2.8 Turbo
06-26-2002, 07:36 AM
#16
Burning Brakes
Join Date: Feb 2002
Location: London, England
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Thanks guys, thats why I asked as my car has just had a pretty expensive engine rebuild just before I bought it 
One to think about for the future or if the right parts happen to come along...
One to think about for the future or if the right parts happen to come along...
06-26-2002, 12:27 PM
#17
Burning Brakes
Join Date: Jan 2002
Location: Fairfax Station, Va
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Hey Turby,
I got your message, but have not had time to respond. I also made a mistake in my first post. It was bored to 106mm NOT 103mm. I'll find my invoice and let you know what the total was and what all I did.
I got your message, but have not had time to respond. I also made a mistake in my first post. It was bored to 106mm NOT 103mm. I'll find my invoice and let you know what the total was and what all I did.
06-27-2002, 02:28 AM
#19
Intermediate
Join Date: Apr 2002
Location: Redondo Beach CA
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How much displacement does the dish in the top of the piston add? All the calculations that I have seen are taking into account for a flat top piston. The dish is considerable size , does anyone know what that adds? Just curious, I have 104 mm sleeves being put in a block now with je pistons (standard dish type pistons) stock stroke. I figure it puts me at 2682.084 not counting the dish in the piston.
06-27-2002, 02:35 AM
#20
Racer
Join Date: May 2001
Location: Albuquerque, NM
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[quote]Originally posted by melted:
<strong>How much displacement does the dish in the top of the piston add? All the calculations that I have seen are taking into account for a flat top piston. The dish is considerable size , does anyone know what that adds? Just curious, I have 104 mm sleeves being put in a block now with je pistons (standard dish type pistons) stock stroke. I figure it puts me at 2682.084 not counting the dish in the piston.</strong><hr></blockquote>
The dish doesn't add any displacement. Displacement is the volume change from BDC to TDC (multiplied by the number of pistons).
In your scenario, we'll call the TDC volume X1 and the BDC volume X2. For a flat top piston, the displacement of that cylinder is X2-X1.
For a dished piston, let's call the dish volume Y. The new displacement is (X2+Y)-(X1+Y). Doing simple math, you get X2+Y-X1-Y which is the same as X2-X1.
Hopefully I have not been too confusing. The dish WILL however change the compression ratio (a more dished piston will have a lower ratio), and also can allow room for valves.
Hope this helped,
Dave
<strong>How much displacement does the dish in the top of the piston add? All the calculations that I have seen are taking into account for a flat top piston. The dish is considerable size , does anyone know what that adds? Just curious, I have 104 mm sleeves being put in a block now with je pistons (standard dish type pistons) stock stroke. I figure it puts me at 2682.084 not counting the dish in the piston.</strong><hr></blockquote>
The dish doesn't add any displacement. Displacement is the volume change from BDC to TDC (multiplied by the number of pistons).
In your scenario, we'll call the TDC volume X1 and the BDC volume X2. For a flat top piston, the displacement of that cylinder is X2-X1.
For a dished piston, let's call the dish volume Y. The new displacement is (X2+Y)-(X1+Y). Doing simple math, you get X2+Y-X1-Y which is the same as X2-X1.
Hopefully I have not been too confusing. The dish WILL however change the compression ratio (a more dished piston will have a lower ratio), and also can allow room for valves.
Hope this helped,
Dave
06-27-2002, 04:41 AM
#21
Addict
Rennlist Member
Rennlist Member
Turby
If you're interested, I've got a standard main/standard rod 3.0L crank with polished journals. E-mail me for details.
In regards to rods, you can use the stock rods with the specific Mahle pistons (relocated wrist pin) provided you clearance (slightly) the bearing girdle. Very little grinding required.
If you're interested, I've got a standard main/standard rod 3.0L crank with polished journals. E-mail me for details.
In regards to rods, you can use the stock rods with the specific Mahle pistons (relocated wrist pin) provided you clearance (slightly) the bearing girdle. Very little grinding required.