When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Measure the bore and measure the piston and subtract. The piston MFG may specify a specific place on the piston to measure. Lacking the inside micrometer... (like me) I push one of the new rings down the bore and measure the end-gap in several places. GL
The thing I have seen lately from machine shops that bothers me is taper in the cylinder. Just got a gague that measures it down to the 1/10,000. Surprising what you see.
All I am looking for is a ballpark figure on what the clearance should be.
I can measure all the pistons and match them to the cylinders that best fit the size.
I just need someone to give me a clue, .002-.010-.050? I just need a small clue.
Thanks a lot guys, I cant tell you how much help I have gotten over the last couple of years. Thanks again!
Curt
Last edited by thatdude; May 17, 2004 at 07:16 PM.
Reason: because
Sorry, missed the last half of the question. It is somewhat dependent on the material the piston is made from. Here is a link that discusses hypereutectic, scroll down to piston clearence section. Asking the MFG is prob the safest route. Sorry I can't be more specific. http://www.speedomotive.com/Building%20Tips.htm
EDIT: Yes, I can. Chilton's publishes .0014-.0022 all years
everyone needs to realize that when a machine shop bores an engine, they use a torque plate, they bolt this plate down where the head would be, it simulates how the block changes shape as the heads are torqued down. To measure acurately bolts your heads down to the proper specs, flip the engine over and measeure from the bottom. thus is much more accurate.
Something to keep in mind is that most pistons are not round. They are finished slightly out-of-round when cold, and will expand when hot to a round shape. Measure your piston across the pin and then again in the same direction of the piston pin. You'll see the difference. ...Terry
My cylinder wall clearances are .025" in my 400.This is what the piston manufactor recommended.If you need any more clearances I can give you all of them for my motor.
What kind of pistons are you putting in? Forged pistons expand more than cast or hypereutectic, and need more clearance. I agree with what has been said, contact the piston mfg.
When I had my block bored (FE, but applies to any motor) I brought the pistons along to the machine shop and they fitted the pistons to the bore, so they could verify the clearance.
Rezvani's Latest Post-Apocalytic Monster Is a Ford F-150 Raptor Underneath
Slideshow: Called the Fortress, the 850-horsepower pickup combines Raptor underpinnings with military-inspired features, survival equipment, and a starting price of $285,000.