elias_799

iTrader: (8)

^^^ i don't think so man, they have to have some sort of liner or coating. otherwise those cylinder bore's will wear pretty quick.

Steve - Race Eng

iTrader: (1)

The H22 Honda and the 2ZZ Toyota four bangers, Subaru EJ257 race blocks among others, use a MMC or metal matrix composite cylinder wall coatings. It is pretty tough stuff and eats my inserts when I sleeve these blocks. The pistons have a coating to make them compatible with the cylinder walls. Any after market race piston can be used after I sleeve these blocks, plus the ductile iron sleeves are stronger.

The Vega and the 430 Can Am blocks were cast in Reynolds 390 aluminum alloy. Mercedes uses or used the same alloy in some of their production blocks. This alloy has a high silicon content. Bores are lapped after honing to leave the hard silicon particles on the surface. Pistons were iron coated in these engines to prevent scuffing. I used to sleeve a lot of Vega blocks back then because many scuffed cylinder walls due to variations in the silicon content of the mass produced blocks.

Steve

Brief Encounter

iTrader: (6)

Im glad someone finally bought up the Reynolds 390 blocks. Those things were incredible, especially the 494 Big Block.

BTW, Ferrari has been on Nikasil liners since the days of the 308. So what does that tell you.

Steve - Race Eng

iTrader: (1)

Actually it is the 328 and later Ferrari engines that have aluminum wet liners. The 308 used ductile iron wet liners. I have a large bore ductile iron wet liner kit for the 308 328 Ferrari engines.

The aluminum liners save weight but they won't stay round nor hold the power that a ductile iron liner will.

Steve

JCR

The American name for the process was Reynolds 390 as Steve describes. It is also known in Europe (Germany) as Alusil. Most manufacturers in Europe that use aluminum blocks have gone from Nikasil (coating) to Alusil since it is cheaper. This link has a good description of the processes. http://www.lnengineering.com/whynickies.html

Krom

B&S engines use a non plated aluminum bore...

Plated cylinders are real common in power sports, and street bikes, there are a couple turbo snowmobiles that make 530 hp from 2 cylinder 1200 cc engines (thats 7.2 hp per cubic inch) The plating is bullet proof, much harder than rings pistons, or any thing else that rides in there. The only time wear or damage becomes an issue is if something else goes wrong and parts bounce around in a running engine.

http://www.mt-llc.com/

and

http://www.usnicom.com/

are 2 places that do it in the US, msrp is about $200 per hole to strip / bore/ re-plate/ and hone.. Far cheaper than the 400 to 800 per cylinder to replace with new on a bike or sled...

elias_799

iTrader: (8)

wet liner ? i think you mean wet sleeve. liner is just a very thin coating, and i do not see how you can run coolant around it without braking the bore.

Tom@SpeedInc

iTrader: (5)

Dunno if it was mentioned, C6R block is aluminum with no sleeves (saves weight/ affects handling), this engine isn't designed for longevity just to run a race.

Jaguar did have a production aluminum block, no sleeves, I don't think most made it to 100k miles

WKMCD

iTrader: (2)

The Yamaha GP bikes (TZ's) had a chomium alloy cylinder coating and ran iron rings. Some tried recoating them with Nikasil with mixed success at the time.

89StripeGT

Most of the Prototype cars in the ALMS and euro Le Mans series use all aluminium bores. They use a Nickel Silicon Carbide type coating (Nikasil?) on them which has a harder surface than iron does, which means less friction, and no heat expansion issues that are associated with iron liners. Even NASCAR engines, which are iron bore/iron block use Nickel coatings because of less friction on the rings and longer bore life.

Wnts2Go10O

iTrader: (12)

running 24 hours of high rpm is pretty damn good longevity.

the original GM aluminum engines had of problems because at first they didnt modify the water jackets to compensate for the different material.

camaropilot

iTrader: (1)

I should be ovious that he has an iron block do does he think he has a iron block w/ aluminum walls

elias_799

iTrader: (8)

^^^^^^ ?

PlatnumStatuz

iTrader: (6)

porsche 968

melsie68

iTrader: (8)

I CANNOT BELIEVE THIS THREAD IS STILL RUNNING