Author Topic: Milwaukee Midget  (Read 3255029 times)

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Offline fordboy628

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Re: Milwaukee Midget
« Reply #6480 on: October 05, 2017, 06:00:34 AM »
Sneakyboy:  In comparing the photos in replies 6471 and 6473 it appears that the headbolt bosses of the original configuration are isolated from the surrounding materials whereas in the “new” configuration everything, including the outer perifery, appears to be coplanar.

What’s going on there?

Are we losing preload to the water jacket and other areas?

In a word, YES.    That is the situation as it stands at this moment.

Although the block has been comprehensively "re-machined" in certain areas, certain other areas were left "untouched" because of the inability of the facility to deal with sizes much smaller than what is "normal" in USA racing.

So the net result of all this is that once the block returns to Beerhaven, some inspection is going to be necessary to evaluate just where the situation is at.   The block and sleeves assembly is now in what I would consider to be in "semi-finished" form.    I expect that with the modifications performed, and the upgraded lower "ladder" combined with the ARP stud kit, that the crank axis will be "distorted" enough to require align honing.   This was an operation that the block facility could not perform.    Some of the machine work (such as the final surfacing) may have been performed "out of order", due to this inability to service small sizes.   But, this is the nature of racing an "oddball", 2 steps forward, 1 step back, if you will.

One of the "evaluations" is going to be considering the differential in expansion between the alloy block and the iron sleeves.   Based on my prior experience, at this point I am "uncomfortable" with the idea of reduced "pre-load".    I need to calculate how much growth "differential" there might be.    If this number is small enough, say .001" or .002" max, I could be convinced into thinking that the increased fastener pre-load will overcome the differential in thermal expansion.    That, in a nutshell, is the position of the block machinist.    I'm waiting to do the numbers before I commit, one way or another.   Of course if the numbers are "unfavorable" resurfacing the head gasket interface to add "pre-load" always remains an option.

And something else to consider is that if there are any problems with water jacket leakage while dyno testing, the head gasket interface may need to be re-evaluated.    What this might require, I can't say at this point, other than to speculate that the engine may require the use of some sort of MLS type head gasket to resolve any problems.    In any event, I'm confident that any problems can be resolved in an orderly and timely fashion.

Like so many other racing engines based on production parts, this one is also going to be: A triumph of development over design.


So to add a personal insight that probably isn't necessary, I'm far more comfortable making decisions based on reviewing numbers that I, or others, calculate.  Even if it "elongates" the development timeline.

As opposed to say, the "speedier" methods of guessing, throwing darts or rolling dice.   I'm perfectly happy to let others use those decision making methodologies . . . . . .  and reap the benefits thereof.

 :cheers:
Slideruleboy
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 forker

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Re: Milwaukee Midget
« Reply #6481 on: October 05, 2017, 02:28:53 PM »
You're still planning to make sure that where the ring pack runs is away from where the headbolt loads enter, aren't you?

I have two of the K 1.8 Kamax bolts in my desk as thought-provokers;  they saved no end of grief by allowing the nice round bore to remain a nice round bore after the bolts were torqued. The trick works universally.

F

Offline fordboy628

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Re: Milwaukee Midget
« Reply #6482 on: October 05, 2017, 06:27:37 PM »
You're still planning to make sure that where the ring pack runs is away from where the headbolt loads enter, aren't you?

I have two of the K 1.8 Kamax bolts in my desk as thought-provokers;  they saved no end of grief by allowing the nice round bore to remain a nice round bore after the bolts were torqued. The trick works universally.

F

That is a resounding yes.

I fact, the whole point of all this "minnow flogging" is to increase the "clamp load" in a fashion designed to increase reliability and create enhanced cylinder sealing at the same time.   And produce the target bhp.

All the readers of Chris' Build Diary get to grade us on how we do, and get to add their comments to this insanity.

Speaking for myself, I prefer suggestions for "darker" barley based beverages fit for human consumption.   Und zince ve now celebrate Oktoberfest, times-a-wastin'!!!  I think I'll have one right now . . . . . .

 :cheers: :cheers: :cheers:
Darkbarleybeverageboy
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 #6483 on: October 09, 2017, 12:29:37 AM »
Block arrived Friday, finally had a chance to scope it out.  A bit of swarf, but nothing that a garden hose and compressed air wasn't able to handle.  Oiled up the cylinder liners.

   The block and sleeves assembly is now in what I would consider to be in "semi-finished" form.   

 :cheers:
Slideruleboy

I concur, and there will likely be some machining of the block above and beyond operational functionality.

To wit, there is an arm cast into the girdle which, in the 2004 MG 25 the engine came out of, was used as an engine mount in a transverse arrangements.  It occupies the area in which we need to put the starter in order to utilize the ribcage transmission.   

Eying it up with the Denso starter, it APPEARS as though we'll be able to make it work, once the actual adapter plate is cut.  The plate we're using for the offer-up is Lexan, which is considerably more transparent than A-36 or T351. 

But the arm will require an amputation, and depending on any layover of the block, we may also need to trim back the outer edge of the flange where the girdle and block join together.  Normally, that might be a worry, but the girdle is only positioned by the bolts around the perimeter - the bulk of the clamp load is carried by the aforementioned long bolts (now studs).

Before we do any more machining on the internals of the block, I want to make sure we have everything fitting together on the outside.  Any further distortions of the block, or modifications which may result in distortions, need to occur before we align hone.

That way, the crank will turn . . . :wink:
"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 #6484 on: October 15, 2017, 01:49:34 AM »
Now that the block is back, I'm making some progress.

One of the issues that concerned me was the potential need to set back the engine.  I MIGHT NOT have to, which is good news.  Everything from the transmission back worked flawlessly, and if I don't have to tear that out and fab up a new transmission hump, that's all to the good.

Trimmed back the offer-up adapter, dropped the engine and transmission into place, and provided we come up with a crank trigger and front pulley arrangement that isn't too wide, I'll only need to fab up a lower crossmember to get the engine to drop into place.  The original is a steel stamping, the upper, a modified square tube arrangement, built by Dave at Streets Chassis in Menomonee Falls.
« Last Edit: October 15, 2017, 02:03:43 AM by Milwaukee Midget »
"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 #6485 on: October 15, 2017, 01:56:47 AM »
pics - still need to remove the aforementioned arm where the starter wants to live.

The crank center is supposed to be on the same horizontal plane as the steering rack.  Right now, it's sitting about 4" high with the bottom of the oil pan resting on the crossmember that needs a haircut..
« Last Edit: October 15, 2017, 02:00:56 AM by Milwaukee Midget »
"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 #6486 on: October 15, 2017, 12:10:53 PM »
Okay, let's see if this will fit.  

Mark, I dropped you some photos in your e-mail.  Some time this week, can you measure the height from the face of the head to the tippy top of the cam wheels?

I'm putting the hood on this afternoon, and should have more measurements tonight.

The 7.75 measurement is from the top of the crossmember to the centerline of the crank - bad drawing on my part.

Ideally, we want the crank centerline at ~4 3/8".
« Last Edit: October 15, 2017, 12:14:30 PM by Milwaukee Midget »
"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 #6487 on: October 15, 2017, 02:41:25 PM »
Okay, here we go -
"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 #6488 on: October 16, 2017, 07:31:11 AM »
Chris,

Under the heading "End of an Era", I am compelled to report that the Cooper 'S' 970cc BMC XSP block, which brought me to your attention, and started our "adventure", has been sold.   It sold of course, on Ebay.    What is interesting is that in spite of heavy interest from the UK and Europe, it was purchased by a gentleman from Japan.    He also purchased the XSP dry sump oil pan you inquired about long ago.

Cie la vie . . . . . . . .

Will look at photos and provide dimensions this week, after the crate leaves for Japan . . . . . . . . .

 :cheers:
Mark
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 #6489 on: October 19, 2017, 08:57:09 AM »
Okay, here we go -

midgerooski,

OK, put cams & cam drive sprockets into a bare head to grab an overall height dimension.   Measured from the face of the head, I've got ~7-1/8th inches, without a cam drive belt.   I'm thinking that a pretty safe minimum dimension is 7-1/4 inches.   This does not allow for any "belt whip" at high rpms, but another 1/4 inch should take care of that.

Sorry, no pics.   Google drive is being "fussy".    I'll send you pics in an email.

Who knows of a good alternative to PhotoBucket? ? ? ?

 :cheers:
Jonesingforagoodfreephotohostingsiteboy
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 Hoody

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Re: Milwaukee Midget
« Reply #6490 on: October 19, 2017, 09:24:56 AM »


Who knows of a good alternative to PhotoBucket? ? ? ?

-->  https://imgur.com/

Offline hoffman900

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Re: Milwaukee Midget
« Reply #6491 on: October 23, 2017, 06:18:07 PM »
I went back to using Flickr.

Offline Milwaukee Midget

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Re: Milwaukee Midget
« Reply #6492 on: November 19, 2017, 09:14:30 PM »
Okay - FINALLY a weekend where I didn't have a family, work, or honey-do commitment.

After measuring everything last month, I tentatively mounted the block and transmission into place.  The bonnet didn't quite fit, although it did close.   When I reached up under the car and tried to turn the cam wheels, the intake sprocket was rubbing against the inside of the hood - too close for comfort.  I'm quite certain it would have self-adjusted, eventually, but there was virtually no room up front for any ancillary drives, including the crank trigger.  

Seeing as this engine has no logical or factory endorsed points-of-reference within the confines of a Midget engine bay, I used the transmission mount as my longitudinal datum.

Carving back the top of the transmission tunnel, I've determined I have 3 inches of rearward room to play with, AND by moving the engine further back in the bay I can align the oil pan flange with the frame rails, giving me about another inch-and-a-half of drop into the chassis.

I'll be modifying the transmission mount, extending it 3 inches to the rear, cutting the driveshaft 3 inches, relocating the driveshaft loop, and learn to get used to the new shifter position, which strangely enough, despite my 5' 17" frame and knuckle dragging arm-length, always seemed to be a bit further away than it should be.
« Last Edit: November 19, 2017, 09:19:56 PM by Milwaukee Midget »
"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 #6493 on: November 19, 2017, 09:15:28 PM »
Additional pic -
"Problems are almost always a sign of progress."  Harold Bettes
Well, I guess we're making a LOT of progress . . .  :roll:

Offline jacksoni

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Re: Milwaukee Midget
« Reply #6494 on: November 20, 2017, 07:59:37 AM »
Sawzall will fix the bonnet clearance as does with the transmission. But wouldn't say this too loudly about setting engine back. Someone might complain..... :|
Jack Iliff
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