Funny Funny

[Mike Farmer]

 

My recently rebuilt A65 bottom end is very smooth and turns easily in the normal direction of rotation, but its got a tight spot when I try to turn it backward. I dont want to start dismantling unnecessarily.

Any ideas Please. I've got an awful feeling about the oil pump fitting. I can't imagine its the pump because thats a brand new SRM pump.
Therefore gents any ideas here will maybe save me some time and swear words.

Mike

[geraldhattrick75]

Is the tight spot in sequence with the oil pump rotation, or is it more in keeping with engine rotation?

Timing side gear meshing?

What stage of engine build are you at? (fully rebuilt? Just bottom end?)

If fully rebuilt, have the spark plugs been removed?

Good luck,
Dave

[Mike Farmer]

 

All good points.

Bottom end at this stage. I suspect the oil pump fitting and in truth I now think its going to boil down to the washer between the pump  drive spiral gear and the main drive gear, in that I may have inadvertantly put the wrong washer in. If that the case---read cockup.
Let you know.

Mike

[chaz]

how does it feel without pump on? same or free,

[geraldhattrick75]

I now think its going to boil down to the washer between the pump  drive spiral gear and the main drive gear, in that I may have inadvertantly put the wrong washer in. If that the case---read cockup.

Welcome to my world....

[Mike Farmer]

 

Hi Chaz. It certainly appearred to be OK before I fitted the pump but I can't honestly say that I turned it backward.

Mike

[DAVE BRADY]

Hi Mike,

Have you fitted the pistons and cylinders?

Dave.

[Mike Farmer]

 

No to cylinders/pistons.

My course of action now is to remove the idler pinion and see if that makes a difference i.e. eliminate cam shaft.
If it persists then start looking at the oil pump assembling and see if I have something wrong.

Let you know.

Mike

[DAVE BRADY]

Hi Mike,

A few basic questions.  Does the crank just have a tight spot or does it stop rotating backwards completely?  Obviously removing the pump drive and or idler will eliminate or implicate the pump or cam.  With no pistons and cylinders fitted it is possible when rotating the crank by hand to not keep the small ends central to the crank.  This can result in the in the big end nuts catching the crankcase and by chance this has only happened when turning it backwards.
I see you have described it as a tight spot so my suggestion may be moot but eliminates a possibility.

Dave.

[geraldhattrick75]

Another thought (as if you needed one...) changing the direction of rotation will cause the load on the oil pump drive to either try to move in or out. And, if the washer you fitted allowed a bit of slack,- might that movement cause the tight spot?......

Good luck,
Dave.

[Mike Farmer]

 

That is seriously likely.

All will be resolved eventually, then I shall have great joy in publishing my result, folly or otherwise

Mike

[Mike Farmer]

 

Well I've got it sorted. What was it??I haven't got a clue except that it was at the oil pump. I suspect either the washer was a smidgen thin or I overtightened it. In truth I am coming down in favour of heavy handed.

So there tis, sorted. Thanks to all for your input. Now I can fit the primary drive etc and  pistons and cylinders and get the motor into the frame.

Mike

[geraldhattrick75]

Excellent news Mike.

Get the rest of the ironmongery built and placed in the correct location (exhaust stubs facing forward).

Don't rush anything. In fact double check absolutely everything.....

It's not that I don't want you to make any mistakes- I just don't want you showing me up by starting your engine before I do mine. (I've been dragging my heels for 20- 24 months)

Best of luck,
Dave

[Mike Farmer]

 

I bought this in 2014 as a quick project.

Mike

[geraldhattrick75]

Nice one Mike. Makes me feel a little better....