At Harvey's request !!!
24 August 2003, 01:14 PM
#31
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the subary engine design will always be a compromise for reasons I am finding out now.
To my knowledge, the phase 2 heads flow in standard form as well as my modded phase 1 heads.
Cam profiles are also far less isgnificant on a turbo charged engine, ut there is no hearm i allowing the engine to breathe in order to extract the horses.
My biggest concern is now that on friday I went out in morays car running 300lbft and it was almost the fastest thing I have ever been in.
I have no idea what I need with almost double the torque.
Harvey. My engine needs one part ordered that is going to take around 4 weeks. the delay was in ascertaining why it was needed and current prognosis is that it was directly related to the liner flexing. I can't me more specific than that at the mo for reasons I have already stated.
There is nothing dodgy, and it is no major set back, merely linked to the already known failure.
I am installing an sti lump because it became available and because I should have done it 18 months ago. Plus if the 2.5 is unreliable, I will, god willing, have a working back up engine.
I don't see your well wishes as insincere, I am grateful to receive them as I was equally with the gaskets you supplied.
as it stands with stonger liners and a rebuilt engine (built better this time but I cant go into that either) it should old together fine and be reliable.
But as I have said before, I dont believe an engine such as this with all the standard design compromises that subaru built in when they designed the engine, I can't see it being reliable at this power output.
When it is running I will be bringing it down to 400 lazy bhp and lbft and I will be grateful for it.
one more thing I just wanted to add. Don't pay attention to static compression ratio, it is effectively a worthless comparison, dynamic compression is a far more important concept with regard to how the engine performs.
To my knowledge, the phase 2 heads flow in standard form as well as my modded phase 1 heads.
Cam profiles are also far less isgnificant on a turbo charged engine, ut there is no hearm i allowing the engine to breathe in order to extract the horses.
My biggest concern is now that on friday I went out in morays car running 300lbft and it was almost the fastest thing I have ever been in.
I have no idea what I need with almost double the torque.
Harvey. My engine needs one part ordered that is going to take around 4 weeks. the delay was in ascertaining why it was needed and current prognosis is that it was directly related to the liner flexing. I can't me more specific than that at the mo for reasons I have already stated.
There is nothing dodgy, and it is no major set back, merely linked to the already known failure.
I am installing an sti lump because it became available and because I should have done it 18 months ago. Plus if the 2.5 is unreliable, I will, god willing, have a working back up engine.
I don't see your well wishes as insincere, I am grateful to receive them as I was equally with the gaskets you supplied.
as it stands with stonger liners and a rebuilt engine (built better this time but I cant go into that either) it should old together fine and be reliable.
But as I have said before, I dont believe an engine such as this with all the standard design compromises that subaru built in when they designed the engine, I can't see it being reliable at this power output.
When it is running I will be bringing it down to 400 lazy bhp and lbft and I will be grateful for it.
one more thing I just wanted to add. Don't pay attention to static compression ratio, it is effectively a worthless comparison, dynamic compression is a far more important concept with regard to how the engine performs.
24 August 2003, 01:55 PM
#32
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Harvey,
I'm sure that your good wishes to Adam are very sincere.
You don't have a go at people for being "open", but would appear to have a go at those people who are open about their figures, or THEIR "aspirations".
I could argue that you shouldn't be quoting your 128mph 1/4 mile terminal, and 176mph top speed run from Elvington, because they resulted in "terminal failure", and maybe you should wait until you're achieving them reliably ?
Adam was VERY unlucky with the block failing. The same blocks have been tested to 2.75bar, without a problem.
When the damage was originally inspected, it appeared that only the block needed replacing, but on closer inspection, it was discovered that some other parts had been damaged, as a direct result of the block failure. I'm sure Adam will post more information, when he feels it's appropriate.
Whilst you were lucky to have a spare head available to replace your damaged one, Adam doesn't have the spare parts required for a speedy re-build, since the parts concerned are "custom", and will have to be special ordered.
Bit confused over this comment. I've never had a go at anyone for keeping quiet about their spec's, or projects.
If you are implying that "I" keep quiet about my spec's, well yes I do, but I don't quote any figures either. I don't feel that I should discuss what I'm doing with any of my engines, until I'm getting the results I want from them.
Since you have made your feelings about what I do very clear, I'm surprised you have even bothered to suggest that I don't talk about what I do. Unless it's so that you can avoid doing the same things
What I have learnt, is that high BHP figures aren't what seem to cause parts to fail, but hight torque is an issue. IMO, you won't have a problem with a 2lt, because they just can't produce the low down torque of the larger capacity engines. Whilst Adams engine let go at 5500rpm, the damage had occured earlier, and when my gudgeon pin snapped, it happened at 4800rpm.
Mark.
I'm sure that your good wishes to Adam are very sincere.
You don't have a go at people for being "open", but would appear to have a go at those people who are open about their figures, or THEIR "aspirations".
I could argue that you shouldn't be quoting your 128mph 1/4 mile terminal, and 176mph top speed run from Elvington, because they resulted in "terminal failure", and maybe you should wait until you're achieving them reliably ?
Adam was VERY unlucky with the block failing. The same blocks have been tested to 2.75bar, without a problem.
When the damage was originally inspected, it appeared that only the block needed replacing, but on closer inspection, it was discovered that some other parts had been damaged, as a direct result of the block failure. I'm sure Adam will post more information, when he feels it's appropriate.
Whilst you were lucky to have a spare head available to replace your damaged one, Adam doesn't have the spare parts required for a speedy re-build, since the parts concerned are "custom", and will have to be special ordered.
As regards people keeping quiet. Bit like the Pot calling the kettle black.
If you are implying that "I" keep quiet about my spec's, well yes I do, but I don't quote any figures either. I don't feel that I should discuss what I'm doing with any of my engines, until I'm getting the results I want from them.
Since you have made your feelings about what I do very clear, I'm surprised you have even bothered to suggest that I don't talk about what I do. Unless it's so that you can avoid doing the same things
What I have learnt, is that high BHP figures aren't what seem to cause parts to fail, but hight torque is an issue. IMO, you won't have a problem with a 2lt, because they just can't produce the low down torque of the larger capacity engines. Whilst Adams engine let go at 5500rpm, the damage had occured earlier, and when my gudgeon pin snapped, it happened at 4800rpm.
Mark.
25 August 2003, 05:57 PM
#33
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Some food for thought chaps....
I think that the notion of torque being an issue more than power is hitting the nail on the head. Turbocharged cars produce the additional torque, not by increasing the peak cylinder pressure dramatically, but by widening the area under the pressure / crank angle curve... it's putting load onto the components for longer periods of time. Also, and quite importantly, it's putting loads into the cylinder liner with the piston further down the bore than would be the case under normal conditions. This can lead to the cylinder walls "ballooning". Also, the additional loading at crank angles far greater than normal will be introducing forces into the block which aren't directly across it, but at an incline. Because the block is bolted across its centre there is great strength in a direction coaxial with the cylinder bore, but less so at an incline.
This additional loading at greater angles will cause the block to flex. I'm still trying to figure out what will be the upper limit on reliability with various blocks. Obviously the closed deck blocks have more support in the upper cylinder area and thus greater structural rigidity, but additionally, and importantly, they appear to have greater material in the crank webs... overall a better block!
I'll post up some more info as and when I get it...
Cheers,
Pat.
I think that the notion of torque being an issue more than power is hitting the nail on the head. Turbocharged cars produce the additional torque, not by increasing the peak cylinder pressure dramatically, but by widening the area under the pressure / crank angle curve... it's putting load onto the components for longer periods of time. Also, and quite importantly, it's putting loads into the cylinder liner with the piston further down the bore than would be the case under normal conditions. This can lead to the cylinder walls "ballooning". Also, the additional loading at crank angles far greater than normal will be introducing forces into the block which aren't directly across it, but at an incline. Because the block is bolted across its centre there is great strength in a direction coaxial with the cylinder bore, but less so at an incline.
This additional loading at greater angles will cause the block to flex. I'm still trying to figure out what will be the upper limit on reliability with various blocks. Obviously the closed deck blocks have more support in the upper cylinder area and thus greater structural rigidity, but additionally, and importantly, they appear to have greater material in the crank webs... overall a better block!
I'll post up some more info as and when I get it...
Cheers,
Pat.
25 August 2003, 09:33 PM
#34
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Turbocharged cars produce the additional torque, not by increasing the peak cylinder pressure dramatically, but by widening the area under the pressure / crank angle curve... it's putting load onto the components for longer periods of time.
Are you saying that the burn rate is slower on a turbocharged engine ? Or just that ignition is generally taking place later on high boost builds hence the peak pressure/angle shift ?
Andy
25 August 2003, 10:09 PM
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Peak pressure's at the same point, but the pressure carries on longer with the additional stuff to burn, so the pressure stays longer, further down the stroke so the loads go all skew on the rods.
Not sure if that answers anything, actually
Not sure if that answers anything, actually
25 August 2003, 11:31 PM
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There are rumours of cars in North America that have been 'splitting' the block - i.e. the block bolts are breaking and the two halves are breaking apart! This is on very high horsepower cars - not sure what their torque figures are. 
Rannoch
Rannoch
26 August 2003, 12:08 AM
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Andy,
as nom has pointed out, it's not so much that the burn rate is slower, there's just more to burn, so it takes a little longer
You normally back the timing off at elevated boost pressures so that the peak pressure doesn't get silly (which will result in autoignition) but also because you aren't doing as much "negative" work as the piston gets to TDC, and of course the pressure doesn't decay as quickly leaving TDC because it's still burning and thus keeping the pressure higher than it otherwise would be, so it's still doing useful work.
If you were able to achieve MBT timing you'de find that it decays with increasing boost anyway, ie there is no point in trying to run shedloads of advance and achieve huge peak pressures, all that happens is that you reduce the output and put more stress into the components... well, that's what would happen if you could achieve MBT at high boost pressure but on a road engine that's unlikely because the compression ratio will be too high and you'll hit autoignition before you hit MBT on normal fuel.
Cheers,
Pat.
as nom has pointed out, it's not so much that the burn rate is slower, there's just more to burn, so it takes a little longer
You normally back the timing off at elevated boost pressures so that the peak pressure doesn't get silly (which will result in autoignition) but also because you aren't doing as much "negative" work as the piston gets to TDC, and of course the pressure doesn't decay as quickly leaving TDC because it's still burning and thus keeping the pressure higher than it otherwise would be, so it's still doing useful work. If you were able to achieve MBT timing you'de find that it decays with increasing boost anyway, ie there is no point in trying to run shedloads of advance and achieve huge peak pressures, all that happens is that you reduce the output and put more stress into the components... well, that's what would happen if you could achieve MBT at high boost pressure but on a road engine that's unlikely because the compression ratio will be too high and you'll hit autoignition before you hit MBT on normal fuel.
Cheers,
Pat.
04 September 2003, 09:12 PM
#40
"I don't recall seeing anyone else break the 400lbft mark yet, but am open to being proven wrong." Adam.
I have exceeded 400ft/lbs on several occasions. At Power Engineering last week on only 1.5/1.55 bar I had 397ft/lbs and 442 bhp. On the same rollers at more boost I have had 422 and 425ft/lbs respectively. Earlier in the year at G-Force I had 415ft/lbs.
Rannoch : Tell us who is building your engine. What compression ratio, capacity, bore and stroke? Any more information on the cam shafts would be of great interest.
I note you are going for a paddle clutch and billet flywheel. Do you know the flywheel weight? As you know I think a light flywheel requires a more accurate and different technique for the occasional drag starts. Having driven a number of cars with paddle clutches, they are awkward and uncomfortable to drive in traffic or around town and the shock and lack of cushion are such that forces put into the transmission can result in premature drivetrain failure. It might be in your interests to speak to someone like Alan G, who has a fair bit of paddle clutch and drivetrain experience.
Mark : You started this thread and it was not at my request.
"I could argue that you shouldn't be quoting your 128mph 1/4 mile terminal, and 176mph top speed run from Elvington, because they resulted in "terminal failure", and maybe you should wait until you're achieving them reliably ?"Mark.
I would hardly call what happened to my engine as terminal. It was fixed easily by changing one cylinder head and that course of action was taken simply because I already had a spare cylinder head for the other engine and it was the easiest option. The repair took under a week and as you have raised it, the repairs to Adam`s engine were going to take two weeks and are now going to take months. Obviously that was a terminal failure but I am glad Adam has the use of his 22B with an alternative engine.
Running an engine to destruction on a dynomometer and taking spot figures is a long way from running reliably on the road and assessing power in situ.
"As regards people keeping quiet. Bit like the Pot calling the kettle black."
"If you are implying that "I" keep quiet about my spec's, well yes I do, but I don't quote any figures either. I don't feel that I should discuss what I'm doing with any of my engines, until I'm getting the results I want from them."
Well, yes I was referring to you and as I have not heard you quoting any figures then I accept you are not getting the results you want but I am also referring to keeping quiet about problems. What do you want to discuss first? Engines or Turbos?
Well what about a current engine. John Banks. The story was that there was a cam tensioner problem which is a 2 1/2 hour job. That was 2 months ago. There was also a rumour that the engine was stripped to check all was well. As you know stripping and reassembling an engine is less than 2 days work unless alternative parts are required. There was also a rumour that the supplier had changed the piston spec without notice. Cannot understand this and it sounds like a euphomism for where is my 100mm micrometer.
Anyway, the mystery of why a simple job is taking 2 months remains because the whole thing has been hushed up which is not unusual.
BTW. I see you are buying up 2nd hand TD05s. Let me know if you need any 20G wheels.
I see Mikee Singh, Rannoch and yourself are down as reserves for Well Lane VI. Will you actually be running? I know your car has been without an engine since last October.
Pat : I have only asked you half a dozen times now for your thoughts on why my car uses 1 litre of oil per 1000 miles approx."and it is nothing to do with Cosworth pistons" Do you know? Do you want to share the information?
I have exceeded 400ft/lbs on several occasions. At Power Engineering last week on only 1.5/1.55 bar I had 397ft/lbs and 442 bhp. On the same rollers at more boost I have had 422 and 425ft/lbs respectively. Earlier in the year at G-Force I had 415ft/lbs.
Rannoch : Tell us who is building your engine. What compression ratio, capacity, bore and stroke? Any more information on the cam shafts would be of great interest.
I note you are going for a paddle clutch and billet flywheel. Do you know the flywheel weight? As you know I think a light flywheel requires a more accurate and different technique for the occasional drag starts. Having driven a number of cars with paddle clutches, they are awkward and uncomfortable to drive in traffic or around town and the shock and lack of cushion are such that forces put into the transmission can result in premature drivetrain failure. It might be in your interests to speak to someone like Alan G, who has a fair bit of paddle clutch and drivetrain experience.
Mark : You started this thread and it was not at my request.
"I could argue that you shouldn't be quoting your 128mph 1/4 mile terminal, and 176mph top speed run from Elvington, because they resulted in "terminal failure", and maybe you should wait until you're achieving them reliably ?"Mark.
I would hardly call what happened to my engine as terminal. It was fixed easily by changing one cylinder head and that course of action was taken simply because I already had a spare cylinder head for the other engine and it was the easiest option. The repair took under a week and as you have raised it, the repairs to Adam`s engine were going to take two weeks and are now going to take months. Obviously that was a terminal failure but I am glad Adam has the use of his 22B with an alternative engine.
Running an engine to destruction on a dynomometer and taking spot figures is a long way from running reliably on the road and assessing power in situ.
"As regards people keeping quiet. Bit like the Pot calling the kettle black."
"If you are implying that "I" keep quiet about my spec's, well yes I do, but I don't quote any figures either. I don't feel that I should discuss what I'm doing with any of my engines, until I'm getting the results I want from them."
Well, yes I was referring to you and as I have not heard you quoting any figures then I accept you are not getting the results you want but I am also referring to keeping quiet about problems. What do you want to discuss first? Engines or Turbos?
Well what about a current engine. John Banks. The story was that there was a cam tensioner problem which is a 2 1/2 hour job. That was 2 months ago. There was also a rumour that the engine was stripped to check all was well. As you know stripping and reassembling an engine is less than 2 days work unless alternative parts are required. There was also a rumour that the supplier had changed the piston spec without notice. Cannot understand this and it sounds like a euphomism for where is my 100mm micrometer.
Anyway, the mystery of why a simple job is taking 2 months remains because the whole thing has been hushed up which is not unusual.
BTW. I see you are buying up 2nd hand TD05s. Let me know if you need any 20G wheels.
I see Mikee Singh, Rannoch and yourself are down as reserves for Well Lane VI. Will you actually be running? I know your car has been without an engine since last October.
Pat : I have only asked you half a dozen times now for your thoughts on why my car uses 1 litre of oil per 1000 miles approx."and it is nothing to do with Cosworth pistons" Do you know? Do you want to share the information?
05 September 2003, 12:01 AM
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Harvey,
thanks for your words regarding my car, it is very nice to be back on the road again, still a few issues with even the standard engine that I want to sort out.
With regard to my car, I wonder why you are arguing with mark about it, its really not a big deal. It looked like more than the liner was damaged when the liner broke (due only it would seem due to standard liner thickness being insufficent) and the distortion in the liner as a result of cracking has damaged a piston. Pistons were custom jobs which take a month to be made, hence the delay. Head piston designer for JE wanted to take a look and see what was going on in the engine to see if the piston design could be modded to improve things, but o changes have been made to my knowledge. His input slowed things somewhat.
I now await my new pistons, rebuild and redyno, but as you know my attentions have turned towards my house purchase and my next set of exams (november). With the car back on the road, I am actually in no hurry to seek out more power. 280bhp (if that) feels like plenty for now!
thanks for your words regarding my car, it is very nice to be back on the road again, still a few issues with even the standard engine that I want to sort out.
With regard to my car, I wonder why you are arguing with mark about it, its really not a big deal. It looked like more than the liner was damaged when the liner broke (due only it would seem due to standard liner thickness being insufficent) and the distortion in the liner as a result of cracking has damaged a piston. Pistons were custom jobs which take a month to be made, hence the delay. Head piston designer for JE wanted to take a look and see what was going on in the engine to see if the piston design could be modded to improve things, but o changes have been made to my knowledge. His input slowed things somewhat.
I now await my new pistons, rebuild and redyno, but as you know my attentions have turned towards my house purchase and my next set of exams (november). With the car back on the road, I am actually in no hurry to seek out more power. 280bhp (if that) feels like plenty for now!
05 September 2003, 01:41 AM
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best ask nicely then.. ringing me tomorrow is your best bet.
05 September 2003, 02:47 AM
#53
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Harvey,
It seems that no matter how many times Adam, or I explain the delays of Adam's engine re-build, you can't quite grasp it.
With regard to John Banks engine, you BATANTLY don't understand the implications of a failed cam belt tensioner, and a cam belt that was found to be flapping around.
When the problem was discovered, the first think I did, was to tell Steve (SMG) NOT to remove anything else, until I had spoken to John. I called John straight away, and [bold]I[/bold] asked him to arrange for someone to be present when the heads were removed, so there was no doubt in his mind as to what was found.
He declined, and said he was happy for Steve to carry on. Fortunately, there wasn't any damaged caused to the pistons, or valves.
Apart from "consumable" parts, NOTHING else has been replaced, regardless of what you may think, or are trying to imply.
John was told that it would take a while to re-build, due to Steve, and I having commitments to other people.
If you are accusing me of keeping quiet over the problem John had with his engine, you're right. Neither Steve, or I had anything to do with fitting the tensioner, or the cam belt, so why would I post anything ?
The concern about the pistons, was based on a few people mis-diagnosing a faulty cam belt tensioner, as "piston slap". There was a question over a design change, but turned out to be not the case.
Your lack of "understanding" of anything I do, is none of my concern. Why you consider anything I do, any of YOUR business, is beyond me.
Yes I'm down as a reserve for WL V1, and if my car is ready, and a place is available, I may run.
Mark.
It seems that no matter how many times Adam, or I explain the delays of Adam's engine re-build, you can't quite grasp it.
With regard to John Banks engine, you BATANTLY don't understand the implications of a failed cam belt tensioner, and a cam belt that was found to be flapping around.
When the problem was discovered, the first think I did, was to tell Steve (SMG) NOT to remove anything else, until I had spoken to John. I called John straight away, and [bold]I[/bold] asked him to arrange for someone to be present when the heads were removed, so there was no doubt in his mind as to what was found.
He declined, and said he was happy for Steve to carry on. Fortunately, there wasn't any damaged caused to the pistons, or valves.
Apart from "consumable" parts, NOTHING else has been replaced, regardless of what you may think, or are trying to imply.
John was told that it would take a while to re-build, due to Steve, and I having commitments to other people.
If you are accusing me of keeping quiet over the problem John had with his engine, you're right. Neither Steve, or I had anything to do with fitting the tensioner, or the cam belt, so why would I post anything ?
The concern about the pistons, was based on a few people mis-diagnosing a faulty cam belt tensioner, as "piston slap". There was a question over a design change, but turned out to be not the case.
Your lack of "understanding" of anything I do, is none of my concern. Why you consider anything I do, any of YOUR business, is beyond me.
Yes I'm down as a reserve for WL V1, and if my car is ready, and a place is available, I may run.
Mark.
05 September 2003, 09:48 PM
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Tell us who is building your engine. What compression ratio, capacity, bore and stroke? Any more information on the cam shafts would be of great interest.
Also as you have made your feelings so crystal clear, and you continue to do so in a vindictive and unhlepful manner, regarding the architect of my engine project and also your disdain regarding engines that have capacity of greater than two litres I am not sure of the point of responding to your question with any further details.
Once my project is up and running, like Wallis' I would be happy to share my spec with anyone who is seriously interested, please feel free to contact me via my address here, or through my website.
The cams are reground STi V cams.
I note you are going for a paddle clutch and billet flywheel. Do you know the flywheel weight? As you know I think a light flywheel requires a more accurate and different technique for the occasional drag starts. Having driven a number of cars with paddle clutches, they are awkward and uncomfortable to drive in traffic or around town and the shock and lack of cushion are such that forces put into the transmission can result in premature drivetrain failure.
Finally thank you for your concerns regarding the paddle clutch - I have driven a car with an identical set up to mine, both in and out of town, and it performed with little or no ******. With my dreamer torque a non-paddle clutch would be troubled on both track and drag.
Rannoch
05 September 2003, 10:10 PM
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am currently driving my car with the clutch which is rated to take the dreamer torque my engine produced on the dyno.
Hand on heart can say it is as easy to drive as it ever was. i.e. very easy.
believe it is the same as that which trout drove and supplied by the same guy.
Hand on heart can say it is as easy to drive as it ever was. i.e. very easy.
believe it is the same as that which trout drove and supplied by the same guy.
