camshaft intake valve closing

[hoffman900]

Finally getting to grips with camshaft specs. So most important event is intake valve closing?

The most important event for cranking compression tests is inlet valve closing.

What is everyone’s obsession with cranking compression outside a specific rule set?

[Tom68]

What is everyone’s obsession with cranking compression outside a specific rule set?

Something they can measure and calculate. Then they relate it to detonation and power off idle.

[Tom Walker]

In the diesel world, low cranking compression means hard starting or no starting, in the gasoline world it tends to make people feel good.

[digger]

an engine with low cranking compression will never make good bottom end

[Tom68]

an engine with low cranking compression will never make good bottom end

632 with 11:1 comp cranking 160 psi.

[bob460]

Warp Speed,
I was referring to the 19000+ cam dyno tests that D. Vizard did while contracted to Crane Cams. You have tested a few hundred? Well you have only got about 18000 to go to catch up to DV.....

I have NEVER mentioned the number 500,000. Someone else did....I also find the number incredible. But maybe it has been taken out of context. They were dyno pulls, not changing cams & dynoing. If he was doing dyno pulls after changing jets, valve lash, ign timing, spark plugs etc then maybe it is possible.

Exactly what I'm talking about. 19,000 cam tests?!? Lol
If I remember right it was over a 3 year period. Do the numbers, it's physical impossible, especially in the 80s! Haha
How many cams do you really think can be "properly" tested in a 10 hour day? 3-4 max, and that is with some bad dudes getting after it with modern equipment and unlimited resources. Do that for even 5 days straight, and your about ready for a different profession!
His claim would be 5.2 cams a day, 365 days a year for 10 years straight!
Now if they weren't changing cams every time, but just doing recorded pulls changing cam timing, lash ect. That would be 6 pulls (not counting warm up pulls) per change. 31 recorded pulls, 365 days a year for 10 years. Not counting the time for cam changes or timing/lash adjustments in between.
Hell, I've built a SBF, with an assistant, and ran it for 60 seconds, in just over 17 minutes and couldn't do what he claims! Lol

He had to sell books somehow............and we all know BULLS**t sells....lol

[digger]

an engine with low cranking compression will never make good bottom end

632 with 11:1 comp cranking 160 psi.

and?

[Tom68]

an engine with low cranking compression will never make good bottom end

632 with 11:1 comp cranking 160 psi.

and?

Should make good bottom end, not good for it's capacity, but still good fun.

[digger]

632 with 11:1 comp cranking 160 psi.

and?

Should make good bottom end, not good for it's capacity, but still good fun.

i guess thats the point, not good for its capacity, so if you dont happen to have 632ci and have half or even a third of that then that's going be a bit crap

[Tuner]

Warp Speed,
I was referring to the 19000+ cam dyno tests that D. Vizard did while contracted to Crane Cams. You have tested a few hundred? Well you have only got about 18000 to go to catch up to DV.....

I have NEVER mentioned the number 500,000. Someone else did....I also find the number incredible. But maybe it has been taken out of context. They were dyno pulls, not changing cams & dynoing. If he was doing dyno pulls after changing jets, valve lash, ign timing, spark plugs etc then maybe it is possible.

Exactly what I'm talking about. 19,000 cam tests?!? Lol
If I remember right it was over a 3 year period. Do the numbers, it's physical impossible, especially in the 80s! Haha
How many cams do you really think can be "properly" tested in a 10 hour day? 3-4 max, and that is with some bad dudes getting after it with modern equipment and unlimited resources. Do that for even 5 days straight, and your about ready for a different profession!
His claim would be 5.2 cams a day, 365 days a year for 10 years straight!
Now if they weren't changing cams every time, but just doing recorded pulls changing cam timing, lash ect. That would be 6 pulls (not counting warm up pulls) per change. 31 recorded pulls, 365 days a year for 10 years. Not counting the time for cam changes or timing/lash adjustments in between.
Hell, I've built a SBF, with an assistant, and ran it for 60 seconds, in just over 17 minutes and couldn't do what he claims! Lol

Warp, I think I see the problem. Your dynos may have reversed polarity somewhere in one of the flux capacitor stages, or simply too few flux capacitors for the number of tests required to sort out all those cams. Or maybe the software didn't correct for space weather, solar flares and proton flows, etc. It is so easy to overlook the simple stuff. As we all know, flux capacitors are exactly like lift and duration, more is always better.

[Art]

Finally, a post that makes perfect sense. That may belong in the Advanced Engine Tech thread though. Not everybody will understand.

[hoffman900]

What is everyone’s obsession with cranking compression outside a specific rule set?

Something they can measure and calculate. Then they relate it to detonation and power off idle.

Not really.

[hoffman900]

632 with 11:1 comp cranking 160 psi.

and?

Should make good bottom end, not good for it's capacity, but still good fun.

It only makes a bunch of power because it’s big, not because it’s good.

[Geoff2]

Tuner,
Do you have anything actually useful to add to this thread....or is this your way of getting even.

[digger]

Tuner,
Do you have anything actually useful to add to this thread....or is this your way of getting even.

speaking of useful, so if the LSA is the most important thing, how would one design and conduct a testing program to identfy or verify that this is indeed the case?