Duke

I too run MID's in my race engine. Kept the bore a bit more conservative to keep the cylinders stronger.

rlm328

I am running MIDs in my engine, I had Darton's recommended shop put them in, and they got it wrong. So I ended up in a very large learning curve. You need someone with knowledge with the alusil blocks. I would have Chris do it if he is available.

Chris White

OK, I suppose I should have qualified that statement....on engines that I have build and tuned there have been no failures. If the tune is not right nothing will last!

GPA951s

Well, This was the result of a Turnkey engine, Your wire Harness, Your machine shop, Your installation and Your tune. Your a super nice guy, But no one is perfect. These were installed and fit by you. This is how the engine was after less than a summer.

ealoken

Outch.. my oem 168000 km engine wasnt that bad.

Humboldtgrin

Now how do we know it's truly Chris's fault on that build? My first thought was did they ever change the oil from the break in oil? Or did they use an extrude honed intake manifold? Just things to think about before throwing a bad *** under the bus.

ealoken

im not throwing anyone under the bus.

but i have den this on some bmw And Volvo builds, Where the tollerance between the sleve And piston has been to tight. So the piston expanded more than the sleeve in high temps.

just a tought.

Humboldtgrin

Maybe a better cooling system could fix that issue?

333pg333

We saw the exact same result on FIVE MiD motors down here. We put it down to different expansion rates of forged pistons and ductile iron sleeves. Later on I also felt that the machinists who installed the sleeves may have not done the job correctly. However the pistons looked exactly like those in the pics. Each successive motor was built with more and more piston to wall clearance and the last one sounded like Sunday Church bells upon startup...but they still seized in the bore like these.

Clearly they can work but I don't know that I'd be revisiting this method again.

blade7

Recently I made enquiries about Mahle PowerPak 968 turbo pistons for Alusil, but they are 2168, and Mahle admitted there would be 'some noise' from cold. That and rumours about the coating coming off made me think maybe only Wossners or dry sleeves are practical for most builders outside the US.

rlm328

Curious as I am using forged pistons in conjunction with the MID sleeves and have had no problems with pistons seizing. I have had to rebuild the motor once due to a wrist pin backing out, when I looked at the pistons there was wear but not excessive.

As a data point I do not coat my pistons.

thingo

Mine made about 900 at the crank,Chris provided the sleeved block and wossners. They work fine if they are done correctly.

GPA951s

I Pretty much know what went wrong with it, originally. I wont throw anyone under the bus and dont badmouth anyone, I WILL however state facts, as well as correct any incorrect statements, that I am 100% sure of. Thats it.... I Squared the bores up, and put in a new set of pistons this spring. I had some hard lessons, but no big deal just head gasket stuff. The Engine ran perfect and I am now fairly confident that I have it figured out. I got in touch with the machine shop that did the sleeves and they gave me some good info.
One thing on its own is OK to change (IMO) BUT! I believe when Three things change at once thats when you enter the "bank account" zone... which is a learning curve that you will eventually get right, but it will cost some bucks to figure it out. When you put Raceware studs in an engine with MID sleeves and a Cometic Gasket, Three things have changed yet whos Tourqe spec do you use? Hint: Dont use racewares spec!

333pg333

To clarify, while the parts (Darton MiD Sleeves and JE Pistons) were supplied by Chris, we had the machining done down here. These were not Chris White blocks that we had issues with.