The DD Known As "Chunk"

And tha dam 'rango will always be a setter or turn into plastic yardart! It's gittin' greener by the week and will be soon moved out back to make space for more real motor vehicles. Throwin' fuel pumps and axles at crap like this beats hail outta throwin' in-tank fuel pumps, pooters, electronic valve bodies, shift-on-the-fly motors, and cam drive belts at plastic trucks.

I'll keep throwin' shit at chunk as long as it takes for it ta stick. Then maybe I'll start on the rot repair.
 
It's been a battle all the way. But I think I won yesterday, I'll know for sure after putting 300 miles on it tomorrow to go up to sheridan days for a club parade entry.

I had lost track of that Holley 4150 core that ihon member (and recently retired marine!!) charlie brown sent me that came off goldie last year. I put the box away onna shelf and never opened it. Found it again when cleaning out all the packaging I have here to put on the burnpile. It is exactly the carb I was looking for to build for chunk so I would not have to buy a new one!

Turns out it was a previous reman (charlie May not have known that??) and the metering blocks had been butchered and re-plugged. It was a hot air choke version so an easy conversion to full electric choke by simply installing an electric cap.

So...I sterilized it and fixed several issues it had (stripped threads, etc.), then jetted it for what I thought this "built" 392 would like. And of course I installed new brass floats, the old nitrophyl floats were both "sunk".

Once installed it proved to be worse that the oem carb! So off it came again for additional work. Turned out one of the new power valves (this list 4150 uses a power valve in both ends) would hold vacuum during testing (I always confirm operation of power valves before installing), but it also leaked raw fuel even though the vacuum component sealed! First time I've ever seen that.

So I also re-jetted again after determining that this motor could not use the jetting I thought would work. That did the trick! Once it was installed again and proper electric choke operation verified, the idle mixtures were able to be controlled in a proper manner. At this point, the idle quality is as good as it can be with a breaker point distributor setup. The cam definitely is still creating an aggressive idle and will never smooth out like a stocker, that is to be expected.

So next on the engine-side agenda is to set up a fresh ignition system using a mag trigger distributor and another mallory or msd six series cd box with a suitable coil that can use the cd system to best advantage. I also need to perform the retrofit on the ac, everything needed for that is on hand right now, I'll get that done before kathy drives it up to Binder Bee with the dawgs.

If...I'm able to make it up and back to sheridan tomorrow without having to call road service for a tow, then I'll pronounce chunk as a dd for us at this point. I've now put about 250 miles on it since the fuel pump issue, this correct carburetor certainly makes it more pleasurable to drive in traffic and the cold start with electric choke is instantaneous, just like the beater truck!
 
You probably should have waited until after the parade to say anything. Now you will most likely have a spectactular meltdown in the middle of the parade.

I hope for your sake anyway "chunk" will hold off on any more breakdowns.

The challenge of owning and rehabbing old iron is it is old iron. Everything has a useful life and most of our old iron is well past the point where things need to be renewed, refurbished, and/or refreshed.

The question always becomes what is most important in regards to time and $$$. Leaking vital fluids always get high priority but the little things can really make you crazy.

Good luck and have fun in sheridan. I "get" to go to forks, wa so that my wife can attend a math camp. I would much prefer to be going to sheridan with my t-all.
 
If you "should" need assistance by the lebanon area, I'd be more the willing to help, or give last rites:incazzato::gringrin:
541-409-3761
 
dkminors said:
I doubt you need anything for chunk, but the sheridan pick-n-pull just got in another '73 IH pickup About a week ago.
Click to expand...

What I need...is the lower half of left and right rear quarter panels that ain't rotten so I can skin chunk. Crashed and bashed uppers are fine from a rig being parted, all I need is the lower 12" between the end cap and the trailing edge of the wheel well. But then, so does everyone else who has a squarebody t'all crapball.

The rest of the rot in the lower extremities is easily repaired with flatgoods.

Just got back from a 100 mile town trip with stop and go city cruisin', sumbitch ran nice and fires instantly hot or cold. But this 9 to 1 compression don't work worth shit with this e10 "regular" shitforgas. I refuse to run any higher octane shit, so a timing computer is gonna go on the list to be combined with the cd sparkbox. The problem is not the distributor curve, it's the dam compression, I'd never bump the compression over stock onna street driven IH tractor motor.

But then, if ya keep yore foot off the loudpedal, the detonation ain't an issue.

A spare alternator is now on board in the spares box, I'm having a fresh starter built at j&s in u-jerzee to pick up next week, they no longer keep IH-pattern starters on the shelf, but he tells me they have built and shipped out five IH units just this past week.
 
You might want to check with superscoutspecialists...

I recall (vaguely) a thread on binder planet a year or so ago about somebody making some... But, I cannot find the thread... To see if any were made
 
robertc said:
you might want to check with superscoutspecialists...

I recall (vaguely) a thread on binder planet a year or so ago about somebody making some... But, I cannot find the thread... To see if any were made
Click to expand...

Quarters and other patch panels are on the the list for future production by light line. But currently not available. Some floor patches along with rockers are available now for pickall.

Light line has continued to roll out many new parts off the original tooling this past year. Even in an economy that is major sukkage, the light line folks are doing what they can to keep this crap alive. Just the costs to refurbish the worn out tooling they have for the sheetmetal is exorbitantly expensive, this shit just doesn't grow like taxpayer-subsidized corn in the midwest!
 
Don't see why 9-1 won't run on regular. The last hand full of IH sv's I have built have all been 9-1 and a few notches up on cam. Neither have detonation issues and are running 35* total timing.

The block must be zero decked though to setup proper quench distances of between .045 and .040. The quench induces very intense combustion chamber turbulence as the flame front begins to mature and ensures even burn and even temperature. While most poo poo zero decking because it can only be a hot rodder trick but on todays shit-gas it is becoming more and more necessary. Even on a stock compression engine it can help fuel economy by allowing a leaner afr and still make good power.


The trick on a bigger cam is more initial assuming the engine can handle it and curved to come all in on the centrifugal an bit later when quench turbulence is up and running like gang busters. The engine can take more timing at that point. The other is the vacuum advance should be retarded also. Basically make the vacuum signal have to be higher before it gives more advance.

On a heavy truck like chunk you might consider slightly later shift points and earlier drop down. Ive not had to do that on the engines I have built but can help.

While I might be preaching to the choir it is good info.
 
I agree with your analysis Robert! But...it's turning out that this engine was basically a botched build from the beginning. I have no idea and no way to verify how the block and heads were prepped in '87 when it was supposedly done and subsequently parked with under 3k miles accumulated.

No doubt the distributor setup is oem (emissions) also, and along with the oem carb I just shitcanned is far from matched to this motor build.

Since I don't have a distributor machine, installing a timing computer will allow the distributor curve to be dialed in that enhances the engine's setup without having to pull it numerous times playing with it and not really being able to effectively read the curve. Then once I hit the right curve, the data can be transferred to the actual mag-trigger distributor that I'm gonna run permanently and the timing computer moved over to the crank trigger system on the stroker 152.

When the initial timing is advanced to the "right" point, the motor begs to be hammered and delivers in an impressive manner....and along with that, detonation is unbearable! With the base timing retarded to the point that it's drivable with only slight detonation under full load, the motor is a dog and not near as strong as a stocker.

But right now, my focus is making this pos a reliable dd. I did 300 miles in it yesterday,...that resulted in what calcs out to 11mpg overall which is fantastic for one of these rigs! And that included about 30 minutes of poking down the street at an idle in gear for the parade. And that kinda putzin' around showed that the carb is prolly still two jets Rich on both primary and secondary, though cold and hot start is now instantaneous.

The ignition system will be addressed after the Binder Bee. For now, the only thing left to do is make the a/c blow cold this week.
 
You will want to swing by my table at the Binder Bee swap meet....

msd1.jpg


I have the instructions and everything..... :ihih:
 
Michael, I'm sure you're way ahead of me on this one, but I'll throw this out and see if it sticks.
I was having similar symptoms with my rig when I got it going. It too is 9.0-1, but the block was zero decked and a composite head gasket used (.041" compressed). Despite what Robert kenny said about quench, I still experienced more knock than I expected (no offense Robert. It sounds like your stuff runs fine!).
When it came time to smog it, I needed a functional egr, and lo and behold, the knock stopped when I got it hooked up. I went from 5 deg btdc to 12 at idle. By 3000 rpm, the Mark is off the scale so I can't say what my total is, but I'm running a mallory unilite w/ vacuum advance (a swap meet score many years ago). I guess I could pull the vacuum line and see what the centrifugal contributes. Or borrow someone's dial-back light.
Bottom line, this made a huge difference in driveability. A friend says this is actually cooling the intake charge (hard to believe...)
also, I too am against running an IH motor on anything higher than 87 octane. Just doesn't seem right. Which isn't to say I wouldn't, but I get your vibe.
Good luck. Hope you get it sorted.
 
dealbreaker74 said:
michael, I'm sure you're way ahead of me on this one, but I'll throw this out and see if it sticks.
I was having similar symptoms with my rig when I got it going. It too is 9.0-1, but the block was zero decked and a composite head gasket used (.041" compressed). Despite what Robert kenny said about quench, I still experienced more knock than I expected (no offense Robert. It sounds like your stuff runs fine!).
When it came time to smog it, I needed a functional egr, and lo and behold, the knock stopped when I got it hooked up. I went from 5 deg btdc to 12 at idle. By 3000 rpm, the Mark is off the scale so I can't say what my total is, but I'm running a mallory unilite w/ vacuum advance (a swap meet score many years ago). I guess I could pull the vacuum line and see what the centrifugal contributes. Or borrow someone's dial-back light.
Bottom line, this made a huge difference in driveability. A friend says this is actually cooling the intake charge (hard to believe...)
also, I too am against running an IH motor on anything higher than 87 octane. Just doesn't seem right. Which isn't to say I wouldn't, but I get your vibe.
Good luck. Hope you get it sorted.
Click to expand...

You are absolutely right about the egr deal...deal!

I run into this constantly when "optimizing" these old junkers by "correcting" the emissions guapo! The distributors are curved for egr (along with the oem cam timing).

On a stock motor, I know what to do to the Holley distributors after much trial and error to eliminate the part throttle/full load detonation. And that mod is much easier to effect if running a delco distributor since the springs and weights are right on top and easily accessible with no teardown...not so on a Holley or prestolite.

And also, since I'm normally setting up a replacement performance-oriented carb on those engines and not dealing with a smogcarb, jetting and a two-stage power valve selection will take care of the detonation just fine. So the combo of carb jetting and distributor re-curve takes care of the egr elimination-related detonation.

Also,...all this is based upon the use of the oem iron egr intake manifold. This egr-related detonation situation was totally eliminated on my beater 392 by swapping to the rpt aluminum intake and running the propane intake gaskets which block the exhaust heat crossover. The rpt intake rejects heat just as efficiently as a heat exchanger!!! In a hot engine shutdown, the bimetallic element on the electric choke cap will close far enough to activate the first step on the fast idle cam within five minutes, even while the carb is still trying to percolate! And that is with no air exchange under the hood.

Setting up the proper curve for the distributor/ignition to match the carb/cam/compression is essential, I've just not had to do this seat of the pants before onna motor with both a cam and compression, only on stockers that are semi-tired. I have a mag-trigger Holley distributor almost ready to install, the mechanical advance has been diddled with but until I run it up I won't know if I diddled the right direction or not!
 
dealbreaker74 said:
It too is 9.0-1, but the block was zero decked and a composite head gasket used (.041" compressed). Despite what Robert kenny said about quench, I still experienced more knock than I expected (no offense Robert. It sounds like your stuff runs fine!).

When it came time to smog it, I needed a functional egr, and lo and behold, the knock stopped when I got it hooked up. I went from 5 deg btdc to 12 at idle. By 3000 rpm, the Mark is off the scale so I can't say what my total is, but I'm running a mallory unilite w/ vacuum advance (a swap meet score many years ago). I guess I could pull the vacuum line and see what the centrifugal contributes. Or borrow someone's dial-back light.
Bottom line, this made a huge difference in driveability. A friend says this is actually cooling the intake charge (hard to believe...)
also, I too am against running an IH motor on anything higher than 87 octane. Just doesn't seem right. Which isn't to say I wouldn't, but I get your vibe.
Good luck. Hope you get it sorted.
Click to expand...

No offense taken but lets get the facts straight in the context of quench detonation and egr function .
The quench deal in not my theory. It is a known engine building technique. The fact that you had detonation on a motor that was calibrated to run with an egr and an in-op egr had nothing to do with compression.
An egr engine can take a far different advance curve due to the fact that the exhaust gasses introduced into the air fule charge retards burn rates, combustion temperatures, inhibits nox formation and prevents detonation to an extent.

Effect of proper quench.
An engine at 8-1 and poor or non existent quench (more than .060) can detonate while a properly setup quench engine @ 9-1 will not with similar calibration.

The last 392 was 9-1 an egr engine originally but had a non egr federal manifold put on it. Correct calibration and no detonation. A tickle at some point according to the customer so the timing was pulled back to 34*. Advance is also set to come in a little late on this rig. An easy spring change.

I have never had access to a dizzy machine for the most part only made relative changes to advance based on results.
 
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Yeah, copy that Robert. The point I was getting to was a functional egr will (inadvertently) reduce detonation, no matter the condition of the combustion chamber. For michael, that May or May not be an easy fix. Just throwing it out there.

As far as distributors, I put some medium-heavy springs in my mallory, trying to bring full advance in late too. I was going on their install instructions which indicated full advance in by 3000 rpm. I can't confirm that's where its at. I need a dial-back light. Do you think that's a good place to be, or should it be later still? The motor will cruise about 2000 rpm, so I'm a little hesitant to go higher. And like I said, with the egr functional, I am out of detonation in most situations. I still have more futzing to do. Secondary q-jet timing, off idle stutter, etc. When all of that is dialed in, I'll revisit the curve.

Know any good trans shops around here?
 
I agree that for mm all of the horses are out. Should get better cruise milage with the 9-1 assuming the cam is not to big.

3000 is a good starting point. Remember that at cruise you will have 10-15* of vacuum advance in so the centrifugal is less important till you are running at high to wot power settings.

Possible you will have ping at partial mid power settings after you dial wot timing due to the vacuum advance reducing late. That is the tough part about dialing an analogue ignition system, without an adjustable vacuum advance diaphragm there is no easy way to alter that.
 
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