camshaft theory

[yellow rose]

Did not know that on the blueprint deal, very interesting and Im sure every bit of it is true but Im gonna keep calling it blueprinting cause everyone recognizes that.

Here is where Im gonna sound super ignorant, years ago you rarely ever saw me on the weekends cause I was spectating at the track, I seen time after time big heavy trucks ( usually Chevy or Ford ) pull up to the line and launch like a bat out of hell. Huge cam, big tires and it still took off like a rocket, if I can find a cam that sounds big and makes my truck take off like a Honda Accord than Id be happy.

I'm going to ASSume those things you were watching had a pretty loose converter or a very well sorted out clutch combo. You'd be surprised how many guys runs converter that is too tight for their application.

 

[1930]

if that cam were 108 instead of 112 lsa i bet it would sound to his liking.

that said, i would run that cam because it seems like it would work great.

Maybe stupid question but could I send the cam I have to have it reground to show the lSA you mention, how would that affect other things?

Numbers 1, 3 and vehicle weight are going to kill you. I'd sell the Jackson GD and either buy a QUALITY 3 gear drive like a Milodon or buy a timing chain. That floating idler gear thing is a timing nightmare, in that every time the engine speed changes, or the load, the floater slides back and forth in there. Since one gear is smaller than the other, the cam moves around.

If you have a stumble when you mash the throttle, that is a tune up issue.

Lightweight bob weight is highly over rated so don't fret over that.

At your weight and gear 9:1 CR is about it unless you get a cam specific for more compression. Even at 9:1 you have to be careful or you will run it into detonation, especially at low speed high throttle opening.

Measuring everything doesn't blueprint anything. Blueprinting is probably one of the most misused words in engine building vernacular. If you are going to "blueprint" an engine, you have to machine everything to the factory blueprint. I can say I've never done that.

There is a difference between building something to a blueprint, and actually building an engine that runs. As an example, if the blueprint calls out a 9.560 deck height and you cut the decks to exactly that number, but the piston is down the hole .060 what good did it do you to set it to the print? Are the rods too short? Stroke too short? Compression height too short? All of that? Some of it?

Most of us are stuck with the Pistons we get. Most shops don't have the tooling to make all the rods the same length so you get what you get with those. Most cranks aren't indexed very close when ground, although aftermarket cranks are almost always spot on.

To me, blue printing is nothing more than making everything the same, not machining to a blueprint. You correct what you can.

After all that, your best money spent, especially looking at your application is a custom ground cam. Yes, it's a few dollars more than a cam out of a catalog, but unless you like to tinker like rumble fish, and you don't mind changing cams in a truck your best bet is to call Jim at RB and tell him exactly what you want and let him grind it.


Jim Dowell
Racer Brown cams
410-866-7660

He prefers phone calls be AFTER 5pm eastern time. He answers the phones. He grinds the cams.

There is also Cam Motion. And Jones cams. Bullet cams.

You have choices other than a catalog guess.

Thanks, Im gonna call tonight. As far as the gear drive its bought and Im gonna use it for the time being, Im no gonna be driving the truck regularly anyway so Im thinking that with any luck Ill be ok

FWIW, Engine Masters episode 19 on YouTube is about cam spec explanation, and couple dyno runs.

Im gonna check this out as well tonight, I like videos

 

[1930]

I called Jim, coudnt have been nicer, Im done, Ill let him grind me a cam.

 

[AJ/FormS]

That's a great decision

 

[1930]

That's a great decision

Now your in trouble, I didnt think you came this far over to the dark side First post I seen you make over here.

 

[yellow rose]

I called Jim, coudnt have been nicer, Im done, Ill let him grind me a cam.

OUTSTANDING!!!!!!!!!!!!!!!!!!!!!!!!!

 

[1930]

OUTSTANDING!!!!!!!!!!!!!!!!!!!!!!!!!

Yeah ,he was nuthin like having to deal with 440 source.....sorry I cant help myself

 

[AJ/FormS]

I live here; over 9000posts, in 27 months,lol
My little 367 has 3.55s and a 3.09 low, and 27" tires. This computes to a starter gear of 9.75 corrected to a 24 inch tire.

Your NP435 might have ratios of 4.56-2.28-1.31-1.00
You have 3.55s, and 33" tires, right so far?
Well, your granny gear computes to an 11.77 starter gear corrected to 24" tire.
That means you have 11.77/9.75=1.2072 or Plus 20.7% more torque multiplication than I do.

Now My combo will smoke 325/50-15 Drs all the way thru first gear and beyond.These are 27 tall and about 10" of rubber on the road
The footprint or contact patch of your 33s, might be a little bigger than on my DRs, so perhaps they will stick a bit better.

But the clincher is you have a 440, with 440/367=1.199, or plus 20% more cubes.

What I'm thinking is you could have a totally screwed up combo, and still smoke the tires all the way thru first. And that is what you wanted right?
You have 20% more engine, and 20.7% more gear, with prehaps a tiny bit bigger patch.

You are at 6000#. I am at 3600# This is no big deal on the street. If anything it will help you, cuz the truck will not accelerate as quickly, so IMO it may spin longer. You don't care about fast, just spinning tires. I am confident that, that first little 220ish cam would have got the job done,allbeit without the raunchy idle. So IMO whatever cam you get, it too will get the job done.

The problem I see is when it hits second gear. This is a 2.28/4.56= 50% split. In other words, whatever rpm you rev first out to, the revs will fall to 50%.
The synchronizers in that tranny were never designed to work at 6000rpm. Nor to be Bang!-shifted. They were probably designed for 3600 to 4000 max. I don't know how they will fare at near 6000, or how long they will keep working.
So, if you carry first to 5000, the Rs will drop to 2500. And at 6000 pounds of chassis, you are done.This will be about 30mph. I hope you are good with that.

I another thing I don't know is how long that unsynchronized granny gear is gonna take that BB torque. It was never designed for this kind of abuse.IIRC this gear is about 7 or 8 inches in diameter, while the cluster gear is maybe 2 or a 2.5.
I suggest figuring out a way to get moving without excessive rpm clutch drops.At least until you figure out she can take it. Maybe get a line-loc.

I'm looking forward to see how this works out.

 

[1930]

I live here; over 9000posts, in 27 months,lol
My little 367 has 3.55s and a 3.09 low, and 27" tires. This computes to a starter gear of 9.75 corrected to a 24 inch tire.

Your NP435 might have ratios of 4.56-2.28-1.31-1.00
You have 3.55s, and 33" tires, right so far?
Well, your granny gear computes to an 11.77 starter gear corrected to 24" tire.
That means you have 11.77/9.75=1.2072 or Plus 20.7% more torque multiplication than I do.

Now My combo will smoke 325/50-15 Drs all the way thru first gear and beyond.These are 27 tall and about 10" of rubber on the road
The footprint or contact patch of your 33s, might be a little bigger than on my DRs, so perhaps they will stick a bit better.

But the clincher is you have a 440, with 440/367=1.199, or plus 20% more cubes.

What I'm thinking is you could have a totally screwed up combo, and still smoke the tires all the way thru first. And that is what you wanted right?
You have 20% more engine, and 20.7% more gear, with prehaps a tiny bit bigger patch.

You are at 6000#. I am at 3600# This is no big deal on the street. If anything it will help you, cuz the truck will not accelerate as quickly, so IMO it may spin longer. You don't care about fast, just spinning tires. I am confident that, that first little 220ish cam would have got the job done,allbeit without the raunchy idle. So IMO whatever cam you get, it too will get the job done.

The problem I see is when it hits second gear. This is a 2.28/4.56= 50% split. In other words, whatever rpm you rev first out to, the revs will fall to 50%.
The synchronizers in that tranny were never designed to work at 6000rpm. Nor to be Bang!-shifted. They were probably designed for 3600 to 4000 max. I don't know how they will fare at near 6000, or how long they will keep working.
So, if you carry first to 5000, the Rs will drop to 2500. And at 6000 pounds of chassis, you are done.This will be about 30mph. I hope you are good with that.

I another thing I don't know is how long that unsynchronized granny gear is gonna take that BB torque. It was never designed for this kind of abuse.IIRC this gear is about 7 or 8 inches in diameter, while the cluster gear is maybe 2 or a 2.5.
I suggest figuring out a way to get moving without excessive rpm clutch drops.At least until you figure out she can take it. Maybe get a line-loc.

I'm looking forward to see how this works out.

Man youve got racing in your brain Your waay off ( as far as abusing the truck ) but Ok I guess it sounds like fun as long as I dont have to pick up the pieces

 

[Lustle]

Respectfully I have to disagree, I think that the only guy that gonna look for whats best for my goal is myself and I can only do that by understanding all the theories behind it all which again Im working on. I have called several cam manufaturers and more often than not they are very knowledgeable and informative but at the the end of the day they have a job to do and thats sell me a cam without spending a whole bunch of time helping me decide what would be best.

I called Jim, coudnt have been nicer, Im done, Ill let him grind me a cam.

This is pretty much exactly what I was going to suggest. Call Jim.

I know it can be hard to think "why would anyone else want to help me". But here's the thing with a custom ground cam. If that cam don't run, you don't recommend him to anyone, he loses business. Period. If that cam smokes everyone in your class, you got guys banging your door down wondering what so special about your setup! That brings him business.

It's ALWAYS in the best interest of the little guys like Jim at racer. Or bullet. Or any of the other guys mentioned. To build you the very best cam they possibly can. Do they always get it right? Not necessarily. Do they try their damn hardest? Absolutely. It's in Jim's best interest to help you decide what is best, because it's his name on the cam. It's your word of mouth that says "That guy was a blast to deal with! And this cam I got from him runs like a scalded dog!".

Maybe someone like Comp. Or Lunati. Or whoe ever else might not care cause they sell 1000 cams a day. But the one off guys sure do. Not only that. But as I understand it, Jim will grind a cam for cheaper than an off the shelf. You just can't go wrong with that.

So I'm glad you called him. He's on my list to call when I get ready to go solid roller in my 340.

Did he give you the cam specs he is gunna grind? I'm curious what he came up with.

 

[1930]

This is pretty much exactly what I was going to suggest. Call Jim.

I know it can be hard to think "why would anyone else want to help me". But here's the thing with a custom ground cam. If that cam don't run, you don't recommend him to anyone, he loses business. Period. If that cam smokes everyone in your class, you got guys banging your door down wondering what so special about your setup! That brings him business.

It's ALWAYS in the best interest of the little guys like Jim at racer. Or bullet. Or any of the other guys mentioned. To build you the very best cam they possibly can. Do they always get it right? Not necessarily. Do they try their damn hardest? Absolutely. It's in Jim's best interest to help you decide what is best, because it's his name on the cam. It's your word of mouth that says "That guy was a blast to deal with! And this cam I got from him runs like a scalded dog!".

Maybe someone like Comp. Or Lunati. Or whoe ever else might not care cause they sell 1000 cams a day. But the one off guys sure do. Not only that. But as I understand it, Jim will grind a cam for cheaper than an off the shelf. You just can't go wrong with that.

So I'm glad you called him. He's on my list to call when I get ready to go solid roller in my 340.

Did he give you the cam specs he is gunna grind? I'm curious what he came up with.

No he was honest enough to tell me that he knew a guy, a mopar truck guy that could rattle off a combo faster than he could sit down in front of his spread sheet.

Cost is less than 2 hundred.

I think ( no big deal ) that my lunati was close to three

 

[Lustle]

No he was honest enough to tell me that he knew a guy, a mopar truck guy that could rattle off a combo faster than he could sit down in front of his spread sheet.

Cost is less than 2 hundred.

I think ( no big deal ) that my lunati was close to three

Well I'm curious to see that cam card. You going hydraulic or solid? Flat tappet or roller? I assume hydraulic flat tappet?

 

[1930]

Ill post it and yes

 

[rumblefish360]

I called Jim, coudnt have been nicer, Im done, Ill let him grind me a cam.

Wow! I come home from my overnight shift and grab some rest, all is done! Your in like flint now!

 

[RustyRatRod]

Not like there's not a gazillion cam threads already. Ever use a search feature?

 

[fishmens67]

I hope the cam works good in your secret combo and I hope you were truthful providing the secrets of the combo to Jim.

 

[yellow rose]

Man youve got racing in your brain Your waay off ( as far as abusing the truck ) but Ok I guess it sounds like fun as long as I dont have to pick up the pieces

Give AJ a couple of beers and he will take pictures of his belly button for you. That's what I heard anyway!

 

[4spdragtop]

Heres a boobtube video thats pretty good.

 

[4spdragtop]

 

[rumblefish360]

Here is another "Fun" one to watch.

 

[1930]

Wow! I come home from my overnight shift and grab some rest, all is done! Your in like flint now!

Thanks

Not like there's not a gazillion cam threads already. Ever use a search feature?

Only about as often as you change your underwear so no, not very often

I hope the cam works good in your secret combo and I hope you were truthful providing the secrets of the combo to Jim.

Of course and Ill let you know

Heres a boobtube video thats pretty good.

Ill check it out

 

[1930]

Heres a boobtube video thats pretty good.

This video is very good, did he ever do the next specific video that he mentioned about cam degreeing?

I noticed you posted the next video by him but it titled 383 stroker build, dosent sound like that is the specific video he had mentioned?

 

[rumblefish360]

No he was honest enough to tell me that he knew a guy, a mopar truck guy that could rattle off a combo faster than he could sit down in front of his spread sheet.

Cost is less than 2 hundred.

I think ( no big deal ) that my lunati was close to three

Now that is awesome. Just straight up awesome. I'm real pleased to hear this. About you and the grinder. You can beat the price ether.

 

[4spdragtop]

Yep cam degreeing very well explained (I think)

This video is very good, did he ever do the next specific video that he mentioned about cam degreeing?

I noticed you posted the next video by him but it titled 383 stroker build, dosent sound like that is the specific video he had mentioned?