Milwaukee Midget

[fordboy628]

Chris,

With good bearings available in the Rover size, using Honda size bearings may be unnecessary.

You need to contact Dave Andrews in the UK about the racing K series he has been doing about bearing wear/issues for advice/feedback.   He may also have the answer to the questions about bearing sizes between the various displacements of the K.

While I'm at it, any of you guys reading this have any K experience or know anybody Chris can contact? ? ? ?
 
Fordboy

[Elmo Rodge]

PJ:

"Balls, said the Queen.  If I had 'em I'd be King!"

Having said that I find that upon close inspection the dead horse is being clubbed on the outside of the left rear hip.  No family items are being threatened.  And anyway, the horse is/was a gelding -- nothing much remains to be clubbed.

That's pretty good, Slim. But, that ain't the way I hear'd it.
"Balls, said the Queen. If I had to (two) I'd be King!"    Wayno

[fordboy628]

midget,

Well, just like living in cheddarland, there is good news and some bad news.    I'll start with the good news . . . . .

After some research I have confirmed that the 1.4L Rover K and the 1.8L Rover K use the same main bearings.   So, quality race bearings are available for the mains.   

Rod bearings are different between the 2 engine types however.   So the search goes on for a race quality rod bearing . . . . .   
 
Fordboy

[jacksoni]

midget,

Well, just like living in cheddarland, there is good news and some bad news.    I'll start with the good news . . . . .

After some research I have confirmed that the 1.4L Rover K and the 1.8L Rover K use the same main bearings.   So, quality race bearings are available for the mains.   

Rod bearings are different between the 2 engine types however.   So the search goes on for a race quality rod bearing . . . . .   
 
Fordboy

What is the stock rod pin diameter? I was rooting around looking and ran across someone selling a crank and it had 48mm=1.8897"="Honda" size. If you want smaller there is the "IRL" ( and Nascar) 1.850".

[fordboy628]

midget,

Well, just like living in cheddarland, there is good news and some bad news.    I'll start with the good news . . . . .

After some research I have confirmed that the 1.4L Rover K and the 1.8L Rover K use the same main bearings.   So, quality race bearings are available for the mains.  

Rod bearings are different between the 2 engine types however.   So the search goes on for a race quality rod bearing . . . . .  
 
Fordboy

What is the stock rod pin diameter? I was rooting around looking and ran across someone selling a crank and it had 48mm=1.8897"="Honda" size. If you want smaller there is the "IRL" ( and Nascar) 1.850".

1.4L  Stock rod journal diameter:     1.6930"  (43mm)
1.8L  Stock rod journal diameter:     1.8897"  (48mm)
Both Stock main journal diameter:   1.8897"  (48mm)

Big rod journal on the 1.8L for crank stiffness? ?

The 1.4L journal diameters seem about right for a 10,000 rpm motorcycle engine . . . . .  
 
Fordboy

[fordboy628]

MILESTONE ALERT! ! ! ! !

This project started in 2008 if you can believe we wasted that much time on this poor bastard. 

5000 replies! !   

Just imagine what we all could have done with that time . . . . . .  if we had spent it, productively . . . . .  say, testing . . . . .  beer!

(Jeez, I wonder how many have been my useless ramblings . . . . . . . .)

 
I'llshutupnowboy

[wisdonm]

I drank to that. 

[jacksoni]

midget,

Well, just like living in cheddarland, there is good news and some bad news.    I'll start with the good news . . . . .

After some research I have confirmed that the 1.4L Rover K and the 1.8L Rover K use the same main bearings.   So, quality race bearings are available for the mains.  

Rod bearings are different between the 2 engine types however.   So the search goes on for a race quality rod bearing . . . . .  
 
Fordboy

What is the stock rod pin diameter? I was rooting around looking and ran across someone selling a crank and it had 48mm=1.8897"="Honda" size. If you want smaller there is the "IRL" ( and Nascar) 1.850".

1.4L  Stock rod journal diameter:     1.6930"  (43mm)
1.8L  Stock rod journal diameter:     1.8897"  (48mm)
Both Stock main journal diameter:   1.8897"  (48mm)

Big rod journal on the 1.8L for crank stiffness? ?

The 1.4L journal diameters seem about right for a 10,000 rpm motorcycle engine . . . . .  
 
Fordboy

But now you are destroking it a fair amount so there should be pretty good overlap, helping stiffness n'est-ce pas? So you can go the larger route, more stiffness etc with stock 1.8 bearings, or start cutting down to IRL/Nascar sizes or less depending on availability and perhaps more important, a rod with journal size and length that fits without being a totally custom (presumably more expensive) piece.

[Jack Gifford]

re: mains grooving- an awful lot of larger performance engines are served very well by 3/4 groove main bearings. Any off-the-shelf 3/4 groove for your miniature mains?

[fordboy628]

re: mains grooving- an awful lot of larger performance engines are served very well by 3/4 groove main bearings. Any off-the-shelf 3/4 groove for your miniature mains?

I think that the problem can be solved by running the grooved upper bearing shells on all 5 mains, (ala Chevy, Ford, etc NASCAR engines), coupled with drilling the crank for rod journal oil feed from both adjacent main journals.   Some BMWs and Alfas are drilled this way.    This gives nearly full 360 degree oil flow to the rods, and retains an ungrooved lower main bearing for better load carrying capability.

Probably still able to run "lower" oil pressure with that setup.
 
Fordboy

[fordboy628]

But now you are destroking it a fair amount so there should be pretty good overlap, helping stiffness n'est-ce pas? So you can go the larger route, more stiffness etc with stock 1.8 bearings, or start cutting down to IRL/Nascar sizes or less depending on availability and perhaps more important, a rod with journal size and length that fits without being a totally custom (presumably more expensive) piece.

Oui.   With a 56mm stroke, (28mm offset), a 48mm main journal diameter and a 43mm rod journal diameter, that gives 17.5mm (.689") of overlap between the two radii.  With a 48mm rod journal of the 1.8L permutation, (and the race quality bearing available for it) the overlap would be 20mm (.787").

As the Aussies would say: "a stiffy" . . . . . .    

Chris is still weighing options for con rods, so the rod journal diameter is for now undecided.   Probably won't go larger than 48mm though.
 
Fordboy

[fordboy628]

Deck Height Measurement

midget,

OK, here are the actual measurements.    The nominal listed deck height dimension you supplied was 201mm.

Main housing bore diameter = 2.031"   (avg. spec.)
Main housing bore / 2          = 1.0155"

Front of block measurement:   7.459"  (-.531" dia ball) + 1.0155"  =  7.9435"  (201.76mm)
Rear of block measurement:    7.456"  (-.531" dia ball) + 1.0155"  =  7.9405"  (201.69mm)

So for design and machining purposes finished deck height is going to be 201.50mm (7.933").

This allows a slight amount to be surfaced off the block to "square" it up, unless the block needs to be align honed.   If that is the case we may need to reduce that deck height dimension by a small amount, say an additional .005"/.010"  (.127mm/.254mm)

This is about the point where dimensions can start to be "fixed" and the "build geometry" locked in, so parts can start to be ordered.   Uhh oh!!   

Oboy!! Oboy!! Oboy!!
 
Fordboy

[jacksoni]

I think that the problem can be solved by running the grooved upper bearing shells on all 5 mains, (ala Chevy, Ford, etc NASCAR engines), coupled with drilling the crank for rod journal oil feed from both adjacent main journals.   Some BMWs and Alfas are drilled this way.    This gives nearly full 360 degree oil flow to the rods, and retains an ungrooved lower main bearing for better load carrying capability.

Probably still able to run "lower" oil pressure with that setup.
 
Fordboy
[/quote]
My crank (Moldex) is drilled this way ("BMW") with feeds from each main. It has spent much of its life above 9500, with excursions well above that with no rod or main bearing issues (when it has oil pressure- have had pump failure twice in which case it toasted the rods but not the mains, never to the point of hurting the crank. The pump failures were not the fault of the pump but mine- piece of valve spring went through it once and the mandrel broke once due to machining issues, now fixed) On my engine had to slow the pump down to keep oil pressure at reasonable levels but still fairly high.  Usually I reuse the bearings on tear down, these two episodes excepted. The stock bearings (Clevite "P" series) are grooved uppers. The have additional drillings placed in the bearing and grooves in the main bearing saddle under the bearing to ensure full flow to the rods. I can supply photos and a reference to that if anyone wants.

[fordboy628]

Krankenshafted, zwei . . . . .

midget,

The total overall length of the new de-stroked billet crank for the Rover/BMC mating is:

Std Rover crank length + Rover crank/block offset + 1/2" thick adaptor plate + BMC crank hub height

              "                   +           .148" avg.           +             .500"                +        .985" avg.

            "                +          1.633"  +.000"/-.015"

This dimension, plus whatever Greg needs extra for roughing out, added to the stock overall length, adds up to the overall length of the material required.

 
Fordboy

[fordboy628]

Deck Height Measurement

midget,

OK, here are the actual measurements.    The nominal listed deck height dimension you supplied was 201mm.

Main housing bore diameter = 2.031"   (avg. spec.)
Main housing bore / 2          = 1.0155"

Front of block measurement:   7.459"  (-.531" dia ball) + 1.0155"  =  7.9435"  (201.76mm)
Rear of block measurement:    7.456"  (-.531" dia ball) + 1.0155"  =  7.9405"  (201.69mm)

So for design and machining purposes finished deck height is going to be 201.50mm (7.933").

This allows a slight amount to be surfaced off the block to "square" it up, unless the block needs to be align honed.   If that is the case we may need to reduce that deck height dimension by a small amount, say an additional .005"/.010"  (.127mm/.254mm)

This is about the point where dimensions can start to be "fixed" and the "build geometry" locked in, so parts can start to be ordered.   Uhh oh!!   

Oboy!! Oboy!! Oboy!!
 
Fordboy

midget,

The next step in the design/layout process is to "fix" the final block deck height at a dimension.    This is dependent on whether the block needs to be align honed.    I'm going to take a wild guess here and say YES.   I think it is prudent to reduce the "design deck dimension" to 7.921" (201.2mm)   That would allow for .010" "crank drop" during align hone and allow ~.010" to be decked off the top off the block for "clean up".

Or, could just reduce the block to 201.0mm if you want to keep it in "even" metric dimensions.     Your call.     I don't think .020" matters much here as a rod C/C length .020" shorter isn't going to do sh!!.

Also: This will mean machining to tops of the existing (or new) cylinder liners for the right deck height.    Just want to be aware of this and not get carried away . . . . .  because your lathe at work won't cut it for this machining operation.   

 
Fordboy