Milwaukee Midget

[jacksoni]

Jenvey makes a manifold for the K and will make TB any size you want (available as 40mm smallest standard) you should be good to go. The standard Direct to head manifold/injector is larger but they may be able to do those in the size you want, when you figure what that is. I had a set of Jenvey TB's for my Cosworth Vega back in the day but as went different direction never used. They are really nice pieces.

[Milwaukee Midget]

Midget/Fordboy,
Just to satisfy my curiosity I finally assembled some information and comparisons of the through-bolt loadings and stresses.  This is on the attached pdf, along with a copy of the ARP stud drawing, in case you don’t already have it.
From the results, it seems there are some conclusions to be drawn.
The 90 x 90 degree make-up rotation spec is most likely bogus.
The Rover upgrade to 10.9 material and 180 x 135 degree rotation makes sense, since that puts it right in the region of the yield strength of the material--not that some yielding is unacceptable.  Clearly, the previous 9.8 spec material probably was, as is roundly noted in various places, loaded into its yield range.
The made-up bolt load appears to be plenty to contain the gas pressures--didn’t bother to estimate bottom end loading.
The ARP 50 lb-ft torque puts it right in alignment with the other schemes as far as generated load.  Plus, the higher strength of the stud material can probably accommodate the thermal loading while still staying under its yield point.  This would be a good thing in that it would retain most of its preload and springiness.  Some preload may be lost due to gasket compression, but at least not more from the bolting.

IO - I was over at Mark's last night, and we discussed your numbers.

Above everything else, we were stunned that anybody's curiosity other than our own would have led anybody else down the path of the calculations you went through in order to produce this information, and we're very grateful for it.

It also led us into the old conversation regarding engineering to a price/cost point, and how often in engines like the K, an overriding idea by a bullheaded engineer can sway a project into unnecessary headaches and disappointments.

An unnamed manufacturer's attempt to build a 90 degree V-6 diesel was recounted to me, but I digress.

If you watch this video from Rover and read between the lines, I can easily see where corporate inertia, combined with commitment to concept and the associated egos involved, coupled with Rover's precarious financial position at the time could easily have led to the problems the initial iteration of the K went through.

3:15 shows the machinery Rover developed to mass produce the design.

https://www.youtube.com/watch?v=Os3b6hVOrFg

Here's the first part of this 2 part video -

https://www.youtube.com/watch?v=4tb-ucz_Fpg

While I think the idea of the expansion of the block with respect to the bolts being utilized producing the final setting of the clamp load and yield is brilliant, it just seems to me that the degree of consistency of so many components - 10 bolts, the head, head gasket, the cylinder case, the girdle, the oil ladder - would need to be held to a much higher standard than Rover was able to carry out.

So yes, I'll be ordering the ARP kit.   

IO, thanks again.

I think we owe you a drink. 

[fordboy628]

IO,

My thanks as well.     

 
Fordboy

[fordboy628]

Here is a bone for you BMC 'A' series guys still reading the diary . . . . . .

Graham, et all,

As perhaps some of you are aware, even though the Milwaukee Midget is "upgrading" to 1980's technology, I continue to work with 'A' series racers in SCCA and Vintage.    Mostly this is design work and geometry analysis, but there is a fair bit of flow testing, since having a "decent" cylinder head is the key to getting any power.   And, as I have stated and posted before, there is no way to tell the "wheat from the chaff" by just looking at the bare heads.

So, without further comment, some advice:

I'm not going to put up any numbers on this today.

Just had the opportunity to flow test an older, Dave Tabor ported Mini head.  12G940 casting, Cooper 'S' size valves, 11 stud.  Stamped CT201 on top.

On intake:
This head flows as well or better, than the latest and greatest from Swiftune, MED, et all, WITH A SMALLER VALVE!

On exhaust:
This head flows MUCH BETTER than the above examples, with an equal size valve.

This head was unearthed from a "dustbin" collection, so has been untouched for probably 20/25 years.

Bottom line is:
a)   Dave Tabor undoubtedly knew something about BMC heads.
2)   If you have the opportunity to procure an older Comptune/Dave Tabor cylinder head, especially at a low price, I say grab it, IF IT HAS NOT BEEN SCREWED WITH.
d)   If it has been "improved" by some nitwit without a flow bench, take a pass.

The ideal situation would be if you could arrange to flow test the head BEFORE purchase.

JMHO
 
Youcan'tknowwithouttestingboy

[grumm441]

You really do shout a lot
G

[Milwaukee Midget]

You really do shout a lot
G

Meah, he doesn't shout, per se . . .

It's just that Fordboy has a writing style that is coloful and audibly assertive to the eyes.   

The only time I've ever heard him actually shout was when the petcock on the gas line in the dyno room was left open and I fired up the fuel pump . . . 

[Ron Gibson]

I consider it speaking assertively, and I listen. Don't always understand, but I listen. 

Ron

[JimL]

MM....might have mentioned it, but, dont forget the ball bearing under the end of each stud.  Just use diameter enough to keep the stud from bottoming in the hole.  This method allows more stud install torque because it compresses the lower threads into the upper and prevents that little ridge that sometimes forms around a threaded hole in a machined flat.  It also prevents bulges in the cylinder bores from studs bottoming in a head bolt hole.

This is pretty important on any "plastic region" type application, especially when the iron might be old and somewhat oil saturated (which leaves cast iron kinda mushy and gooey....technical terms, you know?)

JimL

[Milwaukee Midget]

Hey, Jim -

Actually, the long bolts we're replacing go into the oil ladder under the girdle, and that's tapped all the way through - here's the old and new style pieces -



So the replacement studs - which ARP makes - don't bottom out, they thread through the girdle, which gives you complete thread engagement with the ladder.

I still wish it was made of steel, though . . .

[Peter Jack]

Without seeing the other side it's hard to tell how complex the piece is but it seems to me that machining one out of steel might be an option. Water jet can eliminate an awful lot of the machining.

Pete

[fordboy628]

You really do shout a lot
G

Sorry.   I was trying to be heard in Oz.

Is this better?

Here is a bone for you BMC 'A' series guys still reading the diary . . . . . .

Graham, et all,

As perhaps some of you are aware, even though the Milwaukee Midget is "upgrading" to 1980's technology, I continue to work with 'A' series racers in SCCA and Vintage.    Mostly this is design work and geometry analysis, but there is a fair bit of flow testing, since having a "decent" cylinder head is the key to getting any power.   And, as I have stated and posted before, there is no way to tell the "wheat from the chaff" by just looking at the bare heads.

So, without further comment, some advice:

I'm not going to put up any numbers on this today.

Just had the opportunity to flow test an older, Dave Tabor ported Mini head.  12G940 casting, Cooper 'S' size valves, 11 stud.  Stamped CT201 on top.

On intake:
This head flows as well or better, than the latest and greatest from Swiftune, MED, et all, with a smaller valve . . . . .

On exhaust:
This head flows much better than the above examples, with an equal size valve.

This head was unearthed from a "dustbin" collection, so has been untouched for probably 20/25 years.

Bottom line is:
a)   Dave Tabor undoubtedly knew something about BMC heads.
2)   If you have the opportunity to procure an older Comptune/Dave Tabor cylinder head, especially at a low price, I say grab it, if it has not been screwed with . . . . .
d)   If it has been "improved" by some nitwit without a flow bench, take a pass.

The ideal situation would be if you could arrange to flow test the head before purchase.

JMHO
 
Youcan'tknowwithouttestingboy

[Peter Jack]

Those of us with older eyes like it when you enunciate clearly and don't mumble in your text. 

Pete

[SPARKY]

now that's funny! 

[Interested Observer]

Midget/Fordboy,
FYI, while I was reading up on the K, came across some discussion that you probably already are aware of, but in case not--
Mention was made that when changing head gaskets, and perhaps as the result of head/block skimming, it was possible that the through-bolts in a particular location, I think the front or second set, could possibly bottom out on the oil pan, thereby producing erroneous or insufficient clamp loads. 

Given the through-tapped oil rail and ARP studs (non-headed), this sort of thing might be a consideration to keep in mind.  With the generous threaded length of the bottom end, the stud could easily run out the bottom of the oil rail if it were turned until torqued.  Which brings up the question of how to install the studs and keep them where you left them while torqueing/turning the nuts.  Studs don’t necessarily need to be “bottomed”, but if not, further rotation while running down the nuts should be monitored (if, indeed, this pan interference is a genuine issue).  Or, maybe the pan could be “clearanced”.


Tangentally, given the amount of clamp load available, a bit of non-flatness in the head may not require fixing.  Although I gather you may do some milling anyway in the quest for compression.

Did you ever get any feedback from the UK K-racers or find out who built the Touring Series engines?

[fordboy628]

midget,

Assembled the block, girdle and oil pan.   Dropped off the assembly with Mike @ Deerfield for the reverse engineering of the rear mounting plate/adaptor.

Offered up a Mini flywheel (smaller diameter than a Midget f/w) and a gear reduction starter assembly . . . . .     Piece of cake.   Probably won't have to carve the block at all with some clever mounting and orientation of the starter/solenoid.

I love it when a plan comes together!

 
HannibalSmithboy