My requirements... what to build?
Back in 1999 when I planned this engine out, nobody was talking DCR, and nobody I knew could help me... except the Trigonometry and Algebra I had learned in High-school.
I figured out all about ICA, etc with the little tiny pea-brain God gave me,lol.
What I couldn't figure out was how much actual cylinder pressure, pump gas could take without detonation.
So What I did was back-engineer a few race-winning combos, to see what Dcr/pressure they were running.
Then, I knew they were running best pumpgas, but again, there was no way for me to know if my combo would, so I arbitrarily reduced my pressure target.
but I had figured out that no matter what cam I picked, the unspecified degrees from advertised to actually closed and not leaking, was gonna be a factor. So I arbitrarily increased it up a tad.
Another thing I knew was that the 9.0/9.5 Scr that the machine shops were suggesting I not exceed, was pure BS.
So picked a bigger cam than I really wanted to run and slammed it together at 11.3. And it was a success right from the get-go.
So now I had a psi number that I knew would work.
I sold the 292/292/108 cam, got the cam I had wanted the HE2430AL (270/276/110), reduced the Scr to 10.8(IIRC) to maintain the Cylinder Pressure that I knew would work, and had the most funtastic street-engine I could ever have imagined .... and it burned 87E10 with full timing.
According to the many many numbers you have posted, and I thank you for that, I have learned that;
from advertised to on the seat and not leaking can be anywhere from perhaps as low as ~8*, to as high as ~15*
I measured my 292 and about fell over, but those figures are long-gone; I had not yet heard of FABO, and never gave a thought that someday it might be important.
And as you know, those numbers are really only important to understanding the idle-quality.
And then,
you come along,
And give us mid lift durations, and suddenly the veil is lifted! What I would have given to read those numbers in 1998, during the planning stages. Again; many thanks.
But, I just gotta say that the two Hughes cams I have had, never disappointed.
The 292 either, it just wasn't right for me, never was, but I had to start somewhere to get the Dcr/pressure thing sorted.
Here is a free bit of info I learned to anyone just starting out;
With aluminum heads, and a Tight-Q, I have always run 9.0 to 9.1 Dcr With an .008spec Ica, on 87E10.
Cuz I got lucky and found out it works.
9.1 is NOT the ceiling!
Others here on FABO, are running even more, but on better gas.
I am quite happy running 9.1Dcr on 87E10. That 2430combo was a monster.
Here's a Hughes combo similar to my current engine, with it's HE3038AL cam, same as mine; check out that torque curve!
http://www.hughesengines.com/Upload/TechArticles/land_dyno.jpg
I think you would know that better than I.
Back in 1999 when I planned this engine out, nobody was talking DCR, and nobody I knew could help me... except the Trigonometry and Algebra I had learned in High-school.
I figured out all about ICA, etc with the little tiny pea-brain God gave me,lol.
What I couldn't figure out was how much actual cylinder pressure, pump gas could take without detonation.
So What I did was back-engineer a few race-winning combos, to see what Dcr/pressure they were running.
Then, I knew they were running best pumpgas, but again, there was no way for me to know if my combo would, so I arbitrarily reduced my pressure target.
but I had figured out that no matter what cam I picked, the unspecified degrees from advertised to actually closed and not leaking, was gonna be a factor. So I arbitrarily increased it up a tad.
Another thing I knew was that the 9.0/9.5 Scr that the machine shops were suggesting I not exceed, was pure BS.
So picked a bigger cam than I really wanted to run and slammed it together at 11.3. And it was a success right from the get-go.
So now I had a psi number that I knew would work.
I sold the 292/292/108 cam, got the cam I had wanted the HE2430AL (270/276/110), reduced the Scr to 10.8(IIRC) to maintain the Cylinder Pressure that I knew would work, and had the most funtastic street-engine I could ever have imagined .... and it burned 87E10 with full timing.
According to the many many numbers you have posted, and I thank you for that, I have learned that;
from advertised to on the seat and not leaking can be anywhere from perhaps as low as ~8*, to as high as ~15*
I measured my 292 and about fell over, but those figures are long-gone; I had not yet heard of FABO, and never gave a thought that someday it might be important.
And as you know, those numbers are really only important to understanding the idle-quality.
And then,
you come along,
And give us mid lift durations, and suddenly the veil is lifted! What I would have given to read those numbers in 1998, during the planning stages. Again; many thanks.
But, I just gotta say that the two Hughes cams I have had, never disappointed.
The 292 either, it just wasn't right for me, never was, but I had to start somewhere to get the Dcr/pressure thing sorted.
Here is a free bit of info I learned to anyone just starting out;
With aluminum heads, and a Tight-Q, I have always run 9.0 to 9.1 Dcr With an .008spec Ica, on 87E10.
Cuz I got lucky and found out it works.
9.1 is NOT the ceiling!
Others here on FABO, are running even more, but on better gas.
I am quite happy running 9.1Dcr on 87E10. That 2430combo was a monster.
Here's a Hughes combo similar to my current engine, with it's HE3038AL cam, same as mine; check out that torque curve!
http://www.hughesengines.com/Upload/TechArticles/land_dyno.jpg