sites

1 minute ago, dmr said:

The crank pins are almost certainly at 180 to balance the engine (one piston going up, one coming down). The distinctive exhaust note of a twin is because the firing is uneven:....

 bang bang gap gap

This is percieved as one "complicated" bang per cycle which gives the distinctive and slow revving sound.

I see what you mean. Just like music where you have four beats in a four-beat measure (a four cylinder), a twin has only two beats but we are anticipating a four beat?

Just now, TheCoot said:

I see what you mean. Just like music where you have four beats in a four-beat measure (a four cylinder), a twin has only two beats but we are anticipating a four beat?

...In a very roundabout and crude way of an explanation..

Link to comment
Share on other sites

19 minutes ago, Tracy D'arth said:

What dedication to answer a forum question!  Not many would tear down their engine to make a post.

 

It needed it anyway. Look at the state of that left hand big end journal..!!

  • Greenie 1
Link to comment
Share on other sites

28 minutes ago, dmr said:

bang bang gap gap

This is percieved as one "complicated" bang per cycle which gives the distinctive and slow revving sound.

 

On quite a few 'vintage' type engines the pair of adjacent firing strokes are aurally indistinguishable even at tickover, as tickover is still quite fast. 

 

Once you hear a two cylinder ticking over slow enough, the two combustion strokes become far enough apart to be easily heard, along with the two non-firing strokes. A Kelvin K2 is a good example. 

 

 

Link to comment
Share on other sites

36 minutes ago, dmr said:

The crank pins are almost certainly at 180 to balance the engine (one piston going up, one coming down). The distinctive exhaust note of a twin is because the firing is uneven:....

 bang bang gap gap

This is percieved as one "complicated" bang per cycle which gives the distinctive and slow revving sound.

Because there is a firing stroke only every second revolution, there is no way the firing strokes can be equally spaced with the cranks 180 degrees apart.

 

Different for a two stroke two cylinder engine though.

Bolinder-Swedish-E-Type-engine.gif

Edited by David Mack
Link to comment
Share on other sites

13 minutes ago, David Mack said:

Different for a two stroke two cylinder engine though.

 

Also different for a four stroke twin cylinder with crank pins aligned, e.g. a Kingfisher KD2.

 

And what about Harleys, V twins.....?!! 

Link to comment
Share on other sites

  • Athy changed the title to Gardner 2LW Crankshaft crank pins - offset? Not 180 degrees.
2 minutes ago, TheCoot said:

A V-twin must be very different to an in-line twin.  Sharing a crank pin for example.

Coot, I have changed "offest" i9n your title to "offset". If this is wrong, let me know and I'll change it back.

 

If you still seek further information about the crankshaft, or other aspects of your engine, you could contact Walsh's Engineering in Manchester, who have rebuilt dozens of 2LWs including mine.

Link to comment
Share on other sites

5 minutes ago, Athy said:

Coot, I have changed "offest" i9n your title to "offset". If this is wrong, let me know and I'll change it back.

 

If you still seek further information about the crankshaft, or other aspects of your engine, you could contact Walsh's Engineering in Manchester, who have rebuilt dozens of 2LWs including mine.

Thank you very much for correcting the title of my post.  I did see the typo after I posted it.  Typical of me to rush a post and not proof read it.

I will contact Walsh's - thank you for the suggestion.  I do have the info of who rebuilt mine but forget for the moment.

 

Thank you

Link to comment
Share on other sites

7 minutes ago, TheCoot said:

I do have the info of who rebuilt mine but forget for the moment.

 

Thank you

Depending on how long ago it was, Danny Williamson or Tony Redshaw would be good bets. I think Danny stopped working on engines some time ago; Tony has retired but his son Paul still runs the business.,

Link to comment
Share on other sites

19 minutes ago, Athy said:

Depending on how long ago it was, Danny Williamson or Tony Redshaw would be good bets. I think Danny stopped working on engines some time ago; Tony has retired but his son Paul still runs the business.,

Now I'm curious!  I will dig out the information this evening.  I'm sure I was told that the restorer used to work at Gardner.  I will find out.

Link to comment
Share on other sites

Just now, TheCoot said:

Now I'm curious!  I will dig out the information this evening.  I'm sure I was told that the restorer used to work at Gardner.  I will find out.

Then it will probably be a Walsh's rebuild: the company was founded by two ex-Gardner employees, one of whom is still the managing director.

Mine is one of the "South African" engines, originally fitted in a Hunslet narrow-gauge locomotive which worked in the S'African mines. Is yours? I believe Walsh's bought a container-load of them after many worn-out examples were found acting as markers alongside a lane which led from the main road to the mine.

Link to comment
Share on other sites

3 hours ago, Tracy D'arth said:

What dedication to answer a forum question!  Not many would tear down their engine to make a post.

In true Blue Peter style "One I prepared earlier"

Link to comment
Share on other sites

3 hours ago, TheCoot said:

A V-twin must be very different to an in-line twin.  Sharing a crank pin for example.

Vs are a whole new kettle of fish with the options of different V angles and different firing orders. The classic  V8 "burble" is because those engines are in effect two individual in-line fours each with an uneven firing order, though the combined firing order is even.

Link to comment
Share on other sites

3 hours ago, MtB said:

 

It needed it anyway. Look at the state of that left hand big end journal..!!

It sure did, it was from a South African rebuild, it had done very little running after a rebuild before the big end failed, there were bits of shell bearing lying around the sump.

 

 

DSCF0155.JPG

Link to comment
Share on other sites

In fact the only common  parallel twin engines with both pistons rising and falling together were the british twin cylinder motorbike engines .......notorious for vibration so bad that the bikes would fall to pieces.........when the Japs entered the market ,they decided on one up,one down for better balance .....and so the battle lines were set ....and we all know who lost.

Link to comment
Share on other sites

9 hours ago, TheCoot said:

Was the bearing failure due to a lubrication fail, or was it a faulty end shell?

Don't really know why it had failed, given the level of bodging, it was probably due to being very poorly assembled, maybe even bad regrinding, when I checked the bearings and crankshaft there was more taper in the grinding than the specified clearances for the bearing! 

Link to comment
Share on other sites

The picture does not show the result of a lubrication failure- in that event the white metal melts and is sprayed around the crank case to give a sort of sand- textured deposit in line with the failed bearings.  If looks more like a bearing break-up caused by overload or poor fitting.

 

N

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.