Lapping the head on M20 while I am there

[dprussky]

I am replacing the head from 325i on my 325es, It looks like there are maybe an option to remove the headgasket to increase compression. There is huge amount of labor + valve clearance concerns. Did anybody done this?

[LJ851]

I am replacing the head from 325i on my 325es, It looks like there are maybe an option to remove the headgasket to increase compression.

This is a fantastic idea, why didn't i think of this?

[Dirty325ix]

I always skip the headgasket and chock it up as a weight saver....I also don't use lug nuts for my wheels, every ounce counts

[rcsoundn1]

let us know how that works out ok

[DER E30]

I always skip the headgasket and chock it up as a weight saver....I also don't use lug nuts for my wheels, every ounce counts

Delete the brakes while there too! Brakes are heavy and they only slow you down!!!!

[dprussky]

I sense some sarcasm… but it has been done. It is common to do on the race bikes.

http://www.ri-engineering.com/cylinder-head-lapping.html

http://www.ephotomotion.com/914engine/page29.html

[dnguyen1963]

To do this, both surfaces have to be super smooth. It has to be done on both the head and the block. One hell of an expensive process as compared to the cost of a HG. Racing teams can afford to do this...not average Joe.

[LJ851]

I sense some sarcasm… but it has been done. It is common to do on the race bikes.

http://www.ri-engineering.com/cylinder-head-lapping.html

http://www.ephotomotion.com/914engine/page29.html

I have lapped hundreds of cylinder heads on ducati motorcycles. Nothing with oil and coolant passageways is going to seal without a gasket of some sort.

Some aircooled engines are designed to run gasketless but it's basically just a fire ring and no sealing of fluids.

Show me an inline, water cooled engine without a headgasket of some sort.

[dprussky]

Here is the one that got me on the path to ask the question here. I will look more tonight see if anybody did something like that on the diesel engine.
http://forums.nasioc.com/forums/show....php?t=1967024

[LJ851]

Here is the one that got me on the path to ask the question here. I will look more tonight see if anybody did something like that on the diesel engine.
http://forums.nasioc.com/forums/show....php?t=1967024

Note the use of fire rings around the cylinders and and o-rings around fluid passages, gaskets of a different type to replace the old gasket.


The fire rings alone would cost would cost nearly as much as a set of high compression pistons if they are similar in price to the Ducati ones.

[TobyB]

Hee hee.

single cylinder aircooled race bike = 6 cylinder watercooled BMW iron- blocked aluminum- headed econosedan from 1988

not.

You CAN run a thin headgasket to raise compression, but there are better ways.
If that's what you want to do.

Lorin, my dad had that Scout with the full- length top. And the 'half- a v8' four....

t

[dprussky]

After reviewing and doing some more research. Expansion rates of Iron (Block) and Aluminum (Head) are different so it requires the medium to compensate for those expansions.

It would work if block and head are made out of the same material.

Any recommendations on the nice thin headgasket

[digger]

MLS, otherwise oem 1.75mm