whats the difference between bare ap1 & ap2 blocks
02-21-2008, 09:37 AM
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whats the difference between bare ap1 & ap2 blocks
ok, here is the run down.... i have an ap2.. a good friend of mine has an ap1 with a built bottom end.. he is taking the built bottom end out and putting a stock bottom end in. he is giving me the sleeved block and 89mm forged pistons... my question is, will i be able to install MY ap2 crank and rods over to his built block and forged pistons??
the forged pistons are for FI. the CR is 9.25:1
the forged pistons are for FI. the CR is 9.25:1
02-21-2008, 12:28 PM
#2
It's certainly possible. The only real difference is the crank and rods.
But it's a hell of a rebuild. You'll want to do bearings at the same time.
And to what effect? Are you going FI? If not it's a waste.
But it's a hell of a rebuild. You'll want to do bearings at the same time.
And to what effect? Are you going FI? If not it's a waste.
02-21-2008, 12:37 PM
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Originally Posted by AusS2000,Feb 21 2008, 01:28 PM
It's certainly possible. The only real difference is the crank and rods.
But it's a hell of a rebuild. You'll want to do bearings at the same time.
And to what effect? Are you going FI? If not it's a waste.
But it's a hell of a rebuild. You'll want to do bearings at the same time.
And to what effect? Are you going FI? If not it's a waste.
02-21-2008, 01:32 PM
#4
Yep, 2.2.
On one side of the argument why bother. You'll be going to a whole lot of trouble to up your capacity 200cc and lower your redline. Probably increase your power by as much as a raise of 0.1psi would when turbocharged.
On the other hand, you get parts cheap!
On one side of the argument why bother. You'll be going to a whole lot of trouble to up your capacity 200cc and lower your redline. Probably increase your power by as much as a raise of 0.1psi would when turbocharged.
On the other hand, you get parts cheap!
02-21-2008, 01:54 PM
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Originally Posted by AusS2000,Feb 21 2008, 02:32 PM
Yep, 2.2.
On one side of the argument why bother. You'll be going to a whole lot of trouble to up your capacity 200cc and lower your redline. Probably increase your power by as much as a raise of 0.1psi would when turbocharged.
On the other hand, you get parts cheap!
On one side of the argument why bother. You'll be going to a whole lot of trouble to up your capacity 200cc and lower your redline. Probably increase your power by as much as a raise of 0.1psi would when turbocharged.
On the other hand, you get parts cheap!
02-21-2008, 02:00 PM
#6
I wasn't suggesting you shouldn't use his block and pistons. I was suggesting you use his whole short block rather than rebuild with your cranks and rods.
But if you have cheap access to parts and a competent engine builder go ahead.
But if you have cheap access to parts and a competent engine builder go ahead.
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02-21-2008, 04:24 PM
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Originally Posted by AusS2000,Feb 21 2008, 02:32 PM
Yep, 2.2.
On one side of the argument why bother. You'll be going to a whole lot of trouble to up your capacity 200cc and lower your redline. Probably increase your power by as much as a raise of 0.1psi would when turbocharged.
On the other hand, you get parts cheap!
On one side of the argument why bother. You'll be going to a whole lot of trouble to up your capacity 200cc and lower your redline. Probably increase your power by as much as a raise of 0.1psi would when turbocharged.
On the other hand, you get parts cheap!
(8.9/2)(8.9/2)(3.1415)(9.07)(4) = 2257 cc instead of 2157 cc (AP2)
(radius squared)(Pi)(stroke)(# cylinders)
A 89mm piston couldn't weigh that much more than a 87mm stock piston, especially if it is forged, especially if it has less material in it like a lower-compression piston must.
Increasing stroke will lower redline due to higher piston speeds. A much larger piston would be needed to make its mass test the rod/crank strength.
what WILL kill your power is the lower compression, until you massively overcompensate for it with the turbo.
02-21-2008, 04:51 PM
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Originally Posted by Amphibian,Feb 21 2008, 05:24 PM
No, he will only increase it by 100 cc:
(8.9/2)(8.9/2)(3.1415)(9.07)(4) = 2257 cc instead of 2157 cc (AP2)
(radius squared)(Pi)(stroke)(# cylinders)
A 89mm piston couldn't weigh that much more than a 87mm stock piston, especially if it is forged, especially if it has less material in it like a lower-compression piston must.
Increasing stroke will lower redline due to higher piston speeds. A much larger piston would be needed to make its mass test the rod/crank strength.
what WILL kill your power is the lower compression, until you massively overcompensate for it with the turbo.
(8.9/2)(8.9/2)(3.1415)(9.07)(4) = 2257 cc instead of 2157 cc (AP2)
(radius squared)(Pi)(stroke)(# cylinders)
A 89mm piston couldn't weigh that much more than a 87mm stock piston, especially if it is forged, especially if it has less material in it like a lower-compression piston must.
Increasing stroke will lower redline due to higher piston speeds. A much larger piston would be needed to make its mass test the rod/crank strength.
what WILL kill your power is the lower compression, until you massively overcompensate for it with the turbo.
bottom line, its beneficial to install the built block and forged pistons...correct?
with boost of course..
02-21-2008, 05:31 PM
#10
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If the shortblock is already assembled, I wouldn't swap crankshafts and rods to have to redo all the bearing clearances for the different parts.
No 2 blocks or cranks are exactly the same, and the bearings will change between them.
No 2 blocks or cranks are exactly the same, and the bearings will change between them.
