928 Motorsports can repair Scratched Cylinder Walls
09-27-2005, 06:25 PM
#61
Road Warrior
Rennlist Member
Rennlist Member
Originally Posted by puyi
question from a newbie :
As I know, 928 blocks were treated by alusil method. I had always thought that the 928 block were treated with nikasil method but it seems not.
The reparing treatment which is provide by Nicom or other is Nikasil. I have heard that OEM piston rings are not compatible with nikasil treated blocks. Is that true? What is the material used for these rings? If it is incompatible, what are the replacement solutions?
thank you for the lights
regards
STL
As I know, 928 blocks were treated by alusil method. I had always thought that the 928 block were treated with nikasil method but it seems not.
The reparing treatment which is provide by Nicom or other is Nikasil. I have heard that OEM piston rings are not compatible with nikasil treated blocks. Is that true? What is the material used for these rings? If it is incompatible, what are the replacement solutions?
thank you for the lights
regards
STL
IIRC, millinium mentioned that anything but high tension chrome rings are fine w/nicom bores....
09-27-2005, 07:55 PM
#62
Developer
Thread Starter
You got me, John, I did say "pretzel".
I also said this in the same thread, a few posts later:
...and I said:
and then:
Just my opinion. All opinions are arguable.
John, sorry if I stepped on your toes back then, I did not know you took offense to what I posted until this thread just now.
I'll buy you ar beer at Sharktoberfest!
I also said this in the same thread, a few posts later:
The "Supercharger vs Turbocharger" conversation is a bar stool arguement that has no end. It belongs on the list of other bar stool arguements that have neither answer nor end like: "air-to-air intercooler vs air-to-water" and "Positive-discplacement vs Centrifugal"
There is not doubt that, when properly engineered, they both work.
When it comes to aftermarket applications, centrifugal superchargers have several advantages (as compared to PD blowers and Turbos): easiest installation, ability to retain most if not all OEM anti-polution stuff for EPA recertification, and coolest charged air before an intercooler.
John, sorry if I stepped on your toes back then, I did not know you took offense to what I posted until this thread just now.
I'll buy you ar beer at Sharktoberfest!
09-27-2005, 11:34 PM
#63
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Sorry man....can't make it. I'm exceptionally busy with work right now, ready to head to Germany for the Cemat show next month...beer, next year! I'll bring the Depends for rides in my new maniac machine...I'd better get my tail busy fabbing parts! 2nd time around is always easier...a clear mental plan...but sometimes the best thought out plans still throw you a wrench (but not a pretzel :0)
09-28-2005, 12:26 AM
#64
So I have a quick question.
How much can the Nikasil actually Add to the wall? Lets say you wanted the bore to DECREASE.
How much can the Nikasil actually Add to the wall? Lets say you wanted the bore to DECREASE.
09-28-2005, 05:59 AM
#66
Racer
Originally Posted by 928SS
IIRC, millinium mentioned that anything but high tension chrome rings are fine w/nicom bores....
STL
09-28-2005, 02:51 PM
#68
Could a 928 piston coated by Swain tech with thier low friction PC-9 be put into the nikasil bore?
09-28-2005, 11:15 PM
#70
Developer
Thread Starter
FYI: one of the benefits of boring is to get into "standard" american piston sizes where you can get fancier pistons for less money than OEM.
Here are mine... and thanks to Phil Threshie at 928 Developments for his input to help me pick them out.
We used Arias pistons in the hi-silicone/low expansion alloy (special order) so we could reduce the piston clearance, and thereby reduce blowby. This engine will be boosted, so reducing blowby is is a design consideration for us. We were able to reduce the side clearance of the pistons to 1/2 their original spec.
Less air goes around the piston = less crankcase pressure, + more pressure remains on top of the piston pushing down.
That's a good thing.
Forged of course, and, note the lightened skirting and graphite-impregnated teflon coating on the skirts.
Here are mine... and thanks to Phil Threshie at 928 Developments for his input to help me pick them out.
We used Arias pistons in the hi-silicone/low expansion alloy (special order) so we could reduce the piston clearance, and thereby reduce blowby. This engine will be boosted, so reducing blowby is is a design consideration for us. We were able to reduce the side clearance of the pistons to 1/2 their original spec.
Less air goes around the piston = less crankcase pressure, + more pressure remains on top of the piston pushing down.
That's a good thing.Forged of course, and, note the lightened skirting and graphite-impregnated teflon coating on the skirts.
09-29-2005, 02:30 AM
#71
I think I have asked this, but how much for that set Carl? Very nice crown to first ring distance!
09-29-2005, 12:35 PM
#72
Developer
Thread Starter
Oh man... I think it was about $600 for the set oif 8 pistons, and I had them work with me on selecting rings for those pistons also.
Call Phil Threshie at 928 Developments or email him and see if he can help you with Piston selection. If he cannot or will not, I will. I just want to give him first shot at it before I encroach on his specialty.
Call Phil Threshie at 928 Developments or email him and see if he can help you with Piston selection. If he cannot or will not, I will. I just want to give him first shot at it before I encroach on his specialty.
09-30-2005, 03:55 PM
#73
Road Warrior
Rennlist Member
Rennlist Member
Originally Posted by puyi
It is what I was thinking about. So the thrid piston ring has to be change as it is made w/chrome. Any idea of what ring to replace OEM standard.
STL
STL
good to have choices, although I do wonder how much real power is made w/"special" piston coatings and "extra tight" tols after 5k or 50k miles of street driving.... I never could find a coating that was there after even 20hrs of racing on my race motors, and after looking at my oem chromed KS pistons, even the chrome was gone at 135kmiles (but who knows when it was gone??)
