need advice on boring block
08-11-2004, 06:35 AM
#16
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The engine was dropped off on Monday and picked up Thursday afternoon, for a timeline, if your interested. Duffin needs the block and girdle on the block and tightened down, that's it.
08-11-2004, 09:46 AM
#17
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Just a note on our break in procedure.I simply showed up at Watken's Glen speedway, and drove the car like it was ment to be driven(on the track). We zero blow by, from day 1, and she pulled strong. Unfortunatly, I only got 2 events with these pistons, because of my overboost (see EBC or MBC thread) killed these pistons and cylinder walls. So I'm now waiting for 101mm to come in.
08-11-2004, 10:40 AM
#18
Three Wheelin'
OK...who makes the pistons? Does the same manufacturer apply the coatings? This is the biggest problem/cost with rebuilding these engines. I have tried the Nicom route and it has too many pitfalls for me.
08-11-2004, 11:08 AM
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The pistons are manufactured by Arias pistons in California, then they are sent to the vendor who gets them coated for the alusil bore.The coating is not from swain coating, but from a better coating company. These are exact replicas of the factory 100.5mm pistons, so you can actually use the factory rings or the ones that come with the pistons(Seal power).
08-11-2004, 11:23 AM
#20
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The pistons are actually manufactured by one company but they are coated by another small speciality company in Tulsa OK. The coating is the KEY. The skirts are coated with iron and a touch of graphite(oil retention) and the tops are thermal coated. There are three small rings for the oil ring and then two uppers. I'll get jwl to chime in here and tell you about the rings, which you have instructions on how to set them up.
Call Tom Charlesworth, PCA Technical Committee Chairman,(who got this all set up with permission from Porsche, Mahle), for the pistons.
918-664-8714
Call Tom Charlesworth, PCA Technical Committee Chairman,(who got this all set up with permission from Porsche, Mahle), for the pistons.
918-664-8714
08-11-2004, 03:38 PM
#21
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The oil or wiper ring is a three piece ring and the middle and compression rings are single.
Orientaion as follows:
bottom oil ring - over wrist pin
middle oil ring - 90 deg. of bottom
top oil ring - 180 deg. of bottom
middle ring - 180 deg. of top oil ring
compression ring - 180 deg. of middle ring
Orientaion as follows:
bottom oil ring - over wrist pin
middle oil ring - 90 deg. of bottom
top oil ring - 180 deg. of bottom
middle ring - 180 deg. of top oil ring
compression ring - 180 deg. of middle ring
08-14-2004, 03:48 AM
#22
Drifting
KS Alusil Process Document
Porsche says the max a 2.5L block can bore to is 106mm. After that- sleeving is required. The Alusil honing process is a four-stage one performing:
1)Hone cylinders with coarse stones, to remove old treatment and resurface walls for silicon re-application
2)Light hone bores with smoother stones to etch the lining with cross-hatching, to optimize wear
3)Apply silicium paste to walls; heat block; then dry with liquid nitrogen
4)Buff and polish using felt pads
Be sure you ask the machine shop about the Kolbenschmidt (KS) Alusil process, using the Sunnen CK-10 machine. If they have the machine give them the KS procedures, to ensure the specs are exactly met. The link below is where printable Porsche specs are located:
http://www.msi-motor-service.com/dow...ren/alu_en.pdf
Zach
1)Hone cylinders with coarse stones, to remove old treatment and resurface walls for silicon re-application
2)Light hone bores with smoother stones to etch the lining with cross-hatching, to optimize wear
3)Apply silicium paste to walls; heat block; then dry with liquid nitrogen
4)Buff and polish using felt pads
Be sure you ask the machine shop about the Kolbenschmidt (KS) Alusil process, using the Sunnen CK-10 machine. If they have the machine give them the KS procedures, to ensure the specs are exactly met. The link below is where printable Porsche specs are located:
http://www.msi-motor-service.com/dow...ren/alu_en.pdf
Zach
Last edited by Dilberto; 08-14-2004 at 03:49 AM. Reason: Need Title
08-14-2004, 02:46 PM
#24
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Originally Posted by Dilberto
Porsche says the max a 2.5L block can bore to is 106mm. After that- sleeving is required. The Alusil honing process is a four-stage one performing:
1)Hone cylinders with coarse stones, to remove old treatment and resurface walls for silicon re-application
2)Light hone bores with smoother stones to etch the lining with cross-hatching, to optimize wear
3)Apply silicium paste to walls; heat block; then dry with liquid nitrogen
4)Buff and polish using felt pads
Be sure you ask the machine shop about the Kolbenschmidt (KS) Alusil process, using the Sunnen CK-10 machine. If they have the machine give them the KS procedures, to ensure the specs are exactly met. The link below is where printable Porsche specs are located:
http://www.msi-motor-service.com/dow...ren/alu_en.pdf
Zach
1)Hone cylinders with coarse stones, to remove old treatment and resurface walls for silicon re-application
2)Light hone bores with smoother stones to etch the lining with cross-hatching, to optimize wear
3)Apply silicium paste to walls; heat block; then dry with liquid nitrogen
4)Buff and polish using felt pads
Be sure you ask the machine shop about the Kolbenschmidt (KS) Alusil process, using the Sunnen CK-10 machine. If they have the machine give them the KS procedures, to ensure the specs are exactly met. The link below is where printable Porsche specs are located:
http://www.msi-motor-service.com/dow...ren/alu_en.pdf
Zach
Are you sure about that 106mm spec? I would love to see when and where Porsche said it is ok to open a 2.5liter up to 106mm. Porsche is so conservative with their engineering, that would seem like an unPorsche thing to say...
08-14-2004, 03:13 PM
#25
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Milledge stated the most he would go was 102.5, if you had custom pistons made and coated. You could get those too I guess, just a couple of more hundred dollars for the CAD setup and drawings to be done..??
That bore would give you a true 2.6L with the 2.5 crank.
That bore would give you a true 2.6L with the 2.5 crank.
Last edited by Ski; 08-14-2004 at 03:30 PM.
08-16-2004, 02:20 PM
#30
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Hey peck, No i haven't diagnosed yet. just going on smoke at idle some of the times. but is still good to know worst case scenario just to prepare for it. I'll do a comp. check this week.
P.S.
For info. turbo has been rebuilt. i've noticed that oil press sometimes stays at 4 bar and thats when i smoke(a lot). there is oil consumption, 1 quart in less than 1,000 miles. idle is high 910 rpm, i don't have a idle valve and need it that high so when i turn on the A/C it does not bog down. #1 plug was oil soaked others fine. who knows maybe is a valve guide(hopefully) but could be something related to piston rings????.
P.S.
For info. turbo has been rebuilt. i've noticed that oil press sometimes stays at 4 bar and thats when i smoke(a lot). there is oil consumption, 1 quart in less than 1,000 miles. idle is high 910 rpm, i don't have a idle valve and need it that high so when i turn on the A/C it does not bog down. #1 plug was oil soaked others fine. who knows maybe is a valve guide(hopefully) but could be something related to piston rings????.