Milwaukee Midget

[Andy Cooke]

Congrats on a cracking run    I don't swing by that often, but when I do I like to check on your progres.

With my 1293 coming on at 4K I'm not surprised at your 1000 coming on at over 5K.  I had that 7" maniflow manifold on my mini (45DCOE, 38mm venturis), you might find more bottom end after playing with inlet and exhaust lengths, but I still think it's too much cam.  You won't like my sugestion, but I'd give it a go with standard ratio rockers to get rid of some of the overlap.

I'd love you to prove me wrong so please carry on with your current plan, but humour me and keep that rocker idea in the back of your mind.

Can you run an IDA?  Your trumpets are awful close to your inner arch.

Andy

[Milwaukee Midget]

Chris, I still have those latches for you.

Not forgotten - I am in the studious throws of assembling a virtual cornucopia of uniquely fragrent and brilliantly delicious barley based libations in exchange for these aluminum jewels.


Okay, I haven't stopped at the liquor store yet, but let me drop you an email this weekend. It's a done deal - I've been lazy.

Are you just going to listen for audible knock? If so, you might not catch when it really starts. You might want to ask the dyno guys if they have knock detection tools, like this:
http://store.apexspeedtech.com/phormula-ks-pro-knock-analyser

Knock sensor can be pretty tricky to set up and its not for the faint of heart, because you have to induce knock to do it. Be careful.

I can datalog with the XDI software, and get a visual graph of knock and impending knock situations, but I still need to figure out the trim settings on this.  I'm hitting the books - and yes, you don't want to find out after the fact where detonation begins.

Congrats on a cracking run    I don't swing by that often, but when I do I like to check on your progres.

With my 1293 coming on at 4K I'm not surprised at your 1000 coming on at over 5K.  I had that 7" maniflow manifold on my mini (45DCOE, 38mm venturis), you might find more bottom end after playing with inlet and exhaust lengths, but I still think it's too much cam.  You won't like my sugestion, but I'd give it a go with standard ratio rockers to get rid of some of the overlap.

I'd love you to prove me wrong so please carry on with your current plan, but humour me and keep that rocker idea in the back of your mind.

Can you run an IDA?  Your trumpets are awful close to your inner arch.

Andy

Thanks Andy.  Don't think I wasn't thinking of your advice when I tried to launch this thing last weekend! 

I won't rule it out, but if I go that way, I'll want to try to locate a set of forged Rovers, or maybe stitch up a set of my stamped pieces.  I don't know that I'm up to setting up another set of Harland-Sharpes.

Andy, let me throw this idea at you.  The A-series likes a bigger exhaust opening - any thoughts on maybe ordering up a set of 1.3's for the intake and keeping the 1.5's on the exhaust?

An IDA would protrude through the hood - not legal in GT class.  But it is a nice, cool, dead-air space where the trumpets sit now - I'm not to worried about that.

[Tman]

No hurries here. Sounds good.

[wisdonm]

Good luck on the dyno Chris. I'd like to help you out, but I'm leaving for Florida Thursday morning. Which one are you going to use, King Motorsports?

[Milwaukee Midget]

Good luck on the dyno Chris. I'd like to help you out, but I'm leaving for Florida Thursday morning. Which one are you going to use, King Motorsports?

Ducking the cold, I see.  You're a wise man.

The place is called Late Model Throttle.  Don't know a lot about them - the shop's only about three years old.  They appear to be more of a tuner shop than anything else - Subarus, Hondas, and the usual stack of SBC power stuff.  They seemed enthusiastic about my approach, and willing to work with me. 

I'm certain a mid-tech Midget will give them something interesting to talk about for a few weeks.  They're about a block south of the cemetery where Les Paul is buried.

I'll see if I can't wake him.

[Peter Jack]

Chris, Getting a PROPER reading on the plugs as you sneak up on detonation is well worth the effort. It can save a lot of expense.

Pete

[Rex Schimmer]

Chris,
I would assume that you are planning to use some 104 or better octane race gas when you dyno your screamer so I would bet that you will see start seeing power drop off before you hear any ignition knock. An of course at that point you back up the lead to the highest hp level.

A friend just ran his banger on the dyno and we all swore that it was going to need 40 deg lead to make hp and we ran it at Bonneville, and set the class record, with the lead at 36 degrees. Once it was mounted on the "pump" he found out that max hp was at 25 deg. And as far as I know we never heard ignition knock. The engine is running on alcohol which is very forgiving and has an octane rating of over 150 so race gas might be less forgiving but I still bet you see hp lose before you have ign knock.


Just a comment.

Rex

[Andy Cooke]

Thanks Andy.  Don't think I wasn't thinking of your advice when I tried to launch this thing last weekend! 

I won't rule it out, but if I go that way, I'll want to try to locate a set of forged Rovers, or maybe stitch up a set of my stamped pieces.  I don't know that I'm up to setting up another set of Harland-Sharpes.

Andy, let me throw this idea at you.  The A-series likes a bigger exhaust opening - any thoughts on maybe ordering up a set of 1.3's for the intake and keeping the 1.5's on the exhaust?

An IDA would protrude through the hood - not legal in GT class.  But it is a nice, cool, dead-air space where the trumpets sit now - I'm not to worried about that.

I think for a quick looksie I'd just stitch up what you have and stone the steps off the rocker pads.  If it's better then think about how to do a better job of it. 

I'm not sure about staggered rocker ratios, I think that's best put into the 'future developments' pile.

I'm also a little concerned how it'll run at 4000ft, the ~85% atmosphere will lower the dynamic compression ratio that this cam needs.  I've got no experiance of this as we don't have any roads or dynos at that altitude in the UK, so I'm guessing

Pity about the IDA, my though was that the proximity of the inner wing would reflect pressure pulses from the inlet, depending upon the magic that I don't understand this may be a good or bad thing, but if you ever dyno your engine on an engine stand you'll want a piece of tin sat in the same place.

Have fun on the dyno, and enjoy the scream from the engine.

Andy

[Milwaukee Midget]

Hey, Rex, all -

Rex, you bring up a point I had a brief discussion with another racer about at Maxton, and that's octane.

I think you're echoing his point.

The static CR is right about 13:1 when you calculate the land and gasket into the equation.  Dynamic CR is higher than what would be usual for such a static CR - Off the top of my head, I recall it coming out just shy of 10:1, based on cam events and the RS ratio.

Before leaving for Maxton, there was talk about the ECTA being very low on fuel for the event, and people were advised to bring their own.  Based on its description, I picked up a pail of VP C14 plus.  I went this route because . . .

A - The description indicated it was formulated for high RPM, normally aspirated engines.

B - The engine is completely untested and seeing as I anticipated I might be bypassing the knock sensor for these runs until I had time to get it properly dialed in, I wanted a high octane fuel for some insurance against detonation.

C - While the description of the fuel was based on "Compression ratios over 14:1", I anticipated my higher than average dynamic CR would be an equivalent and the slower fuel burn time that a higher octane fuel provides compensated for by the 2.45 rod to stroke ratio, which would leave the piston toward the top of the chamber for a relatively longer time with respect to the crank throw.

Maybe I'm overthinking it . . .?

The racer I was in line with tunes and races bikes, very enthusiastic, and appeared to be quite knowledgeable.  He insisted I had way too much octane for this engine, and that it would hurt me on power.  His steadfast insistence was that I need to go with the lowest possible octane that prevents knock.

Of course, right now, I don't know what that is. 

To that end, I'm sitting with 4 gallons of C14 plus, so that is what I intended to conduct the dyno runs with.  I'm thinking that this will be my baseline.  I don't want to change too many variables at once - I need to be able to control this process to keep the changes attributable.

I'm hoping the data I draw next week might either confirm my choice, or suggest another.

[iamflagman]

It was good to see the Midget in person and not just pictures of the build here on the forum. I thought that it was difficult to get in and out of the WABBIT but your's looks to be very chalanging to say the least, as far as dealing with the wind on Saturday it was a bear to deal with in light weight cars like ours, if you can run an air dam on the front that seemed to really improve the ill handling that I first experienced with the WABBIT.

I also ran side skirts at Bonneville World Of Speed this year but unfortunately only got in 2 passes before the weather moved in there and I had to head back east. I'm not out to set any records but just to give this old man some thrills. I hope to see you at Wilmington next April.

[Milwaukee Midget]

Thanks for stopping by.

129+ at Loring - that's one wappid wabbit - and I've no doubt you've heard that one before.

GT doesn't permit any aero aids, but I've got this thing slammed about as low as I can go and still get it on the trailer.  There's a little bit of rake to it - I used spring shims from a '75, when they mandated the rubber bumpers, but that's about all I can do with it.  It's the windshield that will kill me - it's virtually flat

You know, getting in and out isn't easy, but everything falls to hand once you're behind the wheel.  I'll live with it.  If I ever let somebody else drive it, I'm pretty sure they'll fit.   

 

[Milwaukee Midget]

Wishing I was at El Mirage right now.  It's been 18 years this month that my dad and I flew out just to see what this whole deal is about.  For me, it's been a life changer.

Glenn just made a post on another thread that I'd like to share here -

From Landracing.com's Beat-Poet Laureate -

Until 2009 I had only attended Bonneville even thought it has now been 126 times.

But when I first walked on the dirt I had a feeling of at last experiencing the real deal.

Chicken skin, a lump in the throat and tears on my cheeks.

I was alone with history and I was humbled.

After all, racers ran on the dirt years before any hot rodder ran at B'ville.

HEROS emerge from the dirt.

God, Bless the DIRT.

FREUD

Bonneville may be the goal and the summit for many, but El Mirage is the heart and soul of LSR.

Anyway, enough misty-eyed wishes and reminisces.

Just prepping for next weekend, dyno day.  Fired it up, got it up to temp, pulled the valve cover checked the lash and -  I ran it this loose? 

Cam card says .020 on exhaust, .018 on intake, everything hot was at about .023~.024.  Nothing appears bent or rubbing - that's good.  I remember adding a couple of thousandths when I put it together cold, anticipating some expansion.  That's something I'll need to address again next weekend after I'm done - I hope something isn't slipping - other than me.

Changed out the oil and filter - saved about a cup that I'll send off for testing.  Yet another baseline.

Also changed out the plugs.  Everything looked pretty good - no visible signs of aluminum or specks or any indication of detonation.  The plugs I picked up today are a range colder, and I've got the ones I pulled cleaned up for next weekend, if I have time to experiment.

Also received a tach from Wheelerdealer, which might actually be of some use to me.  This one goes to 10.  It even has a "HEY, IDIOT!  SHIFT NOW" light.  I'll wire that in tonight.

[Seldom Seen Slim]

"Hey, idiot! Shift Now" lights are dandy, but you car guys have it easy.  You can see (or feel) what gear you're in just by noting the position of the lever (okay, in most stock-type trans, at least).  But on bikes -- the lever makes the same move over and over, even when you get to high gear, so a shift light is nice, but- - -

A couple of years ago I was teching a Brit's bike at bonneville and noticed he had two shift lights on the dash.  I asked, and he explained:  "This one is my "Shift" light, and the other one is my "Don't shift any more!" light for when I get into high gear".

[Cajun Kid]

On a Bike I certainly do understand the need for a " don't shift any more light" LOL

Been there done that stupid shifting from high gear to high gear,,,just makes ya feel stupid....

Charles

[Milwaukee Midget]

"Hey, idiot! Shift Now" lights are dandy, but you car guys have it easy.  You can see (or feel) what gear you're in just by noting the position of the lever (okay, in most stock-type trans, at least).  But on bikes -- the lever makes the same move over and over, even when you get to high gear, so a shift light is nice, but- - -

A couple of years ago I was teching a Brit's bike at bonneville and noticed he had two shift lights on the dash.  I asked, and he explained:  "This one is my "Shift" light, and the other one is my "Don't shift any more!" light for when I get into high gear".

I was always looking for 7th gear on my RD400.  Ever ride one of those old Yamaha 2 strokes?  I looked like a Praying Mantis on it, but man, that was one a quick bike for a 400.