911T 2.2 cylinders sloppy

[stephers]

Hi,

Need some help. I have a 71 2.2 T engine 84mm bore with cast iron cylinders but when I put the cylinders into the case for a trial fit, the cylinders are quite sloppy, this can't be right, can it? I have checked Wayne's book in the appendix for sizing and it all seems to be OK Will have to measure the case bore on the 2.2 tomorrow but does any one know what it should be, I don't think that this case was bored because it has the 84 mm pistons with it

Please help, I am getting eyestrain looking at all the different threads on spgot sizing

Thanks, Rick

[tom1394racing]

The case spigot bore for the 84 mm cylinders should be 92 mm.

[stephers]

Hi Tom

Thanks for the reply, the barrels measure out to 91 mm on the spigots, 84 mm bore, they fit nicely over the piston but will rock in the case bore Engine numbers are 911/07 901 101 102 3R serial # 6116737 From what I can tell it is a 2.2 T engine

How tight should the cylinders fit into the bore, I have always assumed snugly

What Am I missing here?

Thanks, Rick

[tom1394racing]

Rick

The spigot bore should be 92 mm. The base of the cylinder that slips into the case is also 92 mm and is sized for a slip fit into the spigot. There should not be any significant wiggle. If you insert the cylinder all the way into the case, so that the 92 mm shoulder at the base of the cylinder slips into the spigot, you should find a nice tight fit.

Note that my hand held caliper measurements in the attached photos are approximate.

[stephers]

Hi Tom,

Yes, I am a complete idiot, working too late at night or need new glass's I wasn't putting the cylinder all the way down on the shoulder DUH!!! Once I was awake and fitted the cylinder ALL the way down onto the shoulder, everything was fine

Quick question, what is the maximum bore that you can get out of a 84mm cast iron cylinder, also have a set of Alusil cylinders, how much can they be bored out safely?

Thanks, Rick

[tom1394racing]

84 mm cylinders can be safely bored to 86 mm. JE and others make pistons for this application.

A 90 mm Alusil cylinder can be bored and Nikasil plated to 92 mm. A 95 mm 3.2 cylinder can be bored and Nikasil plated to 98 mm. The 95 mm 3.0 SC cylinders are limited to 95 mm because anything larger compromises the integrity of the CE ring groove.