Sorry Nigel, My Zetec knowledge didn’t get as far as the black top. Are the pistons you are using at the moment standard black top ?, if so it might be easiest (and cheapest) to pick up a low mileage bottom end and fit that. Do you know why the piston failed ? My ZVH is running skimmed (0.5mm i think it was) standard silver top pistons and Ex Mathews 2.0 Zetec turbo is running standard pistons with a decompression plate and has lasted way longer than it did when we built a bottom end with forged pistons and rods. One thing you do need to do if using NA pistons in a turbo is check the ring gaps and make sure they are big enough, otherwise since a turbo runs hotter, they can expand until there is no gap left and then jam in the bore.
I know some forged pistons come with the crown unmachined and you machine it down to give you the compression you desire. We never really worked out what happened to Mathews engine with forged pistons (made by Probe Industries in the states) . The pistons picked up in the bores and scored them, not sure if the bores were undersize, the pistons were oversize or it just suffered from oil starvation. I’ve still got the pistons, rods and block, one day i will measure it all up and try and figure it out. Jim From: Nigel Plant Sent: Thursday, March 25, 2021 12:15 PM To: Quantum Owners Group Subject: [Quantum Owners] 2L Zetec Blacktop Pistons Probably one that's right up Jim's street. Does anyone have the Ford specification for 2L Zetec blacktop pistons. Need gudgeon pin diameter, compression height essentially all the key dimensions. I have broken a piston on my Xtreme turbo such that it needs reboring and cannot get any standard but oversize pistons. Am also told that Nural and Mahle have no production plans to manufacture any. I can get forged pistons and rods, which would be better performance wise but didn't want to drop compression to 8:1 or fork out £1200. 9:1 is my ideal for the power I want. I have found a custom piston manufacture for forged pistons alone, but they require a piston (no problem) and the key specs. For information, I have learnt one interesting point that people may find useful. Although the silvertop and black top have different length conrods (ctr to ctr) and different compression heights. The combined total of conrod length and compression height for the silvertop and blacktop are the same, meaning a set of silvertop conrods and pistons can be used to replace the blacktop ones. Thanks for any help on the specs. Nigel Plant -- -- You received this message because you are subscribed to the Google Groups "Quantum Owners Group" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/quantumowners?hl=en IMPORTANT NOTE: All information presented herewith is provided on an "As Is" basis, without warranty or the implication thereof. Neither the Quantum Owners Club nor the individuals associated with the Quantum Owners Club or in the preparation of the above information shall have any liability to any person or entity with respect to liability, loss, or damage caused or alleged to be caused directly or indirectly by the instructions contained within this or related message(s). --- You received this message because you are subscribed to the Google Groups "Quantum Owners Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/quantumowners/f7746385-3a1a-4d8c-b901-f6b726a67128n%40googlegroups.com. -- -- You received this message because you are subscribed to the Google Groups "Quantum Owners Group" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/quantumowners?hl=en IMPORTANT NOTE: All information presented herewith is provided on an "As Is" basis, without warranty or the implication thereof. Neither the Quantum Owners Club nor the individuals associated with the Quantum Owners Club or in the preparation of the above information shall have any liability to any person or entity with respect to liability, loss, or damage caused or alleged to be caused directly or indirectly by the instructions contained within this or related message(s). --- You received this message because you are subscribed to the Google Groups "Quantum Owners Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/quantumowners/6C131B08AD0F471986132917E849B5D6%40JimQuad.
