• Hello Guest, welcome to the initial stages of our new platform!
    You can find some additional information about where we are in the process of migrating the board and setting up our new software here

    Thank you for being a part of our community!

Mahle B230-B230ft pistons


Feb 27, 2005
Are the Mahle B230f pistons and the B230 ft pistons all made of the same material? Are they all cast? Do all the red blocks all come from Volvo with Mahle pistons? Which would be a better pick for a street turbo motor rebuild if I ever get that far?
I can’t answer most of your questions, but my ignorant advice would be to opt for the F pistons (or something of the like) with the higher compression for a street car. It will respond much better than the 8.7:1 FT pistons. Just my experience.

IIRC, all the stock pistons were cast..I think. Except for maybe the earlier turbo engines? B23FT/ET according to a quick search we’re the only forged pistons offered for redblocks from the factory. And they were made by mahle.
The pistons are all cast with the one exception mentioned above. I would ask you what are your goals with a street turbo engine? Are you looking for mileage with some power or some power with a bit of mileage?

Your fuel economy will be better with the F pistons but with lots of boost your are running closer to the limit of knock. Modest boost pressures are a good way to keep a +T rolling.
The FT pistons will give you more boost before knock limits and if you are wanting the boosted power then this is what you would want in my opinion. If you use a fast spooling turbo like the mitsubishi ones then the lower compression won't really have any bad turbo lag.
Where are you planning on sourcing them? I just looked for NA pistons and FCP, Amazon, eBay, and IPD don't stock them.
Mahle pistons

I'm on the side of mileage with some power. I have a rebuilt 16T turbo, Kl turbo cam, hopefully a 3 in. exhaust, white injectors, Mikes chips. Car will be daily driver with aw71. I inherited a partial set of new stock bore b230 pistons. 4 pistons but only 2 pins & 2 pair of clips. I think the decision will come down to whether the stock bores in the b230ft engine I picked up are good enough. Engine is under 100k miles but is a 91 without squirters. Head is still on it, so don't know yet.
What kind of boost is safe to run with F pistons & 16T with mods?
With a better intercooler than the Volvo one it would also help a lot. I would contact Mike since he probably knows the design limits of the programming in the chips. From your description even something modest like 10-12 psi would be a lot of fun and give you a good service life.
I put a new set of stock Mahle pistons in the last B230FT I built, I was pretty impressed with the quality. Put a piston, wrist pin, and retainers on a digital scale, all 4 were exactly the same down to 0.000, the limit of my scale. We didn't even have to gap the rings, we did check them but they needed nothing.
Car was running a T3/T04E 50mm Garrett (with supporting mods) at 15 PSI
All of the Volvo pistons are either cast or forged. To my knowledge B21/23 pistons were all forged, B230 pistons were all cast. All of the pistons are aluminum.

Mahle was the OEM supplier of pistons for Volvo.

Pistons you buy today are cast - unless they specifically say 'forged'. You can easily get either.

Cast pistons work fine for 99.9% of our applications. High power applications would require forged for the additional strength. If you are building a 'fun' motor that isn't a 'max effort' motor, cast would be fine for you. Essentially, if you are 300 hp or less on these motors the cast pistons seem to work fine.

Cast pistons are dimensionally more stable than forged. Forged pistons expand a lot more than cast. This is why most OE suppliers use cast pistons in their applications (besides forged pistons cost more).

In the end its up to you and your wallet. Overkill is consistently more fun however, so I'm a fan of forged pistons...
All of the Volvo pistons are either cast or forged. To my knowledge B21/23 pistons were all forged, B230 pistons were all cast. All of the pistons are aluminum.

Mahle was the OEM supplier of pistons for Volvo.


Only a very few turbo B23 had forged pistons.. very few..Bought a couple of core B23T for rebuilding and oddly one had forged pistons but the crank was cast iron..Never saw one of those before..

The bit about temp stability..Numbers help understand why something is important or just "true but insignificant"..Book spec for piston to cylinder clearance for cast Mahles in the size range---and there is no special material that has been change or "technology" (Part of the contract for supplying stuff as an OEM supplier is that the aftermarket replacement parts IF they are to be called "Vollvo" or whatever parts MUST be done to the exact spec of the original contract..materials all design*) is 0.0012 ish...The OEM forged Mahles the Volvo and Lima Ford and that other Ford that makes fan-bois go insane if mentioned is about 0.0018-.002" and aftermarket good pistons .003-.004 for hard turbo use...

So the difference is from .0006 --6 ten thousandths to at maximum .0022", less than a sheet of paper..

And that's cold, :oops:after warm up its the same...:)
I have only seen cast pistons from mahle (B23/230/ft), and have only seen 1 or 2 cast B23 cranks.
I have a set of B230FT pistons I should sell. 96.010
Your best bet aftermarket forged...I personally don't care for the hyper alloy slugs,I think they're brittle I prefer cast over them.I've used factory cast pistons worth 300 hit in a big block chevy proper tuning is a must just my two cents
I have only seen cast pistons from mahle (B23/230/ft)...
You saw my Mahle pistons...they were forged...

Another issue with the pistons Mahle offers is weight.
The B230-FT pistons available are cast and they are BRICKS! 700+grams (715?)for the complete piston package!
The wrist pin supplied is large diameter (23mm) and very thick soft material, not a performance pin by any name.
The pins look like a diesel pin, but show premature wear due to the soft material.
I'm thinking something more like 450-500 grams for the whole package (pin & rings & retainers).

How much crisper would a RedBlock be loosing 200G per piston???!!! No re-balancing needed, because 4 cyl inline...

I am looking at using a Diamond piston they have a turbo piston for a LS motor that is rated for 2000hp (LS2k).
I am looking at using that piston downsized for a redblock and use the longer 158mm H-beam rods.

But still hoping for an off the shelf solution for a forged piston.....
Open for suggestions

The Mahle cast pistons held up well in this motor, I pulled apart due to noise problems which turned out to be carbon knock.
Under 10k miles of which half was at full throttle (fixing boost control and fueling issues).
I could reassemble the motor after cleaning but someone calling themselves a machinist opened up the pin clearence in the rods and pistons to .002"
And I don't feel right about that.
I pushed the bushings out of the rods to replace them and found they are a non-standard size, and the Chiwan rods were machined really poorly (rough high feed rate finish) under the bushing so they need to be honed first to properly hold the new bushings then hone the bushings to size and by the time I've done that I could buy a new set of rods.
So if I'm buying new rods I'd prefer to use a longer rod with a lighter piston and have a much better package.
Last edited: