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About purepmd

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  • Scale I Build 1/25th, 1/24th

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  • Location Gering, Nebraska
  • Full Name Mark Botzki

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purepmd's Activity

  1. purepmd added a post in a topic Let's Talk Diesels..   

    Clayton, great pictures, some of things you get to see on the road, are amazing. The 386 is pretty sharp, but nothing compares with the long hood and Pete grille on the 379. Timeless design, will alway be the best looking Pete conventional.
    Sam, sounds like a sweet toy. So glad to hear you have that 'adjustable torque convert' under your left foot. I had to go with the Tremec because the Richmond Gear Super T10 did not have a high enough torque rating. The Tremec is right on the edge with 600 ft lbs constant rating. The last 6 big inch Ponchos my engine guy built all made over 620 ft lbs. This one should be a beast as well.
    Michael, when I started, there was no such thing as GPS. A motor carrier atlas and a calculator was how I did all my trip plans. Some companies provide their drivers preset routes, some do not. OTR drivers get paid by the mile, so you try to take the shortest, truck friendly, (no low bridges, weight restricted, no truck route free, etc...), route you can. Paid miles and odometer miles never seem to match up, so you just minimize the difference. Planning fuel stops, loading and unloading time, rush hour traffic and avoiding it, meals, and sleep is the best way to go, but not always possible. Like Clayton said, after a while, you just kind of know how far you have to go, and how fast you have to get there.
    A Diesel engine is like any other internal combustion engine. The more air and fuel you can get in it, the more power you get out of it. More boost, higher rate injectors, reprogrammed ECMs, even propane injection, (nitrous oxide for diesels), are common modifications.
  2. purepmd added a post in a topic Let's Talk Diesels..   

    Hey Sam, 
    Nice to find another Tin Indian fan. It is a 1970. The 455 has Edelbrock aluminum heads, with 2.11 intakes, and 1.77 exhaust, a Comp Cams hydraulic roller cam, 1.65 Comp roller rockers, Diamond pistons, S.C.A.T. steel rods, backed by a Tremec TKO 600. Should be lots of fun smoking the tires, banging gears, and scaring the neighbors.
  3. purepmd added a post in a topic Let's Talk Diesels..   

    Hey Chuck, that is a very cool video, thanks for posting it.
    Sam, That kind of treatment of equipment is sad, and plainly ignorant. Drivers like that, give good mechanics job security. But at what cost. I found something awhile back you might find interesting. It is a nonaqueaous coolant. Instead of being made from ethylene glycol, it is made from propylene glycol. You have to have less than 1% water left in the system. NO electrolysis at all. Operational temp range of -70F. To 375F. Boiling point. No steam pockets from water, and an operational pressure as low as 2 pounds. I plan on using it in a 455 Pontiac going in my Firebird. With no water, the cooling efficiency is far greater, and no corrosion, for any metal. It is pricier than regular coolant, but lasts a lot longer. Evans is the name of the company that makes it. They cater to fleets. Cool stuff.
  4. purepmd added a post in a topic Let's Talk Diesels..   

    Oh, I almost forgot, most of the noise you hear at idle, is the explosion of the fuel combusting. The same effect can be heard in gasoline engines not timed correctly. The rattle of detonation in a gas burner, is normal combustion in a diesel. Clayton is right, again. Piston slap, the piston rocking side to side on the wrist pin, is normal. Especially loud on cold starts. The clearances in such a large bore have to be so large, that piston slap is the norm. Heat and radical increases in cylinder pressure miniseries it. A trained ear can determine manufacturer by the sounds at idle. They don't call them Clatterpillars for nothing.
    In closing, I know finally, right, a little, useless factoid. The distance around the equator of this planet is just under 25,000 miles. That means one would have to drive more than 100 times around the world to equal the miles I racked up in trucks. I apologize if that seems like bragging, but, like my Grandfather used to say, "It ain't braggin if you can do it.", or in this case have done it.
    This has been a very enjoyable topic.
  5. purepmd added a post in a topic Let's Talk Diesels..   

    Michael, I know you asked this of a true mechanic, and I certainly will defer to an expert opinion, so if I am wrong, he will certainly correct me. But summations are, indeed, correct. Most engines are governed at 2100 RPM, so the detrimental harmonics of high crank speeds are not much of an issue. Very strong internal components definitely add to the lifespan. Precision machining does not hurt a thing. Highly efficient and well designed oiling systems, and massive amounts of well filtered oil is essential. Most six cylinders hold 10 to 12 gallons, depending upon oil cooler and filter configuration. Large, conditioned, and filtered cooling capacities try to keep heat, man other engine killer at bay. It helps to have a driver with a equipment minded head on his, or her shoulders. For example, long grades and high air temperatures, the Mojave Desert out of Havasu Cityin August comes to mind, should be enough for you to ease of the throttle a few hundrred RPM, shut the air condition off, roll the windows down and turn the heater on if needed. Making sure the routine maintenance gets done, not driving with your right foot glued to the floor board, and respecting the machines limitations all figure in from the drivers perspective. Mechanics and owners that really want to keep tabs on an engines condition, can send samples of the used oil to be analyzed as to what and how many microscopic metal particle are in it.  You can get an idea of the condition of the rings and bearings, especially, by seeing if the oil is high in the metals the these are made from. Copper, steel, iron, etc, will all show in the analysis. At what level is one of the concerns.
    Another trait that helps them live long lives, is their very design. A large bore, combine with a very long stroke, generate massive amounts of torque. Torque is, arguably, the true measure of an engine. Horsepower sounds all flowery, torque is the force generated by the rotation of the crank that makes all this possible. 1600 to 1800 lbft is to be expected from 14 liter and up engines. And being able to develope this at such relatively low engine speed helps to.
    If 1 single aspect can be put forth as the most import as to long life, it is maintaining the power plant at least to factory recommendation. That is true of any engine, the outboard Mercury on a Bass boat, to the Brigg & Stratton lawn mower, to a Cat in a OTR rig. The harder you work it, the better you maintain it.
    As one who had a driving career span several decades, driving 1 million miles is different from driver to driver. My first year out, I turned just over 100,000 miles. That was by far my worst year. Rookie level for sure. My best year I rolled over 175,000 miles, all solo. Forget sleep and home time. Teams can run, upwards of 300,000 miles in a year, if they are dedicated to making money, not hanging out in truck stops. I drove over the road for 16 years, and racked up just over 2,000,000 miles. That is an average of 125,000 a year, some really good some, not so much. Figure in the time I spent doing route driving, and local hauling, mostly sand and gravel with a belly dump trailer, and I guess I have over 2.5 million miles of windshield time.
  6. purepmd added a post in a topic Let's Talk Diesels..   

    Hey Leo,
    I did not figure the shear numbers of the N14, and N14Plus engines. Cat's win would have to be based on PERCENTAGE with N14s outnumbering 3406s  The N14 is not a bad engine. I have seen several with over 800,000 miles, well on their way to 1 million miles without anything but regular maintenance and an overhead. Even driven a 525 horse N14 Plus, and it was pretty grumpy. It would give a buddy of mine's 550 3406E a scare once in a while.
  7. purepmd added a post in a topic Let's Talk Diesels..   

    It makes you wonder, that, if in the name of weight savings, the engineers are using theory and not practical evidence when it comes to designing the reinforcement of the main journals and caps. Maybe even in the crank itself. For the lack of a few pounds of well placed cast iron and steel, you get ridiculous failure rates. I would almost bet real money, the thrust bearing main journal is flexing and or cap is walking during clutch disengagement and under high load situations. That is one thing to be said for the heavy 3406 family. The bottom ends of those engines were almost bullet proof, as long as you keep fresh oil in it like you were supposed to. Cat had more million mile, in-frame free engines than anyone else. I am sure a lot of mechanics as well as drivers miss the yellow motors under the hoods. Just my 2 cents worth.
    Happy Thanksgiving Everyone.
  8. purepmd added a post in a topic Let's Talk Diesels..   

    Hey Michael,
    Fishing for Gearheads, throwing bait like that in the water.
    K.J. is right. Rudolph Diesel, in the mid 1890s, worked on using the inherent heat from compressing air, to ignite a fuel. After a few experiments, one explosion that almost killed him, he found a by-product of the crude oil refining process. It was cheap, plentiful, and at the time burned off as waste. He found that by atomizing, and injecting this waxy fluid into a piston compressed cylinder, as the piston neared Top Dead Center, the fuel would combust, and the engine would sustain itself, without external ignition source.
    Clessie Cummins work on 4 stroke engines, in the 1930s, and turbochargers, in the 1950s, were huge coffin nails for the 2 stroke Detroits. He used the Indy 500 as his final test bed, having been on the Marmon pit crew for the first 500 in 1911, setting speed records, endurance records through the 1950s, all with diesels.
    California hot rodder Clayton, speaks the truth. Hot rodders, after WWII, started pulling the superchargers off of diesels and adapting then to automotive gas burners. Even today, the size designations of Roots type, (GMC), blowers. 4-71, 6-,8-,10-, 12-, 14-71 all owe the name to the old Detroit engine displacements. The size of the supercharger was determined by case and rotor size needed to fill the given number of cylinders, 6, 8, 12, etc with 71 cubic inches of air per crank rotation.
    Incidentally, the 2 stroke Detroit engines require air to be forced into them by the 'blower', in order to run at all. Being a 2 stroke design, with the intake ports in the cylinder walls themselves, they do not have a separate intake stroke, like 4 stroke, gas and diesel engines use to draw in their own air.
    The most prevalent configuration, today, is the inline 6 cylinder. Early on, Cummins found out that inline engines generate more torque per cubic inch than VEE configuration engines. With a couple of notable exceptions, the V903 Cummins, and the 3408  Caterpillar, the majority of successful Truck engines are 6 poppers. The first, production engine to make 600 horsepower, was a Cummins KTA-600, a 6 cylinder. A benchmark not even the venerable 12V-71 could make.
    As I try to get my inner Diesel Geek under Control, don't forget, even ALLIS - CHALMERS tried to get into the truck engine market, in the 1970s. "Big Al", as it was marketed as, looked good on paper, and even painted purple metallic, but in reality had severe crank longevity issues that made it just another also ran.
    Now, consider all the different developmental series for each mark. The Detroit V-71s, V-92s, V-92 Silver, Series 60, DD 14 and DD15 versions. Cat,s 1693, 3406A, B, C, 3406E, 3408, C-15, C-16. Cummins' NTC series, KTAs, 855 series, ISX, Signature 600, just name a few.
    OK, I'll stop now.
  9. purepmd added a post in a topic Peterbilt Devil's Cut Whiskey Hauler   

    Pretty slick! Great build quality! Going to follow this one, closely. Very cool.
  10. purepmd added a post in a topic White 7400 & Detroit 6V71 project   

    Sean, really looking good. Your six pot Detroit looks way cool. This project is off to a great start. Looking forward to updates.
  11. purepmd added a post in a topic Why a Cab Over?   

    Clayton and KJ hit the nail on the head. Back in the 1960s, a class 8, on highway truck could only be a maximum of 57' and weigh 72,800 lbs. The easiest way to get the most payload within these regulations, was to put the driver over top of the engine, and keep the wheelbases under 190 inches. The cabover ruled the road, especially when you factor in all the restrictive bridge laws that could, and would be enforced. Each state setting something different.
    Look at the AMT truck and trailers were all modeled off equipment of the day, 40 footers, and short wheelbase cabovers.
    l did the math, and it was 33 years ago, I drove my first truck. It was a red and white, white freightliner FLA. Catpowered and 15 speed equipped.  
    One of the best things about cabovers is the visibility. You are not looking around a hood, or exhaust, or sleepers. You are right overtop of the left steer tire, inline with the side of the trailer. Backing up was never easier. Blindsiding was a bit tougher, though.
    Clayton, you tastes and mine run along the same lines. Freightliner FLA, Pete 352, 362, and Kenworth K100 are my favorites. With honorable mentions going to the CL9000, IH9670, Road Commander II, Astro 95, and  IH 4070B.
    There ain't no feelin' like Cabover mobilin'.
  12. purepmd added a post in a topic Shifting Gears..   

    ^^Preach, Brother, Preach.
    If it weren't for the Federal D.O.T., Creeper Cops, Steering Wheel Holders, and ignorant 4 wheelers, it would be the perfect job. 
    I am all teary eyed and nostalgic now, myself. Lol.
  13. purepmd added a post in a topic Shifting Gears..   

    Yes, Michael, very similar effect, only you use the throttle to break the torque lock in the transmission instead of letting gravity do it for you.
    Hey Clayton, you, obviously know what I am talking about. And know it well. It is a great feeling when you row through the gears, hitting each one just right. Did I mention I HATE class 8 trucks with automatics. It is a well practiced, well executed skill set that is dying at an alarming rate. 
    If you notice in the video, the driver's left leg never moves after he gets rolling. Not even when he splits gears, or changes ranges. You can tell, he LIKES driving that truck, and showing off a bit.
  14. purepmd added a post in a topic Shifting Gears..   

    Hey Michael,
    When I first started driving, Over 20 years ago now, it was explained to me in these very words:
    "The clutch is for starting and stopping, ONLY." Spend any amount of time with the same truck, and you learn its peticular traits. You learn how to shift to neutral just by lifting your foot off the throttle. Then, hopefully, you learn how to shift it into the next gear, up or down, just by engine RPM only. Down shift and you raise the engine speed with the throttle, up shift and you wait for the engine speed falls to the normal gear step. The gear step being the difference in engine speed, at the same road speed, (MPH). For example, if at 50 MPH, in 12th gear, and the tach says 1100, drop to 11th gear and the tach would read 1600 RPM. This varies with every different transmission. An 18 speed may only have a 250 step when you split each gear, 1-2, 3-4, etc. While a 9 speed will drop, say 500 RPM, having only half the available forward gears. A car, with a manual transmission does the same thing, just with a bigger swing of the tach needle. 
    Floating the gears, basically, is shifting, up or down using only your right arm and right foot. No clutch. With practice, the shift lever, almost 'floats' into the desired position. No grinding, nashing, or missed gears. It will literally shift with surprising little effort. The alternative, is 'Jamming' it into gear. Yes, the term Gear Jammer, long before my time, was a derogatory term.
    Clear as mud?
  15. purepmd added a post in a topic Movin On Kenworth color.   

    Angel, if you have an air brush, I have the exact colors, mixed by Scale Finishes. A 2 oz bottle of Kenworth Ivy Bronze, metallic, and 1 oz bottles of Kenworth Lime and White. I was going to build a 1/16th VIT, but it is so far down the list of projects, I would let them go, if you what them. All 3 are premixed, brand new, and unopened. P.M. Me if you are interested. Reasonably priced as well.