Milwaukee Midget

[Seldom Seen Slim]

So we're back to the "rodeo" bra -- yanno, the kind that rounds 'em up and points 'em out.  Yippee!

[WOODY@DDLLC]

Pointy lobes, aren't they?

Regards, Neil  Tucson, AZ

I'm reminded of Bettie Page . . .

Without nipples they're really pointless! 

[Milwaukee Midget]

Some say "bigger is better", but in this case, I think what we need is something between Bettie Page and Jane Russell.

[4-barrel Mike]

   You talkin' lift or duration?

Mike

[Milwaukee Midget]

  You talkin' lift or duration?

Mike

Yep.

[fordboy628]

midget,

Cams & bits were picked up by Jr yesterday.    I suspect they are across the street from Miller Park right now.

Can you get Bud Selig to drop them off at your abode?     That would be CATtastic!!!!!

Unless Bud suffers from Ailurophobia . . . . . . . . .

 
Cynophilistboy

[Milwaukee Midget]

Baseball's "commissioner emeritus" is no closer to M. B. Jr.'s place of employment than I am.  Besides - that would be physical work - something Bud swore off back when he became a used car dealer.

Even at the ceremonial groundbreaking for Miller Park, Selig wasn't sure which end of the shovel he was supposed to grab . . .

But if talking and cajoling alone could deliver camshafts, Bud would be my first call.

Did I mention Milwaukee County Residents are STILL paying for the stadium? 

[fordboy628]

midget,

Jr's got all the cams and bits in the back of his Prius 'C'.

Call his cell # to arrange the transfer.    Call soon, unless you want everything coated with dog hair.

 
Shippingmanagerboy

[fordboy628]

I want to say it's a 34 mm bucket - well sized.  Kibblewhite makes one that will work, but it might make more sense to order a valve kit "in toto" from Britain.

I'm ready to pull the trigger on new cams.  I've got new Piper adjustable cam sprockets already, I'm just trying to determine which grind to go with.

Even with the Rover head in stock form, we're getting more flow at .250 than we got at .450 on the Grenade.  If we do nothing with the head, I'm thinking either one of these might be a good choice - and keeping in mind that these applications are intended for the 1.8 - both are Piper grinds -


ARKBP285M   

Int -                     Exh -

276°   0.440″          276° 0.438″   

34‑62                 64‑32              

104°                       106°


ARKBP300M

Int -                       Exh -
                                          
                                          
280°    0.442          280° 0.440″      

34-66                   70-30

104°                       106°   

Mark is going to do some limited prep on the ports - if we could anticipate what to expect from that work, I'd order right now.  But I'd like to see what the flow curve on the modified head looks like before I load up the MasterCard.

That said, I'm kinda pancaking to get this thing back on the front burner.  Even with the shorter of the two cam choices, I'm certain we'll be able to make a lot more power than with the Grenade - and likely with an engine that isn't quite as stressed or peaky.

midget,

Measured the tappet bore in the cylinder head at 33.02mm (1.300"), so a nominal 33mm tappet is the size.
That is a big enough diameter to accept all but the most aggressive Lotus, Jaguar, or Cosworth cam grinds.

And I can always look at Coventry Climax race grinds as well.   Now that I have recovered all my old cam records from the "Frankenputer", it puts a wealth of information at my fingertips . . . . . .

"Let your fingertips do the walking . . . . ."

 
Earlytoriseboy

[Milwaukee Midget]

Mark, am I right that we need to be thinking torque first?  It seems the least of our concerns will be getting it to rev.

One other thought - Piper makes a few Hydraulic HP grinds as well.  Here's one -

288° 288°
0.445″

 
0.445″

 
40‑68
70‑38
 104° 106°

In a 1.8 - the power band claim is 2500 - 7500.

Mark, what would you expect the maximum RPM from a hydraulic setup might be?

Given my propensity for 9500 RPM hole shots, a little bit of physical limiting on the part of the engine itself might not be a bad deal . . .

 

[fordboy628]

Mark, am I right that we need to be thinking torque first?  It seems the least of our concerns will be getting it to rev.

One other thought - Piper makes a few Hydraulic HP grinds as well.  Here's one -

288° 288°
0.445″

 
0.445″

 
40‑68
70‑38
 104° 106°

In a 1.8 - the power band claim is 2500 - 7500.

Mark, what would you expect the maximum RPM from a hydraulic setup might be?

Given my propensity for 9500 RPM hole shots, a little bit of physical limiting on the part of the engine itself might not be a bad deal . . .

midget,

I'd need a LOT of convincing to run a hydraulic cam in this application.    Why give up bhp and torque?   My main concern is whether any of their hydraulic grinds is of "adequate" intensity for the application.   You give up low lift "intensity" with a hydraulic grind in exchange for no/low valve adjustment/maintenance.   I'm not ruling it out, just let me run some numbers on this before chosing a path.


As far as 9500 rpm is concerned:

The design spec is: peak bhp @ 8500 rpm
                            peak tq    @ 7000 rpm

We might be off a bit from that, but that's the goal I'm using.   8500 would be an increase of 400/500 rpm over your "Perfect Storm" record run, ie, faster.   Since you are not planning on changing your tire or diff, more rpm is the only way . . . . .

Since the greatest area under the bhp curve will be ~ centered on 8500 rpm, safe valve train limiting speed should be for 10,000/10,500 rpm.   With a belt drive ohc setup, this should be easily achievable.   I have not forgotten about your "hole shots".

Yes, we are also going to concentrate on making more torque, everywhere in the usable rpm range.   The goal for bmep this go around is 205 psi minimum, @ peak torque.   With the 4 valve low lift flow available, that goal should be achievable as well.

 
Thinkyboy

[fordboy628]

More Thinky . . . . . . .

midget,


If you recall, the max tq from the Grenade, Ver 2.0, was ~ 75 #/ft.    This translates to 185.4 psi bmep.

Long time readers of your Build Diarrhea, er, Diary, will recognize 185 psi bmep as what I consider to be the floor of professional engine builder respectability.    Given the limitations of the Grenade's Build Specification (© ), this value was more difficult to achieve than the casual observer might surmise.

However, based on the enhanced breathing capabilities of the Rover 4 valve architecture, the 205 psi bmep goal should be achievable, especially considering the new Build Specification (©)   This represents an ~ 11% increase.

Working the bmep formula backwards:  205 = tq * 150.8 / cubic inches,   so then:   205 / (150.8 / 61)   for a resultant tq of 82.92 #/ft

The other portions of the curve would be representative of the increased bhp & tq.

For example, the peak bhp goal of 125 bhp @ 8500 rpm translates into 77.23 #/ft        ([125 bhp * 5252 rpm] / 8500 rpm)

Compare this to the Grenade Ver 2.0  tq @ peak bhp:  65.05 #/ft

Et cetera . . . . .

I suspect that this might qualify as "more torque everywhere", a pre-requisite to going faster @ Bonneville, or wherever . . . . . .


See, you really DO need math after high school . . . . . .

 
Thinkyboy

[wobblywalrus]

Your engine is real similar to mine in many ways.  It is easy to over cam these four valve engines where the cams work efficiently at an rpm beyond what is desirable.  The knockers that worked best in mine during the virtual modeling have net lifts equal to the flow capacity of the ports with as narrow duration as available grinds allowed.  I had my radical race cams ground to milder profiles. 

[fordboy628]

Your engine is real similar to mine in many ways.  It is easy to over cam these four valve engines where the cams work efficiently at an rpm beyond what is desirable.  The knockers that worked best in mine during the virtual modeling have net lifts equal to the flow capacity of the ports with as narrow duration as available grinds allowed.  I had my radical race cams ground to milder profiles. 

WW,

Yes, that is exactly the problem.    Even cams for full race 4V Cosworths are very conservative on lift, with lots of duration.

This is the reason for all the planned simulation work in EA Pro on this particular Build Spec combination.    It's a TOTAL orphan, with displacement in the opposite direction of standard 'K' series race engines.   Some of that works in Chris' favor, but it is all uncharted territory.    And nobody wants to spend a small fortune on a "walkabout" to Uluru, with no chance of getting a sighting . . . . . .

The low lift flow is good enough so that high lifts are not required.

The trick is going to be the choice of duration(s):

Low enough for high efficiency and outstanding torque,
Coupled with high enough for adequate top end power.     (Although I can't imagine a situation where the first permutation of the 'K' does not significantly outperform the venerable 'Grenade' . . . . . .)

As you are aware, it is MUCH cheaper to heat up the battery in your laptop with a batch of sim time, rather than whittle metal parts and have a go on the dyno . . . . . . .

Either the test stand one, or the big white one . . . . . . .

I have approximately 30 profiles, (perhaps more) in my 4V, full race, cam profile database.   And I have access to the complete databases of a couple of knowledgable cam manufacturers.    I'm pretty certain that a usable grind is available already and will not have to be "invented".

This is just the first of a number of "selection for tuning" issues on this particular build.    We could end up being "brain surgeons" on this, or perhaps "hemarrhoid surgeons", depending on how this project turns out.    Maybe both, at the same time . . . . . . .     I know which one I want to be.     Hemarrhoid surgery has a much higher chance of success . . . . . . . .

Just my 2¢

 
Thinkyboy

[hoffman900]

As Mark knows, it's not as clearcut as "this cam for this rpm range".

It's going to be dictated by the curtain area as well as the velocity through the port. I can build an engine to peak at 4000rpm or 18000rpm, but at the end of the day, the port is going to be sized for an average of 300fps (+/- 10-20fps or so) at 28" H20. If the port is slower, it's going to want to keep revving, if it's smaller, you'll have sonic choke issues and power will drop off.


A 4 valve head has more valve area than a 2 valve head, thus it needs less lift and duration for the same rpm range than a 2 valve head. This has the advantage of allowing an engine to have a broader power band for the same amount of peak power. Allowing the Ford Modular engines into the Engine Masters Challenge a few years ago served to illustrate this point - and they were using a lot of stock parts compared to their 2 valve competitors.

As for valve lift curves and the such, here is a simulation I ran of very dialed in engine combination (in the sim and in person):



This is the Mach index at different points in the intake and exhaust port as it relates to the cam profile. You can see where maximum piston speed occurs as well. I can easily integrate this to show % of flow as it relates to the lift curve.


Being smaller displacement means the ports of the K head are going to push the rpm point up a lot higher than stock. To get the power range you guys want, it may mean leaving them as is (and just making them more efficient (ie: cfm per area)) or even mean shrinking the ports...