Author
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Topic: Piston Flycuts??
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67fastback2+2 Journeyman Posts: 30 From: Pennsville,New Jersey Registered: Oct 2001
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posted 02-03-2002 10:56 PM
I have 8-Clevite 224-2108.060 / 9-1177.060 Pistons for my 67 289 . Being new at this and trying to learn could someone tell me why every piston is cut differently at the top and one even looks like a different material. This may be the norm but I don't want to be getting taken advantaged of either IDGI Pete
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SteveLaRiviere Administrator Posts: 20031 From: Saco, Maine USA Registered: May 99
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posted 02-04-2002 08:31 AM
Were these new?------------------
'70 Mustang Mach 1 M code 351C 4V/FMX/3.25 open '72 Mustang Sprint Coupe 351C 4V/FMX/4.30 Trac Lok '94 F-150 XL 5.8L/E4OD/3.55 Limited Slip '97 Probe GTS 2.5L DOHC MCA Member # 47773 Of all the things I've lost, my mind is what I miss the most.
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67fastback2+2 Journeyman Posts: 30 From: Pennsville,New Jersey Registered: Oct 2001
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posted 02-04-2002 10:08 AM
Yes Steve, They were ordered thru NAPA Auto parts on the advice of the machinist. He said these would raise my compression but I could still run Premium gas
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SteveLaRiviere Administrator Posts: 20031 From: Saco, Maine USA Registered: May 99
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posted 02-04-2002 11:52 AM
They should all look identical, and made of the same material. This is out of the box, meaning nobody has flycut them yet?What does your machinist say? He's the best one to ask since he can take a close look at them. ------------------
'70 Mustang Mach 1 M code 351C 4V/FMX/3.25 open '72 Mustang Sprint Coupe 351C 4V/FMX/4.30 Trac Lok '94 F-150 XL 5.8L/E4OD/3.55 Limited Slip '97 Probe GTS 2.5L DOHC MCA Member # 47773 Of all the things I've lost, my mind is what I miss the most.
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67fastback2+2 Journeyman Posts: 30 From: Pennsville,New Jersey Registered: Oct 2001
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posted 02-04-2002 07:48 PM
My shop man says that they were shipped from all over as they are a special size(.060) and were made at different plants but to the same specs. He assured me that even though the 1/2 moon cuts appear different all is well. Does this sound about right.Or is it possible I'm being paranoid.
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SteveLaRiviere Administrator Posts: 20031 From: Saco, Maine USA Registered: May 99
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posted 02-04-2002 08:27 PM
Well, it's not optimal, but it should work. Are you having the engine balanced? ------------------
'70 Mustang Mach 1 M code 351C 4V/FMX/3.25 open '72 Mustang Sprint Coupe 351C 4V/FMX/4.30 Trac Lok '94 F-150 XL 5.8L/E4OD/3.55 Limited Slip '97 Probe GTS 2.5L DOHC MCA Member # 47773 Mechanic's creedo: If it jams, force it. If it breaks, it needed replacing anyway.
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SteveLaRiviere Administrator Posts: 20031 From: Saco, Maine USA Registered: May 99
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posted 02-04-2002 08:37 PM
Just how much do they differ? Can you post a pic?What kind of engine are you building? Stock, warmed over, Street/strip, drag? ------------------
'70 Mustang Mach 1 M code 351C 4V/FMX/3.25 open '72 Mustang Sprint Coupe 351C 4V/FMX/4.30 Trac Lok '94 F-150 XL 5.8L/E4OD/3.55 Limited Slip '97 Probe GTS 2.5L DOHC MCA Member # 47773 Mechanic's creedo: If it jams, force it. If it breaks, it needed replacing anyway.
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Boss302 Journeyman Posts: 8 From: Registered: Jan 2002
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posted 02-04-2002 08:46 PM
i'm no genious, but i think that one should be exactly the same as another
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67fastback2+2 Journeyman Posts: 30 From: Pennsville,New Jersey Registered: Oct 2001
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posted 02-04-2002 09:33 PM
I was sticking to the plans Alex had posted, 270 H cam, roller rockers, SS tapered valves, bored.060 over, except for the pistons. I will put up pics tomarrow. I will not be racing it but must have the power and lope like when we were younger. Guess it's something to do with turning 40..
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richard bohm Gearhead Posts: 260 From: Registered: May 2001
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posted 02-04-2002 11:36 PM
have the rotating assembly balanced. this will prevent any problems from the pistons being different wieghts. when you assemble the motor check the valve to piston clearance on each cylinder. this will prevent problems of differing valve notches. it will take longer this way but in the end you will prevent having to rebuild the motor again.
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Ryan Wilke Gearhead Posts: 561 From: Stanton, Michigan Registered: Oct 2000
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posted 02-05-2002 06:56 PM
Hey Guys: If Pete has the rotating assembly dynamically balanced it will "correct" for any weight differences that may exist between the different looking pistons; but if the tops are cut differently, won't these combustion chamber volume differences make for different compression ratios in each cylinder - causing an imbalance of power production?
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67fastback2+2 Journeyman Posts: 30 From: Pennsville,New Jersey Registered: Oct 2001
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posted 02-05-2002 09:50 PM
Hey Fellas, I wasn't able to get pics today. I did E-mail Dr. Dipstick( help line @ Clevite Pistons) but no answer yet. All the cuts on top of each piston are different.. I don't know what is mean't by balancing? Is thier a way of finding out the volume to see if each might come out the same?? I don't want to have done all this work and then find out things are not right. Thanks for all this help!
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SundanceKid Gearhead Posts: 480 From: UT Registered: Feb 2001
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posted 02-06-2002 01:08 AM
IMHO The pistons better look the same, better be within .5 oz. of each other 1 oz. max! If they were made by differant manufacturers they can (will) not be matched. I'd like to see that pic when you get it. Seems fishy to me. Did the machinist Fly cut them? Or did they come from the four corners of the earth that way? At the very least I'd have the pistons matched.
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SteveLaRiviere Administrator Posts: 20031 From: Saco, Maine USA Registered: May 99
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posted 02-06-2002 02:26 PM
That's why I asked if this was going to be a high performance application. A little difference in the notches is no big deal in a stock rebuild, but it's a big deal in a high performance application. {when I worked as a tech, I did a lot of engine work and you should have seen what I got for replacement pistons. Many times they weren't even close to what the engine had in it, and GM did not pay to have all pistons replaced, just the failed one[s]. 67fastback2+2, in balancing an engine the reciprocating {pistons and connecting rods} parts are made to all weigh the same, and the bobweights on the crankshaft are ground or heavymetal {mallory metal} is added to match the weight of the reciprocating parts. This reduces vibrations which helps produce more power and is easier on parts. Every engine should be balanced when rebuilt, in my opinion. It's a good investment. ------------------
'70 Mustang Mach 1 M code 351C 4V/FMX/3.25 open '72 Mustang Sprint Coupe 351C 4V/FMX/4.30 Trac Lok '94 F-150 XL 5.8L/E4OD/3.55 Limited Slip '97 Probe GTS 2.5L DOHC MCA Member # 47773 Mechanic's creedo: If it jams, force it. If it breaks, it needed replacing anyway.
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SteveLaRiviere Administrator Posts: 20031 From: Saco, Maine USA Registered: May 99
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posted 02-06-2002 02:34 PM
quote: Originally posted by 67fastback2+2: Is there a way of finding out the volume to see if each might come out the same??
Yes, it's called CCing the piston tops. For domed pistons, you lay out some Play-Doh and make impressions with the piston tops and use a buret to see how much liquid is needed to fill them. Dish pistons can be checked without Play-Doh. If you can get some pics, we'll really be able to tell you what we think. ------------------
'70 Mustang Mach 1 M code 351C 4V/FMX/3.25 open '72 Mustang Sprint Coupe 351C 4V/FMX/4.30 Trac Lok '94 F-150 XL 5.8L/E4OD/3.55 Limited Slip '97 Probe GTS 2.5L DOHC MCA Member # 47773 Mechanic's creedo: If it jams, force it. If it breaks, it needed replacing anyway.
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Ryan Wilke Gearhead Posts: 561 From: Stanton, Michigan Registered: Oct 2000
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posted 02-06-2002 06:25 PM
#1) If the "acceptable" weight difference between pistons can range from 0.5 to 1.0 ounces in a street engine buildup, what is the "acceptable" range for a Street/Strip engine seeing 7K+ rpms?#2) When looking at different shaped/sized piston valve reliefs, what is an acceptable range of volume [cubic centimeters (cc)] differences in combustion chamber volumes between each cylinder in a street engine - or a race engine? Still learning,,,, Ryan
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SundanceKid Gearhead Posts: 480 From: UT Registered: Feb 2001
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posted 02-06-2002 08:24 PM
Ryan, It's all a matter of what you feel is criticle. I usualy lie on the anal retentive side myself so I want everything to be matched within .5oz or better street or strip...either way it will last longer and balancing even adds horse power by using less energy to shake the engine and more to turn it. If you realy want to get picky about things you can go through the pistons and cc them and cc and smooth the combustion chambers to be exactly the same, don't forget to index those plugs! To me a street car is not worth the time. And even a strip car isn't unless thats how you get paid!In NASCAR they buy 1000 restrictor plates and flow bench every single one. They select 50 of the best ones and LOCK them up for the season in a sealed container if they visualy see even the tinyest scratch they chuck it....oh and heaven forbid a fingerprint! Were talking coton gloves. It's all a balance of performance longevity and economy. My toyota truck I just bought had all the sparkplug threads striped, ALL of them! I re-threaded them and coiled them but one didn't seat right so now I have more volume in that cylinder then the others and the emissions shows it. With a tiny bit more NOX emissions then before. Do I care? Nah,It runs fine. An engine will run fine with differant pistons, not exactly ideal, but it will run and probably give years of service. In this case, if they are made by differant manufacturers and aren't matched you would be IMHO stupid to not have each idividual piston balanced. Just look at Mopar they have been useing whole engine balancing (dynamic)for years. Ever seen an original non-shaky 360 before? [This message has been edited by SundanceKid (edited 02-06-2002).]
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67fastback2+2 Journeyman Posts: 30 From: Pennsville,New Jersey Registered: Oct 2001
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posted 02-07-2002 09:48 PM
Hey Guys, Just got word back from the Clevite Tech.expert Dr. Dipstick : Subject: Re: Doc Page Date: Thu, 7 Feb 2002 17:29:20 -0800 From: [email protected] To: [email protected] Dear Pete,
You should return those pistons to the purchase point and get a set that appear the same. Dr. Dipstick om> To: cc: 02/05/2002 Subject: Doc Page 07:30 AM Thanks for all your help!!
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SundanceKid Gearhead Posts: 480 From: UT Registered: Feb 2001
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posted 02-07-2002 11:09 PM
Usualy, I question anyones advice if their surname is Dipstick, but in this case I would agree.
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SundanceKid Gearhead Posts: 480 From: UT Registered: Feb 2001
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posted 02-07-2002 11:11 PM
Oh, that's reguardless of if they have a doctorate or not. Dr. Dipstick LOL
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SundanceKid Gearhead Posts: 480 From: UT Registered: Feb 2001
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posted 02-07-2002 11:14 PM
Who did he study under Prof. Nimrod? or Ima DumbA$$ M.D. RLMAO...Sorry LOL...It hurts...LOL
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Moneymaker Administrator Posts: 10487 From: Lyons, IL, USA Registered: May 99
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posted 02-08-2002 12:57 AM
They were apparently from different production batches. ------------------ Alex Denysenko Co-Administrator and Moderator NHRA/IHRA/SRA member NHRA and IHRA SS/LA National Record Holder '00, '01, & '02 Fleet of FoMoCo products including 88 ASC McLaren Mustang #28 Part time secret agent license #0089 US Class Nationals link
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AKBOSSMAN Gearhead Posts: 2223 From: WASILLA , AK USA M&M #743 MCA #40857 Registered: Oct 2000
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posted 02-11-2002 08:09 PM
Why bother til its right ? Takem back way back ------------------ WAYNE CURTIS
70 GRABBER GREEN BOSS 302 01 Sangria Red Focus ZX3 65 Shelby GT-350R Has long doc. winning history 03 Boss 302 (5.0) (waiting on order form) 92 SHELBY 4X4 (K-9 IDITAROD LEAD DOG) My old '71Torino GT "If your under control then your not going fast enough" Parnelli Jones
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