View single post by Esprit2
 Posted: 09-04-2019 04:17 pm
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Esprit2

 

Joined: 05-01-2005
Location: Minneapolis, Minnesota USA
Posts: 575
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 Have you talked with Gary Kemp about the pistons you have and the compression they will produce? The stroker crank's longer stroke would normally drive any stock pistons too far up the bore, and they would hit the head. To prevent that, either the rods need to be shorter, or the wrist pin bores must be higher up on the pistons (Lotus did that between the 2.0 & 2.2), or a combination of both.

It's possible, that the low compression Turbo pistons would have created a 'high performance' compression ratio with the appropriate length rods on the long stroke crank.

If you do pursue custom pistons, then know before you order just what wrist pin height is required in order to work with the 2.4 crank and whatever the length of the new rods is.

All that comes first. Then allow for the loss of compression due to the thicker composite gasket.

What vintage is the 910 block you have? If before Jan 1993, then it has the old, higher deck height, so the composite head gasket will lower the compression ratio about half a point.

If the block was produced after Jan 1993, then the deck height was cut 0.5mm / 0.020" lower to allow for the thicker composite gasket.

All that needs to be coordinated in order to successfully build a composite engine out of a mixed bag of parts.

The easiest 'out' would be for you to put the Monkey on Kemp's back to provide you with the correct pistons to work with everything else he has already sold to you.

Regards,
Tim Engel


Max_dvdt wrote:
Sorry Tim - not a Turbo...

its a 910 block from Gary Kemp
with a 2.4 stroker crank

Gary made a slight oops and I ended up with a set of Turbo pistons which when I get to that bit will not give me the compression I want- so for about 30 minutes I entertained a supercharger.. but decided in the end to have a set of custom pistons made (path of least resistance)

What I bought:
the 2.4 crank
some billet con rods
the turbo pistons
and nikasil liners

easiest path I see is to just get some custom pistons. I'm guessing that between the crank and conrod billetyness and the nikasil liners a set of stock pistons wont work

Last edited on 12-31-2019 03:50 pm by Esprit2