2.5 limits?
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#13
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I have been running 500+ of each for the best part of 18 months but the car was spec'd for track and competition use. It has been very reliable during this period, which I hope will continue. This is on the standard casing and cylinders, albeit with some machining based mods to the block to assist head gasket / liner issues. Nothing is gauranteed though.
Several other methods exist around re-lining the block, but as of yet, nothing exists that I am completely sure is any more reliable than what I already have. These consist of a top hat liner design as well as a conventional liner.
The block is inherently flawed in design, as regards to using the same casing as the 2ltr, but upping the cylinder capacity to 2.5ltrs. This results in less space available for cylinder thickness and stability.
A couple of "other" solutions exist, but they involve machining the liners and fitting complete inserts to enable a more "closed deck" nature. One in particular has just been designed and released, which also takes the capacity up to 2.6ltrs. I am tempted to look at the latter during 2009.
You pay your money and take the risk...... because at this level of 500+ on a 2.5ltr, that is exactly what you will be doing. Nothing is absolute at this level and above, regardless of what people may lead you to believe.
Dependant on your use, it can get very very expensive at this level. Hence why not that many true 500+ 2.5ltr Subaru engines exist and continue to work without reliability issues.
Last edited by Shaun; 06 December 2008 at 11:37 AM.
#15
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This engine built by APi, is on a standard block.
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#16
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You pay your money and take the risk...... because at this level of 500+ on a 2.5ltr, that is exactly what you will be doing. Nothing is absolute at this level and above, regardless of what people may lead you to believe.
Dependant on your use, it can get very very expensive at this level. Hence why not that many true 500+ 2.5ltr Subaru engines exist and continue to work without reliability issues.
I would happily run 600bhp on my 2.5ltr lump without fear of trashing it
#18
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Last edited by C. J.; 06 December 2008 at 06:31 PM.
#19
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Steve,
I would be happy to run 600+bhp on my block as well (with a suitably spec'd turbo)! My block spec has already ran a fair bit more than that for most of a Time Attack race season without any cylinder issues. Regardless of that, suggesting that there is no risk is being some what naive. Are you stating your engine is bullet proof at 600bhp then?
I would be happy to run 600+bhp on my block as well (with a suitably spec'd turbo)! My block spec has already ran a fair bit more than that for most of a Time Attack race season without any cylinder issues. Regardless of that, suggesting that there is no risk is being some what naive. Are you stating your engine is bullet proof at 600bhp then?
#26
Scooby Regular
Steve,
What does Chy charge for a fully built bottom end and what does he fully expects is it's safe limit for track use?
Cylinder pressure is an issue, but so is det and the affect of det when experiencing headgasket issues. I have seen det start to eat away the top of the liner.
Keeping the torque at sensible levels should see you OK, assuming everything else being equal.
It also has a lot to do with your intended use..... the harder you push the engine, in say track conditions, the more chance you have of finding a weakness.
What does Chy charge for a fully built bottom end and what does he fully expects is it's safe limit for track use?
Keeping the torque at sensible levels should see you OK, assuming everything else being equal.
It also has a lot to do with your intended use..... the harder you push the engine, in say track conditions, the more chance you have of finding a weakness.
#28
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Std Ej257 engine, rods and pistons have been run over 400 bhp / 400 lb/ft without issues. but you are eeeking into a dangerous area there and I would expect problems at some point.
I wanted to run over 450 of each on a reliable basis so the engine built for me by Area 52 Autosport has been over-engineered (as per my spec) in order to do this without worry. I have been able, as a result, to run whatever boost pressure I want (up to 2.5 bar) on bolt on turbos of various sizes and get to 545/600 most recently and I still dont think the engine is stressed too much.
Any engine, badly mapped and not listened to, looked after or maintained well will hold its hands up and say enough. Mine has done 11,000 miles in this spec so far and get used for Time Attack as well as daily duties but I look, listen and (as daft as it sounds) smell for problems.
The myth about 2.5 engines being unreliable is unfounded in my opinion.
I wanted to run over 450 of each on a reliable basis so the engine built for me by Area 52 Autosport has been over-engineered (as per my spec) in order to do this without worry. I have been able, as a result, to run whatever boost pressure I want (up to 2.5 bar) on bolt on turbos of various sizes and get to 545/600 most recently and I still dont think the engine is stressed too much.
Any engine, badly mapped and not listened to, looked after or maintained well will hold its hands up and say enough. Mine has done 11,000 miles in this spec so far and get used for Time Attack as well as daily duties but I look, listen and (as daft as it sounds) smell for problems.
The myth about 2.5 engines being unreliable is unfounded in my opinion.
Last edited by dynamix; 07 December 2008 at 06:07 PM.
#30
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Subaru impreza turbo 2.5 closed deck short motor on eBay, also Engine Tuning Parts, Performance Tuning Parts, Car Tuning Styling, Cars, Parts Vehicles (end time 17-Dec-08 12:04:33 GMT)
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