Mahle Piston to wall clearance
#17
Rennlist Member
Thread Starter
I think that is the problem. The block was oversized and honed using KS NOT Sunnen system. The silicon was exposed with corundum pads not felt pads with An30 paste. after it came back form the machine shop the bores was shinny almost mirror like. Send it back to be exposed with paste ( KS paste) and when it came back again was looking dull but not like an used original cylinder. So I think this is the problem.
#19
Rennlist Member
Thread Starter
I found a company in Germany who can Nikasil plate the cylinders, but they need to go to the next size. This also means other pistons. I already sent the block to another machine shop to install dry iron sleeves. I'am not sure with PTW clerance in this configuration.
#20
Nordschleife Master
I found a company in Germany who can Nikasil plate the cylinders, but they need to go to the next size. This also means other pistons. I already sent the block to another machine shop to install dry iron sleeves. I'am not sure with PTW clerance in this configuration.
With Nikasil they should be able to bring you back to stock spec on the bores and you can still use your Alusil compatible pistons just with different rings. Alusil (KS) dry sleeving is very expensive last time I looked and steel sleeves would mean new pistons and really not cost effective. In the US 928 Motorsports will Nikasil a 944 for under $1,500, plus Nikasil is much more hardwearing than Alusil.
#21
Good reading and learning material from Refresh951
http://www.refresh951.com/
Also check out all the videos from flat6innovations there is some good learning material there
http://flat6innovations.com/
Also search posts by "Blown 944" talking about building sleeved engines and piston to wall clearances
This is transferable skills information to help understand more about this type of work.
http://www.refresh951.com/
Also check out all the videos from flat6innovations there is some good learning material there
http://flat6innovations.com/
Also search posts by "Blown 944" talking about building sleeved engines and piston to wall clearances
This is transferable skills information to help understand more about this type of work.
#22
West
#23
Drifting
#24
Drifting
So Alex are you based in Germany or the US?
With Nikasil they should be able to bring you back to stock spec on the bores and you can still use your Alusil compatible pistons just with different rings. Alusil (KS) dry sleeving is very expensive last time I looked and steel sleeves would mean new pistons and really not cost effective. In the US 928 Motorsports will Nikasil a 944 for under $1,500, plus Nikasil is much more hardwearing than Alusil.
#25
Nordschleife Master
#26
Drifting
Seeing as Porsche used Nikasil on the 911 turbo and 968S engines you'd think it's the best finish. The only place here that does it requires you to remove every ferrous part from the block first though.
#27
Race Car
Yep, every stud, dowel, etc has to be removed.
Millennium Technologies in USA is best alternative.
A shade under $1k for inline 4 plating, they even have a 944 block pictured as an example - https://www.millennium-tech.net/serviceInfo.php?id=12
T
Millennium Technologies in USA is best alternative.
A shade under $1k for inline 4 plating, they even have a 944 block pictured as an example - https://www.millennium-tech.net/serviceInfo.php?id=12
T
#28
Rennlist Member
Thread Starter
So Alex are you based in Germany or the US?
With Nikasil they should be able to bring you back to stock spec on the bores and you can still use your Alusil compatible pistons just with different rings. Alusil (KS) dry sleeving is very expensive last time I looked and steel sleeves would mean new pistons and really not cost effective. In the US 928 Motorsports will Nikasil a 944 for under $1,500, plus Nikasil is much more hardwearing than Alusil.
#29
They pressed in the sleeves and then cut the sleeves to match the existing ports with a die grinder, it appears. Then they apologetically gave the block back to me unfinished. A second shop decked and honed to size.
West
West
#30
Drifting
Thanks for the update. I've seen pics of a couple of lined 104mm blocks done over here, that have the ports all but blocked by the liner. Didn't make sense to me, as the ports are one of the benefits of that block.