standard size forged pistons?
- Thread starter gteatr6
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- Jan 21, 2007
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I would reuse the pistons if in good shape. SAVE THE MONEY for another go fast part.
- Joined
- May 26, 2001
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There is no way you can use a standard size forged piston in a used 109 block.
After it is cleaned and honed, you will have way too much clearance for the forged piston. I have NEVER seen this possible in hundreds of 109 rebuilds.
Even the stock cast pistons would probably be too loose after a hone job?
There is no way you can use a standard size forged piston in a used 109 block.
After it is cleaned and honed, you will have way too much clearance for the forged piston. I have NEVER seen this possible in hundreds of 109 rebuilds.
Even the stock cast pistons would probably be too loose after a hone job?
I'm at 3.799 to 3.8005 for my bore sizes. I can still see the cross hatch pattern in the cylinders. Motor is out of my 42,000 mile Gn I'm doing a frame off on. To me, it looks like I can just have the crank polished and ball hone the cylinders. I have no ridge on top either. I opened the motor just to verify what I'm dealing with.
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- May 26, 2001
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If you already decided you were going to re-use the 25 year-old stock pistons which are worn, in cylinders that are also worn, why the hell did you ask for an opinion here?
If you already decided you were going to re-use the 25 year-old stock pistons which are worn, in cylinders that are also worn, why the hell did you ask for an opinion here?
I guess just to get a smart ass reply from you??????
If you already decided you were going to re-use the 25 year-old stock pistons which are worn, in cylinders that are also worn, why the hell did you ask for an opinion here?
Take it easy Nick, Jeeeezz.
I'm putting my original 109 back together with the original pistons and rods also.
I took great pains to get the bores and pistons measured up, and all are still WELL within original factory specs. This is for a stock rebuild btw.
turbodave231
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- May 24, 2001
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I've rebuilt just a few engines........... and I would never use a ball hone on anything!! Those things have there place, but not in your cylinder bores!! You will never see ball hones in any competent machine shop. They will destroy your finish. Goodson sells a soft brush hone that will break the glaze and will not destroy your bore finish. I highly recommend this approach over using a ball hone!
It sounds like you have already measured for taper and out of round in each cylinder. If you have less that .001" taper and out of round, you are lucky and in good condition.
The stock pistons are heavy, but extremely strong.........and you already paid for them!!! If you are not building a race engine, reusing the stock pistons is an option. If you can find a media blaster who uses "Soda", have them "Soda Blasted" clean. The soda dissolves with water and is very friendly to the aluminum surfaces. You won't even need to remove the pistons from the con rods if you use this method. Even if you have a bit too much clearance, you can have the piston skirts coated and that will take up the excessive clearance.
A nice set of Total Seal file fit rings and some good cleaning will put you back in the game!!
UF-250 <BR />Ultrafinish Soft Hone 3in Dia. | Item #UF-250. | Goodson Tools & Supplies for Engine Builders
It sounds like you have already measured for taper and out of round in each cylinder. If you have less that .001" taper and out of round, you are lucky and in good condition.
The stock pistons are heavy, but extremely strong.........and you already paid for them!!! If you are not building a race engine, reusing the stock pistons is an option. If you can find a media blaster who uses "Soda", have them "Soda Blasted" clean. The soda dissolves with water and is very friendly to the aluminum surfaces. You won't even need to remove the pistons from the con rods if you use this method. Even if you have a bit too much clearance, you can have the piston skirts coated and that will take up the excessive clearance.
A nice set of Total Seal file fit rings and some good cleaning will put you back in the game!!
UF-250 <BR />Ultrafinish Soft Hone 3in Dia. | Item #UF-250. | Goodson Tools & Supplies for Engine Builders
I have only removed number one main cap and the bearing looks great. I had doubts about the motor's miles and that is why I opened it. I think I am going to build another one and leave this one alone since I did not remove the pistons and crank, I'll just clean it up and put it back together. I will then hide it in my garage since it is a numbers matching block to my car.
If you're refering to me, I didn't mention ball hones anywhere. I woiuldn't use them either. I don't hone, I leave that to a professional.
And yes, the out of round and taper were all well within spec, BEFORE and AFTER a light hone was done. Even with 100,000+ miles.
But it's my numbers matching block and was never abused.
turbodave231
Moderator
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Dave,
You're good........some one else made reference to using a ball hone. Those things will trash a cylinder wall.
Honing is both an art and a science that is best left to professionals with experience and the right equipment.
You're good........some one else made reference to using a ball hone. Those things will trash a cylinder wall.
Honing is both an art and a science that is best left to professionals with experience and the right equipment.
Just a Six??
OK! Who Farted??
- Joined
- Jul 4, 2003
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I just tore down a lower mile 87 longblock & after all the measuring the machine shop said for stockish type HP just new rings & go but for 600 HP we used custom 5 thous over CP pistons I got from Nick. They assemble & warranty it so I spent the extra $$ with K-1 rods etc etc. I have never blown up one of their motors except head gaskets. So it could have just gone back together on a budget cruiser build easily but not for 26lbs plus boost!
I would never take a good motor 20 over tho! 5-10 max.
I would never take a good motor 20 over tho! 5-10 max.
