Inside a newly-acquired engine

[Ian Williams]

If its a freshly built engine that has not had the oil changed regularly during the running in period I would suggest that the sludge you have found is to be expected. I would make a few checks for assembly errors that could have been made by the previous owner but otherwise probably an excellent engine. I had problems with two sets JP pistons but that was about 25 years ago now so you would expect those issues would have been solved a long time ago. It seems they were not ground properly and with normal bore clearances seized on gudgeon pin bosses even after extensive running in.

[David Grear]

JP Pistons have WS100 Cast into the piston under the crown( Just above the Gudgeon)

[Bob Culver]

Original solid skirt Austin pistons, which few now would have encountered, were finished round but with a relieved circular area around the gudgeon not extending quite to the lower skirt edge. Some soiid skirt copies were uniformly circular and tended to scuff on the sides due slight rod misalignment and deflection. I have added relief by filing a series of overlapping small flats.

[Tony Griffiths]

JP Pistons have WS100 Cast into the piston under the crown( Just above the Gudgeon)

Thank you for the information. I wonder if I can get an endoscope up there to check?

[Colin Reed]

HI Tony,
Personally i would not expect that amount of gung in the sump from what appears to be a low mileage  engine,
regarding number 3 rod being offset this might just be the photo it looks to have not been machined so that the side thrusts are equal ,
if you do take the rod caps off fit NEW nylocs  as they are One use only.
as Ian said check it has been assembled correctly for peace of mind

Colin
NZ

[Bob Culver]

The grey sludge is similar that seen in engines 60 years ago often after low mileage cold running. If classic oils are truly so and non detergent it may be related. Hopefully no hint of porous cylinders.

[Greig Smith]

You mentioned that this engine may have stood for a long period of time - Regular applications of squirty spray stuff down the plug holes to keep the bores lubricated can result in sludging as most sprays while doing a fair job of lubricating your garden gate hinges can negatively affect oil to a certain degree.... We found gunge in the bottom of the rebuilt '26 Chummy engine after standing for many years & it turned out to be layers of squirty stuff & oil mixed. Cleaned out & the oil pan & motor were perfect.

Charles is spot-on, clean it out & only worry if it returns

Aye
Greig

[Charles P]

JP Pistons have WS100 Cast into the piston under the crown( Just above the Gudgeon)

Thank you for the information. I wonder if I can get an endoscope up there to check?

The cheap endoscope attachement for my phone would do it easily. 

C

[Chris KC]

Looks nice Tony. I guess two things would be in the back of my mind:

1. Why did someone spend a lot of money building what looks to be quite a decent engine and then shelve it for years? (Maybe you already know the answer, but I'd still give it a good once-over).

2. Has any of the gloop from the sump ended up in the pump and oilways?
Even so I reckon a quick flush through should sort it.

[Tony Griffiths]

Looks nice Tony. I guess two things would be in the back of my mind:

1. Why did someone spend a lot of money building what looks to be quite a decent engine and then shelve it for years? (Maybe you already know the answer, but I'd still give it a good once-over).

2. Has any of the gloop from the sump ended up in the pump and oilways?
Even so I reckon a quick flush through should sort it.

Yes, the engine rebuild was completed on 24/11/1998 and the invoice lists parts at £1488 with labour at £15 an hour adding £900 - giving a total of £2574. The main work and parts itemised include a new crank (make unspecified); white metalling; new main bearings; rebore to 0.060" and new pistons; block faced top and bottom; new valves and guides; flattened tapped blocks, and - get this - hardened valve seats. Head faced; new clutch; all studs replaced; replacement exhaust manifold, dynamically balanced, run-in, and two oil changes.
The MOTs until the point where they were no longer needed all show zero miles added - but who knows if the speedometer was working....
I'll certainly give it a very good flush followed by a couple of oil changes.
A letter accompanying the invoice recommended using Castrol GTX or Duckhams Hypergrade - and changing it every 500 miles.