Block boring needed in Seattle area!
03-19-2012, 09:42 PM
#1
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Block boring needed in Seattle area!
I need to find a shop around the Seattle area that can bore out my S2 block, someone who knows these cars and knows how to work with alusil. I know there are shops in the area, I just need some contact info. recomendations?
Last edited by 944meister; 03-20-2012 at 05:21 AM.
03-19-2012, 11:02 PM
#2
Nordschleife Master
Mercedes also use Alusil in some of thier blocks so don't rule out a specialist Merc engine shop. If you need the correct KS procedure for doing the job pm me with your email. Good for judging a shop knows what it's talking about. Sorry cannot upload it's a large PDF.
03-20-2012, 05:30 AM
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there is scoring that i can catch a fingernail on in cylinders #1,#2,#3, 2 and 3 are the worst, however #4 has two large patches where the alusil coating is worn away completely on opposing sides of the cylinder. compression test showed 120psi in #4 (to compare, 195psi in #3) and excessive amount of air getting into the crankcase during a leakdown test. im not sure that just reconditioning the cylinders would be enough to get rid of the scoring, either way the block is getting stripped down, the head also needs a good rebuild too 
, looking forward to a full teardown next weekend 
, looking forward to a full teardown next weekend
Last edited by 944meister; 03-20-2012 at 05:45 AM.
03-20-2012, 08:37 AM
#5
Nordschleife Master
"two large patches where the alusil coating is worn away completely on opposing sides of the cylinder."
Just to clarify, Alusil is NOT a coating and what you are considering as coating wear is in fact normal on these engines. Alusil is referring to the composition of the metal the block is made off which is an aluminum-silicon composite. The bores are then finished to wear away the aluminum at the surface and expose the silicon particles. The only coating is actually on the pistons where an iron coating is applied to be compatible with the exposed silicon in the bore. Without the iron on the pistons the exposed silicon in the bore would quickly wear the aluminum pistons.
I had this done to my engine a few years back and the process to restore the bore is to hone the scratches out and re-lap the bores with AN-30 to expose the silicon again. Then Swain coat the pistons to spec and match the new bore size and gap rings to match.
I could catch my nail on the scratches before and I was told that if the scratches were too deep they would have to bore and sleeve but that option wasn't necessary in my case.
Just to clarify, Alusil is NOT a coating and what you are considering as coating wear is in fact normal on these engines. Alusil is referring to the composition of the metal the block is made off which is an aluminum-silicon composite. The bores are then finished to wear away the aluminum at the surface and expose the silicon particles. The only coating is actually on the pistons where an iron coating is applied to be compatible with the exposed silicon in the bore. Without the iron on the pistons the exposed silicon in the bore would quickly wear the aluminum pistons.
I had this done to my engine a few years back and the process to restore the bore is to hone the scratches out and re-lap the bores with AN-30 to expose the silicon again. Then Swain coat the pistons to spec and match the new bore size and gap rings to match.
I could catch my nail on the scratches before and I was told that if the scratches were too deep they would have to bore and sleeve but that option wasn't necessary in my case.
