AFR 325 flow sheets.... anyone ever flow these heads?
12-28-2016, 04:47 PM
#52
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12-28-2016, 04:50 PM
#53
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Also from speedtalk
Here is a few that I have built for power boats. 540-548 bbc's, ported Iron eagle 308 heads, not radical porting, but detail work, chamber work, ex port work, the intake received attention thru the whole runner, about 320cc ish when done. 10:1, the Dart single plane that came on the boat originaly, on the mecruiser HP 500 502, Custom comp hydraulic roller, 252-260 at .050, .640 lift, 112 lobe sep. For numerous reasons. Did like 8-10 of those, either 540's or 548's out of the original 502 blocks. THey would make 715-730 hp, and about the same for tq, peaked about 5800 for hp, in the 4500ish for tq, depending on carbs used. And they rocked.
Here is a few that I have built for power boats. 540-548 bbc's, ported Iron eagle 308 heads, not radical porting, but detail work, chamber work, ex port work, the intake received attention thru the whole runner, about 320cc ish when done. 10:1, the Dart single plane that came on the boat originaly, on the mecruiser HP 500 502, Custom comp hydraulic roller, 252-260 at .050, .640 lift, 112 lobe sep. For numerous reasons. Did like 8-10 of those, either 540's or 548's out of the original 502 blocks. THey would make 715-730 hp, and about the same for tq, peaked about 5800 for hp, in the 4500ish for tq, depending on carbs used. And they rocked.
12-28-2016, 04:53 PM
#54
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My head guy flowed my heads before doing anything to them. To get a baseline.
Realistically, thats what a flow bench is for. Just a tool for cylinder head development.
Now, does that mean tims heads are crap, because they werent flowed, I dont think so. Most head guys who are good, know that doing things like back cutting the intake valve, adjusting the throat diameter, blending the seats, unshrouding the valves, etc etc will help things. Although, its simply good practice to do an A to B test when porting a head , especially if you have never ported that exact casting before. If youve done several sets of afr 325s, thats different.
When mine were done, i was kinda comparing the numbers we got, to what others were getting out of the same heads , from other sources. Of course the numbers werent exact, but definitely in the ballpark .
AFR makes a very good head, but anyone who believes they are better than dart, brodix, profiler, etc, are lying to themselves. They all make a good cylinder head these days. Esp when in the right hands.
Now the question lies, is full force going to go faster this summer or not with the winter mods !?
Realistically, thats what a flow bench is for. Just a tool for cylinder head development.
Now, does that mean tims heads are crap, because they werent flowed, I dont think so. Most head guys who are good, know that doing things like back cutting the intake valve, adjusting the throat diameter, blending the seats, unshrouding the valves, etc etc will help things. Although, its simply good practice to do an A to B test when porting a head , especially if you have never ported that exact casting before. If youve done several sets of afr 325s, thats different.
When mine were done, i was kinda comparing the numbers we got, to what others were getting out of the same heads , from other sources. Of course the numbers werent exact, but definitely in the ballpark .
AFR makes a very good head, but anyone who believes they are better than dart, brodix, profiler, etc, are lying to themselves. They all make a good cylinder head these days. Esp when in the right hands.
Now the question lies, is full force going to go faster this summer or not with the winter mods !?
Tks
12-28-2016, 04:54 PM
#55
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If I had results close to that I would be VERY happy...
Also from speedtalk
Here is a few that I have built for power boats. 540-548 bbc's, ported Iron eagle 308 heads, not radical porting, but detail work, chamber work, ex port work, the intake received attention thru the whole runner, about 320cc ish when done. 10:1, the Dart single plane that came on the boat originaly, on the mecruiser HP 500 502, Custom comp hydraulic roller, 252-260 at .050, .640 lift, 112 lobe sep. For numerous reasons. Did like 8-10 of those, either 540's or 548's out of the original 502 blocks. THey would make 715-730 hp, and about the same for tq, peaked about 5800 for hp, in the 4500ish for tq, depending on carbs used. And they rocked.
Here is a few that I have built for power boats. 540-548 bbc's, ported Iron eagle 308 heads, not radical porting, but detail work, chamber work, ex port work, the intake received attention thru the whole runner, about 320cc ish when done. 10:1, the Dart single plane that came on the boat originaly, on the mecruiser HP 500 502, Custom comp hydraulic roller, 252-260 at .050, .640 lift, 112 lobe sep. For numerous reasons. Did like 8-10 of those, either 540's or 548's out of the original 502 blocks. THey would make 715-730 hp, and about the same for tq, peaked about 5800 for hp, in the 4500ish for tq, depending on carbs used. And they rocked.
12-28-2016, 05:03 PM
#56
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Pipemax program suggests, for a 540 like Tim's, a header diameter, of 2 1/8, to 2 3/8 , with a 30-33" long primary, and an 18" long collector.
So, pretty much a big dyno header. Not a 1 7/8 CMI E TOP, more like a CMI big tube. Definitely not a stainless marine/GIL style manifold, with short runners, and a 3.5" tube that has water mixing in. Not if you're looking to make some power that is. That above claim from speedtalk, making 715hp-730hp, I'll bet you pull off the dyno headers, stick tims manifolds on it, you'll knock 50+hp and a bunch of torque right out of it.
I'm still standing by my statement, that out of anything on that engine, the exhaust is the single biggest thing holding it back, from making 700+ hp. You could port the heads all day, put in a 750 lift solid, but unless you step up in the exhaust department, I think you're pullin your weiner.
So, pretty much a big dyno header. Not a 1 7/8 CMI E TOP, more like a CMI big tube. Definitely not a stainless marine/GIL style manifold, with short runners, and a 3.5" tube that has water mixing in. Not if you're looking to make some power that is. That above claim from speedtalk, making 715hp-730hp, I'll bet you pull off the dyno headers, stick tims manifolds on it, you'll knock 50+hp and a bunch of torque right out of it.
I'm still standing by my statement, that out of anything on that engine, the exhaust is the single biggest thing holding it back, from making 700+ hp. You could port the heads all day, put in a 750 lift solid, but unless you step up in the exhaust department, I think you're pullin your weiner.
12-28-2016, 05:18 PM
#58
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12-28-2016, 05:22 PM
#59
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And, this is exactly why I'm building a 24' single engine boat!
I'm just a poor white kid from the west side trying to keep my head above water!
*edit in- this isn't a judgement on Tims finances as that is none of my business, just a general "take" on how expensive these damn thing's can be*
I'm just a poor white kid from the west side trying to keep my head above water!
*edit in- this isn't a judgement on Tims finances as that is none of my business, just a general "take" on how expensive these damn thing's can be*
Last edited by vintage chromoly; 12-28-2016 at 05:36 PM. Reason: Clarification
12-28-2016, 05:24 PM
#60
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