AFR 325 flow sheets.... anyone ever flow these heads?
01-31-2017, 08:34 PM
#601
Registered
Not necessarily. Its just pipe.. If you extend them, and for some weird, strange, unneccessary reason, you decided you want to go back to shorter wet risers, its nothing a chop saw can't fix.
01-31-2017, 08:52 PM
#602
Platinum Member
Platinum Member
just for ****z and giggles, here are the numbers of my 317s as of 6pm this evening, for further info see my facebook page AK Racing
Alan Kranczoch
Intake .200 = 155cfm, .300 = 228, .400 = 289, .500 = 336, .600 = 368, .700 = 388 .800 = 392 exh .200 = 117, .300 = 158, .400 = 205, .500 = 228, .600 = 258 (w pipe 277) .700 = 260, (280) .800 = 261 (283)... so this is the preliminary flow test done after minor bowl work and marine valve job...
just sayin!! can't wait for my CNCs to be ready!! Giddythefukup!!!!
Alan Kranczoch
Intake .200 = 155cfm, .300 = 228, .400 = 289, .500 = 336, .600 = 368, .700 = 388 .800 = 392 exh .200 = 117, .300 = 158, .400 = 205, .500 = 228, .600 = 258 (w pipe 277) .700 = 260, (280) .800 = 261 (283)... so this is the preliminary flow test done after minor bowl work and marine valve job...
just sayin!! can't wait for my CNCs to be ready!! Giddythefukup!!!!
01-31-2017, 09:03 PM
#604
Registered
Gil's with longer tails will also perform better. They are within a few HP of each other and neither is going to have an advantage performance wise over the other. Stainless has an advantage that you can rotate the tails, but with Gil's you can use spacers if the holes are to high or to low, which you can't do with SM. Each has their benefits, performance wise they are equals.
Gold Member
01-31-2017, 09:41 PM
#606
Registered
I get the budget deal and where do u stop deal completely. Tim if endeavour32 will let you dyno a set of his headers and don't take advantage of it I think your crazy. A 15 minute swap for a whole lot of knowledge would be awesome. Same day, same dyno and so on. What a great opportunity. I know they will kick my stellings green tags ass and that's fine but at least I will know what to put on to buy list even if it takes a year or so to find a couple sets.
Last edited by getrdunn; 01-31-2017 at 09:44 PM.
01-31-2017, 09:58 PM
#607
Registered
If I see only a 10 hp difference on a 700-750 build then would scratch it off my list. Or it's still a possibility I may still go SC and that would be real interesting comparison. What would the difference be on a 1,000 hp engine? I would imagine the gains would be a remarkable difference. Just curious at what point the gains really come into play at hp wise. Regardless I will be testing exhaust and getting real world data. Not some BS article that's one sided for promotional purposes etc.
Last edited by getrdunn; 01-31-2017 at 10:01 PM.
01-31-2017, 10:06 PM
#608
Registered
just for ****z and giggles, here are the numbers of my 317s as of 6pm this evening, for further info see my facebook page AK Racing
Alan Kranczoch
Intake .200 = 155cfm, .300 = 228, .400 = 289, .500 = 336, .600 = 368, .700 = 388 .800 = 392 exh .200 = 117, .300 = 158, .400 = 205, .500 = 228, .600 = 258 (w pipe 277) .700 = 260, (280) .800 = 261 (283)... so this is the preliminary flow test done after minor bowl work and marine valve job...
just sayin!! can't wait for my CNCs to be ready!! Giddythefukup!!!!
Alan Kranczoch
Intake .200 = 155cfm, .300 = 228, .400 = 289, .500 = 336, .600 = 368, .700 = 388 .800 = 392 exh .200 = 117, .300 = 158, .400 = 205, .500 = 228, .600 = 258 (w pipe 277) .700 = 260, (280) .800 = 261 (283)... so this is the preliminary flow test done after minor bowl work and marine valve job...
just sayin!! can't wait for my CNCs to be ready!! Giddythefukup!!!!
02-01-2017, 12:19 PM
#610
Platinum Member
Platinum Member
Nice thing about dyno'ing, is you can really see what the engine likes. I mean, if you plan on simply locking the timing at 34*, and tuning for a specific air fuel ratio, then yes, dyno'ing isn't gonna do much.
But, if you take the time to see what the engine actually likes, fuel and timing wise, you can get a really nice tune. I have always been an advocate of 02 sensors in the boat, but I don't think they are the end all. Its really nice to be able to see which cylinders are running the hottest with EGT probes, or, eight 02 sensors, to see how the fuel mixture is being distributed.
On that 1000hp 522ci build, we got to use the Daytona ignitions for the first time. Prior to that, we always ran locked timing. I pulled out 9 degrees of timing in the midrange, and we saw an INCREASE in torque output. To me, that told me that we simply were firing the plug much too early in the midrange, and it simply wasn't doing anything for the engine, except, possibly going to induce preignition, or run the plug much hotter than it needs to be. I don't see how you can really re-create that scenerio, in the boat.
You can view brake specifics, fuel consumption, CFM consumption, and a bunch of stuff. Last year, I went to a local shop, for some balancing work I needed done. It was a new shop I had never been to or even heard of, even though the guys been there for 40 years. Anyhow, he gave me a tour of their shop. They do some intense work there. He showed me his dyno cell, and he had an engine strapped on the dyno. I noticed, that he had two oxygen sensors on each side. One was mounted in the collector, the other was a bit further downstream. I asked him if he see's a different reading from them, and he said "absolutely".
These portable widebands we use nowdays, are great tools, but they certainly aren't as accurate as stuff that they have at really high end places, or general motors, ford moco, chrysler, etc. I still think there is validity in tuning an engine on the dyno, and observe what its telling you it likes, or doesn't like. When we dynoed Icdedppl's blower motors, they simply made their best power at around 11.5 afr on the dyno's meter. Leaner, it lost power. Timing and fuel mixture definitely play against or for each other. A lean fuel mix, might not like the higher spark advance, where a richer mixture will. And vice versa. Too little timing, you melt exhaust valves and lose power. Too much, you detonate, and lose power. From what I've learned, you'll see a drop in peak HP on the dyno, before you actually get to detonation/preigniton from too much timing. If the engine likes 36* at 6000rpm, try 38*. If it gains 10hp, it likes it. If it gains zero, leave it at 36.
I've heard the storys about not running anymore than 30 or 32* in a bbc blower motor, or you'll melt it down. I was just reviewing my data logs last night, 35.4 timing at 6200RPM, with 9lbs of boost and IRON heads. Plugs look great after that run. So much for that theory.
But, if you take the time to see what the engine actually likes, fuel and timing wise, you can get a really nice tune. I have always been an advocate of 02 sensors in the boat, but I don't think they are the end all. Its really nice to be able to see which cylinders are running the hottest with EGT probes, or, eight 02 sensors, to see how the fuel mixture is being distributed.
On that 1000hp 522ci build, we got to use the Daytona ignitions for the first time. Prior to that, we always ran locked timing. I pulled out 9 degrees of timing in the midrange, and we saw an INCREASE in torque output. To me, that told me that we simply were firing the plug much too early in the midrange, and it simply wasn't doing anything for the engine, except, possibly going to induce preignition, or run the plug much hotter than it needs to be. I don't see how you can really re-create that scenerio, in the boat.
You can view brake specifics, fuel consumption, CFM consumption, and a bunch of stuff. Last year, I went to a local shop, for some balancing work I needed done. It was a new shop I had never been to or even heard of, even though the guys been there for 40 years. Anyhow, he gave me a tour of their shop. They do some intense work there. He showed me his dyno cell, and he had an engine strapped on the dyno. I noticed, that he had two oxygen sensors on each side. One was mounted in the collector, the other was a bit further downstream. I asked him if he see's a different reading from them, and he said "absolutely".
These portable widebands we use nowdays, are great tools, but they certainly aren't as accurate as stuff that they have at really high end places, or general motors, ford moco, chrysler, etc. I still think there is validity in tuning an engine on the dyno, and observe what its telling you it likes, or doesn't like. When we dynoed Icdedppl's blower motors, they simply made their best power at around 11.5 afr on the dyno's meter. Leaner, it lost power. Timing and fuel mixture definitely play against or for each other. A lean fuel mix, might not like the higher spark advance, where a richer mixture will. And vice versa. Too little timing, you melt exhaust valves and lose power. Too much, you detonate, and lose power. From what I've learned, you'll see a drop in peak HP on the dyno, before you actually get to detonation/preigniton from too much timing. If the engine likes 36* at 6000rpm, try 38*. If it gains 10hp, it likes it. If it gains zero, leave it at 36.
I've heard the storys about not running anymore than 30 or 32* in a bbc blower motor, or you'll melt it down. I was just reviewing my data logs last night, 35.4 timing at 6200RPM, with 9lbs of boost and IRON heads. Plugs look great after that run. So much for that theory.
