c32b overbore pistons work with FRM sleeves?

What vendor besides TODA has pistons for the c32b engine to work with the special Fiber Reinforced Metal sleeves? I need to overbote an c32b (at least one cylinderwall needs an overbore) and have this options:

option 1: shipping block to SOS and back with Darton MID sleeves + SOS pistons: ~5500 usd with shipping.
option 2: ordering a set of TODA pistons 93,5mm overbore and pay 3700 usd with shipping.
option 3: ording one OEM Honda piston/rod combo + rings and pay 1900 usd

:/

FRM sleeves in theory is a good material but in practice it sucks.
The rings will over time start to pass oil and it will consume it at about 1/2 qt of oil per tank of fuel.

Honda used it on some of their engines in the past, (B20A) and it didn't work so they dropped it as a sleeve material.

Cheers
nigel

nigel said:

FRM sleeves in theory is a good material but in practice it sucks.
The rings will over time start to pass oil and it will consume it at about 1/2 qt of oil per tank of fuel.

Honda used it on some of their engines in the past, (B20A) and it didn't work so they dropped it as a sleeve material.

Cheers
nigel

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Actually they still use FRM with out any issues.
AP2 S2000's with F22C engines run FRM liners,
J37 series engines in RL,MDX,ZDX, etc run them as well.

Your correct about B21A engines suffering from oiling issues due to ring oil control rings not working properly with the liner,
I recall there being a fix for that though, (not sure if early H23A FRM engines have that designed in to them)

A.S. Motorsport said:

Actually they still use FRM with out any issues.
AP2 S2000's with F22C engines run FRM liners,
J37 series engines in RL,MDX,ZDX, etc run them as well.

Your correct about B21A engines suffering from oiling issues due to ring oil control rings not working properly with the liner,
I recall there being a fix for that though, (not sure if early H23A FRM engines have that designed in to them)

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H23A VTEC and H22A VTEC engines have them. About 6 out of 10 of these engines suffer from excessive oil consumption.

FRM is used on a lot of Honda engines still to this day.

It is a coating not a liner, so boring or honing the cylinder will remove most if not all of the coating. You will have to sleeve your c32b to go oversized properly.

Here's how Honda described FRM when the C32B was released:

"The NSX's block has cylinder bore surfaces consisting of an 0.5-mm-thick layer with fibers of carbon and alumina (aluminum oxide, or Al2O3) in the aluminum alloy. In production, the cylinder block's aluminum alloy is poured around cylinder cores composed of these two fibers. The cores absorb the molten aluminum during the casting. After casting, the cylinders are bored to a slightly smaller diameter than the cores, leaving a tough, wearresistant, composite cylinder wall integral with the block but reinforced by the fibers. The process allows larger bores within the same external block dimensions and bore spacing, and makes open-deck block construction possible. In turn, this is appropriate for the new NSX engine's higher performance level. And with the elimination of iron cylinder liners, the reduction in engine weight by 2.4 kilograms was made possible." source: http://www.honda.com/newsandviews/article.aspx?id=2636-en

In the Service Manuals, a reboring limit is listed for the iron cylinder liners of the C30A engine. For the C32B with its 0.5 mm thick layer of FRM in the cylinder bores, no reboring limit is given.

greenberet said:

In the Service Manuals, a reboring limit is listed for the iron cylinder liners of the C30A engine. For the C32B with its 0.5 mm thick layer of FRM in the cylinder bores, no reboring limit is given.

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My understanding is Honda's FRM liner is basically indestructible and will last the life of the engine with no measurable wear. The advice I got from the experts was if I had no plans for bottom end work, get a 3.2 bottom end for this reason. Ultra reliable.

May want to contact Mahle, they have made FRM compatible pistons for other Honda blocks, don't see why they couldn't make one for the C30a application.

Honcho said:

My understanding is Honda's FRM liner is basically indestructible and will last the life of the engine with no measurable wear. The advice I got from the experts was if I had no plans for bottom end work, get a 3.2 bottom end for this reason. Ultra reliable.

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Correct it's very strong, (that caused early wear issues as rings just couldn't handle the abrasion, I recall they changed the ring material and coating mid nineties)

In the eighties and nineties Honda was still developing the technique thus a few suffered from extra ring wear,
B21's did have this, some H's got the issue but as with many things that gave the H a stigma of wearing rings.

Now C32B's don't have the issue nether do from what i know the S2000 or J engines.
The technique is a very cool one as it's a much better than what BMW tried with Nikasil that reacted badly with sulfur containing.

Nikasil if my memory serves me correctly here was developed by Mahle in the late sixties for apex seals on Wankel engined NSU cars. (mazda's din't use it though)
Alusil replaced Nikasil as more-stable solution in the late nineties and is most common nowadays .

I'd need to look that up in my Porsche manuals but I recall race Porsche's and turbo variants still use Nikasil to help heat dissipation.

How does the FRM hold up to turbo pressure above 500whp? Are the 3.0 sleeves better for that without this coating?

Well the trick with C30 is that you can install heavy duty custom race sleeves that are designed for boost.
I'm unsure how FRM works under boost, you'd need special piston rings for it to work correctly.

Perhaps checking in with the Prelude crowd should yield a insight.

I'm investigating a new style sleeve for the NSX, but i'm in very early stages on that.

So what is it exactly that caused aftermarket forged pistons to not work with Honda FRM cylinder walls? Is it the thermal expansion property of forged? Would extra clearance fix the problem? Does this also mean, after market non-Honda cast pistons should have no problem working with original Honda FRM walls?

I may be ressurecting a semi-old thread here but i'll chime in a but as i used to have a Prelude and read a lot of documentation on this FRM issue.
What i gathered was Honda used a special coating on their pistons and rings so that they would not score the FRM liners. That coating is not there on aftermarket pistons, which means you have to install new sleeves along with the new pistons - that was the common practice on H22/H23, i recall seeing the results of not doing the re-sleeving and that was not pretty at all.
I also recall one manufacturer providing properly coated pistons and claiming FRM compatibility - i cannot recall which but someone with enough free time can do some thread digging on honda-tech (that's where most of the FRM related info is buried).
If i was to change the pistons in my C32B i'd definitely get corresponding sleeves, i wouldnt take any risk. I am new on that C32B stuff so maybe someone can give me some insight on (long term) reliability of aftermarket forged pistons usage on C32B, probably Toda are using the proper coating (given the price, they ought to)...

Well getting forged pistons to work with FRM is possible we've discussed a different approach to the ring issue with piston manufacturer and we should be able to custom make them for C32B.
A pair of custom pistons with FRM provisions is rather expensive but would allow you to run your stock bore's.

Personally my opinion to C30A/C32B connecting rods is that unless your going to run a longer stroke, one should always try to retain the Titanium rods.
Since these are lighter and stronger (by ratio) than aftermarket rods.

With the (stock for NSX) 78mm stroke C series engines can displace up to 3.3L with corresponding sleeves and pistons.

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GhettoRacer said:

So what is it exactly that caused aftermarket forged pistons to not work with Honda FRM cylinder walls? Is it the thermal expansion property of forged? Would extra clearance fix the problem? Does this also mean, after market non-Honda cast pistons should have no problem working with original Honda FRM walls?

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The issue with FRM is the abrasion the FRM liner has to a normal piston ring,
It will wear the ring out and quite rapidly.

For the German nikasil and alusil liners there are quite a few piston ring options, but since Honda uses a fiber reinforced metal system it's much stronger.
It's basically a fiber matrix (I recall it being kevlar or carbon) mixed with aluminum oxide to create a ultra though wall.

It's extremely reliable and does not have the issues that for example nikasil liners have (Nickle silicone liner) in that FRM does not react to sulfur in low quality fuel. (common issue in UK and US Jaguar & BMW engines)
The liner is extremely rigid with FRM due to the fiber matrix allowing larger bores and lighter castings.

Down side is that it's not easily/impossible repaired once damaged (which would is less likely due to its strength)
Other factor that we in the performance end run in to is that it requires special rings and coatings.

Nero Tenebre said:

How does the FRM hold up to turbo pressure above 500whp? Are the 3.0 sleeves better for that without this coating?

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It literally melts the walls or blows holes in the liner because of cylinder pressure. I have seen it happen on H22 engines that were running very modest boost levels. 10-13 psi. I cannot vouch for how tough the NSX liners are. I always tell people to sleeve and get it over with. I would choose the factory 3.0 sleeves over the FRM not just because of the material, but because they are thicker as well. Even something as small as .25mm makes a lot of difference with higher cylinder pressures. Hope this helps you.

Bumping this up to see if there has been anymore developments for pistons and rings for NA application on the FRM lining. If you were staying NA and wanted to lighten the moving parts but keeping the C32B block what options are there without sleeving, its not something I want to do now however for a fully balanced bottom end would you just try and improve what you have and get that balanced and not go aftermarket?

I'd get the Toda pistons and camshafts, and get everything balanced. But i'd make sure 110% that they are FRM compatible. One of the results that has not been mentioned, and seen on H series was aftermarket pistons were destroying the FRM liner. As mentioned by Adnan, FRM compatible pistons should have a special coating.

Just to bring this back up, I emailed TODA and they said that their pistons do work with the FRM lining and if I ever wanted to go full Toda crank and the works to go with the FRM C32b block I could get comfortably 440hp.
I declined on that since we all know that cost

Here's a guy who did it but there is no explanation....
https://www.youtube.com/watch?v=8O9z1V_aE7w

scammy said:

Just to bring this back up, I emailed TODA and they said that their pistons do work with the FRM lining and if I ever wanted to go full Toda crank and the works to go with the FRM C32b block I could get comfortably 440hp.
I declined on that since we all know that cost

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If your really intrested we can work on a piston set for your build.
FRM compatibility is more than just a coating.

A.S. Motorsport said:

If your really intrested we can work on a piston set for your build.
FRM compatibility is more than just a coating.

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Toda are adamant their pistons work with the FRM coating on the C32B, I am sitting on the fence at present but would always like more knowledge on the topic. My next mods going in now are an intake an the OS Giken LSD so got plenty happening for now this can wait until next year.

Considering that the OP is in Austria and probably doesn't have time and resources to "redo" a hap-hazard engine build I would recommend Darton sleeves with Wiseco 4032 partial skirt forged piston for NA application or 2618 forged full skirt for FI application.