A question for AFR
02-06-2005, 09:48 AM
#1
A question for AFR Since alot of people on this board and myself are wondering the same thing.Why not make your head with a smaller chamber like 62cc without milling them so LS1 owners can run bigger Cams without milling/valve notching?We know most apps like 10.6 to 11-1 compression to get full potential from there package and your own car had this done,from what I've read.I truly believe this would be a step forward for AFR 
Also stepping up production will help too
Also stepping up production will help too
02-06-2005, 09:56 AM
#3
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My compression worked out to be 10.855:1 with 66cc chambers so the 66cc works great for me but maybe not for others.It is easier to remove material than add.Plus I have a question,Tony said if you mill you will hurt flow #s of the head,then why is he doing so and everyone else following suit.I think my #s are good for not milling.Just something to think about.
Anthony
Anthony
02-06-2005, 12:37 PM
#4
Guys...
We could give you a chamber thats 60 cc's out of the box and has the same "valve drop" as a 66 cc 205 for arguments sake. (Obviously its the "valve drop" that will determine how much piston to valve you ultimately have). The problem is the only way for that to happen is if we packed the chamber full of aluminum and now when your valves open they are completely shrouded by the tight chamber walls etc., and the cylinder head flows like %&@* . What have we accomplished?...less power with a lower flowing cylinder head even though the compression ratio might be higher. The 62 cc chamber in the 225's has been carefully thought out and designed so when the smoke clears, we had a smaller chamber (than the current 205 & 225) without hurting any of the flow the larger chamber 72 cc 225 displays. However, the trade-off will be that the 62 cc 225 will have significantly less piston to valve than it's 72 cc brother. But the good news is that if you took a 72 cc head and whacked .060 off the deck to get to 62 cc's, the flow numbers would be quite a bit lower and you would have even LESS piston to valve than the new 62 cc chamber design. The new 62 cc version could easily be milled .025-.030 yeilding a chamber somewhere in the 57 cc range and still flow close to what an un-milled 72 cc (or 62 cc) head will flow....with the added obvious benefit of a ton more compression from the smaller chamber. Besides the loss of piston to valve clearance, that's about as much of "having your cake and eating it to" as it gets. Notching pistons or buying aftermarket pistons with notches already in them is a part of life if your looking for "all the money" out of your current engine build. AFR has spent tremendous time to insure that a small chamber 225 will get you the compression you desire AND the flow numbers as well....(achieveing both was not an easy task). THIS has been a major cause of the delay and ultimately you guys are benefiting from it.
As far as the other two issues mentioned, the AFR 205 is more of the "direct replacement" performance head, hence the chamber volume falling right in between the LS1/LS6 architecture, and regarding "production capacity", we are currently installing 3 more CNC machines in our current facility to help hold us over till we finally land in a brand new, much larger building hopefully in the next 9-18 months.
Also, one last thing....milling a cylinder head up to say .035 or so will cause a slight reduction in airflow (usually), but EXCESSIVELY milling a cylinder head (say .060 or so) will change the combustion chamber shape enough to possibly cause a significant decrease in airflow....some heads are more effected than others so take that info to be more "generalized".
Tony M.
We could give you a chamber thats 60 cc's out of the box and has the same "valve drop" as a 66 cc 205 for arguments sake. (Obviously its the "valve drop" that will determine how much piston to valve you ultimately have). The problem is the only way for that to happen is if we packed the chamber full of aluminum and now when your valves open they are completely shrouded by the tight chamber walls etc., and the cylinder head flows like %&@* . What have we accomplished?...less power with a lower flowing cylinder head even though the compression ratio might be higher. The 62 cc chamber in the 225's has been carefully thought out and designed so when the smoke clears, we had a smaller chamber (than the current 205 & 225) without hurting any of the flow the larger chamber 72 cc 225 displays. However, the trade-off will be that the 62 cc 225 will have significantly less piston to valve than it's 72 cc brother. But the good news is that if you took a 72 cc head and whacked .060 off the deck to get to 62 cc's, the flow numbers would be quite a bit lower and you would have even LESS piston to valve than the new 62 cc chamber design. The new 62 cc version could easily be milled .025-.030 yeilding a chamber somewhere in the 57 cc range and still flow close to what an un-milled 72 cc (or 62 cc) head will flow....with the added obvious benefit of a ton more compression from the smaller chamber. Besides the loss of piston to valve clearance, that's about as much of "having your cake and eating it to" as it gets. Notching pistons or buying aftermarket pistons with notches already in them is a part of life if your looking for "all the money" out of your current engine build. AFR has spent tremendous time to insure that a small chamber 225 will get you the compression you desire AND the flow numbers as well....(achieveing both was not an easy task). THIS has been a major cause of the delay and ultimately you guys are benefiting from it.
As far as the other two issues mentioned, the AFR 205 is more of the "direct replacement" performance head, hence the chamber volume falling right in between the LS1/LS6 architecture, and regarding "production capacity", we are currently installing 3 more CNC machines in our current facility to help hold us over till we finally land in a brand new, much larger building hopefully in the next 9-18 months.
Also, one last thing....milling a cylinder head up to say .035 or so will cause a slight reduction in airflow (usually), but EXCESSIVELY milling a cylinder head (say .060 or so) will change the combustion chamber shape enough to possibly cause a significant decrease in airflow....some heads are more effected than others so take that info to be more "generalized".
Tony M.
Last edited by Tony Mamo @ AFR; 02-06-2005 at 12:42 PM.
02-06-2005, 01:47 PM
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Originally Posted by Tony Mamo @ AFR
Guys...
We could give you a chamber thats 60 cc's out of the box and has the same "valve drop" as a 66 cc 205 for arguments sake. (Obviously its the "valve drop" that will determine how much piston to valve you ultimately have). The problem is the only way for that to happen is if we packed the chamber full of aluminum and now when your valves open they are completely shrouded by the tight chamber walls etc., and the cylinder head flows like %&@* . What have we accomplished?...less power with a lower flowing cylinder head even though the compression ratio might be higher. The 62 cc chamber in the 225's has been carefully thought out and designed so when the smoke clears, we had a smaller chamber (than the current 205 & 225) without hurting any of the flow the larger chamber 72 cc 225 displays. However, the trade-off will be that the 62 cc 225 will have significantly less piston to valve than it's 72 cc brother. But the good news is that if you took a 72 cc head and whacked .060 off the deck to get to 62 cc's, the flow numbers would be quite a bit lower and you would have even LESS piston to valve than the new 62 cc chamber design. The new 62 cc version could easily be milled .025-.030 yeilding a chamber somewhere in the 57 cc range and still flow close to what an un-milled 72 cc (or 62 cc) head will flow....with the added obvious benefit of a ton more compression from the smaller chamber. Besides the loss of piston to valve clearance, that's about as much of "having your cake and eating it to" as it gets. Notching pistons or buying aftermarket pistons with notches already in them is a part of life if your looking for "all the money" out of your current engine build. AFR has spent tremendous time to insure that a small chamber 225 will get you the compression you desire AND the flow numbers as well....(achieveing both was not an easy task). THIS has been a major cause of the delay and ultimately you guys are benefiting from it.
As far as the other two issues mentioned, the AFR 205 is more of the "direct replacement" performance head, hence the chamber volume falling right in between the LS1/LS6 architecture, and regarding "production capacity", we are currently installing 3 more CNC machines in our current facility to help hold us over till we finally land in a brand new, much larger building hopefully in the next 9-18 months.
Also, one last thing....milling a cylinder head up to say .035 or so will cause a slight reduction in airflow (usually), but EXCESSIVELY milling a cylinder head (say .060 or so) will change the combustion chamber shape enough to possibly cause a significant decrease in airflow....some heads are more effected than others so take that info to be more "generalized".
Tony M.
We could give you a chamber thats 60 cc's out of the box and has the same "valve drop" as a 66 cc 205 for arguments sake. (Obviously its the "valve drop" that will determine how much piston to valve you ultimately have). The problem is the only way for that to happen is if we packed the chamber full of aluminum and now when your valves open they are completely shrouded by the tight chamber walls etc., and the cylinder head flows like %&@* . What have we accomplished?...less power with a lower flowing cylinder head even though the compression ratio might be higher. The 62 cc chamber in the 225's has been carefully thought out and designed so when the smoke clears, we had a smaller chamber (than the current 205 & 225) without hurting any of the flow the larger chamber 72 cc 225 displays. However, the trade-off will be that the 62 cc 225 will have significantly less piston to valve than it's 72 cc brother. But the good news is that if you took a 72 cc head and whacked .060 off the deck to get to 62 cc's, the flow numbers would be quite a bit lower and you would have even LESS piston to valve than the new 62 cc chamber design. The new 62 cc version could easily be milled .025-.030 yeilding a chamber somewhere in the 57 cc range and still flow close to what an un-milled 72 cc (or 62 cc) head will flow....with the added obvious benefit of a ton more compression from the smaller chamber. Besides the loss of piston to valve clearance, that's about as much of "having your cake and eating it to" as it gets. Notching pistons or buying aftermarket pistons with notches already in them is a part of life if your looking for "all the money" out of your current engine build. AFR has spent tremendous time to insure that a small chamber 225 will get you the compression you desire AND the flow numbers as well....(achieveing both was not an easy task). THIS has been a major cause of the delay and ultimately you guys are benefiting from it.
As far as the other two issues mentioned, the AFR 205 is more of the "direct replacement" performance head, hence the chamber volume falling right in between the LS1/LS6 architecture, and regarding "production capacity", we are currently installing 3 more CNC machines in our current facility to help hold us over till we finally land in a brand new, much larger building hopefully in the next 9-18 months.
Also, one last thing....milling a cylinder head up to say .035 or so will cause a slight reduction in airflow (usually), but EXCESSIVELY milling a cylinder head (say .060 or so) will change the combustion chamber shape enough to possibly cause a significant decrease in airflow....some heads are more effected than others so take that info to be more "generalized".
Tony M.
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02-13-2005, 03:43 PM
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Originally Posted by LSonederfull
Tony, can you explain how milling hurts airflow? This has no effect on shortside turn height,(unless milled into top cut of valve job) and with 15* valve angle, they aren't that close to cylinder wall in any form. Also chamber shape is reduced but not physically changed by milling, so i am curious how this hurts airflow?
Tony?
02-13-2005, 06:05 PM
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But I don't understand this fully, your say milling .035 reduces flow? Didn't you mill your heads down .040? And If I'm not mistaken doesn't LG order all his heads milled .040?
