Lazeum Posted December 31, 2011 Author Share Posted December 31, 2011 (edited) crankshaft journals have only been polished, no machining on them so everything should be as new - meaning as it was when it went out of the factory, not perfect. Rods haven't been touched, they are stock rods with no work done on them. So Only pistons are not stock on the bottom end. Block wasn't straight so it has been decked (hence the troubles with the head gasket) I'm not building a F1 engine that goes over 10k rpm so I call it a day. The "while I'm at it" syndrom is very true - that's why all parts have been derusted, galvanized/painted/polished or shot blasted, front & rear suspension torn down, bushings have been changed, wheel bearings also, same goes for ball joints, steering has also been reworked, suspension bolts are all brand new, etc. all of this is due to a bad oil pump Edited December 31, 2011 by Lazeum Quote Link to comment Share on other sites More sharing options...
z-ya Posted December 31, 2011 Share Posted December 31, 2011 crankshaft journals have only been polished, no machining on them so everything should be as new - meaning as it was when it went out of the factory, not perfect. Rods haven't been touched, they are stock rods with no work done on them. So Only pistons are not stock on the bottom end. Block wasn't straight so it has been decked (hence the troubles with the head gasket) I'm not building a F1 engine that goes over 10k rpm so I call it a day. The "while I'm at it" syndrom is very true - that's why all parts have been derusted, galvanized/painted/polished or shot blasted, front & rear suspension torn down, bushings have been changed, wheel bearings also, same goes for ball joints, steering has also been reworked, suspension bolts are all brand new, etc. all of this is due to a bad oil pump While you have it apart again, I would have the rods checked and resized if needed. This is key to any rebuild. The rods may be the source if the height difference. I would have your machinist check the pistons as well. Quote Link to comment Share on other sites More sharing options...
Tony D Posted December 31, 2011 Share Posted December 31, 2011 Yes, rod resizing is not an "F1" level of prep. It was standard practice for all rebuilds when I was apprenticing in the late 70's. If rod check/resize is standard on 4500rpm redline flathead Ford and Hercules F-Head four cylinders... Quote Link to comment Share on other sites More sharing options...
Lazeum Posted January 1, 2012 Author Share Posted January 1, 2012 To check rods is very doable. I see no reason not to check them so it will be done. and... happy new year to you guys and thanks for insights on my rebuild, it is always appreciated Quote Link to comment Share on other sites More sharing options...
Tony D Posted January 1, 2012 Share Posted January 1, 2012 Yes, it's more than just the C-to-C distance that can be inspected. Even as little as 0.001" twist in a rod can alter the wearing pattern in the cylinder and get scuffing issues due to thrust being incorrect. Twist, Bend, C-to-C, Big End Diameter, Small End Diameter are the minimum checks I know should be performed. Some places weight match or at least give you the weights of each end and overall. This is more prevalent on V engines and 'rod pairs' but it's always nice to know. That way you don't go 'WOW!' at the next e-bay auction with 900gm forged billet rods knowing yours are really about 1/2 that weight already! Quote Link to comment Share on other sites More sharing options...
Lazeum Posted January 3, 2012 Author Share Posted January 3, 2012 (edited) I've called the machinist. Cost would be 15€ per piston for milling and 14€ per piston for pin removal & install. I end up with a total cost of 174€, not worth the hassle of ordering new head gasket. I'll drop everything tomorrow Edited January 3, 2012 by Lazeum Quote Link to comment Share on other sites More sharing options...
Lazeum Posted January 5, 2012 Author Share Posted January 5, 2012 (edited) Despite risk of damaging pistons & pins during teardown, we've decided with the machinist to give it a try (new pistons would have been as expensive as a new gasket anyhow). They did it carefully with no damage So pistons have finally been milled down by 0.3 / 0.4mm, I'll pick them up tomorrow. Hopefully engine will be built very soon with no more road block... I'll let you know the outcome. They even gave me a rebate from the initial quotation @ 130€. Edited January 5, 2012 by Lazeum Quote Link to comment Share on other sites More sharing options...
Lazeum Posted January 9, 2012 Author Share Posted January 9, 2012 (edited) Since it is never going the way things should go, I have a new situation L Machinist mixed up pistons and as a result, he forgot to machine one piston and machined 1 piston twice. One f the remaining pistons is a little out versus the good ones. Outcome is: - 3 pistons are protruding over deck surface at 0.20mm (0.008â€) which is perfect with Felpro gasket - Piston #1 is 0.13mm (0.005â€) over the deck. I call this one acceptable - Piston #2 is untouched, it protrudes at 0.49mm over deck surface – easy to fix - Piston #4 is exactly at 0.00mm over deck surface, which is not good. I’m concerned I cannot use piston #4 as is since compression ratio is out, weight is not OK, quench (= mix rate) is out compared to other pistons. What would you do? please consider I’m in Europe, - Will 0.2mm height difference on 1 piston change anything, could I leave everything the way it is without being bother? is it safe? - Remachine all pistons to 0mm deck height – quench distance would be 0.9mm (0.035â€) – quite high I’m going to lose engine efficiency and quench benefit - Order one new piston to redo the “bad†one - Leave the engine the way it is – it is even possible??? - Should I worry about piston #1 at 0.13mm? I believe if I order a new piston, I could order a second one to fix piston #1 (maybe!) I need to take a decision. So far, I’m leaning toward ordering new pistons. What’s your call? Edited January 10, 2012 by Lazeum Quote Link to comment Share on other sites More sharing options...
Tony D Posted January 10, 2012 Share Posted January 10, 2012 Your machinist buys you a new piston, machines it correctly, and gives it to you as compensation for his error, and his error alone. Otherwise, you take your parts and don't pay him. Isn't that the way things are done in Europe? If this was in Germany, the machinist would have been apologising that the new replacement piston wasn't already there, and have refunded your money as a general principle for failing in the most basic of apprenticeship skills: Marking those bits with their completed machining numbers! Mistakes will happen, there is ABSOLUTELY NO REASON that you should have to pay for it though. He owes you a piston, machined properly. Quote Link to comment Share on other sites More sharing options...
Lazeum Posted January 10, 2012 Author Share Posted January 10, 2012 (edited) Machinist has been fair with me. They've already proposed to fix everything at no cost, except piston since I'm the one sourcing them. I agree they should pay for them but they believe it is acceptable to have one piston lower by 0.2mm versus the rest and have the remaining piston machined. I disagree since I want the piston to be ok so they've proposed to machine for free 3 more pistons: 1 to get better clearance than current piston #1, 1 new to fix the bad piston & 1 to machine the forgotten one. All and all, it is going to cost me 100€ to fix this situation. I'm probably too nice but 100€ won't change much my budget to restart this engine. On European engine, "quench distance" at 0.3mm is acceptable and they believe I would be also on my engine. So far I'm trusting HBZ more than my machinist so I stay with original plan and 0.022" min clearance (0.6mm). Regarding part marking, they've done it but before and after. Since one piston was missed, there was no in between marking "after" was already there I know: Lame! Edited January 11, 2012 by Lazeum Quote Link to comment Share on other sites More sharing options...
Tony D Posted January 11, 2012 Share Posted January 11, 2012 Of course they will say it's fine. They aren't paid to cut the pistons to THEIR specifications, they were to cut the to YOUR specifications. They failed to do that, and turned a piston into scrap according to YOUR specifications. Tell them they can put the piston in THEIR engine if they think it's fine, but they still owe you a piston. Doesn't matter WHO supplied them, THEY screwed up your part. They should replace it. Quote Link to comment Share on other sites More sharing options...
clarkspeed Posted January 12, 2012 Share Posted January 12, 2012 Yes I agree with Tony here. I'm in Germany right now building engines of a different sort. Parts orders are specified clearly and inspected 100% upon receipt before "ownership". Rejects are responsibility of supplier. Nothing passes through. All of EU pretty much follows this practice. I assumed in earlier post you had already reconditioned the rods. As stated before, it is typically a routine process for rebuilds. So is balancing as far as I am concerned. If you are going to spend the time and money on a rebuild.......? So, if the rods are reconditioned you shouldn't have more than a few thou difference in piston heights. Especially after the pistons are cut. You can mix and match rods to get the final match. But that may be difficult if you are running press fit pins. I never said cut pistons to match. Back to your problem. Machining all pistons to match #4 is a possibility. 0.035" is not excessive clearance and is what many books and builders will recommend. My machinist insists this is the number to shoot for and he builds many race engines, but I don't always listen to him. It's not what you wanted, and I don't suggest you accept this, and I'm not exactly sure you machinist is competent, but it is possible. And to Tony's earlier post, I hardly think it's child's play to run 1:20's at Road Atlanta with a production based car. But you are entitled to your opinion. Quote Link to comment Share on other sites More sharing options...
Gollum Posted January 12, 2012 Share Posted January 12, 2012 If .20mm "isn't a big deal" when why would you have had them machined down a mere .3mm? In essence they're off the mark by more than 50% of what the job was for. I can understand they've been great so far, and that they really don't want to deal with parts they didn't sell. But at the end of the day if ANYONE ELSE had come in and paid the same price to get pistons shaved down and they did the same goof that customer should NOT be paying for that service until a correction has been sorted out. Shops have ate the cost of parts for much simpler mistakes... Quote Link to comment Share on other sites More sharing options...
Tony D Posted January 12, 2012 Share Posted January 12, 2012 @ Clarkspeed: Better re-read my post, I made no reference at all to times at Road Atlanta. I do stand by my 'childs play' reference in the context it was quoted. Fewer people wear The Red Cap than have climbed Everest. Every year Everest gets easier, every year getting a Red Cap gets harder. Quote Link to comment Share on other sites More sharing options...
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