Re: 470 dyno test article
[Re: mopar dave]
#2455757
02/22/18 07:03 PM
02/22/18 07:03 PM
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Joined: Aug 2011
Posts: 2,864 Pattison Texas
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David Vizard has a graph for selecting lobe sep angles. He says its the best way to do it as he finds more power in big blocks than most anyone else. I have never seen anyone use it. Looking at his graph shows my 511 would need a lob sep of 100*. I have never seen anyone use a cam with those kind of lobe sep angles. Anyone know if Vizards gragh is BS or is there some validity to it. I am assuming his engines are race only. are you talking LSA or LCA ? two different things .
1968 Charger COLD A/C Hilborn EFI 512ci 9.7 compression, Stealth heads, 4.10 gear A518 ODtrans 4100lb,10.93 full street car trim 2020 T/A 392 Stock 11.79 @ 114.5
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Re: 470 dyno test article
[Re: mopar dave]
#2455782
02/22/18 07:56 PM
02/22/18 07:56 PM
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Joined: Jan 2003
Posts: 31,050 Oregon
AndyF
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David Vizard has a graph for selecting lobe sep angles. He says its the best way to do it as he finds more power in big blocks than most anyone else. I have never seen anyone use it. Looking at his graph shows my 511 would need a lob sep of 100*. I have never seen anyone use a cam with those kind of lobe sep angles. Anyone know if Vizards gragh is BS or is there some validity to it. I am assuming his engines are race only. There have been some very long threads on SpeedTalk about Vizard's LSA chart. Most engine builders think he is nuts although not everyone. I think the trick is that Vizard's chart was really only designed for 23 degree head SBC engines but I'm not sure. I do know that if you follow his advice you end up with cams that seem very strange and the cores might not even exist to make them. However, as Dwayne hinted at, some of the EMC guys had success running a super narrow LSA. I recall engines with 99, 100 and 101 lobe angles. That kind of stuff is way off the chart in my world. I used to have an old Crower cam that was 103 or something like that. I never ran it so now idea how well it worked. It must have worked at some point for someone though. I'm not sure what I'm going to do with this engine. I might just put my old cam back in it or I might try one of these new lobes that Comp has released. The DGO 14669 looks like it would work on the intake for my engine or perhaps the DSP 12177. I think the DSS lobe might be pushing the lift just a tad too far.
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Re: 470 dyno test article
[Re: mopar dave]
#2455794
02/22/18 08:36 PM
02/22/18 08:36 PM
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Joined: Jan 2003
Posts: 15,439 Val-haul-ass... eventually
BradH
Taking time off to work on my car
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Taking time off to work on my car
Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
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... My 410 that came apart on the dyno was a real good education of the expenses of this hobby. About a $5000 education. Ouch. Sorry to hear that...
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Re: 470 dyno test article
[Re: krautrock]
#2455797
02/22/18 08:44 PM
02/22/18 08:44 PM
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Joined: Jan 2003
Posts: 15,439 Val-haul-ass... eventually
BradH
Taking time off to work on my car
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Taking time off to work on my car
Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
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It's not as simple as they make it out to be, but it's better than some crap I've seen published on the subject. Many years ago the late Joe Sherman (who only recently passed away) had an article in Car Craft or Hot Rod where he did a 106 / 108 / 110 LSA comparison on a fairly hot (close to 600 HP) SBC 23* build with a solid flat-tappet cam. The 106 made more power & torque everywhere except the last couple of hundred RPM. The 110 never made as much anywhere as the 106; the 108 was the cam that made a little bit more than the 106 only at the very top of the RPM range. It was valid for that specific build, but the YMMV caveat always comes into play.
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Re: 470 dyno test article
[Re: BradH]
#2455808
02/22/18 08:57 PM
02/22/18 08:57 PM
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Joined: Jan 2003
Posts: 6,591 Canton, Ohio
Sport440
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It's not as simple as they make it out to be, but it's better than some crap I've seen published on the subject. Many years ago the late Joe Sherman (who only recently passed away) had an article in Car Craft or Hot Rod where he did a 106 / 108 / 110 LSA comparison on a fairly hot (close to 600 HP) SBC 23* build with a solid flat-tappet cam. The 106 made more power & torque everywhere except the last couple of hundred RPM. The 110 never made as much anywhere as the 106; the 108 was the cam that made a little bit more than the 106 only at the very top of the RPM range. It was valid for that specific build, but the YMMV caveat always comes into play. You should always cam for the build, but with that said. I think one of the reasons the old MP .590 does so well for A lot of people Even to this Day, is its 106 LSA, and its 271 @ .050. The 106 LSA helps in the lower torque range, and the 271 @ .050 gives it some upper HP range. A pretty broad range race cam IMO. Ive even heard some early racers refer the Mp 590 cam torque cam compared to others in the race environment.
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Re: 470 dyno test article
[Re: BradH]
#2455849
02/22/18 10:11 PM
02/22/18 10:11 PM
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Joined: Jan 2003
Posts: 31,050 Oregon
AndyF
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I'm not sure what I'm going to do with this engine. I might just put my old cam back in it... There's my suggestion... but you have more time & $ than I do at this point. It is a spare engine so I'm not in any hurry to figure it out. I can leave it sit until I come up with another idea.
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Re: 470 dyno test article
[Re: AndyF]
#2455854
02/22/18 10:26 PM
02/22/18 10:26 PM
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Joined: Aug 2011
Posts: 2,864 Pattison Texas
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The thing about a wide lsa cam is they retard the intake lobe, & that will affect low end TQ, I have advanced a wide 112 lsa cam from 111 Intake LCA to 106 & it pick up lots of low end & still pulled on the top end, yes this was tested on a dyno.
1968 Charger COLD A/C Hilborn EFI 512ci 9.7 compression, Stealth heads, 4.10 gear A518 ODtrans 4100lb,10.93 full street car trim 2020 T/A 392 Stock 11.79 @ 114.5
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Re: 470 dyno test article
[Re: AndyF]
#2455855
02/22/18 10:35 PM
02/22/18 10:35 PM
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Joined: Jan 2003
Posts: 6,591 Canton, Ohio
Sport440
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I've read that article a few times and I think it needs some editing for clarity. I don't think the author ever says how the cams were installed. Were they all installed straight up? He also doesn't talk about the big effect that LSA can have on valve to piston clearance. And I think some of his conclusions are wrong. He says the 101 LSA cam has a wider powerband but I think that is wrong. Looks to me like the 101 cam falls off faster than the others. The 101 does Fall off faster at the Top of the rpm, past 5600. I guess it depends on where you start and stop your power band measurements. If you look at his dyno graphs, the 101 LSA did have the Wider Stronger power band up to 5600 rpm Now if you compared the 101 LSA from say 5000 to 6500, clearly the other two cams had the wider power band. In this case, if you had a 5000 stall vert, the wider LSA cams would be the better choice. A 4000 stall vert, probably the 101, just by the visual of the graph. Didn't spec the numbers out. 1500 vert, the 101 Blows the wider LSA cams away. With that said, wouldn't want the 101 LSA cam in my race car. Edit, And Dave, yes I have the specs for the MP 590. I will post them up for you later.
Last edited by Sport440; 02/22/18 10:41 PM.
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Re: 470 dyno test article
[Re: mopar dave]
#2455891
02/22/18 11:49 PM
02/22/18 11:49 PM
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Joined: Jan 2003
Posts: 6,591 Canton, Ohio
Sport440
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Do you have all the specs of the .590 cam for BB? Open/close and lift both valves? Some measure the cam at 271 @ .050, mine measured 272 @ .050, that makes the math more simple. But, for Strait up at a 106 ICL --------open------ close------- int: 30* BTDC, 62* ABDC exh: 62* BBDC, 30* ATDC But, as MP suggests a 104 ICL -------open------ close------- int: 32* BTDC, 60* ABDC exh: 64* BBDC, 28* ATDC But, Racers in the know, set it around a 100 ICL -------open------ close------- int: 36* BTDC, 56* ABDC exh: 68* BBDC, 24* ATDC See how Strait up works with symmetrical cams. With the Piston ATDC, the cams intake and exhaust lobes are centered as well between Max lift so the opening and closing numbers events match but on opposite sides of the pistons TDC
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Re: 470 dyno test article
[Re: BradH]
#2455909
02/23/18 12:28 AM
02/23/18 12:28 AM
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Joined: Jan 2003
Posts: 31,050 Oregon
AndyF
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I'm not sure what I'm going to do with this engine. I might just put my old cam back in it... There's my suggestion... but you have more time & $ than I do at this point. One thing I could do that might make sense would be to get another 264/268 cam ground but on a different LSA. Maybe tighten it up to 106 and see what happens. That way most of the variables would be controlled. Not sure it would worth the time and effort to do that test, but it would be a logical thing to do.
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