need some help indentifying pistons/liners

[lotus-62]

Hi, I have an 912LC engine in my '85 esprit s3 N/A however I came across a invoice in the car’s history for an engine rebuild (60000mls into his life and 13years / 20000mls ago) it is a 4500 pound bill and there is a note “1397 pound for special high comp pistons and steel liners” but no more information than this. I don’t want to open the engine yet but need to take the head of this winter. Is there a way to indentifying them looking from the top?

thanks, rick

[andydclements]

Easiest way (for genuine parts) is the thickness of the liners (ali ones for HC are thicker than iron), but when you look down the bores it should be apparent, the ali ones with the coating will appear shiny (with honing marks) but not metalic whereas the iron ones wil look like polished meatal (assuming all trace of honing marks will have gone).

The pistons are identified by the cut-outs for the valves. best to post an image of one showing the valve areas of the piston crowns if you want somebody to confirm they are the HC ones..

[lotus-62]

I hope the honing marks are still there after only 20000mls .lnvoice had "steel liners" on it so maybe it is after market......

thanks, rick

[andydclements]

In which case it will just be by piston identification.

[richardvg]

interested to see how the engine turns out.Bearing in mind the excel engine had 20 more kw than the 907 in the esprit...

[andydclements]

There was very little difference in power outputs whether fitted to the Excel or Esprit, any difference was really just due to air ducting in and exhaust configuration, but that would be minimal difference as we are still looking at the same manfilds being in use.

The extra 20 Hp was only realsied when the NA went from LC (or original compression ratio) to HC and with it got a few other tweaks (changes water flow to resolve kettling near one cylinder, improved gas flow, changed exhaust manifold design, adjusted carburation)

[lotus-62]

well I am going for fuel injection and a better exhaust mani. some port matching/cleaning but thats it.looking for 170-180 bhp