difference between 2.5l 16 valve and 2.5l 8 valve late blocks?
05-17-2012, 09:12 AM
#1
Burning Brakes
Thread Starter
difference between 2.5l 16 valve and 2.5l 8 valve late blocks?
I'm in need of a new block for my 1990 turbo.
I cannot find any good 2.5l 8v blocks from 87 or later, but overe here in Europe I can find plenty of 16v engines, both 2.5l and 3l. Should I buy a 2.5 16v. break it up and use the block with my 8V head? I can possibly sell the pistons, head and crank.
I do not think the authorities will allow me to use the 16V head. If they do allow me to use the 16V, will there be any benefits around 300 RWHP? We are taxed pr. horse power, roughly $2000 pr. 30HP so I cannot afford a large increase. I want to run a dual tune setup though so I could possibly benefit from the increased HP when on the track.
If I am to run the 16V head valve require a different DME?
Is the 2.5 8V head a straight swap with the 2.5 16V head?
I cannot find any good 2.5l 8v blocks from 87 or later, but overe here in Europe I can find plenty of 16v engines, both 2.5l and 3l. Should I buy a 2.5 16v. break it up and use the block with my 8V head? I can possibly sell the pistons, head and crank.
I do not think the authorities will allow me to use the 16V head. If they do allow me to use the 16V, will there be any benefits around 300 RWHP? We are taxed pr. horse power, roughly $2000 pr. 30HP so I cannot afford a large increase. I want to run a dual tune setup though so I could possibly benefit from the increased HP when on the track.
If I am to run the 16V head valve require a different DME?
Is the 2.5 8V head a straight swap with the 2.5 16V head?
05-17-2012, 09:39 AM
#2
Nordschleife Master
There is no difference between the 2.5L 8 and 16V motors, the heads swap direct between the two (they even use the same head gasket)!
For 300 HP, the 16V would really be overkill.. but could be done (would be an expensive 2.5L turbo motor for 300 HP... considering the 20,000 in taxes)!
For 300 HP, the 16V would really be overkill.. but could be done (would be an expensive 2.5L turbo motor for 300 HP... considering the 20,000 in taxes)!
05-17-2012, 10:14 AM
#3
Burning Brakes
Thread Starter
Thanks. I realize I underestimated the complexities involved in going 16V. I will consider breaking an engine to get to the block, but it seems a shame breaking a running 16v engine just for the block.
(The taxes are on the additional HP. It would be around $3000 to go from 250 to 300hp.)
(The taxes are on the additional HP. It would be around $3000 to go from 250 to 300hp.)
05-17-2012, 10:32 AM
#4
Nordschleife Master
Thanks. I realize I underestimated the complexities involved in going 16V. I will consider breaking an engine to get to the block, but it seems a shame breaking a running 16v engine just for the block.
(The taxes are on the additional HP. It would be around $3000 to go from 250 to 300hp.)
(The taxes are on the additional HP. It would be around $3000 to go from 250 to 300hp.)
You would need, at a minimum, pistons, intake, exhaust, fuel rail, and some way to tune (reliably) for the new engine setup... also to be considdered would be a second exhaust cam to eliminate the cam chain drive, but this would also eliminate the belt covers, and require a dual pulley setup (Chris White has been doing this)..
The costs add up pretty quickly to get the 16V turbo motor, but the rewards can be large! not to mention having a setup that would likely be one of a kind in your home country, if not continent!
05-17-2012, 10:44 AM
#5
Rennlist Junkie Forever
Hold on....
I believe the front part of the head where the water returns to the radiator is different on 2.5L 8V blocks vs the 16V blocks (perhaps not on the 2.5L 16V block).
And I don't believe the head gaskets to be the same in terms of bore size or the area of he head where the radiator water return is located.
It's been years so I might be off here. But I would verify before proceeding.
TonyG
I believe the front part of the head where the water returns to the radiator is different on 2.5L 8V blocks vs the 16V blocks (perhaps not on the 2.5L 16V block).
And I don't believe the head gaskets to be the same in terms of bore size or the area of he head where the radiator water return is located.
It's been years so I might be off here. But I would verify before proceeding.
TonyG
05-17-2012, 11:44 AM
#7
Nordschleife Master
Hold on....
I believe the front part of the head where the water returns to the radiator is different on 2.5L 8V blocks vs the 16V blocks (perhaps not on the 2.5L 16V block).
And I don't believe the head gaskets to be the same in terms of bore size or the area of he head where the radiator water return is located.
It's been years so I might be off here. But I would verify before proceeding.
TonyG
I believe the front part of the head where the water returns to the radiator is different on 2.5L 8V blocks vs the 16V blocks (perhaps not on the 2.5L 16V block).
And I don't believe the head gaskets to be the same in terms of bore size or the area of he head where the radiator water return is located.
It's been years so I might be off here. But I would verify before proceeding.
TonyG
The 2.7 and 3L (S2 and 968) blocks are interchangeable, with the major difference being the cranks.... which is why a 2.7 head (89 N/A) is sourced for building an 8V 3L turbo motor... it will bolt to the intake and exhaust of the turbo engine, and bolt to the 3L block without modification... nice and easy bolt together solution..
