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DIY Classic Mini Piston Articles

CHECKING PISTON COMPRESSION RING GAPS (Engine)
Checking Piston Compression Ring Gaps in Classic Mini, Sprite and Midget There are lots of differing opinions when it comes to engine assembly and ring end gap. Checking and/or adjusting the end gaps of the pistons rings when new rings are installed is a sane first step.Below are 3 Essential Steps to Checking the Piston Compression Ring Gaps. Correct end gaps assures a good combustion seal which is critical to  minimize blow-by.  The correct clearance between the ends of the rings also assure they do not butt up against each other and cause the rings to scuff the cylinder walls. STEP 1: The first step is to place the ring to be checked into the bore in such a way as to keep it 'square'.  this is best done by simply inverting the piston to push the ring into th...
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Crankshaft - Standard production crank identification (Engine)
Below is a list of crankshaft identification data by forging or stamped numbers - yes, contrary to what many say/express, all cranks are forged. None are cast. They wouldn't last 2 minutes in an engine if they were cast - they'd be way too brittle. The differences are in the material used, finish machining detail and any heat treatments applied. It is by no means complete and utterly correct/infal...
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Piston Fact File (Engine)
1275 PistonsOver the years, there have probably been a dozen "stock" 1275 pistons. Currently, three different designs are available from AE/Hepolite as "stock" replacements. All (AE Brand) have an 8.4cc dished top, but compression ratios are carried by changing pin height (Pin height is the distance from the top of the piston to the center of the wrist pin- see dimension "A" shown here). All of t...
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Piston Information (Engine)
When Omega quit making A-Series pistons, Mini Spares took it upon themselves to design and build a better Piston.         Recruiting the AE Hepolite Group for their unquestionable and renowned design and manufacturing expertise, the goal was to produce the most robust piston possible given reasonable cost and weight limits. Applying current technological adv...
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PISTONS -Features for Maximum Performance (Engine)
Having determined what sort of material best suits your needs/application, the main design and detail features of the piston now need consideration. The over-riding factor that influences just what is best for an A-Series engine is the block's propensity for flex at higher rpm, and the crank's equal propensity for flex at the same sort of rpm levels. Both combine to require a piston that is as sta...
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Pistons - Mega piston performance report- Classic Mini Cooper (Engine)
Mini Cooper Pistons - Mega piston performance report The two other articles I have done on this site concerned what pistons are all about, different design and construction pros and cons, material specs, ring set-ups and so on. Under 'Pistons - Favorable features for maximum performance' it would seem that the Mega pistons fit the bill just about spot on for all but perhaps the most extreme of ...
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Small bore piston applications (Engine)
Small piston applications and availability have been changing over time.  A number of different pistons have been discontinued and/or superseded and thus this Quick Reference chart we hope will help..NOTE- Connecting rods for a Circlip piston will not accept Press-fit pistons   ...
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PISTONS - Whys and Wherefores (Engine)
This is another of those subjects abused for ‘bar stool b*llsh*t’ one-upmanship. Ignorance is the main problem. Particularly as trying to get any really useful information out of the manufacturers concerned. Try ‘phoning AE Hepolite technical. Getting hold of someone takes real perseverance. Having achieved that meagre goal, enquiring about piston specification gets those ‘...
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Arias Pistons (Engine)
What's in a name?If the name is ARIAS, it is over thirty-six years of forged piston innovation that has set the standard for piston performance. Founded in the workshop and on the racetrack by Nick Arias Jr. in 1969, ARIAS PISTONS blends its unique experience, state-of-the-art equipment, engineering excellence and dedicated team to produce pistons that have forged a reputation for power! The ARIA...
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Classic Mini Cooper Piston Ring Compressor Tool (Engine)
See Available Piston Ring Compressor Tools to the Right or Click Here >>>>>Installing piston rings in a Mini engine has never been easier.  With the availability of a simple precision tool the entire process will take only minutes.  When you purchase a new set of pistons and rings it is safe to be comfortable that the 'end gap' on the factory rings will have already been ...
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