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Old 03-07-2008, 08:04 AM   #61
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Originally Posted by Roelof View Post
Yes, just move the upperside of the piston over sandpaper....
And by grinding differen depths on the edge of the piston you can alter the timing on each port.
This post have gotten very interesting
Right Edward! LOL

I guess Pig do fly.. just kidding.

try this mod, it will save you making the massive changes
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Old 03-07-2008, 09:53 AM   #62
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I had 6 of my motors running at the Canadian Winter Nationals last weekend...2nd year in a row !!!!! clearly and honestly we had the fastest, most efficient motors on the track..........this is my second year at the Canadian Nationals as well.... in offroad my motors have no equal !!!!!

I knew edward had a trick up his sleeve, but i figured i'd take the bait and and let him prove me wrong.....

I cannot see being able to alter much timing by cutting the piston top...definitely not the same as cutting the actual port... my C6 needed 16 degrees of exhaust timing cut, which is massive !!!!!
0.3 mm give you 7 degrees of timing on a .12, which is not that much.

The piston/sleeve I got from Edward, when we still had the 4.5mm exhaust height rule, was a total screamer at the time and the cuts were barely visible.

It's much easier to work on the piston than on the sleeve and if you mess up, you just need a new piston...
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Old 03-07-2008, 09:35 PM   #63
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Maximo.
Today is Friday and it is pretty calm day at work, so I had chance to make some 3D model of piston and make pic of it. I hope it will help you understand how to alter transfer and exhaust timing without touching sleeve. It is very old technics, may be like 20-25 years old. And as Stefan mentioned we did use this as trick to go around the 4.5 mm rule ( the way the rule was written give us a chance to alter exhaust and still have 4.5 mm) . BTW in 2004 Winternats we brought one of the engine to tech and ask them to measure it and we pointed to this trick, they open book and everything was by the "wrighting" so it had pass after that we use it many times.
About measuring cranck with caliper as it shows on the pic-we can only determinate if it was cut or not from machined version (I can see it without caliper just by looking on surface). If you ask-is it correct way and if I will use it-nope. I am interesting to know when port open and when it is close-the rest is just "water". Again it is my way to do it, may be somebody do it differently-then it is their style and I have no problem with that at all.
Again, please don't forget to read my signature and don't blame for BS I just wrote
Have fun!
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Old 03-08-2008, 09:23 PM   #64
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Originally Posted by EdwardN View Post
Maximo.
Today is Friday and it is pretty calm day at work, so I had chance to make some 3D model of piston and make pic of it. I hope it will help you understand how to alter transfer and exhaust timing without touching sleeve. It is very old technics, may be like 20-25 years old. And as Stefan mentioned we did use this as trick to go around the 4.5 mm rule ( the way the rule was written give us a chance to alter exhaust and still have 4.5 mm) . BTW in 2004 Winternats we brought one of the engine to tech and ask them to measure it and we pointed to this trick, they open book and everything was by the "wrighting" so it had pass after that we use it many times.
About measuring cranck with caliper as it shows on the pic-we can only determinate if it was cut or not from machined version (I can see it without caliper just by looking on surface). If you ask-is it correct way and if I will use it-nope. I am interesting to know when port open and when it is close-the rest is just "water". Again it is my way to do it, may be somebody do it differently-then it is their style and I have no problem with that at all.
Again, please don't forget to read my signature and don't blame for BS I just wrote
Have fun!

Very crafty work there Edward.... But I knew all along you had a ace up your sleeve.... So it appears pigs do indeed fly and that its possible to alter timing without touching the sleeve........
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Old 03-09-2008, 12:03 AM   #65
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Oh yes, he does, and he's probably one of the few who understands the numbers he's getting...
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I do not have an Xdyno. I do have an inertia dyno that is similar to the X dyno. When I tried to get an Xdyno I could not get any answer from nitrodyne for what seemed like a year, so I ended up having to build my own dyno. I did want an Xdyno, but mine is working great.
ouch
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Old 03-10-2008, 01:05 AM   #66
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Originally Posted by EdwardN View Post
Maximo.
Today is Friday and it is pretty calm day at work, so I had chance to make some 3D model of piston and make pic of it. I hope it will help you understand how to alter transfer and exhaust timing without touching sleeve. It is very old technics, may be like 20-25 years old. And as Stefan mentioned we did use this as trick to go around the 4.5 mm rule ( the way the rule was written give us a chance to alter exhaust and still have 4.5 mm) . BTW in 2004 Winternats we brought one of the engine to tech and ask them to measure it and we pointed to this trick, they open book and everything was by the "wrighting" so it had pass after that we use it many times.
About measuring cranck with caliper as it shows on the pic-we can only determinate if it was cut or not from machined version (I can see it without caliper just by looking on surface). If you ask-is it correct way and if I will use it-nope. I am interesting to know when port open and when it is close-the rest is just "water". Again it is my way to do it, may be somebody do it differently-then it is their style and I have no problem with that at all.
Again, please don't forget to read my signature and don't blame for BS I just wrote
Have fun!

why do people always bad mouth you EdwardN, when you obviously now your stuff??
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Old 03-10-2008, 07:35 AM   #67
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why do people always bad mouth you EdwardN, when you obviously now your stuff??
Hi Tom.
Just because I know/can do something.

Edward
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Old 03-10-2008, 04:44 PM   #68
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why do people always bad mouth you EdwardN, when you obviously now your stuff??
who bad mouths him?
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Old 03-10-2008, 04:53 PM   #69
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EdwardN: Q: Looking at the piston, would you say the exhaust or the intake port edges are the most important side to mod.....

This is my thinking.....A little off the Exhaust edge would be better for more RPM.... I'm working on a .09 Sirio
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Old 03-10-2008, 09:46 PM   #70
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EdwardN: Q: Looking at the piston, would you say the exhaust or the intake port edges are the most important side to mod.....

This is my thinking.....A little off the Exhaust edge would be better for more RPM.... I'm working on a .09 Sirio
You know, I can't say like this simple-exhaust is most important or transfer-everything is important and more is better (in reasonble limits). I don't know Sirio 0.9 engine, but I know they are winding really bad.
In engine is everything should be in balance-induction-transfer-exhaust. Evry sinlge event give positive and negative impact on engine performance. Just for instance if we have realllllllllllllllllllly good pipe I would do closing on induction as late as I can-pipe will suck mixture through the engine from carb and will "supercharge" engine, but this is ideal situation. So base on this ideal situation more transfer, induction and exhaust are better, but in the mean time we have case volume close late and amount of negative pressure which will be build is less, so initial charging of case with mixture will be less. Well, as I sad taking and giving situation. Needs balance.

Edward
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Old 03-11-2008, 12:18 AM   #71
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Originally Posted by EdwardN View Post
You know, I can't say like this simple-exhaust is most important or transfer-everything is important and more is better (in reasonble limits). I don't know Sirio 0.9 engine, but I know they are winding really bad.
In engine is everything should be in balance-induction-transfer-exhaust. Evry sinlge event give positive and negative impact on engine performance. Just for instance if we have realllllllllllllllllllly good pipe I would do closing on induction as late as I can-pipe will suck mixture through the engine from carb and will "supercharge" engine, but this is ideal situation. So base on this ideal situation more transfer, induction and exhaust are better, but in the mean time we have case volume close late and amount of negative pressure which will be build is less, so initial charging of case with mixture will be less. Well, as I sad taking and giving situation. Needs balance.

Edward
Interesting way of modification to change the timing. I see that the idea is very similar on the new Nova pistons. The 353 and the plus 2 ct. They have created a convex mould in the middle of the piston as well. Seems to me that they did it to prevent detonation and to guide the exhausts flow. Am i right in saying that?
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Old 03-11-2008, 12:33 AM   #72
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Interesting way of modification to change the timing. I see that the idea is very similar on the new Nova pistons. The 353 and the plus 2 ct. They have created a convex mould in the middle of the piston as well. Seems to me that they did it to prevent detonation and to guide the exhausts flow. Am i right in saying that?
thats for combustion most likely. There is no reason for a engine manufacter to do this.
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Old 03-11-2008, 01:48 AM   #73
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I would assume they made it to increase piston top area-more area-more force down-formula is easy Force=PressureXArea. So making dome/dish-they increase area probably 10-15%, but it didn't increase total height of piston tramendosly. I didn't calculate on Novas 12 yet difference in area (not sure if will do any time soon), but it has been done for while on 21 engines. It is very smart move, but again similar kind of design been use while back in 1990's , but as many other things been forgoten.
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Old 03-12-2008, 03:53 AM   #74
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Originally Posted by Maximo View Post
I had 6 of my motors running at the Canadian Winter Nationals last weekend...2nd year in a row !!!!! clearly and honestly we had the fastest, most efficient motors on the track..........this is my second year at the Canadian Nationals as well.... in offroad my motors have no equal !!!!!

I knew edward had a trick up his sleeve, but i figured i'd take the bait and and let him prove me wrong.....

I cannot see being able to alter much timing by cutting the piston top...definitely not the same as cutting the actual port... my C6 needed 16 degrees of exhaust timing cut, which is massive !!!!!
How did your engines fair at the Canadian Nats ? Did you win ? Who were the drivers of your engines?
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Old 03-12-2008, 08:48 AM   #75
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How did your engines fair at the Canadian Nats ? Did you win ? Who were the drivers of your engines?

i had 6 motors there... but we didnt win LOL !! Gary Guest had that honour !!

motors performed awesome though... more power and better run time then any other motors there..
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