Thread: Engine re-assembly techniques

Thanks dave that would be good If you cam give a run down on your findings...I haven't used them or bothered watching the fitters at work use them so looks like ill be finding out very soon...

Plastigage measurement is the one stage I didn't photograph but all the others from the build are here. It's dead simple to use, and remarkably informative. Out of interest I had one crank to bearing clearance that didn't match the others. I disassembled it, turned the crank 90° and tried again only to find the same result. It was only a tiny difference but I was curious to see what the effect was.

The full rebuild picture thread is here.

https://www.youtube.com/watch?v=Q3Qm7vRoPKo

The bits missing from my photos are covered here. Plastigage is dead simple to use and only involves another couple of hours to check everything if working very slowly. I did every bearing clearance on the crank and rods, each one by one.

It's easily removed with a single wipe of clean cloth and prepsol / wax and grease remover.

esentially

clean dry and blow dry what you're assembling
(using con rod big ends as an example)

conduct the nip check, swap bearings until the nip check comes up as a pass (or surface grind the mating faces (if permissable) and rebore before repeating)

• place a section of plastigauge parallel to the crank axis (it should sit about .5mm clear of the journal relief grind on both sides
  EXTRA CAUTION REQUIRED FROM NOW- Do not permit rotation of the bearing being measured on the crank
• seat the rod side shell in the rod and offer up the rod to the crank journal from the underside
• install the cap and torque the cap bolts to the nominated check torque (usually full tension but some torque to yield systems permit the use of only the first +angle tensioning to allow reuse of the new studs)
• remove the cap
• on the edge of the plastigauge package is a scale compare the thickness of the gauge to the pattern on the scale.
• the section of the scale that is the same thickness as the squished plastigauge gives the nominated clearance value.

wipe off the plastiguage oil the bearing face and re-assemble, paint mark/lockwire the cap nuts to indicate assembly complete

In the bad old days we "threw" together a falcon 6 from old parts and a bit of luck.
Even "ported and matched" everything using a diegrinder.

Nothing measured nor checked. Just plenty of oil.

The damn thing was a weapon and ran sweet for 3 years before selling the car.

Originally Posted by Tombie

In the bad old days we "threw" together a falcon 6 from old parts and a bit of luck.

Been there.... Amazing how far an out of spec engine will go.

Anyone here use the "Tally Ho" method of bottom end maintenance? With one or two layers of cigarette paper under each big end bearing shell, a penniless lad (me) could get a few rattle-free months out of an engine before having to open it up again.

Can't say I've done that one...