Milwaukee Midget

[Peter Jack]

Chris, do you have enough parts around to put on a pair of Skinner Unions. If the car acted similarly then you can chase the ignition, otherwise I'd find a Weber guru, probably from the road racing crowd and let him go over things. To me the severe lack of performance sounds like more than ignition.

Just Guessing!

Pete

[Milwaukee Midget]

Hey Chris
Why don't you reset the retard to zero° on the knock sensor so as it does nothing but record the event
I did it with spigot of sunshine motor on the dyno.
It didn't fix the problem, but it ruled out the knock sensor.
My only other suggestion would be to put the distributor back in it and see how it runs
If it fixes it, you know it's in the ignition system, if it doesn't, you know it's not
G

Good approach - I'll keep it in mind - although the mere idea of reinstalling a Lucas distributor just gives me shudders.

I've been cautious about doing anything with the knock sensor as I'm viewing that as my safety net, but yes, I do need to confirm that it's functioning properly, and if it's actually causing the problem, I need need to work through it.

Spent a little time last night with lights and mirrors trying to confirm the crank trigger alignment.  Marked TDC on the pulley is lining up on the 12th tooth, which is about 6 degrees mechanical advance.  Moving it up on the adjuster causes interference between the belt and the jam nut - it's ridiculously tight down there  It was late, so I didn't wake the neighbors, but tonight I'll start from scratch on the setup with that information, and redial from the ground up.  The program says I should be able to reset on the 12 tooth.

As to reinstalling the distributor - I don't know if I can.  The dizzy drive was left out and the hole plugged, and while I can't say for sure, I think I'd need to drop the pan to do it.  And secondly, I'm not confident enough with either of the distributors I've got lying around to be convinced it would give me a decent benchmark.

I'm committed to de-Lucasizing this thing.

Chris, do you have enough parts around to put on a pair of Skinner Unions. If the car acted similarly then you can chase the ignition, otherwise I'd find a Weber guru, probably from the road racing crowd and let him go over things. To me the severe lack of performance sounds like more than ignition.

Just Guessing!

Pete

Me, too! 

I've got a pair of HIS-4's that I pulled off of the MGB a number of years ago, but they've been dry for years, and I've got no manifold for them for the A-block - although I suppose I could grind out a stocker.

I'm pretty far down this path - I think I'm close to making it work - I've second guessed a few too many things already.  I just need to be a bit more methodical.

Thanks, guys.

[jdincau]

I seem to remember a tale about knock sensors not playing well with solid lifters.

[Milwaukee Midget]

I seem to remember a tale about knock sensors not playing well with solid lifters.

??!!

That makes huge sense.  A knock sensor is nothing more than a microphone, I've got .018 lash, virtually no ramp and a very rapid lift profile.

Hmmm . . .

[Captthundarr]

Can you say tappity,tappity,tappity, tappity, tappity goes the lifters. hope that takes the knock sensor out of the equation.

[grumm441]

I seem to remember a tale about knock sensors not playing well with solid lifters.

??!!

That makes huge sense.  A knock sensor is nothing more than a microphone, I've got .018 lash, virtually no ramp and a very rapid lift profile.

Hmmm . . .

I am assuming that you can program how many degrees the knock sensor takes out of the ignition
G

[4-barrel Mike]

On Ford Turbo 2.3's, the factory knock sensor is a known hp robber.  The common solution is to simply unplug it.

Mike

[38flattie]

Chris, plenty of guys with solid lifters run knock sensors, with no problem.

Of course, plenty of guys have problems too! Depends on the engine, cam etc. When the knock sensor 'senses' the lifter, the computer pulls a bunch of timing out.

Can you unplug your sensor, 'lock' your timing in the program, and see what happens? If the same thing occurs at that point, at least you've ruled it out.

[Dr Goggles]

Go Dude, I'm feeling your pain, and I have nothing, nothing to offer.

[Milwaukee Midget]

Talked with Dave Anton at APT.  He confirmed my carb settings and talked me out of the accelerator pump mods, save the one I already did - and thanks for that tip, Graham.

He also suggested a less aggressive advance curve, which I entered into the computer on a separate file. 

I also pulled the knock sensor out of the program and reset the computer to read on the 12 tooth, checked it with the timing light and everything set to 0 - just cranked it with no gas - I'm within a few degrees - close enough to tweak with the computer.

One more quick run up and down the ally and - same story.

But it got me thinking -

Just because my symptoms are the same as last year does not necessarily mean I'm encountering the same problems.

I'm now confident I don't have a vacuum leak.

I can now quickly and confidently dial up new ignition parameters and compare them, store them, and modify them.

The cam is dialed in precisely where it's supposed to be.

The bottom end and reciprocating assembly is balanced and all tolerances are good.

A few months back, Andy Cooke posted this -

That's a lot of cam for a small engine, I ran a megadyne 310 in a 1293; below 4K it ran like 3 leads were unplugged and came on like a switch.  It revved plenty, but I'm pretty sure a milder cam would have made more power. 

Last year I had ~260 degrees of cam in a 78 cubic inch engine - this year I've got 320 degrees of cam in a 61 cubic inch engine.  Is it possible I simply haven't been gutsy enough to launch it hard enough to come up on the cam?  :|

I haven't really done a 5K clutch dump. 

[38flattie]

Only one way to find out!

[Rex Schimmer]

Chris,

I am with Buddy, 5000 comes right after the 4999 on the tach, do it!!! No guts, No glory!!!

Rex

[racergeo]

  What? Goggles with nothing to add.Nothing? Now I feel pain. False alarm, it was just gas.

[Milwaukee Midget]

 What? Goggles with nothing to add.Nothing? Now I feel pain. False alarm, it was just gas.

The good Doctor knows what he knows, and knows what he doesn't know - which makes him wiser than me.

Damn the transmission, screw the diff, clutches are cheap - full speed ahead.

I held it open against the 9K limiter tonight - and I mean I just held it there.  It's hitting on all 4, it doesn't vibrate, the clutch is new, the driveshaft is balanced, it sounds awesome. 

I suspect it's just time I learned how to drive a peaky, tempermental race car.

Hell, I've only got to go a mile with it.

[Captthundarr]

Chris. Bring down and air it out. it's only a mile!!