AFR 325 flow sheets.... anyone ever flow these heads?
01-09-2017, 09:44 AM
#172
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I know the duration thing was always a question but don't think the problem was limited to it alone. I would still look at cam 245/250 max. 305 heads would have been nice to see pushing that hull.
01-09-2017, 10:23 AM
#173
Gold Member
Gold Member
These cam guys love preaching the static compression vs cam topic. They make you think its a go/no go scenerio. I loved when bob M told endeavor32, the crane 741 cam just wouldnt work , and be a turd, in his build, because there wasnt enough static. It does, and it did work, just fine.
Mercurys 420, 440, 525efi, all have low static compression. The 525efi , has a 236/244 cam in it, with like 8.75:1 if i recall. But a 540ci, that has 9.6:1 static, gets 5 more deg intake, and 2 more deg exhaust?
The 525efi idles great, makes plenty of torque.
Heck, i remember back when 9:1 was high compression. In the 70s cars, 7.6:1 statics were common. The stock cam in my 78 Trans am was in the 200* at .050 range. I remember swapping that cam out for a much hotter replica of the Ram Air IV cam if i recall, which was a 230ish plus range duration cam. Compression stayed same. Car picked up a bunch, with the cam, headers, intake, etc. Basically a 16 second smog dog, turned into a mid 13 second car with some minor changes. Was still sub 8:1 static 400ci deal. Slow by todays standards, but damn that thing was a turd in stock form. Embarrasing actually. Lol
Of course the idle was no longer a 400rpm in gear , station wagon idle after the cam change, and she liked some advance at idle. That was when all my high school buddys were rockin 5.0 mustangs , and 5.0 TPI camaros, and the occasional 350 Iroc. That old TA would stomp those guys in those days on the street. Of course that was pre LS1 days, and once I lost to a bone stock SS camaro, I just had to go and buy a new WS6 TA with an LS1.
Mercurys 420, 440, 525efi, all have low static compression. The 525efi , has a 236/244 cam in it, with like 8.75:1 if i recall. But a 540ci, that has 9.6:1 static, gets 5 more deg intake, and 2 more deg exhaust?
The 525efi idles great, makes plenty of torque.
Heck, i remember back when 9:1 was high compression. In the 70s cars, 7.6:1 statics were common. The stock cam in my 78 Trans am was in the 200* at .050 range. I remember swapping that cam out for a much hotter replica of the Ram Air IV cam if i recall, which was a 230ish plus range duration cam. Compression stayed same. Car picked up a bunch, with the cam, headers, intake, etc. Basically a 16 second smog dog, turned into a mid 13 second car with some minor changes. Was still sub 8:1 static 400ci deal. Slow by todays standards, but damn that thing was a turd in stock form. Embarrasing actually. Lol
Of course the idle was no longer a 400rpm in gear , station wagon idle after the cam change, and she liked some advance at idle. That was when all my high school buddys were rockin 5.0 mustangs , and 5.0 TPI camaros, and the occasional 350 Iroc. That old TA would stomp those guys in those days on the street. Of course that was pre LS1 days, and once I lost to a bone stock SS camaro, I just had to go and buy a new WS6 TA with an LS1.
Just wondering where that point is?
I understand there is more to dynamic compression other than overlap and static compression.
01-09-2017, 10:35 AM
#174
Registered
Put some 290 cnc ovals on it, some tunnel ram intakes, carbs with plenty of available cfm, a good exhauast that scavenges well, and the short duration cam might work a heck of alot better, and extend the rpm band.
With the components Tim has/had, and his peak torque occuring where it did, Its not surprising she was running out of breath at the upper rpm.
Many times people blame the intake system for being the rpm limiting factor. Which is true, they certainly can. However, sometimes extending the duration, can or is simply needed, to crutch the setup.
The majority of cam companies, have no idea what the airspeed in the port is, they just ask for flow numbers. Getting FPS measurements is not common practice from your average head guy. As a generalization, we can generally assume the smaller port head flowing the same cfm, has better airspeed, but how much faster, is unknown without measuring.
With the components Tim has/had, and his peak torque occuring where it did, Its not surprising she was running out of breath at the upper rpm.
Many times people blame the intake system for being the rpm limiting factor. Which is true, they certainly can. However, sometimes extending the duration, can or is simply needed, to crutch the setup.
The majority of cam companies, have no idea what the airspeed in the port is, they just ask for flow numbers. Getting FPS measurements is not common practice from your average head guy. As a generalization, we can generally assume the smaller port head flowing the same cfm, has better airspeed, but how much faster, is unknown without measuring.
01-09-2017, 10:52 AM
#175
Registered
i don,t know what tim is going to do about his exhaust system but if he does not change that he won,t see much if any performance gain.i can just see his head exploding after doing all the changes and going no faster.
01-09-2017, 11:46 AM
#176
Registered
Hold on a minute......Ive been following FF's engine dilemma for quite some time, and.......
Joe, do you work ?? LOL....
The reason I ask, is you are on OSO alot during the day giving help and sound advice to performance boaters, some you really dont even know! Its really cool of you to show interest in alot of these builds that you arent making a dime on. There are others on here that do the same, but you seem to make it your part time job! I know I have contacted you in the past with my needs, and you had no problem taking the time to answer my questions too. Mike Tkach and a few others do alot of volunteer work too.....but, I just wanted to take a second to say THANK YOU to you few guys that get very involved in boaters builds and do it just to help others out. This type of knowledge is priceless to most of us and you are giving it away for FREE.....carry on.....
Joe, do you work ?? LOL....
The reason I ask, is you are on OSO alot during the day giving help and sound advice to performance boaters, some you really dont even know! Its really cool of you to show interest in alot of these builds that you arent making a dime on. There are others on here that do the same, but you seem to make it your part time job! I know I have contacted you in the past with my needs, and you had no problem taking the time to answer my questions too. Mike Tkach and a few others do alot of volunteer work too.....but, I just wanted to take a second to say THANK YOU to you few guys that get very involved in boaters builds and do it just to help others out. This type of knowledge is priceless to most of us and you are giving it away for FREE.....carry on.....
01-09-2017, 11:54 AM
#177
Registered
Hold on a minute......Ive been following FF's engine dilemma for quite some time, and.......
Joe, do you work ?? LOL....
The reason I ask, is you are on OSO alot during the day giving help and sound advice to performance boaters, some you really dont even know! Its really cool of you to show interest in alot of these builds that you arent making a dime on. There are others on here that do the same, but you seem to make it your part time job! I know I have contacted you in the past with my needs, and you had no problem taking the time to answer my questions too. Mike Tkach and a few others do alot of volunteer work too.....but, I just wanted to take a second to say THANK YOU to you few guys that get very involved in boaters builds and do it just to help others out. This type of knowledge is priceless to most of us and you are giving it away for FREE.....carry on.....
Joe, do you work ?? LOL....
The reason I ask, is you are on OSO alot during the day giving help and sound advice to performance boaters, some you really dont even know! Its really cool of you to show interest in alot of these builds that you arent making a dime on. There are others on here that do the same, but you seem to make it your part time job! I know I have contacted you in the past with my needs, and you had no problem taking the time to answer my questions too. Mike Tkach and a few others do alot of volunteer work too.....but, I just wanted to take a second to say THANK YOU to you few guys that get very involved in boaters builds and do it just to help others out. This type of knowledge is priceless to most of us and you are giving it away for FREE.....carry on.....
01-09-2017, 11:56 AM
#178
Registered
01-09-2017, 12:02 PM
#179
Registered
^^^ Thanks. Its all in good fun. I enjoy discussing this stuff, and learning, but thats probably because I am not doing it 9-5. My hat goes off those those guys, who take the time to post info on the forums that do it all day long building engines and stuff to pay the bills.
But yes,
I do have a full time job, as well as a part time " googler "
But yes,
I do have a full time job, as well as a part time " googler "
01-09-2017, 12:50 PM
#180
Gold Member
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Join Date: Oct 2005
Location: Olmsted Falls,Ohio Marblehead,Oh
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The plan is to address exhaust if I can now, if not it will go together and I will asap, I can only do so much at once, engines are out and apart so. Is is the time to do that, I have life and houses to pay for bedsides boating... I pay cash as I go with zero debt sonits hard to do so much at once... exhaust may wait till summer or next winter, all depends on $$
