2L Zetec Blacktop Pistons

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Nigel Plant

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Mar 25, 2021, 8:46:46 AMMar 25
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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

susanandmartin

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Mar 25, 2021, 11:28:04 AMMar 25
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Not that it helps with your quest, but (hopefully) of interest.

When I was working at Ford we had an engine being tested for cold start durability at a University. As proof (if it was ever needed) that starting an engine repeatedly from cold with a fuel-enriched intake mixture would wreck an engine, there was a need for new pistons after several months and x000’s of start procedures. When trying to source new pistons, however, it was found they were not listed as a spare and could only be bought with an engine block. As this wouldn’t help our engine block durability testing, great discussions ensued taking several hours and it was agreed some pistons could be supplied direct from the assembly line (maybe one car was released without pistons? 😊). This is a good example of how Ford goes to great lengths with their testing (and probably other manufacturers do as well).

Martin Scott

 

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Jim Hearne

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Mar 25, 2021, 12:20:58 PMMar 25
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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
 
 
 
Sent: Thursday, March 25, 2021 12:15 PM
Subject: [Quantum Owners] 2L Zetec Blacktop Pistons

Jim Hearne

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Mar 25, 2021, 12:23:31 PMMar 25
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As you say, i don’t think Ford sells pistons for a Black top Zetec as a spare, they want you to replace the whole bottom end.
The Zetec SE is the same.
 
Jim

Nigel Plant

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Mar 25, 2021, 2:36:23 PMMar 25
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Thanks Jim, will respond to your other later, some interesting points! Oversize pistons for blacktop are quoted for on plenty of web sites, but are never available. Supplier calls the manufacturer and they all come back with same story.
Regards

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list...@liberator-systems.co.uk

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Mar 26, 2021, 12:37:16 PMMar 26
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I was planning to drop a 2.0l blacktop and possibly turbo into my saloon. This piston availablity issue is making me think twice. Is it the same problem for the old silvertop? How many manufacturers are there for standard type pistons? Wondering how the engine reconditioning businesses source their pistons.

John

Jim Hearne

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Mar 26, 2021, 12:45:22 PMMar 26
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I remember all a lot of engine re-conditioners needed was a pressure washer and a can of black spray paint...
Fixes all problems...
 
Does anybody get an engine reconditioned nowadays ?,  i think most normal cars would be scrapped if they needed a engine rebuild, either that or another s/h engine  fitted.
 
Jim

Jim Hearne

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Mar 26, 2021, 12:48:45 PMMar 26
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Actually, i think only the good ones used the pressure washer before the black paint.
 
Jim

Derek Clews

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Mar 26, 2021, 12:51:44 PMMar 26
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I have had contact with specialists in Coventry.  They seem to be more into racing and modifying as the main workstream but would help with or build whatever you wanted.   Also had a gearbox reconditioned around five years ago and that was fine.  Tried looking at reconditioning a starter motor but decided it was not worth it. 

Derek  

Nigel Plant

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Mar 26, 2021, 1:09:23 PMMar 26
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Silvertop oversize pistons are readily available.
I think mine failed due to about 20 track days approx 10 with turbo and too much fuel at start up. I also ran with standard compression and there was significant evidence of pre detonation particularly on the #3 piston which failed. However I dont think it was significant enough to be the cause. I dont yet have the piston, so haven't inspected it in detail.
I do have a second engine but that has worn bores. One option is to use that but with the block sleeved so I can reuse those pistons. Does anyone have experience of sleeving, I dont, so am hesitant to go that route.

Jim Hearne

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Mar 26, 2021, 1:20:39 PMMar 26
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Detonation will kill a turbo engine really quickly.
And running standard compression it’s going to detonate at anything above a tiny level of boost.
What boost were you running ?
I assume it has a aftermarket ecu ?, does it have a knock sensor on it ?
 
Not really heard of sleeving being used on a cast iron block but i guess it’s possible.
The joint between the sleeve and the block may reduce it’s heat transfer ability which is of course just what you don’t want.
 
Jim
 
 
 
 
Sent: Friday, March 26, 2021 5:05 PM

list...@liberator-systems.co.uk

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Mar 26, 2021, 2:24:32 PMMar 26
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@nigel
My big bore cvh motor is linered according to Power Engineering who did the engine conversion work. It hasn't blown up yet although as I said earlier I was planning to replace it with a 2.0 zetec blacktop  for easier power increases - may need to re-think that if blacktop piston availability is an ongoing issue.

@jimLOL your comments re engine reconditioners - there are certainly some dodgy ones. To be fair there are also some decent companies - I have been inside several - impressive machinery and skiled folks operating them.  Of course s/h engine is always going to be the cheapest option but most are an unknown quantity - even if you get a short guarantee you can waste a lot of time installing only to discover it has problems and has to be pulled out again....

John

Nigel Plant

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Mar 26, 2021, 6:03:24 PMMar 26
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To answer some of the questions, think mainly Jim's:

There is a lot of history to my turbo zetec. Too much for here, however will try to pick out relevant points.

My original aim for the turbo was significant performance increase at a decent price and push the boundaries a little.  The engine originally cost £150 with 30k miles and had done about another 30 in standard form. I wasn't worried about the engine at that price and general consensus was that at LP the zetec would be OK with 8psi boost. I designed and made my own manifold and modified an intercooler etc. I decided on using a Chinese Garrett copy turbo. Why? Because when I investigated,  noone could tell me how good they were, based on data and evidence. Everything was heresay. I wanted to know so I used one and at £150 was essentially disposable. Anyway the turbo worked fine no lag and great performance. On the RR it pulled about 240bhp and 240 ft lb torque.
It did a number of track days, but finally cried enough at Snetterton, when a chufgjng noise and heavy crankcase pressure indicated a compression issue.
At the time I bought a second engine from a breakers, stripped and rebuilt, with a spreader plate to reduce compression to 9:1. This was intended as a temporary configuration to drop the compression to a safe level, with no real loss of non turbo torque or turbo lag. This configuration was successful, but the engine was tired and obviously had done a lot more mileage than the claimed 80k.
So recently I set about rebuilding the original with the intent of finding the problem and rebuilding to a good and reliable standard.
The current issue is:
Engine 1: scored bore and one broken piston.
Engine 2: worn and oval bores, good pistons.

My first choice is to get the custom forged pistons made through Cambridge motorsport that use the standard rods, with a plan B of forged pistons and rods with silvertop con rod lengths and compression height. .
Sorry for the long post and trust me this is very much abbreviated.

Nigel 


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