when porsche went from 2.5 liters to 3.0 liters...
11-18-2010, 06:04 AM
#16
Olli, your article is in German!!!
Purpose of 951 head's ceramic liners is very well descriped in 944 Turbo Information Technik manual.
11-18-2010, 07:10 AM
#17
Race Car
11-18-2010, 08:46 AM
#18
With any larger displacement engine you are going to want to upgrade the oil cooler. The factory one is barely adequate for a stock car on the track.
(well, I'm repeating what most of the track guys have said/learned).
Haven't really heard of drastic engine cooling issues in my research or long conversations with Chris White.
(well, I'm repeating what most of the track guys have said/learned).
Haven't really heard of drastic engine cooling issues in my research or long conversations with Chris White.
11-18-2010, 08:10 PM
#19
Racer
Thread Starter
HIgh horsepower
Reliability
Not super, super expensive.
You can have any 2 of the 3 you want. Unless you get a V8.
Reliability
Not super, super expensive.
You can have any 2 of the 3 you want. Unless you get a V8.
With any larger displacement engine you are going to want to upgrade the oil cooler. The factory one is barely adequate for a stock car on the track.
(well, I'm repeating what most of the track guys have said/learned).
(well, I'm repeating what most of the track guys have said/learned).
11-19-2010, 09:50 AM
#20
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I have not found any cooling issues with the 3.0 block – its one of those ‘stories’ that you see every now and then. I would guess that somebody built a 3.0 turbo had lots of overheating problems and then blamed it in the block instead of poor tuning….
The 3.0 block is stronger and one of the really good features are the windage holes between the cylinders – this helps a lot with oil control. Keep in mind that one of the water passages is a different shape so a 951 head will not be a direct bolt on to a 3.0 block. You can modify the head to fit if you want.
On the ceramic ports – the purpose is to keep the heat in the exhaust - not for the sake of head cooling but to keep as much heat energy in the system to drive the turbo. For those that missed Turbo 101 – it’s the heat that drives the turbo – not the gas velocity.
If you are going to build a 2.8 keep in mind that 2.8’s have their own tuning requirements that are different than a 2.7 or 2.5. The ignition timing needs to be addressed in order to keep the engine ‘happy’!
The 3.0 block is stronger and one of the really good features are the windage holes between the cylinders – this helps a lot with oil control. Keep in mind that one of the water passages is a different shape so a 951 head will not be a direct bolt on to a 3.0 block. You can modify the head to fit if you want.
On the ceramic ports – the purpose is to keep the heat in the exhaust - not for the sake of head cooling but to keep as much heat energy in the system to drive the turbo. For those that missed Turbo 101 – it’s the heat that drives the turbo – not the gas velocity.
If you are going to build a 2.8 keep in mind that 2.8’s have their own tuning requirements that are different than a 2.7 or 2.5. The ignition timing needs to be addressed in order to keep the engine ‘happy’!
11-19-2010, 11:29 AM
#21
One of the reasons ceramic liners were used was that in the days of early testing of the 944 turbo engine, back in 1984, headgaskets were consistently blowing.
Obviously I can only relate to my limited experience, and when my engine is idling fully warmed-up I see on average a whole bar less than I used to with the 2.5, with the same cooling system and the same oil. Bearings have 12k miles on the 3.0, had 170k miles the 2.5.
A 3.0 warms up more than twice as quickly as a 2.5, probably because it contains half as less coolant. My 3.0T actually warms up exactly as quickly as my 3.0 NA (S2).
From these very basic observations it's quite difficult not to come to the simple conclusion that the 3.0 block produces heat more quickly than the 2.5 and that running a 2.7 head with no ceramic liners on a turbo application, with cylinder pressures/heat production higher than on a NA engine, is never going to offer an optimum level of heat insulation towards the HG.
Obviously I can only relate to my limited experience, and when my engine is idling fully warmed-up I see on average a whole bar less than I used to with the 2.5, with the same cooling system and the same oil. Bearings have 12k miles on the 3.0, had 170k miles the 2.5.
A 3.0 warms up more than twice as quickly as a 2.5, probably because it contains half as less coolant. My 3.0T actually warms up exactly as quickly as my 3.0 NA (S2).
From these very basic observations it's quite difficult not to come to the simple conclusion that the 3.0 block produces heat more quickly than the 2.5 and that running a 2.7 head with no ceramic liners on a turbo application, with cylinder pressures/heat production higher than on a NA engine, is never going to offer an optimum level of heat insulation towards the HG.
10-14-2021, 09:53 AM
#22
Modify 951 Head?
I have not found any cooling issues with the 3.0 block – its one of those ‘stories’ that you see every now and then. I would guess that somebody built a 3.0 turbo had lots of overheating problems and then blamed it in the block instead of poor tuning….
The 3.0 block is stronger and one of the really good features are the windage holes between the cylinders – this helps a lot with oil control. Keep in mind that one of the water passages is a different shape so a 951 head will not be a direct bolt on to a 3.0 block. You can modify the head to fit if you want.
On the ceramic ports – the purpose is to keep the heat in the exhaust - not for the sake of head cooling but to keep as much heat energy in the system to drive the turbo. For those that missed Turbo 101 – it’s the heat that drives the turbo – not the gas velocity.
If you are going to build a 2.8 keep in mind that 2.8’s have their own tuning requirements that are different than a 2.7 or 2.5. The ignition timing needs to be addressed in order to keep the engine ‘happy’!
The 3.0 block is stronger and one of the really good features are the windage holes between the cylinders – this helps a lot with oil control. Keep in mind that one of the water passages is a different shape so a 951 head will not be a direct bolt on to a 3.0 block. You can modify the head to fit if you want.
On the ceramic ports – the purpose is to keep the heat in the exhaust - not for the sake of head cooling but to keep as much heat energy in the system to drive the turbo. For those that missed Turbo 101 – it’s the heat that drives the turbo – not the gas velocity.
If you are going to build a 2.8 keep in mind that 2.8’s have their own tuning requirements that are different than a 2.7 or 2.5. The ignition timing needs to be addressed in order to keep the engine ‘happy’!
10-23-2021, 02:18 AM
#23
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10-23-2021, 11:59 AM
#24
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