All good but 101 installed 101, 107 installed 107 but then 113 is installed at 109 or there's a typo.
In Cl.jpg
The cranking pressure varied by an equal amount.
Ideally they'd do them all 4 degrees advanced from straight up since that's how the majority of cams are installed, that'd be interesting for the 101 cam.
Oddly the crossover isn't at 5250 for all the tests.
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Ignorance leads to confidence more often than knowledge does.
Nah, I'm not leaving myself out of the ignorant brigade....at times.
panic wrote: ↑Sat Nov 26, 2022 10:16 am
Oddly the crossover isn't at 5250 for all the tests
That's called a "mistake".
HP is defined by torque (if using lb./ft) and RPM, the lines always cross there.
It crosses over at 5200 or 5300rpm if you count. The data wasn't recorded at 50rpm increments, so it's whatever the computer rounded to for display reasons, weirdly.
That test showed about what I expected. People do this all the time with DOHC valvetrains and it's hardly controversial. Put the centerlines where it makes the most power for your application and use.
Cranking compression means nothing. The compression that is important is the cylinder pressure just before the plug fires in a firing engine.
I post on another forum where stock an super stock racers post. One of them posted this.
I'm still using my Flowmaster 4-2-1 collectors, be for warned if you're going to use them with a " tight " lobe seperation , they don't work well with that.
The flowmasters seem to like a little wider lobe seperation angle. The Burns style collector works better with a tight lobe seperation. At least tha'ts what I've found over the years, and you have to try some adjustments to get everything from them.
Cranking compression means nothing. The compression that is important is the cylinder pressure just before the plug fires in a firing engine.
Cranking compression is an indication of DCR which can be used to calculate other factors. And of cylinder leakage.
The cylinder pressure at IVC is the most important, since it tells us something about trapped charge.
What is the benefit of knowing cylinder pressure at ignition angle? If combined with cylinder temperature at ignition firing, pressure could provide an insight to the firing voltage required.
Stan Weiss wrote: ↑Sat Nov 26, 2022 11:14 am
Just to add something else about testing. Stan
Agree, Stan. Everything affects everything else. Changing the overlap and the exhaust opening affects how the header scavenges. Crucial to evaluating the test result, is the build going to be run with dyno headers or on the strip with full street exhaust? Same overlap, different result.
It also affects and is affected by the intake; same overlap, a low-rise single plane 4-bbl, a tunnel ram and an IR system, all will behave differently and be affected differently by change in LSA/overlap.
Jack Vines
Studebaker-Packard V8 Limited
Obsolete Engineering
As a control for this test a 4th camshaft, same 230/236 cam in/ex lobes ground on 110 LSA could have been run on 101° intake C/L and 107° intake C/L and on 113° intake C/L.
and then "straight up" 110/110 in/ex C/L's
Lay these power and torque curves over the others and show the effect of just moving the exhaust installed C,/L around or moving the whole cam around.(110 LSA) (101/119), (107/113), (113/107) and (110/110)
Every power curve will be a bit different. No two exactly alike. ... BUT....
You'd then see that its where the intake C/L is installed that makes up the MOST DIFFERENCE in how the power,/ torque curve is shaped.
Think that that conclusion is wrong.
Do the same thing but use the 107 LSA camshaft.
run the 107° LSA cam installed 101/113, 107/107, 110/104. and 113/101 installed in/ex centers
and compare these power curves to the others.
F-BIRD'88 wrote: ↑Sat Nov 26, 2022 2:57 pm
As a control for this test a 4th camshaft, same 230/236 cam in/ex lobes ground on 110 LSA could have been run on 101° intake C/L and 107° intake C/L and on 113° intake C/L.
and then "straight up" 110/110 in/ex C/L's
Lay these power and torque curves over the others and show the effect of just moving the exhaust installed C,/L around or moving the whole cam around.(110 LSA) (101/119), (107/113), (113/107) and (110/110)
Every power curve will be a bit different. No two exactly alike. ... BUT....
You'd then see that its where the intake C/L is installed that makes up the MOST DIFFERENCE in how the power,/ torque curve is shaped.
We need one of these.
Twin Cam V8.jpeg
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Ignorance leads to confidence more often than knowledge does.
Nah, I'm not leaving myself out of the ignorant brigade....at times.
F-BIRD'88 wrote: ↑Sat Nov 26, 2022 2:57 pm
As a control for this test a 4th camshaft, same 230/236 cam in/ex lobes ground on 110 LSA could have been run on 101° intake C/L and 107° intake C/L and on 113° intake C/L.
and then "straight up" 110/110 in/ex C/L's
Lay these power and torque curves over the others and show the effect of just moving the exhaust installed C,/L around or moving the whole cam around.(110 LSA) (101/119), (107/113), (113/107) and (110/110)
Every power curve will be a bit different. No two exactly alike. ... BUT....
You'd then see that its where the intake C/L is installed that makes up the MOST DIFFERENCE in how the power,/ torque curve is shaped.
We need one of these.
Twin Cam V8.jpeg
Last edited by juuhanaa on Sat Nov 26, 2022 5:21 pm, edited 1 time in total.
A balanced person dares to stagger, and modify ports bigger
F-BIRD'88 wrote: ↑Sat Nov 26, 2022 2:57 pm
As a control for this test a 4th camshaft, same 230/236 cam in/ex lobes ground on 110 LSA could have been run on 101° intake C/L and 107° intake C/L and on 113° intake C/L.
and then "straight up" 110/110 in/ex C/L's
Lay these power and torque curves over the others and show the effect of just moving the exhaust installed C,/L around or moving the whole cam around.(110 LSA) (101/119), (107/113), (113/107) and (110/110)
Every power curve will be a bit different. No two exactly alike. ... BUT....
You'd then see that its where the intake C/L is installed that makes up the MOST DIFFERENCE in how the power,/ torque curve is shaped.
We need one of these.
Twin Cam V8.jpeg
Wtf is that?
A separate intake and exhaust cam so you can change the lobe centers on the fly on a pushrod V8.
Ignorance leads to confidence more often than knowledge does.
Nah, I'm not leaving myself out of the ignorant brigade....at times.
