anthonym Posted March 19, 2019 Share Posted March 19, 2019 Anyone any idea how to identify which type my car has? Apparently it's to do with the manner of connection of the conrods to the pistons - one is "pressed" the other is "floating". I am going to put a camera down the spark plug hole and take some pics, but only hope against hope this offer some evidence of the piston type - whereas really I would need to see upwards from underneath and I can't think of a way to poke an endoscopic camera in there - oil hose aperture? Anthony Link to comment Share on other sites More sharing options...
rj Posted March 19, 2019 Share Posted March 19, 2019 You can remove the dry sump pan, but even if you do you'll struggle to get evidence. You'd need to see if there's a bushing in the small end of the conrod.The circlips locking will be on the side of the pistons.Why is it important to know?I think Oilyhands can modify your conrods if they are the fixed pin type.I'm going to modify a (new old stock) set of Omega pistons on Friday, but you are not likely to be able to remove a fixed pin without damaging the pistons. Link to comment Share on other sites More sharing options...
anthonym Posted March 19, 2019 Author Share Posted March 19, 2019 Considering refresh, and for that it will need pistons this time ("they" said last time, now ten years ago), and availability is always an issue every time I explore this. What's the score with these things? Link to comment Share on other sites More sharing options...
Leadership Team SLR No.77 Posted March 19, 2019 Leadership Team Share Posted March 19, 2019 If the pistons are still in the engine why do you need to know? If you plan to replace them you’ll know what they are when they come out.Stu.Must type faster! Link to comment Share on other sites More sharing options...
anthonym Posted March 19, 2019 Author Share Posted March 19, 2019 When they come out is too late. Link to comment Share on other sites More sharing options...
rj Posted March 19, 2019 Share Posted March 19, 2019 Buy a new set of rods for floating pins and then new pistons. Link to comment Share on other sites More sharing options...
anthonym Posted March 19, 2019 Author Share Posted March 19, 2019 d'ye know I was wondering if that was the sort of solution I could employ. Are floating pins a better solution than fixed? i.e. it's an upgrade? Link to comment Share on other sites More sharing options...
rj Posted March 19, 2019 Share Posted March 19, 2019 It is a lot easier to replace the pistons with floating pins Link to comment Share on other sites More sharing options...
oilyhands Posted March 20, 2019 Share Posted March 20, 2019 It’s highly unlikely that the pistons are fully floating if they are the originals as the Cosworth pistons did not come with circlip grooves and the rods as manufactured by Farndon were not bushed as supplied. A clue can be garnered by looking for blue discoloration at the small end of the conrod which would indicate the rod has been heated to fit the pin with an interference fit. This would require the sump to be off and a powerful torch.The pistons can be removed without damage given the right equipment, however following removal the rod interference fit is compromised and is not safe to reuse. The rods can be bushed to convert to fully floating and the pistons can be machined in the pin tunnels to allow circlips to be fitted. It is probably easier and not much more expensive to go with new steel rods which are already bushed as these will also have new ARP bolts.Fully floating is the best way to go when RPM goes over 7500.Oily Link to comment Share on other sites More sharing options...
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