A block that has been bored 030..

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May 19, 2006 | 08:12 AM

devilfish

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Melting Slicks

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From: Sweden/Stockholm

A block that has been bored 030..

..and torqueplate honed for moly rings. Can I put in what ever type of flattop +030 pistons in there, ofcourse I will use the recomenden ring gaps? Or does diffrent kind of piston manufacture require diffrent kind of hone techniques?

Devilfish...

May 20, 2006 | 06:38 PM

comp

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From: eville in

bore's should be honed to/for the piston's

May 21, 2006 | 11:23 AM

devilfish

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Melting Slicks

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From: Sweden/Stockholm

but if I measure the bores then the pistons for each cylinder to se that the piston to wall clerance is within spec i should be ok, right?

May 21, 2006 | 12:30 PM

Cruz59

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Thats the way mass production is done!...

Bore and hone to a certain spec, pistons are also within a certain spec, and then they fit together!

If your bore is within specs, no problem.

Making it for each piston is top notch, doing it the other way, is the same as you get on new cars and engines.

Nobody does individual measurements for mass production!

Cruz59

May 21, 2006 | 12:40 PM

devilfish

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Melting Slicks

Joined: Oct 2000

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From: Sweden/Stockholm

In my case the engine builder and I hade a missunderstanding on what kind of pistons to use. Instead of hyperxxx he used cast pistons. Of course he will give me the new hyper pistons for free to correct his misstake. The block is bored +030 and then torqueplate honed for moly rings. Thats why I asked if its ok to "just" install the new hyperxx +030 pistons into the bores, or if you need to "rehone" the block for the hyperxx pistons?
The new pistons is within the same weight aswell so no rebalance is nessesary, this we have double cheked.

thanks

May 21, 2006 | 03:17 PM

Pete K

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The bore is honed to it's final size to suit the piston. It's final finish"texture" or ra is set for the rings.

May 21, 2006 | 04:00 PM

devilfish

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Melting Slicks

Joined: Oct 2000

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From: Sweden/Stockholm

So to be sure its best to mesaure the bores to se that its within spec for the new pistons i guess?

May 21, 2006 | 05:58 PM

Pete K

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Quote:

Originally Posted by devilfish

So to be sure its best to mesaure the bores to se that its within spec for the new pistons i guess?

It is always best to double check. If the bores are exacty 4.030, in theory pistons will be correct. Manufacturer of the pistons typically build them to fit the hole with the minimum skirt clearance. Most race engine builders add a thousanth or 2 to open up the minimum clearance to what they feel makes the most sense. Every builder has his own opinion of "correct" clearances. Piston manufacturers give a minimum and maximum skirt clearance. Engine builder does what he wants.