Toda pistons FRN or Iron application
04-24-2017, 07:05 AM
#11
Nikasil is just one of the coatings they do, so I "thought" that it might be worth asking if they are able to replicate the FRM coating? So PB could provide liners with the correct coating on them AND to the correct size, which would allow you to use OEM pistons, or they may even be able to bore and re-coat your existing block (but that then leaves you with piston sourcing problems?
It may be that they could analyse the friction coefficient of the block to see if Nikasil is close enough even to allow the use of OEM pistons?
Got to be worth a phone call at the very least
.
It may be that they could analyse the friction coefficient of the block to see if Nikasil is close enough even to allow the use of OEM pistons?
Got to be worth a phone call at the very least
.The cylinder 'liners' are spun in carbon fibre and then the aluminium cast around them as part of the block. They are then honed back to reveal the CF, which acts as the hard running surface for the rings. They can only be lightly-homned again, otherwise you have to grind the lot out and fit a new lump of liners - usually Nikasil ones.
04-24-2017, 07:25 AM
#12
Thread Starter
I'd just do a K Swap 
https://www.balladesports.com/produc...k2024-swap-kit
K20 and K24 are peanuts in comparison and arguably a better engine. Certainly they modify better!
Given an F20 full block is about £3k, the ballade kit for £2k and a £1500 K engine, plus selling your dead F20 isn't a bad option.
https://www.balladesports.com/produc...k2024-swap-kit
K20 and K24 are peanuts in comparison and arguably a better engine. Certainly they modify better!
Given an F20 full block is about £3k, the ballade kit for £2k and a £1500 K engine, plus selling your dead F20 isn't a bad option.
04-24-2017, 07:29 AM
#13
If both processes have been designed to do a similar job, it may be that Nikasil has properties close enough to the FRM - if it is only a "hardening" process, so it may be that Nikasil will be equally as resistant for the use of OEM piston / rings, but I would be wanting someone like PB to confirm. Would be good to know, as the FRM seems to be in the realms of "magic" with no-one really knowing specifically what can and can't be used.
04-24-2017, 07:52 AM
#14
Member
04-24-2017, 01:12 PM
#15
Thread Starter
Though still would not know engine condition,there was a brand new a K full motor on egay for £4k
link: Using oem piston & steel sleeve combo results !!.
https://www.s2ki.com/forums/s2000-un...168823/page18/
link: Using oem piston & steel sleeve combo results !!.
https://www.s2ki.com/forums/s2000-un...168823/page18/
04-24-2017, 10:52 PM
#16
Member
True. They are much easier to rebuild though where the F20is a higher risk unless you bought one from here (I believe my old engine is still going strong!) and from what i've seen you can pick up a good K20 for £1500 and a K24 even less.
It's deffo not for everyone and makes the car not so original anymore but if I hadn't been running ITBs specific to the F20 i'd have done a K swap.
It's deffo not for everyone and makes the car not so original anymore but if I hadn't been running ITBs specific to the F20 i'd have done a K swap.
04-25-2017, 02:36 AM
#17
Thread Starter
From what I have read the silicon content in forged piston and silicon content in the FRM OEM block bores,has a <glass on glass> effect.
So:
The difference between hypereutectic pistons and conventional cast pistons is the amount of silicon in the aluminum. “Hypereutectic” refers to the concentration of silicon in the alloy. When silicon is added to molten aluminum, the “eutectic” point is reached when silicon starts to solidify and form hard little particles dispersed throughout the metal matrix as the molten metal cools. This point occurs at 12 percent silicon content. Alloys with less than 12 percent silicon are therefore called “hypoeutectic” (which includes the ductile alloys used to make forged pistons) while those with more than 12 percent silicon content are called “hypereutectic.” Conventional cast pistons typically contain 8 to 11 percent silicon while most hypereutectic pistons contain 16 to 20 percent silicon.
Silicon adds hardness to the alloy, which increases wear resistance, durability and high temperature fatigue strength. This eliminates ring pound out, scuffing, and allows the top ring groove to be located closer to the top of the piston to reduce emissions.
Most hypereutectic pistons also undergo less thermal expansion than conventional cast pistons which means they can be installed with somewhat tighter tolerances than conventional pistons to improve cold sealing and reduce blow-by. Closer tolerances also allow quieter operation because piston rattle is reduced.
If you’re replacing the pistons in an engine that was originally equipped with hypereutectics, follow the manufacturer’s recommendations for clearances. But if you’re replacing conventional cast pistons in an older engine with hypereutectic pistons, piston-to-cylinder wall clearances can often be decreased by .0005˝ over the stock specifications.
For high performance, severe service or heavy-duty applications, replacing stock cast pistons with hypereutectic or forged pistons would be recommended. Forged would be the preferred choice for any application involving nitrous oxide or extensive modifications.
Forged pistons may contain from almost no silicon up to 11.5 percent depending on the alloy and application. The important difference here is the way the pistons are made: they’re forged under high pressure rather than cast into shape. The forging process increases the density of the metal, which significantly improves its strength (up to 40 percent or more over conventional cast pistons), resistance to cracking and thermal characteristics. Forged pistons can often survive a close encounter with a valve without shattering, and generally run 18 to 20 percent cooler than cast pistons because they transfer heat more efficiently. That, in turn, provides added protection against detonation and preignition.
Some people think that the same thermal characteristics that allow forged pistons to run cooler also causes them to swell more as they heat up. Consequently, there’s a common misconception that forged pistons always require greater skirt-to-wall clearances. This is a notion that isn’t necessarily true because clearances depend on the type of alloy that’s used in a forged piston, the design of the piston itself and the application in which the piston will be used. Some forged alloys actually have a lower coefficient of thermal expansion than the alloys commonly used in conventional cast pistons!
One way to control thermal expansion in a piston is to manufacture it so the piston is slightly elliptic rather than round. The diameter of most pistons (forged as well as cast) measures anywhere from .010˝ to .035˝ shorter across the wrist pin axis than the diameter perpendicular to the pin (the “major” axis). This compensates for the greater mass in the wrist pin area, which causes the piston to swell sideways as it heats up. This allows the piston to fill the hole as it heats up for a tighter all-round seal.
Piston growth is also influenced by the temperature differential between the top and bottom of the piston. The top can be 300 degrees F or more hotter than the bottom. Since the top runs hotter and swells more than the bottom, growth can be controlled by making the skirt profile taper in towards the top. The typical piston is widest at the bottom of the skirt and narrowest at the top (which is why it’s so important to always measure a piston at the location specified by the piston manufacturer, which may be either perpendicular to the pin at the pin centerline, one inch up from the bottom of the skirt or at the top of the skirt).
When all these factors are taken into consideration, there can be considerable differences in recommended minimum skirt clearances between various brands of forged pistons. In some applications (such as a low compression, moderate horsepower output engine), a forged piston may be installed with the same clearances as an OE cast piston. In other applications (high compression, high power output), the pistons may need additional clearance.
So:
The difference between hypereutectic pistons and conventional cast pistons is the amount of silicon in the aluminum. “Hypereutectic” refers to the concentration of silicon in the alloy. When silicon is added to molten aluminum, the “eutectic” point is reached when silicon starts to solidify and form hard little particles dispersed throughout the metal matrix as the molten metal cools. This point occurs at 12 percent silicon content. Alloys with less than 12 percent silicon are therefore called “hypoeutectic” (which includes the ductile alloys used to make forged pistons) while those with more than 12 percent silicon content are called “hypereutectic.” Conventional cast pistons typically contain 8 to 11 percent silicon while most hypereutectic pistons contain 16 to 20 percent silicon.
Silicon adds hardness to the alloy, which increases wear resistance, durability and high temperature fatigue strength. This eliminates ring pound out, scuffing, and allows the top ring groove to be located closer to the top of the piston to reduce emissions.
Most hypereutectic pistons also undergo less thermal expansion than conventional cast pistons which means they can be installed with somewhat tighter tolerances than conventional pistons to improve cold sealing and reduce blow-by. Closer tolerances also allow quieter operation because piston rattle is reduced.
If you’re replacing the pistons in an engine that was originally equipped with hypereutectics, follow the manufacturer’s recommendations for clearances. But if you’re replacing conventional cast pistons in an older engine with hypereutectic pistons, piston-to-cylinder wall clearances can often be decreased by .0005˝ over the stock specifications.
For high performance, severe service or heavy-duty applications, replacing stock cast pistons with hypereutectic or forged pistons would be recommended. Forged would be the preferred choice for any application involving nitrous oxide or extensive modifications.
Forged pistons may contain from almost no silicon up to 11.5 percent depending on the alloy and application. The important difference here is the way the pistons are made: they’re forged under high pressure rather than cast into shape. The forging process increases the density of the metal, which significantly improves its strength (up to 40 percent or more over conventional cast pistons), resistance to cracking and thermal characteristics. Forged pistons can often survive a close encounter with a valve without shattering, and generally run 18 to 20 percent cooler than cast pistons because they transfer heat more efficiently. That, in turn, provides added protection against detonation and preignition.
Some people think that the same thermal characteristics that allow forged pistons to run cooler also causes them to swell more as they heat up. Consequently, there’s a common misconception that forged pistons always require greater skirt-to-wall clearances. This is a notion that isn’t necessarily true because clearances depend on the type of alloy that’s used in a forged piston, the design of the piston itself and the application in which the piston will be used. Some forged alloys actually have a lower coefficient of thermal expansion than the alloys commonly used in conventional cast pistons!
One way to control thermal expansion in a piston is to manufacture it so the piston is slightly elliptic rather than round. The diameter of most pistons (forged as well as cast) measures anywhere from .010˝ to .035˝ shorter across the wrist pin axis than the diameter perpendicular to the pin (the “major” axis). This compensates for the greater mass in the wrist pin area, which causes the piston to swell sideways as it heats up. This allows the piston to fill the hole as it heats up for a tighter all-round seal.
Piston growth is also influenced by the temperature differential between the top and bottom of the piston. The top can be 300 degrees F or more hotter than the bottom. Since the top runs hotter and swells more than the bottom, growth can be controlled by making the skirt profile taper in towards the top. The typical piston is widest at the bottom of the skirt and narrowest at the top (which is why it’s so important to always measure a piston at the location specified by the piston manufacturer, which may be either perpendicular to the pin at the pin centerline, one inch up from the bottom of the skirt or at the top of the skirt).
When all these factors are taken into consideration, there can be considerable differences in recommended minimum skirt clearances between various brands of forged pistons. In some applications (such as a low compression, moderate horsepower output engine), a forged piston may be installed with the same clearances as an OE cast piston. In other applications (high compression, high power output), the pistons may need additional clearance.
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chrispayze (09-19-2023)
04-25-2017, 03:37 AM
#18
Member
05-26-2017, 02:53 PM
#19
Thread Starter
True. They are much easier to rebuild though where the F20is a higher risk unless you bought one from here (I believe my old engine is still going strong!) and from what i've seen you can pick up a good K20 for £1500 and a K24 even less.
It's deffo not for everyone and makes the car not so original anymore but if I hadn't been running ITBs specific to the F20 i'd have done a K swap.
It's deffo not for everyone and makes the car not so original anymore but if I hadn't been running ITBs specific to the F20 i'd have done a K swap.
Found a great replacement F20C- 57660 miles from an 05 GT had it in 2 weeks now and running brilliant
was a right pain getting the engine & box to mate up on the release bearing <new oem clutch kit, gearbox in situ engine mounts removed>
& single handed
,i remember why I gave this up for a living long ago
...
