A tale of 2 cams

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PRH said:
106 in at 100 with street type closed exhaust?

No thanks.

For a car that’s primarily driven on the street, and from the sounds of it not “optimized” for track use....... I’d give up 15-20hp to have the car drive better.
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Who's cam are you referring to? If its mine ..I have 1 7/8 TTi headers with 3.5" collectors then 3" exhaust.
The cam was meant to be a compromise for street strip.
I dont think it will be lacking torque with a 4" stroke , a 4sp and 3.91s... I might run a 3.09 1st gear as well for sparking lot crawling.
My car wont tech for 10s so it is a moot point to wring every last HP out of it.
I will have to short shift to keep it at the 11.30 mark the way it is.
 
PRH said:
106 in at 100 with street type closed exhaust?

No thanks.

For a car that’s primarily driven on the street, and from the sounds of it not “optimized” for track use....... I’d give up 15-20hp to have the car drive better.
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Is the thinking here that the extra back pressure will work with the slightly larger overlap and cause more reversion at the lower RPM's?
 
It is.

Especially when it’s advanced a lot, so you get the added reversion helper with the intake valve opening earlier during the exhaust stroke(piston coming up).

Tight lsa and mediocre exhaust has never really worked well for me.

Race car with open headers....... different situation.

As with all of this stuff.......Ymmv.
 
my68barracuda said:
As you are running cam 2, if you do pull the motor and swap in cam 1, after you have some experience with cam 1 revive this thread. It would be interesting to hear how the two compare performance wise.
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IF I pull the engine and IF I swap cams it would not be for cam 1. I would probably use a grind I ran a few years ago. Very similar except 110 LSA installed at 106. Now THAT cam was my all-time favorite. Very responsive and a monster on top. Don't know why I decided to try the Bullet. Experimentation is my weakness.
 
Ironmike said:
IF I pull the engine and IF I swap cams it would not be for cam 1. I would probably use a grind I ran a few years ago. Very similar except 110 LSA installed at 106. Now THAT cam was my all-time favorite. Very responsive and a monster on top. Don't know why I decided to try the Bullet. Experimentation is my weakness.
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How do you install a 110 LSA at 106?
 
my68barracuda said:
Advancing the cam changes the intake (and exhaust) center line,
ICL, not the lobe separation angle.
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I never said I was changing the LSA. I simply stated where(ICL) I installed it. It's done with a degree wheel, dial indicator set up, and a good(Cloyes) adjustable timing set.

Sometimes you can't hit your intended install position dead on the money, but the Cloyes true roller set has always got me within a half degree. A big degree wheel helps also.
 
PRH said:
It is.

Especially when it’s advanced a lot, so you get the added reversion helper with the intake valve opening earlier during the exhaust stroke(piston coming up).

Tight lsa and mediocre exhaust has never really worked well for me.

Race car with open headers....... different situation.

As with all of this stuff.......Ymmv.
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As usual Dwayne, you are right on the money. Tight LSA's like a certain member here LOVE'S do not drive well in the REAL world. J.Rob
 
'except 110 LSA installed at 106.'

is what was written,, I took that to mean you some how shifted a 110 LSA to a 106 LSA, which can't be done
it appears that what you were saying was that the cam you liked has a 110 LSA and it was installed at a 106 ICL..

we are clear now, thanks
 
RAMM said:
Wrong again Mike, experimentation is your strength. If you experiment and fail AND fail to learn from it then and only then is it a weakness. J.Rob
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Thank you, sir!. Appreciate the encouragement.. I learned a lot from this last motor. Now it's going to get redone. Found a pretty nasty scratch on number 8. Smack dead center of the intake side of the cylinder wall.I can barely catch a fingernail on it so I think I'm screwed. Dont know what the heck got in there. Im pretty anal at assembly about dirt and such.

Not sure what happens until my machinist looks at it. Sure don't want to go to 4.060 unless absolutely necessary.
 
Wanted to bring this back to ask about cranking compression. Most agreed that cam #1 would be higher.

Here's where I'm confused....so as said, I ran cam #2 last summer in a 11.25 to 1 aluminum headed stroker that made an honest 576 HP. Cranking compression was only 167lbs.
I refuse to get into all that timeslip crap, but it ran 126.4 mph. I'm NOT normally a track guy......thing is, on the street it didn't FEEL all that fast. Kinda boring.

2 years ago, I ran a 10.5 to 1 stroker with a Voodoo, similar lift and duration as the 2 above BUT a 110 LSA installed at a 104 ICL, per Lunati. That engine had 185 lbs cranking compression. AND it scared the crap outta ya, it was so much fun. But it was 40 less HP than my current combo with cam number 2.

All this mumbo jumbo is just saying I guess I really don't like the cam number 2, in spite of the power it makes. Seems like the cranking compression should be higher. Now that it's all apart for a "freshen up", I find myself not wanting to stick that cam back in.

Man I'm confused and I TYPED this!
 
Sounds like you know what you want to do even though the cam you like is slower according to the track times.
 
Ironmike said:
Wanted to bring this back to ask about cranking compression. Most agreed that cam #1 would be higher.

Here's where I'm confused....so as said, I ran cam #2 last summer in a 11.25 to 1 aluminum headed stroker that made an honest 576 HP. Cranking compression was only 167lbs.
I refuse to get into all that timeslip crap, but it ran 126.4 mph. I'm NOT normally a track guy......thing is, on the street it didn't FEEL all that fast. Kinda boring.

2 years ago, I ran a 10.5 to 1 stroker with a Voodoo, similar lift and duration as the 2 above BUT a 110 LSA installed at a 104 ICL, per Lunati. That engine had 185 lbs cranking compression. AND it scared the crap outta ya, it was so much fun. But it was 40 less HP than my current combo with cam number 2.

All this mumbo jumbo is just saying I guess I really don't like the cam number 2, in spite of the power it makes. Seems like the cranking compression should be higher. Now that it's all apart for a "freshen up", I find myself not wanting to stick that cam back in.

Man I'm confused and I TYPED this!
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I just have a lil 367 with about 180 psi, and I agree it can be scarry. I don't get a lotta repeat ride-alongs,lol. In fact, I haven't had a passenger for several years,lol, just the way I like it. If I'm gonna die in this car, I'd rather not take anyone else with me. Kidding; I don't drive like that anymore.
I will never go back to iron heads and sub-160psi,ever. I'm still burning 87E10, so next time out, I'm gonna push the envelope a lil higher. Mine went 93 in the Eighth at 3467#. It has amazing throttle response with a 750DP and a manual trans.
I think about the why of this every now and again, and it seems to me that what 180+ psi is doing, is when the piston goes down on the intake stroke, and because the chamber is so small, and because the header has made a low-pressure in that little chamber, Because of all that, atmosphere is very eager very early, to get in there thru the 750DP. And I think it gets a pretty good head of steam going, and when the piston turns around at the bottom, and the valve is heading for the seat, that atmosphere doesn't exactly know it's supposed to slow down, so it keeps coming until the valve finally closes. That's what I think.
And I think with a lower compression chamber, this all takes too long to get going and never quite reaches it's glory. So it seems soft and lazy.
IDK if there is any reality in these thoughts, but my car shouldna gone 93 in the Eighth. I even went back to the tower to argue, and to visit the guy in the other lane, and both agreed that my time was correct.
So what makes 185psi so great?
IDK but I was ecstatic about the 93 and went home a happy man.
 
Well AJ, I tend to agree. I think that means reality has no bearing on seat of the pants feel..

That old Voodoo roller I had was 255/263 @ .050 with .640/.640. It was a 110 LSA installed at 106 ICL. I just dug out the old card. Wonder if they have one on the shelf......

I'll save the gear drive talk for later:BangHead:
 
Ironmike said:
Well AJ, I tend to agree. I think that means reality has no bearing on seat of the pants feel..

That old Voodoo roller I had was 255/263 @ .050 with .640/.640. It was a 110 LSA installed at 106 ICL. I just dug out the old card. Wonder if they have one on the shelf......

I'll save the gear drive talk for later:BangHead:
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I just happend to notice the gear drive line,dont stop there let us know how those makes you feel.
 
That old Voodoo roller I had was 255/263 @ .050 with .640/.640.
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That cam came into the Lunati line up when they hired Harold Brookshire to develop some lobes for them.

Those are actually lobes that Harold did in the UltraDyne days.
 
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Seems like every cam someone specs for me, it turns out to be "an old ultradyne lobe".
Wonder who TRULY specs a cam for a guy...

I'm thinking about that Voodoo pretty seriously. That and maybe a Milodon gear drive. I can pick up a never used one for practically nothing. Don't like the idea of drilling into my block though. Looks like just 1 hole right on the outside wall of cyl number 1.

Well some progress was made today. Put in new mains and got the bottom all torqued.
20190119_184406.jpg
20190119_184336.jpg
 
Ironmike said:
Wanted to bring this back to ask about cranking compression. Most agreed that cam #1 would be higher.

Here's where I'm confused....so as said, I ran cam #2 last summer in a 11.25 to 1 aluminum headed stroker that made an honest 576 HP. Cranking compression was only 167lbs.
I refuse to get into all that timeslip crap, but it ran 126.4 mph. I'm NOT normally a track guy......thing is, on the street it didn't FEEL all that fast. Kinda boring.

2 years ago, I ran a 10.5 to 1 stroker with a Voodoo, similar lift and duration as the 2 above BUT a 110 LSA installed at a 104 ICL, per Lunati. That engine had 185 lbs cranking compression. AND it scared the crap outta ya, it was so much fun. But it was 40 less HP than my current combo with cam number 2.
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40 HP less peak HP...

Everyone forgets about the HP and TQ curves as well as the power it makes under the curve.
 
Ironmike said:
Seems like every cam someone specs for me, it turns out to be "an old ultradyne lobe".
Wonder who TRULY specs a cam for a guy...

I'm thinking about that Voodoo pretty seriously. That and maybe a Milodon gear drive. I can pick up a never used one for practically nothing. Don't like the idea of drilling into my block though. Looks like just 1 hole right on the outside wall of cyl number 1.

Well some progress was made today. Put in new mains and got the bottom all torqued.View attachment 1715277808 View attachment 1715277809
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Mike @ Jones Cams uses a proprietory computer program to grind a cam specifically to your needs. He can change ANY thing but you really need to provide accurate info to get the best cam.

I gave him my engine info and his recommendation was pretty mild compared to what all my buddies are running in their dirt cars. I used the PO's cylinder head flow info plus comments from this board, and others, to "guess" on the flow for my ported W-2's. Now I find that an old friend from 30 years ago has a flow bench in his shop so I'm taking a head to him to get it flowed so I have accurate info.

I'll get Mike to grind a cam based on that new info...

BTW... Ultradyne Harold was a genius with cam design and many of his grinds were copied. Howard's has some of his Mopar grinds in their catalog of custom grinds.

RIP Harold.
 
Yeah Harold really knew his job. I ordered the Voodoo mentioned earlier, just today. Sticking with a cam I ran and loved. Really a "smack in the mouth" cam. Should be even better with a point more compression and better heads. Can't wait!

Actually talked to the guy who Harold worked with until he passed. I didn't know Lunati was his last official "employer".
 
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