JASKOLKA 1.5cc DIESEL REBUILD

Here's the engine as recieved from Adrian. Lacking compression and with a fair amount of crankshaft main bearing play.

Dismantled and ready to go under the knife as they say.

Adrian mentioned to us that this engine had suffered a broken crank in the past and whilst it had a new crank made and fitted at some stage it just wasn't the same engine anymore. Upon inspecting the case it was found that the damage from the previous crankshaft failure had damaged the bearing face on the inside of the case and the main bearing portion of the case was well worn, so we set it up in the machines and proceeded to remachine in case internals to give a nice clean bearing thrust face and a resized main journal taken out from 8.0mm to 8.5mm in diameter.

Here's the case all ready for the new parts to be fitted up.

Now it's onto the new crankshaft.

Here's the start of the new crankshaft.......

Cleaned up the original prop driver and test fitted to the new crankshaft blank.

Now we check the fitting of everything in the crankcase to make sure they all play nicely together. We also refitted the original N.V.A.

 

Prop is fitted up to test running tightness to confirm that there's enough clearance between the prop driver and case, perfect approx 0.25 mm

O.K. now we know that's all good we'll press on and machine in the big end journal and porting.

And all nicely fitted together again.

Now it's onto the cylinder and piston assembly.

Here's the cylinder liner, relapped and cleaned up with the new piston and contra piston blanks made and ready to final machine and fit.

As per Adrians instructions to "make whatever mods to improve performance you feel  necessary" we took the liberty of lightening the piston somewhat.

Contra piston finished and fitted.

Piston all finished and ready to refit to the con rod and into the engine.

Now it's time to reassemble the engine ready for test running.

Well that didn't quite wotk out how we had planned, upon test assembling the engine we've discovered that our desicion to reuse the orginal con rod was not a good one as it is not quite straight, causeing the piston to bind under compression. So we've decided to just make a new one and then carry on with the reassembly once thats completed.