Thread: 302 Stroker??

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1500 rpm=25rps=12 1/2 ignition sparks per second= 0.08 second per spark




3000 rpm=50 rps=25 ignition sparks per second = 0.04 second per spark


6000 rpm =100rps=50 ignition sparks per second=0.02 second per spark


think about where your piston is at in the cycle dealing with TIME ( a constant in physics ) in relation to your degrees of timing according to crank rotation------------


Keep that too much advance at the lower rpm levels for the sake of cruising economy is probably more destructive when you moderately accel (no downshift) to pass or climb a hill than if you downshift and rev it up---cutting the time wave before top for that dreadful knock-----------


And if I opened a box of pistons that said limit timing-----------------

Originally Posted by jerry clayton

.....And if I opened a box of pistons that said limit timing-----------------

For some, Jerry, it's a matter of being prudent in understanding any limitations that may exist for the components that were selected when the engine was assembled by someone else, and not being asked/aware of those limits at the time selections were being made. Knowing the limitation that Keith Black, who's products I consider to be of very good quality, put on these particular pistons it's simply a matter of prudence to set limits accordingly. The option would be to tear the engine down and change out pistons which would, in my book, put my sanity in question. I could limit my total timing to 30 degrees and likely not notice the difference given the power to weight ratio we have in these cars. I'm perfectly happy with the KB Hypereutectics that were selected, and care not a whit that they have a timing limit.

Roger-----I did it more as a joke than anything-------------


However, since you mentioned Keith Black, I guess you don't remember/know that he passed away years before his name was sold by family members to this piston company-----------I knew Keith personally, and he, like many others, knew no limits----

Originally Posted by jerry clayton

Roger-----I did it more as a joke than anything-------------


However, since you mentioned Keith Black, I guess you don't remember/know that he passed away years before his name was sold by family members to this piston company-----------I knew Keith personally, and he, like many others, knew no limits----

Jerry, I did not know that about Keith Black. I do recall that he was one of the strong runners back in the day, and that's why we remember his name today.

Originally Posted by rspears

Jerry, I did not know that about Keith Black. I do recall that he was one of the strong runners back in the day, and that's why we remember his name today.

I'm not sure about strong runner, he was the engine builder for the Greer, Black, Prudhomme car that was practically unbeatable, especially at Lions. As I recall it seemed he, Prudhomme, ran mostly from the spectator lane and more often than not he would lift the front wheels for at least 60 feet or so.

I think I'll start another thread instead of detouring this one anymore-----don't know if I should do all KB, or link in Ed Pink, Donovan, Waterman, Milodon, Aviaid, the piston and cam folks, etc-------cranks, rods , magnetos, clutches---what would you all like to read??? will be mainly late 60s to mid/late 70s------------(before corporate )

Originally Posted by jerry clayton

I think I'll start another thread instead of detouring this one anymore-----don't know if I should do all KB, or link in Ed Pink, Donovan, Waterman, Milodon, Aviaid, the piston and cam folks, etc-------cranks, rods , magnetos, clutches---what would you all like to read??? will be mainly late 60s to mid/late 70s------------(before corporate )

Sounds like a winner to me, Jerry. I know a lot of stuff was trial and error and proven on the strip.

Originally Posted by jerry clayton

Pistons are dumb----------------


The issues of timing------------people talk about degrees of timing before top dead cender---it actually comes down to Time ( you know, one of them absolutely constant values, like gravity????) If spark could be set by time in milli seconds, you could run many more degrees of timing ----


Reason we are limited on the street to more restricted numbers with the lower quality fuel is it burns much faster (ever noticed how often you got to stop for gas?) and with the timing numbers we run for midrange(to me that's low range--) there is more time for the fuel to burn and reach that pressure point at say 2000 rpm than at 8000 rpm----------The reason we can/need to run more advance for wot operations is to enable the flame front to reach that sweet spot for the flame/pressure front, piston/rod/crank angles, etc which ironilly is past top center on the way down------------

And that's what we call the "OTHER 359" degrees!
Also, gas with a lower octane number doesn't mean it's of a lower "quality", but it does burn quicker for a shorter power cycle. And many vehicles actually achieve a better mpg on a lesser octane rated fuel!

Originally Posted by 34_40

...Also, gas with a lower octane number doesn't mean it's of a lower "quality", but it does burn quicker for a shorter power cycle. And many vehicles actually achieve a better mpg on a lesser octane rated fuel!

I agree 100%. I took a class in college, Internal Combustion Engines, and one of the things we learned was that at a given timing setting you get the most power and highest efficiency with the lowest octane fuel that your engine tolerates without any pre-ignition "ping", and to clarify, "ping" precedes "knock" which is detonation. Back in the day when we had only two grades, "regular" and "ethyl", guys would pull in and say they were going to fill up with ethyl for more power, and actually the reverse was true.

Originally Posted by rspears

I agree 100%. I took a class in college, Internal Combustion Engines, and one of the things we learned was that at a given timing setting you get the most power and highest efficiency with the lowest octane fuel that your engine tolerates without any pre-ignition "ping", and to clarify, "ping" precedes "knock" which is detonation. Back in the day when we had only two grades, "regular" and "ethyl", guys would pull in and say they were going to fill up with ethyl for more power, and actually the reverse was true.

You and I took the same class!

I stayed at a Holiday Inn Express!!!!!!!!!!!!

Good to know! Dr. Jerry Clayton!

Well, I won't go into any long specifics but I finally got my dash back and started getting it ready to go back together.

Thought some might like to see a pic or two.. Hard to not get the gauges reflecting back...

Looks great! How's the rest of the project coming, almost time to get back on the road???

Originally Posted by Dave Severson

Looks great! How's the rest of the project coming, almost time to get back on the road???

I am way behind schedule and projects have stacked up! Once I get the dash and new gauges installed I still need to figure out the tune-up for the carbs.
Last time I ran it - it would set your eyes on fire!

As a teenager... I'd love the sting! Now, not so much.