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Discussion Starter · #1 ·
Hello,
could someone help me with the following basic question please:
to what EXACT size are cylinders bored out to install the 95" pistons ?
I will use the standard Big-Bore Flat-Top Cast Pistons Kit.

Thanks
Jef
 

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i fit to each piston but factory spec is 3.875 -.000 +.0002
 

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If you have somebody doing the boring who doesn't know that, I'll guess they don't have torque plates, either...
 

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Discussion Starter · #4 ·
Otto, thank you very much for the quote - really appreciated.

Megaglide , I understand your confusion. I have found a very good mechanical shop here in Belgium but they are not used working on HD parts and want the precise size for the bore. Through 'a friend of friend' I have access to the tools of a HD shop - and yes I could ask them too - but over here all shops just say buy the big bore cylinders, but as the prices of all HD parts are double the price or I have to pay quitte some shipping costs I would like to avoid that and bore them out.

Jef
 

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Jef said:
Otto, thank you very much for the quote - really appreciated.

Megaglide , I understand your confusion. I have found a very good mechanical shop here in Belgium but they are not used working on HD parts and want the precise size for the bore. Through 'a friend of friend' I have access to the tools of a HD shop - and yes I could ask them too - but over here all shops just say buy the big bore cylinders, but as the prices of all HD parts are double the price or I have to pay quitte some shipping costs I would like to avoid that and bore them out.

Jef
your piston manufactor will provide the specs-------trust them and yes they are different.
 

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of course, all the US piston manufacturers quote everything in inches I do believe, at least for HD stuff, Just take the pistons with the cylinders...
Be sure they have the torque plates!
 

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Jef-> when you will have new pistons take them with old cylinders to the shop. They should match pistons with cylinders without problem. this is the way I want to do it :)
 

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Could just order bored cylinders / pistons from one of the guys on here and have them ship them to you. Seems a lot easier and cheaper.
 

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When you buy the pistons they should have a spec sheet w/ them. Each type will be different. Cast pistons have a tighter clearance cause they don't expand as much as forged. Sometimes forged will knock a little on cold start cause they have a little looser clearance than cast. This is normal. Someone correct me if I'm wrong. Just my -2$en#e-

:nope:
 

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whats the clearence clarence?

the dude is right your pistons should come with a spec. sheet and clearences
some piston manufactures will not give you a clearence they will tell you what they want for a final bore size because some of the new skirt profiles are difficult to measure.Make sure your mikes are calabrated! Also on the twin cam cylinders I "bore"
! and hone them with torque plates. These cylinders distort badly under stress I found that I get a truer cylinder that way.
 

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the next thing is when boring tc cylinders .025 per pass max. have seen cylinders where they take too heavy a cut and the cylinder will squirm in the plates youll think you have it sized untorque and oops hey the things not straight when retorqued
 

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Discussion Starter · #13 ·
Thanks for all the replies.
I have opted out and ordered the HD cylinders, the $ difference was too small compared to all the hassle in the end.

Nevertheless, again thanks for the info.

Jef
 
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