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fiveoformula Member
Joined: 08 Aug 2007 Posts: 1799 Location: OR
1988 Pontiac Formula
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Posted: Tue Oct 15, 2013 3:44 pm Post subject: |
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So you wouldnt rebuild a engine without balancing at all? |
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Twilightoptics Hardcore (12sec Club)
Joined: 13 Jan 2004 Posts: 9191 Location: Auburn , WA
1987 Chevrolet Camaro IROC-Z
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Posted: Tue Oct 15, 2013 5:13 pm Post subject: |
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If I'm just rebuilding, no.
If I change the crank - yes
If I change piston(s) - yes, single I make sure the new piston is lighter or the same.
If I change rod(s) - yes, single I match the weights to one of the rods I already have. _________________ A redline a day keeps the carbon away! |
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fiveoformula Member
Joined: 08 Aug 2007 Posts: 1799 Location: OR
1988 Pontiac Formula
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Posted: Tue Oct 15, 2013 5:34 pm Post subject: |
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Alright well I guess id be better off doing it. Its not really about the cost, they quoted me $200 to do it, I can swing that, its Just another step before I get it together. I want to put some trouble free miles on it and have it run smooth. |
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fiveoformula Member
Joined: 08 Aug 2007 Posts: 1799 Location: OR
1988 Pontiac Formula
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Posted: Tue Oct 15, 2013 5:37 pm Post subject: |
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Looks like the one rod that had spun, the machinist says I should be able to re-use it. I'm having them re-size all 8. So I'm using original rods and pistons, just a crank from a different engine, its .010 under sized, so I ordered the rod bearings that match. _________________
'88 FORMULA |
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chevymad Master B
Joined: 11 Jan 2004 Posts: 5474
1987 Pontiac Formula
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Posted: Tue Oct 15, 2013 7:14 pm Post subject: |
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I've built motors like this one and they've been fine unbalanced. I would be more afraid changing a rod/piston then changing the crank. Both Rod and I have had success building half worn blocks. They may not last as long, afterall the cylinders are allready half worn out since you're not boring.
But not balancing did bite Paul once. That's a spendy lesson to ignore. So to be totally safe, if you have the money have it balanced. Or toss the dice..
My 327 is unbalanced and has actually been running a 307 crank in it for the last dozen years and untold miles. It's also been bored 0.040 over with cast pistons and resized rods. Of course with the shorter stroke its easier to get away with that too. |
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fiveoformula Member
Joined: 08 Aug 2007 Posts: 1799 Location: OR
1988 Pontiac Formula
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Posted: Tue Oct 15, 2013 7:31 pm Post subject: |
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This is an interesting debate..
The other thing the machinist mentioned was that these style pistons like to break when removed from the rod due to the way they have to be pressed off |
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chevymad Master B
Joined: 11 Jan 2004 Posts: 5474
1987 Pontiac Formula
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Posted: Tue Oct 15, 2013 7:32 pm Post subject: |
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That's definately a good point. Never had much luck trying to remove stock pistons and keep them in useable condition. |
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Twilightoptics Hardcore (12sec Club)
Joined: 13 Jan 2004 Posts: 9191 Location: Auburn , WA
1987 Chevrolet Camaro IROC-Z
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Posted: Tue Oct 15, 2013 7:36 pm Post subject: |
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The piston is part of the little end. You can do the math and weigh properly. You can resize with the piston installed too.
With the proper piston pin press tool set you can separate and install no problem. _________________ A redline a day keeps the carbon away! |
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rjmcgee The Hammer
Joined: 08 Jan 2004 Posts: 2320
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Posted: Tue Oct 15, 2013 7:40 pm Post subject: |
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I still remember Dad and I pressing the pins out of my stock pistons and pressing them right back into the new ones! Little rickety press and I think a piece of wood. I look back at how he assembled that short block and am still amazed. Didn't check any clearances, just kept turning it over as we went, just told me it will be a little loose and back in the day they would really run good loose,,, for a while. 11 years and counting |
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fiveoformula Member
Joined: 08 Aug 2007 Posts: 1799 Location: OR
1988 Pontiac Formula
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Posted: Tue Oct 15, 2013 7:47 pm Post subject: |
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So I can have them balance the pistons and rods together? Like best they can? I was thinking of weighing them myself. They are resizing the rods with the pistons still on, they said it was more work but they can do it for me.
Damnit. Maybe I should be buying rods and pistons, re-bore it and balance it all.
If I take a chance and they break a piston them I'm kinda stuck anyways. |
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fiveoformula Member
Joined: 08 Aug 2007 Posts: 1799 Location: OR
1988 Pontiac Formula
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Posted: Sun Oct 20, 2013 9:32 pm Post subject: |
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Wahoo clean enough to eat off of! _________________
'88 FORMULA |
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fiveoformula Member
Joined: 08 Aug 2007 Posts: 1799 Location: OR
1988 Pontiac Formula
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Posted: Sun Oct 20, 2013 9:38 pm Post subject: |
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And the block in the jeep, reminding me that the jeep really needs new leaf springs.... so many projects so little time...
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fiveoformula Member
Joined: 08 Aug 2007 Posts: 1799 Location: OR
1988 Pontiac Formula
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Posted: Thu Oct 31, 2013 10:28 am Post subject: |
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Alphius Peanut
Joined: 05 Sep 2006 Posts: 2429 Location: Grand Mound
1984 Chevrolet Camaro Z/28
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Posted: Thu Oct 31, 2013 11:55 am Post subject: |
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Looking good!
Did you Plastigauge those? _________________ 84 Camaro Z28 - LS1/T56
85 Silverado - Low and Slow |
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aaron_sK Member
Joined: 23 Jan 2006 Posts: 8834 Location: Back in beautiful Tacompton
1987 Chevrolet Camaro IROC-Z
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Posted: Thu Oct 31, 2013 12:06 pm Post subject: |
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Alphius wrote: | Looking good! |
Not so.
All that beer is terrible, and an Ikea stick table makes a poor workbench. |
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fiveoformula Member
Joined: 08 Aug 2007 Posts: 1799 Location: OR
1988 Pontiac Formula
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Posted: Thu Oct 31, 2013 1:00 pm Post subject: |
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My other work bench is on the other side of the car with all kinds of other crap on it so this will have to do. Lol And I'm on a cheap beer budget due to money going into that block!
Now that all that is cleared up, no I did not plastigage the mains. But there not torqued down yet either. The machinist checked clearances between the rods/crank (sorry I forget which method he used). But I don't think he checked the mains at all. _________________
'88 FORMULA |
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Twilightoptics Hardcore (12sec Club)
Joined: 13 Jan 2004 Posts: 9191 Location: Auburn , WA
1987 Chevrolet Camaro IROC-Z
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Posted: Thu Oct 31, 2013 1:39 pm Post subject: |
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Must check clearances yourself for all mains and rods!!!! Pbr tastes better and tends to be cheaper. Don't forget to set the thrust bearing too. _________________ A redline a day keeps the carbon away! |
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fiveoformula Member
Joined: 08 Aug 2007 Posts: 1799 Location: OR
1988 Pontiac Formula
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Posted: Thu Oct 31, 2013 2:09 pm Post subject: |
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Nobody likes Budweiser anymore. I buy it, then I get to drink the whole pack so it works out. |
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Alphius Peanut
Joined: 05 Sep 2006 Posts: 2429 Location: Grand Mound
1984 Chevrolet Camaro Z/28
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Posted: Thu Oct 31, 2013 3:29 pm Post subject: |
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Yeah, prevent an expensive oversight by checking everything you can yourself. Who has the most to lose if something happens to have been overlooked by the machine shop?
PBR is honestly the worst ever; Bud is cheap and drinks like water. I can get behind it for a guy on a budget.
Ikea table is not much worse than my shop's door table so meh. _________________ 84 Camaro Z28 - LS1/T56
85 Silverado - Low and Slow |
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fiveoformula Member
Joined: 08 Aug 2007 Posts: 1799 Location: OR
1988 Pontiac Formula
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Posted: Thu Oct 31, 2013 3:59 pm Post subject: |
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Definitely will be checking as much as I can myself. Thanks for the advice. They sell plastigauge at NAPA? I've never bought/seen it anywhere.
Oh also, when I torque the mains, Alldata says 15ft/lbs plus 73 degrees. what do you guys use to get the proper angle? |
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