Help with 2.7 Nikasil Piston and Jug
 

Hi

I need some help please folks! my 1976 911S (2.7) started smoking the other day.

Following a low compression on jug #1 (25psi) compared to the others (165psi) a tear down of #1 has uncovered damage to the jug and piston.

Unfortunately with very limited funds (and time!) I want to resort to just replacing (or reweld and replate the damaged jug) and piston. They are a 11 fin Mahle with shiny finish so 99% cetain it is a Nikasil set.

The car is a definately no show queen and has lots of miles under it's wheels so not too precious about chucking a second hand part in to get it back on the road.

Does anyone have either a spare used piston and or jug to get me out of this deep hole!

Happy to pay and cover shipping to UK - would be a life saver (the car was bought from Pelican Parts for sale page so a true P.P car!)

Thanks, Jackhttp://forums.pelicanparts.com/uploa...1625127876.jpg

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The casting numbers inside the piston decrees the cylinder
90L58 is nikisil
90L61 is mahle alucil
In 2.7, Mahle made both types
If you’re going to be curious about used send the cylinder out and get it re nikisiled
My take on it is weigh the piston so you know what to balance to, match the cylinder specs triangle 5 or 6 and stamped size 0, 1, 2.
There is plenty out there…
Bruce

I have a few 2.7 pistons. PM sent

I'm in the UK and have a new 2.7rs nikisil cylinder you can have, unfortunately no piston. It has one cracked fin but is brand new and the fin wont affect usage. We had a 2.7rs nut and bolt resto and obviously couldn't use it due to the cracked fin, despite it not causing any problems. PM me your address and I'll send it over. Obviously check your other 5 cylinders and made sure the specs are the same, if they are not you can still match the heights etc...

That bluish tint to the aluminum cylinder sure looks like an Alusil to me.
Check it with a magnet

IIRC the 10 vs 11 fin count only works on 3.0-3.2 cylinders.
Use the magnet, nikisil has a very slight pull, alusil has nothing.

yup your are correct it is alusil, just rechecked.

I have been gifted a nikisil barrel (brand new) I assume it won't make any difference putting that on with a new matching piston as long as the heights, weights, etc match up to get me back on the road?

Long term plan when funds allow will be completely strip the engine and build back at RS spec.

It wont make any difference so long as the barrel heights are all the same. If not the cam tower wont be flat and your cam will be tight. There might be some variation in heat up and cool down expansion rates, but not enough that you wouldn't use it to put the car back on the road.