3 replies to this topic

[sam138]

Just wondering if someone could help please with a diagnosis on my 1380cc engine. It’s done around 500 miles since fully rebuilding. Upon use at the weekend I noticed smoke coming from the transfer case breather.

Remove spark plugs which showed cylinder 3 and 4 with some oil on the plug. Done a compression test which showed the below.

1 - 190 psi
2- 190 psi
3 - no compression when dry then with small amount of oil 210psi
4 - 205 psi dry test - did not add any oil to this bore

I’ve attached some images of cylinder three from an endoscope check with spar plug colours, does this look like bore wash which has caused this ?

Would this mean a full strip down and hone/ new rings ?

Engine spec as follows

1380 block offset bored
Powermax 73.5mm pistons 20659
All new bearings and centre main strap
Ac Dodd Rs camshaft with new followers
Minispares MSE 4 head
1.5 forged rockers
ST2 MED clutch kit
Guesswork fully rebuild helical box with minispares x pin diff


Oil pressure around 65 psi on start up and 40 when hot idle with 50-60 psi around 2-3k rpm

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Edited by sam138, Yesterday, 08:56 PM.

[Earwax]

Was it running any differently - ie did you also notice it was running on 3 cylinders. Transfer case breathing is typically pressure lower down, not at the head  but  I would run it up to temp - go up a hill and feel the pulling power, take off lead 3 and feel the pulling power just to ensure your compression reading isn't inaccurate. 

[sam138]

Was it running any differently - ie did you also notice it was running on 3 cylinders. Transfer case breathing is typically pressure lower down, not at the head  but  I would run it up to temp - go up a hill and feel the pulling power, take off lead 3 and feel the pulling power just to ensure your compression reading isn't inaccurate.

Before I actually noticed this when I returned home with the car it was running fine with no sign of lack of any power whilst driving.

Could I try the plug lead off to see if the engine cuts out or starts running rough to tell if running on three cylinders ?

[Earwax]

Yep pull a lead , - for one or two cylinders down _ (if Head Gasket related it is often the middle two - so pull lead 2 then replace pull lead three and i would even check the leads and spark plugs through elimination - always good to x things off a list) but if it is rings only the one cylinder -- - but crossed fingers it is not anything dire.       Note there could still be a potential problem with valve stem seals or ring seal or plug fouling up - but you can often live with those things for a while , whilst keeping an eye on them.  If the engine build was outsourced - it would be good to run the situation by the engine builder