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Author Topic: Milwaukee Midget  (Read 1886537 times)

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Offline hoffman900

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Re: Milwaukee Midget
« Reply #6750 on: February 04, 2018, 02:17:09 PM »
Fordboy has two cams of mine and I’m sending him two more to have profiled. I use them for simulation work and to evaluate what the aftermarket companies are doing. With a OHC rocker set up the geometry requires a specific lobe shape due to the varying rocker ratio. As you profile, you sometimes find out that the lobe was taken from another application and while close, it may have weird dynamics. One aftermarket cam I measured had a large spike in positive acceleration at valve closing. Not good.

A smart move - for that very reason.

You really, really want to believe the cam manufacturers are doing it right, but having now seen dozens of cam profiles and comparisons, it's way too often a crapshoot.

And as with any part, the manufacturer will seldom stand behind it after it's been installed.

As to the engineering, it seems they all steal from each other.

But if you take it out of the box, run a profile, and call them on the issues, the reputable grinders will either fix it or get you a refund.

I'm reasonably certain most of the engineers at the cam companies hate it when their work is checked, and non-conforming cam profile files fill their e-mail in-boxes.  And in 9 out of 10 applications, their grinds probably work just fine.

But given the small displacement of what you, me and Mark are doing, and the slim margins for error, an incorrect cam, or an improperly ground lobe can mean the difference between success and shrapnel.

Mark checked the Piper Cams when they came in last summer.  They were spot on, which is great.  The idea of sending cams back and forth between the US and Great Britain is not my idea of a fun time.  

Oh, absolutely. When you realize there are less designers than there are camshaft grinding outfits, it should tell you something.

You also realize that a bunch of the designers have bounced around and left their mark across several places. For example, Harold Brookshire (RIP) started at Reed Cams, then went to General Dynamics, from there he went to Comp Cams as their first designer (where he started designing assymetrical pushrod lobes) and wrote their first design program, then he went out on his own (Ultradyne - which Bullet Cams bought the masters (they also bought Lazer when the owner passed away)). After that ran into cashflow problems due to core availability and the UPS strike and the Feds shut him down, then he designed the VooDoo series for Lunati, then he went from there to Custom Camshaft Company (Arrington) doing NASCAR and Pro Stock work, CCC was sold off and the lobe designs went to Howard Cams. His last stint was back at Lunati and he designed the TL2 (flat tappet) and TR2 (roller) lobe family before his health deteriorated. He did say he always improved on his designs as he moved around, but certainly had his own style (good enough for NHRA Championships, a couple Daytona 500 wins and other NASCAR wins, and other USAC, NHRA, 24hrs of Daytona, etc. wins). Billy Godbold who is the designer at Comp Cams (got his start when his PhD funding ran out in the middle 90s) certainly is influenced to a certain degree by Harold as some of their flat tappet designs look similar to Harold's and he was also coached a lot by Harvey Crane. Harvey and Harold were also pretty similar in their designs techniques.

Harvey Crane layed out all the people he accidentally got into the camshaft business: http://web.archive.org/web/20100112082128/http://harveycrane.com:80/founders.htm#individuals . Of the ones named, only Harold Brookshire didn't steal any of his stuff.

Ideally you need to talk to a cam designer. Mike Jones (Jones Cam Design) is easy to get a hold of, Billy Godbold (Comp Cams) is accessible via social media, Harold Brookshire (RIP) was easy to get a hold of before his passing, but others are hard to get a hold of and you may have to pay a consulting fee, have died, or have moved on and are retired. I never dealt with Dema, but that's what Fordboy is for (amongst other things)!

You get what you pay for and to get what you really need, outside of a pushrod application of common tappet / roller diameters / base circle diameter, you likely will have to have a design produced, a master cut if applicable, have a core made, etc. It adds up really fast. A friend of mine has about $900 in each Triumph TR4 camshaft, and he was able to use existing lobe designs!

Most aren't maximizing performance. A lot of the common pushrod flat tappet cams are for Chevy .842 flat tappets. I know some of the UK grinders have used whatever the small Ford pushrod engine is. Other comapnies may have built their offerings off something like an air cooled Kawasaki with bucket lifters.

With OHC rocker and finger follower designs, the lobe design has to be proprietary to that particular head's / set up geometry as the rocker ratio is variable. Some other applications may be close, and for most it's good enough, but as you said, if you're pushing performance then it's not what you want.

Obviously, the diameter of the lifter / bucket will cause a ceiling to be placed on peak velocity and you could be giving up a lot of performance.

It's actually to easy to see what kind of safety factor your lobes are designed to for a flat tappet / bucket lifter type valvetrain.

Edge Distance = -1((Velocity*57.3)-(Tappet Diameter/2))

Velocity is in inches / degree. Diameter is in inches.

This will allow you to see what safety factor your cam designer is using. Pushrod engines, designers typically use .018-.020" for off the shelf stuff with a typical chamfer. OHC with stiffer valvetrain systems might be as tight as .009" for off the shelf designs. With work, you can tighten those up and gain more velocity which equals more lift area. This is why NASCAR put into place a tappet diameter rule as racers were using mushroom flat tappets. Even with the .875" diameter tappet that NASCAR ended up with, they ran their tappets with no chamfer and right out to the edge of the tappet. That's a risky place to play, but they had the resources and money to make it work.

Use this equation to plug and play and see how much velocity you could have:

Velocity = ((Lifter Diameter/2)-Edge Distance)/57.3

This will impact how much lift area you can have (even with valve lift limits).

Acceleration is the tricky one.
« Last Edit: February 04, 2018, 02:40:09 PM by hoffman900 »

Offline fordboy628

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Re: Milwaukee Midget
« Reply #6751 on: February 06, 2018, 07:20:05 AM »
Bob, et all,

Your post mirrors what I have been saying for years about camshafts in general, ie: that there was NOT a lot of original thinking going on . . . .

Now in the interest of fairness to all "cam professionals"  manufacturing bits in the harsh market place, everybody has to obey the rules of physics, OR, be penalized.    And what can happen because of this "reality" is that given the "limitations", even clever guys end up at the same, or very similar places.    I have seen this time and time again, partly because I'm at the tail end of a long run, and I can see my "finish line".


The trick is:  How do you know who is an "innovator" Vs who is just a copy?    It's a tough question that is difficult to answer, but here are some clues:

A/    True innovators are typically "brutally honest" with you, and you may not "measure up" to the type of client they want to deal with.   Usually they do not suffer fools well.   Can be difficult to contact, as their time is in high demand.    Typically willing to produce "cutting edge" designs for you, at your risk, and at high cost.     Usually point out the risks involved in "close to the edge" performance potential.    A client had better be able to calculate and supply the needed information, or the relationship can suffer . . . . . . .

2/    Copy types typically want to stick with "their proven designs".    This is confirmation that they are "risk adverse".     The best you will ever get from them is what 90% of your competition gets, which is probably enough, IF, some other part of your performance equation is "stellar" . . . . . . .   Usually don't get involved in "technical discussions" because they don't want to talk tech.   Potential clients should decide why that is.

d/    Charlatans.    Yes Virginia, unfortunately, some of these exist.     They market bad copies of other folk's intellectual property.    This is more common than most people realize, simply because most clients DO NOT check their camshafts.     Usually talk a lot, without saying anything . . . . . .  Usually want to deal directly with clients and not with engineers or knowledgeable builders.

z/    Mistakes.    If you are dealing with a "high volume" grinding operation, and request something "oddball", you need to check it before installation.     No reputable manufacturer "intends" to make an error, but they do happen, even on CNC grinders.     Human errors occur, don't dwell on it.     Reputable places will be glad to know that you are checking, and a replacement will be "No problem".


One final note about checking cams:    If you are using your block/head/whatever, realize that compared to a "fixture", you are adding variables.     If you "presume" that your block is "perfect", well, I wish you the best.

And to finish up:    Cost, has no bearing on whether you get a "good" product.    "Junk" can be as expensive as "cutting edge".     BUT, usually, you get what you pay for.

Caveat emptor
Iwon'trunanuncheckedcamboy
I used to be a people person.  But people changed that relationship.

"There is nothing permanent except change."    Heraclitus

"Only two things are infinite, the universe and human stupidity, and I'm not sure about the former."     Albert Einstein

Offline fordboy628

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Re: Milwaukee Midget
« Reply #6752 on: February 06, 2018, 07:49:12 AM »
Re: Cams

MOST applications, DO NOT require anything extraordinary to produce competitive power.

All that is required is a well thought out, high quality produced product, thoughtfully integrated into a comprehensive build plan.

Sounds simple doesn't it?    And that, is where most builds falter . . . . . .


Food for thought . . . . . .

 :cheers:
Fordboy
I used to be a people person.  But people changed that relationship.

"There is nothing permanent except change."    Heraclitus

"Only two things are infinite, the universe and human stupidity, and I'm not sure about the former."     Albert Einstein

Offline fordboy628

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Re: Milwaukee Midget
« Reply #6753 on: February 06, 2018, 07:58:05 AM »
midget,

Good news, bad news department . . . . .

Good news:
T&T had a Diamond epoxy chamber mold kit on the shelf . . . . .    :-)

Bad news:
Product dated: 6/15/2009   and was: unusable . . . . . .    :-(


Good news:
Ordered up a fresh one from Diamond.    :-)

Possible delivery today, but with the snow storm, probably tomorrow.


Will cast up a mold asap and send off immediately.    :-)


Two steps forward, one step backward, etc, etc, etc . . . . . .

 :dhorse:
Processboy
I used to be a people person.  But people changed that relationship.

"There is nothing permanent except change."    Heraclitus

"Only two things are infinite, the universe and human stupidity, and I'm not sure about the former."     Albert Einstein

Offline fordboy628

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Re: Milwaukee Midget
« Reply #6754 on: February 06, 2018, 10:06:36 AM »
midget,

Good news, bad news department . . . . .

Good news:
T&T had a Diamond epoxy chamber mold kit on the shelf . . . . .    :-)

Bad news:
Product dated: 6/15/2009   and was: unusable . . . . . .    :-(


Good news:
Ordered up a fresh one from Diamond.    :-)

Possible delivery today, but with the snow storm, probably tomorrow.


Will cast up a mold asap and send off immediately.    :-)


Two steps forward, one step backward, etc, etc, etc . . . . . .

 :dhorse:
Processboy

midget,

Just advised via text that Diamond epoxy kit has arrived @ T&T.       So UPS outperforms USPS, in spite of consonant handicap . . . . . . . .   :-D

Will cast 2 molds tomorrow and ship 1 off to Diamond tomorrow pm.

Blue chamber mold photos to follow . . . . . .  :wink:

 :dhorse:
Moldyboy
I used to be a people person.  But people changed that relationship.

"There is nothing permanent except change."    Heraclitus

"Only two things are infinite, the universe and human stupidity, and I'm not sure about the former."     Albert Einstein

Offline Milwaukee Midget

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Re: Milwaukee Midget
« Reply #6755 on: February 06, 2018, 10:52:18 AM »
Thanks for making that happen.

I know a lot of people slag UPS, but between my eBay sales and incoming guitars and car parts, I've never had a problem with them.

It's Amazon that I hate dealing with.
"Problems are almost always a sign of progress."  Harold Bettes
Well, I guess we're making a LOT of progress . . .  :roll:

We are NOT rebuilding . . . We are reloading.

GOD SAVE MG - The Queen can take care of herself!

Offline fordboy628

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Re: Milwaukee Midget
« Reply #6756 on: February 06, 2018, 03:37:14 PM »
"I love when a plan comes together."     Colonel John "Hannibal" Smith

midget,

Piston rings arrived at the ranch today, approximately 13:00 CST, synchronize your watch . . . . .

Will hand carry to location, "g", on the morrow . . . . . . .

To be placed in the pile of offerings to the 'K' gods . . . . . . .

Verification photos at a later date . . . . . .

 :dhorse:
Clandestineoperativeboy
I used to be a people person.  But people changed that relationship.

"There is nothing permanent except change."    Heraclitus

"Only two things are infinite, the universe and human stupidity, and I'm not sure about the former."     Albert Einstein

Offline Milwaukee Midget

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Re: Milwaukee Midget
« Reply #6757 on: February 06, 2018, 05:12:50 PM »
And I should have a print of the rods by tomorrow afternoon.  Yes, coming together . . .
"Problems are almost always a sign of progress."  Harold Bettes
Well, I guess we're making a LOT of progress . . .  :roll:

We are NOT rebuilding . . . We are reloading.

GOD SAVE MG - The Queen can take care of herself!

Offline hoffman900

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Re: Milwaukee Midget
« Reply #6758 on: February 06, 2018, 07:34:36 PM »
Re: Cams

MOST applications, DO NOT require anything extraordinary to produce competitive power.

All that is required is a well thought out, high quality produced product, thoughtfully integrated into a comprehensive build plan.

Sounds simple doesn't it?    And that, is where most builds falter . . . . . .


Food for thought . . . . . .

 :cheers:
Fordboy

I think that's what I love about your guys' approach on the A-Series. You could be so much more trick with it, but it was just a very solid and well thought out package. Sometimes it takes going back to the basics and attention to the entire system.  :cheers:

Offline Milwaukee Midget

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Re: Milwaukee Midget
« Reply #6759 on: February 07, 2018, 06:28:20 AM »
And here is our rod design -
"Problems are almost always a sign of progress."  Harold Bettes
Well, I guess we're making a LOT of progress . . .  :roll:

We are NOT rebuilding . . . We are reloading.

GOD SAVE MG - The Queen can take care of herself!

Offline Interested Observer

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Re: Milwaukee Midget
« Reply #6760 on: February 07, 2018, 07:47:27 AM »
Unsolicited comments on the (admittedly unfinished) rod drawing...

Bolt hole dimensions?
Bolt head seat area seems rather vaguely defined.  Awfully small shoulder.
Dimension across the corners--for bore fit?
Small end has blind oil hole?

Offline jacksoni

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Re: Milwaukee Midget
« Reply #6761 on: February 07, 2018, 08:03:52 AM »
Shows 74.8 across the flats big end, into a 75mm bore!!?? Like IO says.
Jack Iliff
 G/BGS-250.235 1987
 G/GC- 176.245  2018
 G/GMS-178.835 2010

Offline Milwaukee Midget

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Re: Milwaukee Midget
« Reply #6762 on: February 07, 2018, 09:27:26 AM »
Hypotenuse of 79.25 - I need more detail.
"Problems are almost always a sign of progress."  Harold Bettes
Well, I guess we're making a LOT of progress . . .  :roll:

We are NOT rebuilding . . . We are reloading.

GOD SAVE MG - The Queen can take care of herself!

Offline manta22

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Re: Milwaukee Midget
« Reply #6763 on: February 07, 2018, 10:21:00 AM »
Chris;

I suggest specifying an overall rod bend & twist spec. Bolt seating surfaces need generous radii, flatness & parallel spec.

Good luck with this project!

Regards, Neil  Tucson, AZ
Regards, Neil  Tucson, AZ

Offline ggl205

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Re: Milwaukee Midget
« Reply #6764 on: February 07, 2018, 10:31:54 AM »
And here is our rod design -

Saenz rods are of good quality. Some of the best racing transmissions too. I used to visit them occasionally when doing business in Buenos Aires.

John