Author Topic: Milwaukee Midget  (Read 3255341 times)

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Offline Rex Schimmer

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Re: Milwaukee Midget
« Reply #6810 on: February 15, 2018, 12:30:15 PM »
If you happen to go to the web site that Fordboy has listed, (
http://www.vintageracerules.com/forums/ubbthreads.php/topics/14439/Re:_RACING_ENGINES,_A_TECHNICA#Post14439) do not miss the article reprinted from Kevin Cameron!! Read it several times! These are the things that happen to engines that most of us have a hard time understanding. Great info!!

165 hp from a 2 port farm tractor engine is amazing. Using these numbers the original Grenade would have made over 120 hp!! and we all know the effort that Chris and Mark put into it .

Fordboy, thanks for the info!!!

Rex
Rex

Not much matters and the rest doesn't matter at all.

Offline Jack Gifford

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Re: Milwaukee Midget
« Reply #6811 on: February 16, 2018, 02:19:49 AM »
Thanks for pointing out Cameron's discussion of Spintron learning. As usual, it's excellent. I've read a whole bunch of Kevin's writings, but need to look up more of his recent stuff.
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Offline hoffman900

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Re: Milwaukee Midget
« Reply #6812 on: February 16, 2018, 09:07:37 AM »
If anyone is on Facebook, Billy Godbold has pretty good discussions on his page concerning Spintron results regularly.

Also this is a great interview: https://www.youtube.com/watch?v=whmOxK4XDYQ&t=4274s

Between Billy's stuff on social media, Mike Jones' posts on ST, and the late Harold Brookshire's on ST and the Chevelle forum, you can learn A LOT about racing camshafts. You can also access Harvey Crane's site still on Wayback archive. I have all the graphs from his site that you can look at along with the text on his site. PM me if you want them.

As for Aaron's engine, he has had the airflow to get there and found some other improvements in the head, going to the .875" lifter in the GT-L engine (FP restricts this to stock size) helps him out in getting there, but it took the fuel injection for the engine to be able to keep up with the fueling - the ram tuning doesn't hurt one bit either. He's a very sharp guy and is applying a lot of modern racing engine techniques /knowledge to these old lumps.

« Last Edit: February 16, 2018, 09:27:03 AM by hoffman900 »

Offline fordboy628

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Re: Milwaukee Midget
« Reply #6813 on: February 17, 2018, 10:08:12 AM »
midget,

When it has been a tough week, it helps to maintain some perspective . . . . .



This framed cartoon has been hanging over my desk in my office, at every venue I have worked at, for the last 36 years . . . . .

It now hangs over my desktop in my "dungeon laboratory".

I'm not sure if it helps to reflect on how I started "down the wrong path" . . . . . . . . .

 :dhorse:  :dhorse:  :dhorse:
Igorboy
Science, NOT Magic . . . .

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

"There is nothing permanent except change."    Heraclitus

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Offline WOODY@DDLLC

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Re: Milwaukee Midget
« Reply #6814 on: February 17, 2018, 11:55:45 AM »
I'm not sure if it helps to reflect on how I started "down the wrong path" . . . . . . . . .

Second-hand glue sniffing?  :? :-o :? :-o
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Offline Stainless1

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Re: Milwaukee Midget
« Reply #6815 on: February 17, 2018, 02:43:53 PM »
I usually claim to have fallen in with a bad crowd when I was young....  :cheers:
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Offline Milwaukee Midget

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Re: Milwaukee Midget
« Reply #6816 on: February 17, 2018, 02:45:18 PM »
I usually claim to have fallen in with a bad crowd when I was young....  :cheers:

And you're STILL hanging out with us . . .

er . . . uhhh . . . I mean, THEM . . .
"Problems are almost always a sign of progress."  Harold Bettes
Well, I guess we're making a LOT of progress . . .  :roll:

Offline fordboy628

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Re: Milwaukee Midget
« Reply #6817 on: February 17, 2018, 02:50:20 PM »
I'm not sure if it helps to reflect on how I started "down the wrong path" . . . . . . . . .

Second-hand glue sniffing?  :? :-o :? :-o

I have a "vague" recollection that it may have been first-hand glue "intoxication" . . . . . .  :roll:

At least it would explain the fascination with weird beers . . . . . .  :wink:

 :cheers:  :cheers:  :cheers:
Braindamageboy
Science, NOT Magic . . . .

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 #6818 on: February 17, 2018, 03:13:09 PM »
Since a picture is worth a thousand words . . . . . .

Here are a few thousand words about how you can upgrade an older Rimac Valve Spring Tester to digital vertical measurement . . . .


Any brand of 6" (150 mm) vertical digital measuring unit can be used to replace the original Rimac scale and pointer



No doubt you will have to "fiddle" with the mounting bracket,
and probably have to fabricate your own mount for the measuring unit



But the finished product will be able to be "zero set" for ANY retainer thickness



The Shars unit I chose has the choice of English, Metric and Fractional measurement



These spring testers were the "state of the art" for decades, but lately have been supplanted by fully digital spring checkers, also with data recording capability.   Very trick for the "Pro" engine shop, but way over the top for home builders and other small shops.    And although the company that produced them has ceased doing business, they are available sporadically on "fleabay".     The selling price varies according to tester capacity and condition.    Expect to pay $300 to $500 for a 350# to 500# unit in good to nice condition.     Expect to pay more for a 750# or 1000# one.    Some examples are really "beat up" so check carefully.

Calibration springs are still available for most ranges, check ebay or Comp Cams.     Comp Cams also has a 1" dial indicator height accessory that can be set to measure in one inch increments.

 :cheers:  :cheers:  :cheers:
Shoptipboy
Science, NOT Magic . . . .

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 #6819 on: February 17, 2018, 04:51:42 PM »

165 hp from a 2 port farm tractor engine is amazing. Using these numbers the original Grenade would have made over 120 hp!! and we all know the effort that Chris and Mark put into it .

Rex


Well, yeah, there was a lot of effort, but I think we could have made a bit more hp.     I have dyno sheets from the early 90's for 998 BMC F/Juniors that produced 105 bhp.   I estimate that 108 bhp would have been about the most we could have gotten from the "Grenade" without turning it into a "hand grenade" . . . . .

The shortcomings of Chris's build Vs Aaron's are these:

EFI Vs Weber Carb
2 problems here, fuel curve of the Weber Vs the linear fuel delivery of the EFI.    Better atomization of the EFI, although this may not be so important with BMC's.    Notice the very flat torque curve of the EFI.   Typically, an engine's Tq curve "duplicates the shape" of the bsfc curve.    In a Weber, the overall curve is a product of the emulsion tube and jetting.    We spent a lot of time on the dyno "flattening" that curve with various Weber parts.    After 2 days of dyno pulls, it was as good as we could make it.    I seem to recall we tested 8 different emulsion tubes x various jet sizes.   LOTS of pulls.    Flattening out the top of the bsfc might have been worth 5 bhp or so . . . . .

Curves in the Weber inlet manifold Vs the straight tapered stack of the EFI setup
Probably worth 2 bhp minimum


Static C/R
We should have used a "domed" piston to get the static C/R up from where we were, into the 14.5/1 range.    It was an expense that Chris did not choose.     And the BMEP we achieved, 183 psi, proved out that the static C/R was "light".   195 psi BMEP Vs 183 psi = +5 #/ft Tq     @ 8100 5 #/ft = 7.7 bhp . . . . .     Aaron's engine is 204.8 psi, very well developed.      As an aside, it is MUCH easier to get to 14/1 C/R with a 1310 cc engine Vs a 999 cc engine.


More valve to piston clearance for a cam with a narrow(er) LCA
Again a domed piston with deeper valve notches would have allowed a different cam spec.      + ? bhp . . . .


Dry sump Vs wet sump
This is an unknown, but 3/5 bhp is reasonable.


But, as always, hindsight, is usually 20/20 . . . . . .   :|

The trick is to turn hindsight into "foresight".    :-D

 :dhorse:  :dhorse:  :dhorse:  :dhorse:  :dhorse:  :dhorse:  :dhorse:  :dhorse:  :dhorse:  :dhorse:
Conjectureboy
« Last Edit: February 17, 2018, 05:01:04 PM by fordboy628 »
Science, NOT Magic . . . .

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 #6820 on: February 17, 2018, 06:14:42 PM »
Mark's been bugging me to post up something.  After all, not ALL of the fun happens in Illinois . . .

Picked up a Walbro fuel pump for a 5 liter Mustang.  255 lph - plenty of pressure, but it's too tall -

DSCN0981 by Chris Conrad, on Flickr

So I've designed a turret under which I can plumb fuel and electrical connections.  Picked up a piece of 4" aluminum tubing -

DSCN0982 by Chris Conrad, on Flickr

I'll be down in Illinois on Wednesday, so I'll use T&T's band saw to cut it down - it will only have to be about 1 1/2 inches above the current access - and make a C-plate, with the plan being to plumb the output toward the front of the car.  Trick is getting from the barb output of the pump to a -6 fitting.  Dug around and found some bulkhead fittings -

DSCN0984 by Chris Conrad, on Flickr

And as it turns out, I should be able to tap the AN fitting under the turret with a 1/4" pipe/barb fitting -

DSCN0987 by Chris Conrad, on Flickr

I also picked up some threaded brass rod, nuts and washers, along with nylon collars and washers, which will press fit into the turret and get the electricity in - hopefully without the interference of Lord Lucas -

DSCN0983 by Chris Conrad, on Flickr

I'll be utilizing the original fuel send as a return line, so I removed the sock from the original pickup in the tank and relocated it (aka "bent it") so that the return fuel is less prone to aerating the fuel already in the tank.  To further "still the waters", I'll be cutting a hole in this fuel cell foam, which will be held nominally in place by the fuel pump and the required bracketing.

DSCN0989 by Chris Conrad, on Flickr


"Problems are almost always a sign of progress."  Harold Bettes
Well, I guess we're making a LOT of progress . . .  :roll:

Offline Milwaukee Midget

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Re: Milwaukee Midget
« Reply #6821 on: February 17, 2018, 06:16:51 PM »
Oh - and the connecting rod bearings arrived yesterday.
"Problems are almost always a sign of progress."  Harold Bettes
Well, I guess we're making a LOT of progress . . .  :roll:

Offline salt27

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Re: Milwaukee Midget
« Reply #6822 on: February 17, 2018, 10:25:57 PM »
Dry sump Vs wet sump
This is an unknown, but 3/5 bhp is reasonable.
Conjectureboy

Mark, I assume you are indicating that the dry sump may be worth 3/5 bhp more than the wet sump system in the "Gernade".
(if not don't bother reading the rest)   :roll:

In one of Smokey Yunicks sb chevy books he states "Make no mistake, switching to a dry-sump will cost some power".

He says in the sb chevy "at least 8 to 10 HP or more over a wet-sump".

So is this windage vs dry sump pumps?

What's your take on this?

I'm not questioning your knowlage on this, I'm just trying to increase mine.    :-D

Thanks, Don


« Last Edit: February 17, 2018, 10:35:42 PM by salt27 »

Offline forker

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Re: Milwaukee Midget
« Reply #6823 on: February 18, 2018, 03:07:31 AM »
Excuse me distracting you all if I missed something; erm, aluminium tube joint to steel fuel tank carcass..? Lots of bolts and an o-ring?

Also, typical road car practice these days for fuel system plumbing, at a high level, is for returnless fuel flow. Connections need to be a bit tougher, too, with ~5 bar output.

Returning fuel flow was previously the more or less universal method; that has the effect of perpetually recirculating fuel between tank and nice warm engine bay (fuel rail bolted to nice warm engine etc) so gradually warms up the tank content. Evaporation emission is then an issue (for a road car) plus there are more joints to go wrong, fuel aeration to handle, hot fuel in low tank level,etc.

Would there be an inescapable driver to return fuel from the engine bay to the tank for this project? Bulk fuel won't be cold for long unless there's loads of it to absorb engine bay heat and dissipate it via tank walls into underfloor air flow but that's warm too, isn't it, from engine outflow and exhaust.

Road cars use nylon fuel lines routed away from the trans tunnel and exhaust, plus heatshielding. Fuel arrives cold at the engine, or at least not warmed up. Nylon can be moulded so shaped to the underfloor, allowing again less joints (as above). Is there perhaps a rule about hard fuel lines required to be metallic? If so copper is easier to bend than steel.

Would you want cold fuel? If so perhaps a returnless fuel cell in a bucket of ice would do cold fuel well.  Yes, more fab, more leak opportunity, more of (not my) cost. Its easy for me to speculate about how to spend someone else's money. And there would have to be some ice; the salt pix look like it's a warmish place compared to Blighty so it'd be necessary to take a huge bucket of ice from the hotel..

Or a fuel cooler. Yes, your modern road car has that, too, in at least some cases.

Perhaps this class mandates unmolested fuel tank architecture; if so that kills the above idea anyway.

(Another bit of modern trickery is to use direct injection for fuel delivery instead of port injection; all of the flow past the valve is air, rather than most of it, so there's more air available for burning fuel. There is need for an into-cylinder injector so no context of that for the midget case (even if it was my money!). Cold-engine behaviour is better so unburned fuel emission goes down in EPA tests etc; all good. But you all know that anyway; mile/half-mile etc dirt-track motors (Shaver etc) have been DI for ages)

Just, as they say, my two penn'orth.


Offline hoffman900

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Re: Milwaukee Midget
« Reply #6824 on: February 18, 2018, 06:10:59 AM »
Dry sump Vs wet sump
This is an unknown, but 3/5 bhp is reasonable.
Conjectureboy

Mark, I assume you are indicating that the dry sump may be worth 3/5 bhp more than the wet sump system in the "Gernade".
(if not don't bother reading the rest)   :roll:

In one of Smokey Yunicks sb chevy books he states "Make no mistake, switching to a dry-sump will cost some power".

He says in the sb chevy "at least 8 to 10 HP or more over a wet-sump".

So is this windage vs dry sump pumps?

What's your take on this?

I'm not questioning your knowlage on this, I'm just trying to increase mine.    :-D

Thanks, Don




There is a lot of information that Smokey shared, that while probably true at the time, just hasn’t hold up. This doesn’t mean he wasn’t smart, just that 30+ years of engine development later, people have learned things and found ways to measure other things.

With the dry sump, you can pull a lot of crankcase vacuum (NASCAR engines pull 20in/Hg +). This allows one to obtain better ring seal. It also allows one to run low tension rings and get them to seal. You make horsepower due to better ring seal and you make horsepower with increasing rpm by reducing drag. The ring/bore interface is responsible for the most friction in the engine and increases exponentially with rpm. NASCAR engines have blowby numbers in the neighborhood of .1%.

A lot of wet sump drag and circle track racers use dedicated vacuum pumps for this as well, but dry sump is the way to go if rules allow and you have the money.

With really high vacuum numbers however, you’ll need piston oil squirters to get oil to the small end and the pins have to be DLC coated. Keep it around 10in and you’ll get benefits without all the other engineering.

Remember, NASCAR engines are using rings down to .7mm thick. Those are available for small bore applications as well. I know Aaron has worked with CP on pistons for that engine and no doubt he’a taking advantage of what he can.

Mark,

The biggest gain for Aaron with EFI was just getting enough fuel into the engine beyond what the SPVP-5 and the HL12 could make power up to. ;)

Carburetors can do a pretty good job with charge cooling. Both NASCAR and NHRA Pro Stock lost power going to EFI. NASCAR was able to gain a lot of that back with individual cylinder ignitions. Unfortunately,  both series spec'ed the location of the injectors (in the runners) and the type of throttle body, so it isn't ideal, but everyone is on the same page. Last year there were rumors of Pro Stock builders using internal fuel rails with "leaky seals" to fog the plenum.  Now the rails have to be on the outside  :-D

Blank slate, EFI allows one to straighten out the runners, give the runners an ideal taper (and not to fit whatever carburetor you need to fit), and lack of parts in the way (booster) + lack of change of CSA (venturir) allows ram tuning to be MUCH more effective!
« Last Edit: February 18, 2018, 09:52:45 AM by hoffman900 »