I would be interested to see what the desk top says with the stock heads compared to mild port and then Snakes port. Same cam just differant flow numbers and a cam with .500 lift
Ask and you shall receive. Specs are 401, 9.5:1, 850cfm, open headers, and a cam spec'd at 228*/228* .500"/.500" 110*LSA 110* ICL. The ordering goes Snake, mild Gessler, and then stock.
I ask lol. plug in 091 vs isky and a third cam of 224- 228 duration on a 109 lsa 107 cl 525 intake lift and 530 exhaust lift.
Here you go Joe! I used Snake's head flow values for each test, with the same specs as my last post. The order goes your cam, 091, then Isky. For the 091 cam I assumed 207* @ 0.050, and that it was installed straight up. As you can see, the 091 was WAY out performed.
thanks a lot Andy, that's not my cam just throwing out some numbers like a fast ramp cam would be with the higher lift per duration. but look at the torque of the 091 cam, looks like a bigger cam will make more hp but less tq. lower the duration on the cam I made up 222-226 might give that extra tq and make perfect street cam if your not trying to chase peck hp numbers.
Andy, Not sure if this is enough info or if it is any different than what you plugged in for the 091, but try this: Duration @ .050 is 205/215 and a .454/.483 lift on a 110 LC This is Russ Martin's version of the 091. The one he says to be as close as you can get to the original. I'm still unfamiliar with all the cam specs and flow numbers so excuse me if I am asking for the same thing.
Exact same specs as before, but with the above cam specs, installed straight up. The extra exhaust lift and duration seem to have REALLY helped, which shouldn't be a surprise. And just for the hell of it, again same combo, but with the Comp Cams Thumpr that's in my '62, which is relatively radical compared to most of the cams being discussed thus far.
Andy, can I ask for one more. 230/235 at .50 540/550 lift on 109ls and 107 c l . Also could you plug in 401 and 425. Promise, last thing I will ask. Just wondering the change the cubic inch plays with the desk top. Thanks
am thinking the desk top dosnt know about extra exhaust duration it just goes by total over lap. so 205-215 might come out the same as 210-210 just a guess. its all peck numbers we are looking at. the power curve of a cam might make more of a difference in the 1/4 mile.
No problem Bob! The engineer in me loves this! First is the 401, and then the 425. Joe, I can't comment directly as to how the program works as I didn't develop it, but it much more sophisticated that just looking at the overlap values. I did check and a 210/210 cam didn't perform as well as the 205/215 cam. And just for clarification purposes for those trying to make sense of all the data, I used the "dual plane high torque" manifold selection in the program, trying to replicate the factory single 4bbl intake manifold. In reality as most of us have ported them to some degree or another, and based on what I've seen trend wise, most of the combinations I have posted should make slightly more peak horsepower, and a little less torque. However, the comparisions are all still valid, as the same set of parameters were utilized among each camshaft change.
I ran a few more tests using my head flow numbers, and the rest of the specs from my boat engine. 1100cfm, dual plane, open exhaust. .040 oversize 425. I was able to generate some seat to seat specs for an 091 using LSA and advertised duration. If advertised duration was figured using .006 the industry standard they should be pretty accurate. For each test the compression ratio was optimized for an 8.25:1 DCR. The cams I checked were an 091, Isky 280HL, and an original Ed Winfield grind that came from Max Balowsky. The specs on the Winfield in terms of lift are small by today's standard .438/.460 but duration is huge 241/252@.050, 112 LSA 83 degrees of overlap. Whats very odd to me that for such a large cam it out performs the 091 from 2000 rpm's up. Also all of these tests were using my ported heads which flow 148 cfm @ .400 lift. These numbers tell me that a Nailhead needs more exhaust. That Winfield camshaft was ground in the late 1950's (I think). While camshaft design has progressed the use older engines get has changed. 60 years ago they were trying to squeeze every drop of power they could get out of those engines, they were racing them. Nowadays most people just want a lopey idle for the car show and the cruise night. Sometimes I think we might be a little better off if we started looking backwards on some stuff. For fun heres a link to that Winfield camshaft running in my boat: http://www.youtube.com/watch?v=zuYjaawUsOc&feature=youtu.be
Wow, that 091 peaks really high compared to the other cams used on desk top and the ones that were dynoed. That should put a smile on Docs face. Thanks 487
487, what input values are you using for the 091? Something still isn't right. It should make way more low end torque, and not make peak HP so high. If your still using the seat to seat figures, that's the problem.
2x4's, ported heads, open exhaust, 10.10:1 compression. Still out performed by the Isky across the board.
The 091 specs I used were. IVO 38.5 IVC 76.5 EVO 80 EVC 42. I generated these with Pat Kellys DCR calculator. It uses LSA and advertised duration to figure seat to seat valve timing. Elgin Industries has specs for their stock nailhead cam. It is 295/302 .430 lift on a 112 LSA. .050 specs are 207 9 36 39 12 67 overlap. I think those 050 specs are an error because I got some funny readings using them. I still am using seat to seat timing beacuse I cannot locate any .050 figures.
487, I haven't profiled a 091 cam, but did profile the 090 cam that was more common. It had the 114 deg LSA. These 090 figures might give you a better idea of the open/close ramps on the 091: Intake opens 34.5 deg, closes at 95 deg at 0.002" lift = 309 deg duration (Buick advertised) Intake opens 19.5 deg, closes at 72 deg at 0.006" lift = 271.5 deg duration Intake opens 7A deg, closes at 36 deg at 0.050" lift = 209 deg duration Lobe lift= 0.270" Valve lift= 0.448" Exhaust opens 75 deg, closes 42.5 deg at 0.002" lift = 298 deg duration (Buick advertised) Exhaust opens 65 deg, closes 21 deg at 0.006" lift = 266 deg duration Exhaust opens 40 deg, closes 12 deg at 0.050" lift = 208 deg duration Lobe lift= 0.261" Valve lift= 0.425" Published cam specs from Dennis Manner are: BTW, nice work Andy:TU:
if you use the advertise duration like Walt shows 271.5 intake duration and 266 exhaust duration on a 109 lsa, that will be closer and not 295/302 112 lsa
Again, I can't explain why, but the program does not produce accurate results when using seat to seat valve events. Therefore trying to make a meaningful comparisons to the 091 cam utilizing this methodology isn't possible. Realistically, you could use the @ .050 duration values that Walt got, and simply change the valve lift, LSA, and ICL figures to that of the 091 and get pretty close.
Since your on a roll Andy here is the complete package, could you please dyno it. 425 .030 over Isky cam 270 int 280 ext. 110 LC @ 050 214 int 224 ext. 1966 qjet intake ported gessler style, 1972 BBB qjet 800 cfm, my ported heads , my ported exhaust manifolds collector ported at 2.25" pipes with 2.25" with camero style flow master 2 in 2 out muffler switch pitch 400 with 300 converter on 3.23 gears Petronix dizzy curved to dual quad specs and Petronix coil. Don't think I'm forgetting anything else!
