Tag Archives: Mini Sprint-T

Lots of road course racing this weekend

There are two road courses today on the tube and one yesterday. And there was an Indycar race from a short (by Indycar standards) oval. And for those wondering we are way north (about 250 miles) of the hurricane down on the coast so all we have gotten was a few showers and some slightly damp kitties. I’m worried about my Houston friends as H is getting drowned with feet (not inches) of rain. Last report they are expecting 5 feet of rain total. I have some friends living less than ¼ mile from the Brazos river which is way out of its banks last report. I’m especially worried for them and their dogs.

I have been thinking about the Mini Sprint-T and the scale mockup for the TGS2 as they both need a body. What I have been thinking about is making a mold off of the AMT kit body then casting a plug from Bondo to use making a vacuformed body after making the desired body modifications to the plug. The plug would then be split in half to draw the body material over to a form with no undercuts so the body can be removed easily from the mold. The TGS2 mold would have the rear hatch molded separately so it can be hinged to work on the engine and I can test side versus top hinges for access to the rear suspension and engine.

Still thinking about making the little V6 run on E85 only. There is a hypereutectic piston I can use that is flat topped and can be zero-decked for the minimum clearance between the head and the piston, and then the heads will have to be angle-milled to shrink the combustion chamber in the head without taking too much material off the bottom of the head. And I realize that the preceding sentence read like technobabble to about 90% of my readers who were not brought up hard-core gearheads, but every word was a valid technical term or connecting word between. IOW it was all English, just not a common dialect of English. Translation: There is a cast piston made with a low expansion rate high-strength aluminum alloy that is flat across the top and can be fitted flush with the top of the cylinder. Then the heads will have to be milled on an angle with more taken off on the big side of the combustion chamber to get the chamber as small as required with the least amount of material removed. Hypereutectic pistons can support about 375 HP on gas for this engine, and I’m only hunting 225 to 250 HP with cooler-burning E85 so well within estimated stress limits, plus they are inexpensive especially compared to forged pistons. In this case that is especially true because forged pistons would have to be custom made, they aren’t available as regular production items.

The last sentence of the previous paragraph pretty much sums up my biggest frustration with this build, almost everything is $pecial order or cu$tom made, especially in the engine. Some of that is because there were no performance applications for this engine aside from the 1991 Shelby Can Am series which only made 150 engines putting out about 225 HP. The other reason is the last one left the production line in 2011, 6 years ago. Compare this to the ubiquitous SBC that was in production as a factory-installed engine from 1955-2001 and is still in production as a replacement engine for emission controlled vehicles of that era, and as a crate engine for new cars that are not required to meet emissions controls like the Sprint-T. There were literally tens of millions of SBC made in dozens of different sizes from 265 to 455 cubic inches when you include the hybrids made from mixing different blocks and cranks. One of those hybrids actually made production status as the Z28 302 in3, which was a hybrid of the 283 crank in a 327/350 block. One of the most popular hybrids is the 400 crank in a 350 block bored 4.030″ to produce 383 in3. How popular is it? There are now twice as many 400 cranks as there were 400 SBC engines made, the aftermarket is producing brand new cranks with the 3.750″ stroke of the 400 crank with the smaller main journals of the 350 block. It’s even easier to get parts for the LS/LT engine families than it is the 3.3/3.8l Mopar V6.

And that’s enough kvetching about the free engine I was given, at least stock replacement parts are cheap and easy to find because of the millions of them on the road. And some of those factory parts are suitable for use in a high-performance engine with a little preparation, like balancing or grinding off flash and light polishing to remove stress risers.

And I have to go now because my friends on the Gulf are finally starting to check in and I don’t want to miss any. Also my back is starting to hurt again. I did pretty well for several hours today but the pains are back.

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I’m melting, melting, what a world…

Heat indexes have been off the charts lately, from what I can tell. I haven’t been able to go for my walks so I have been spending most of the time indoors and hardly check the weather, but it’s 86°F in my office as I type this with the AC going. So it can’t be anything but hot outside. But just FYI my phone says it is currently 98°F outside. At 1855. So by deduction it must have been over 100 at some point today, say like between 1400 and 1500. ETA the 2200 news weather report had a 100° high temperature. And the urban heat island effect keeps the nighttime temperatures up, too. And this is where today’s headline came from YouTube

I’m not happy with the way the floor came out for two reasons. Number one is I forgot to include the front support for the front fenders, and 2) I made the rear cutouts too wide, as shown in the pictures. Seriously I left enough room for a 16″ wide tire and the widest race tire I have been looking at seriously was 14″ with the street tires in the 12″ range. And I have plenty of raw stock for the floor, finally. So the floor will get a do-over. And that’s why those 9″ wide tires in the pictures looked so lost in there. Even the 10″ wide tires for the Mini Sprint-T would have been swallowed up.

While I am on the subject of the TGS2 I have been looking at a pull-rod spring instead of direct mounted springs for 2 reasons. One reason is I can change the spring rate just by changing 2 bolts, either a little or a lot, The second reason is the unsprung part of the pull-rod is much less than the direct mount spring because the entire spring and shock are moving with the car. Yes they move with the axle but they are entirely supported by the frame so they are sprung weight. The bellcrank and mount add a couple of pounds but it is all sprung weight. But the primary reason to go with the pull-rod springing is adjustability, I can change spring rate and ride height in just a few seconds and swapping a different length pull-rod is much cheaper than swapping different shocks and springs. Literally a dollars to donuts comparison, I can buy or make a custom pull-rod for about the price of a dozen donuts where a spring and shock absorber are $200-300 assembled. With my budget this is a cost-benefit ratio I can most definitely live with.

And I need to take a shower and hit the hay.

Still working on the spindles

I spent hours working on one bushing last night and it still won’t take the kingpin. It’s getting close but won’t let me slide the pin through the bushing, and I have 3 more bushings to go after I finish that one. Either the stones are worn out or these are very hard brass bushings. I think they are actually bronze rather than brass, but still, not supposed to be that hard. I was using cutting oil and everything so unless the stones are worn out already from the axle boss I’m at a loss.

Moving on to the scale mockup TGS2 I found some more card stock to use for the floor. There was an expired TGIFriday mailer under my computer that was printed on extra thick stock. I have revised the clearance cutout for the front tires, so now all I have to do is find time to cut it out. I think if I skip a day blogging I’ll have the time to do a couple of floors, maybe?

I’m going to have to switch to my backup scale bucket body because I have already modified my first one to build the Mini Sprint-T. That means I have to open the chopped T-Coupe rod model. I really haven’t decided what I want to build from that one. There are so many choices… And I have really no time to build models. Models from boxed kits that is, mockup models are required for, reasons.

And because I need to get to work on something I’m closing this one down now.

Mrs the Poet has only been gone one day and already my diet has gone to pot

Just got back from my first walk in over a week. Slight right glute pain because that’s my “long” leg and has to work more, and in my left foot which takes more of a pounding because it’s on the short leg. But otherwise I’m good after 2.6 miles there and back.

Tonight I had frozen Mexican Pizza for dinner. Yeah, I know, but I wasn’t in the mood for beans and rice. I took care of most of the leftovers last night, the little half-servings of stuff that was too little to make a meal out of but too much to throw away earlier in the week. And I think I might be dairy-intolerant in my old age. I have always had gas that varied from infrequent toot to crime against humanity in volume. Well just for grins and giggles I stayed away from cereal and milk, used non-dairy creamer in my coffee and skipped my nightly dab of yogurt and had a gas-free 24 hours. Next test is soy milk on my cereal, and maybe in my coffee, and no yogurt. The no yogurt thing is what is gonna kill me since I have some almost every night.

I have been thinking about how to show you guys what I have been thinking about, since my (free) CAD program doesn’t output files that can be read except by that CAD program and a few 3D printers and I don’t have a 3D printer (yet). What I do have is a bucket body in 1/25th scale, some tires in various widths and diameters, and some card stock, both the plastic and paper kind. So I’m thinking that I can dispatch two avians with a singular lithic projectile and get some actual building done while I make a visual aide for the blog. And actually see my thoughts in 3D outside of a computer screen or my head. Mostly my head, but I have managed to get it once or twice on the computer.

I’m listening to my YTM channel while I’m posting this, and it’s almost as ADHD as I am. The last 4 pieces were a Charleston demonstration, “Les Toreadors” from the Opera Carmen, “Immigrant Song” by Led Zeppelin, and Skynyrd’s “Simple Man”. There’s classic rock, classical, electro swing, ’60s surf rock, boogie woogie, psychedelic, ambient… and nearly every one was something I “liked” or similar to another I “liked”. I have probably caused the electronic equivalent of an aneurysm to the poor algorithm trying to decide what I like based on what I already liked and disliked. And now I really tossed a monkey wrench into the works by searching for the theme from the Alfred Hitchcock TV show under its real name “Funeral March of the Marionette”. And “liked” two of the pieces. My playlist “Opus’ fun junk” is almost as bad but I have at least listened to the whole thing end to end.

I have meandered on long enough, time to shut the brain down for bed.

I should do something with the mini Sprint-T

I have been neglecting the model version of the Sprint-T in favor of trying to fix the handling problems inherent in the design of the TGS2. I mean I know I should be doing something on it, but the inspiration has been lacking compared to the TGS2 and posting in the blog.

After it quit raining Sunday evening I went for my walk and picked up a bag of cereal. Yes I’m cheap and buy the bag cereal. It’s slightly cheaper per ounce than the box, we just don’t always have the $ to pay for a bag. I also get PopTarts in the big box except when the sales on the small box makes them cheaper per breakfast. Why cold cereal and PopTarts for a grown man’s breakfast? Simple, those are relatively non-lethal to prepare when I’m pre-caffeine. Cognitive functions generally don’t kick in until the second half of the cup, and it’s much safer to have things that don’t require the use of the stove or anything more complex than pushing the lifter down on the toaster. Even the measuring out of the various ingredients of my cup of coffee have become mostly autonomous. I can’t quite do them in my sleep yet, but I’m close. It’s when things change like switching from milk and sugar to pre-sweetened creamers that stuff gets messed up. More than once I took a swig of what was supposed to be coffee and got a slug of liquid candy instead. And for some reason that stuff just seemed to get sweeter and sweeter during the day. A few hours after pouring my coffee in I felt like pouring it out.

Speaking of my walk, it was so humid after all that rain I could have almost gone for a swim instead. It was 71°F with a 70° dew-point. UGH! sticky! At least it wasn’t hot to go with that sticky.

I would do more writing but my neck and shoulder are starting to bother me and make it hard to type.

Yay beer! And other things.

Just got back from the store with a new (to me) beer, Shiner Homespun Cream Ale. I have a new favorite beer. Seriously, this is the beer I have been looking for for years, slightly sweet and not over hopped with just the right balance of sweet and bitter. I must send a letter to Shiner and tell them this.

Work on the Mid-Bucket has slowed while waiting on the parts to arrive, some of which are still not made yet. I mostly have been analysing the frame for things to leave off and make it lighter. I have found 2 tubes that are redundant so far for a total weight savings of 5.5 pounds.

yay

On the Mini Sprint-T I’m almost done resizing the wheel halves for width after taking some time off for the Mid-Bucket. Filing the resin wheel halves is much quicker than the stainless steel steering arms on the Mid-Bucket, but because they have to be within a thousandth of an inch precision it’s only quicker in how long I spend actually filing them down compared to fitting the steering arms on the Mid-Bucket.

On the RPG front we are having some difficulty creating my character based on my life. Specifically my HP and natural armor or DR or in the terms of the game we are playing, Body and Hardness. Here’s the rub, the getting hit by cars doing from 25 to 30 MPH and walking away with minor abrasions is how Hard my body is in game terms. Getting hit by a truck at 60 MPH and barely dying is how much Body I have. Un-dying is a whole ‘nother kettle of fish that is covered by the rules but only for creatures in-game. And in-game I’m 129 years old, Mrs. the Poet has been dead at least 40 years, and I’m still living in the same house in Garland. I’m still mostly riding my bikes to get around except when I’m being a Runner when I have a couple of vans and cars. Also I’m an actual walking Urban Legend in-game having been a Runner since the events that created the game world. There are a number of people in law enforcement who don’t believe I actually exist, there are rumors I’m not actually human, that I’m some kind of avenging spirit, and even weirder stuff than that. This is going to be FUN!

On another front, my musical tastes are giving my YTM app apoplexy. So far on my saved music I have Jazz, Swing, Hip-hop, Classic Rock, Acid Rock, Electronica, Ambient, Trance… and whatever they classify Blue Man Group as. Seriously my tastes cut across so many genres My Channel is like listening to a radio that can’t stay on-station. If you can, do a search for Opus’ Fun Junk playlist. And prepare for your mind to get blown. 😀

And now I’m just doing the keyboard equivalent of babbling to hear my own voice, so I’m packing it in now. Happy Easter!

I have been busy even without Internet

Even without Internet access I have been busy on the Mid-Bucket and the Mini Sprint-T. For the Mini Sprint-T I have been modifying the resin castings into the right width wheels with the file and the digital calipers to keep track how wide the front and back halves of the wheel were. That takes a couple of hours for each wheel. For the Mid-Bucket I have been sketching to get the things I see in my mind on paper where you can see them, but not yet because they look like crap and are only partly done. I got the basic ideas down but as I was working I realized I had forgotten something very important, I neglected to include a mounting point for the front 4-bar on the frame. That’s kinda important as that’s what keeps the front axle in front, and not someplace in the middle of the car. And also controls axle wind-up under braking.

How I discovered that was I was thinking about what size links to put in my build list, and couldn’t remember how far the axle was from the 4 bar mounts. Then I tried to remember where the mounts were by remembering where the structure went when the penny dropped and I realized I had left some very important bits off the frame. And also left off the bits that triangulated the mounts for both the front and rear 4 bars. Not a great tragedy, but there would be some flex in the mounts without the bracing, enough maybe to feel under hard braking while racing. I did figure out where to mount the frame ends of the 4 bars, on the roll cage front and rear hoops. And I did figure out how to brace them so they won’t move around. It made the frame about 10 pounds heavier, but really there was nothing else I could have done except leave the mounts all floppy. Also the braces make getting in and out of the car much easier, like having a ladder permanently mounted on the side of the car.

The other thing that sketching out the frame did was confirm the engine mounts will in fact come naturally close to frame members, especially the front and rear mounts on the center rear frame member, but the left and right mounts are going to be right on and real close to the rear diagonal frame members, respectively. That means all the engine mounts are going to be on the bottom plane of the frame, but with the braces the rear of the frame is going to resemble a Birdcage Maserati.

All those tubes but no rollover protection...

Look at all those weld joints!

Now obviously I’m not going to go with such a complicated design, especially since it isn’t any lighter or stiffer than what I’m doing.

And since I need to get up early-ish tomorrow I’m putting this one to bed, and then me right after.

This is when I write about what I did

Earlier this week I was too busy doing things to write a blog post. Now I have a few minutes to write what happened. All I need to do is get the story straight in my head so I can put it on the screen. That is easier said than done.

Big news first, I lost my wallet again. Exact same way I lost it last time, from the same pair of shorts. I thought I was putting the wallet into the pocket, but it didn’t stay there. I probably lost it when I was sitting down after buying the day pass on the first bus of the day.

Second thing is I am no longer hairy. Well as hairy. I used a ½” guard on the top of my head and no guard at all on the beard. Then I charged up the electric razor and finished off the beard. Voila semi-fuzzy.

On the Mini Sprint-T, I think I have my tire mounting problems solved. I mentioned in an earlier post that I would be using a discarded insulin syringe to inflate the tire out to the edge of the wheel, well the other problem is the wheel making the tire grow larger in diameter by a substantial amount because it’s just too thick, for structural reasons. The resin used to cast the wheels is not as strong as the styrene plastic used in commercial model kits so it has to be thicker, basically all the way out to the flange diameter of the wheel. This in turn stretches the tire diameter by a similar amount, which drastically alters the scale relationship of the tire to the rest of the car. Well I’m going to try sanding out the inside of the tire bead so the oversize wheel so it doesn’t force the tire larger and see how that works. I have a spare set of wheels, and tires that I won’t be using on either model, to experiment with.

And I’m starting to get fuzzy around the edges of my mind, so I’m quitting while I can still hit the correct keys on the laptop.

Bille @€0.02, Opus the Unkillable but sleepy

A State of Detent Has Been Reached At Casa de El Poeta

Mrs. the Poet has been complaining about how I’m “not helping” her throw away my stuff when she does it during the part of the day when I’m still asleep. I don’t understand this. I don’t complain that she’s not helping me write when I start composing stuff at 0300 when the Internet is fastest locally and I can get to reference materials most quickly.

So we reached a compromise, in that Mrs. the Poet will not start throwing my stuff away until I get up, and because we both have things to do over the weekend I will start helping her on Monday afternoon after I have had coffee. There is something in the garage that she calls a “box full of rusty metal stuff” that I’m almost afraid to open. Then we don’t go into the garage again until after I get up Friday.

On other things I’m playing some more Shadowrun tomorrow, and there is a late race on Sunday, the Las Vegas race for the Monster Energy NASCAR Cup. And now that I have a new tube of GOOP™ I can continue to mock up the Mini Sprint-T street version. I haven’t found a model kit that has the Pentastar V6 as an option so kitbashing is right out. But I have that first wheel glued up and ready to test fit to the tire when the glue dries. I’ll probably do that Sunday while I’m watching the race during commercials.

Billed @€0.02 Opus the Unkillable

I think too much

I was on a long walk to get some stuff at the hardware, and well, my mind also wandered. Specifically it wandered around the Sprint-T. What I was thinking about was what it could be like with the Pentastar 3.6l V6 DOHC aluminum block and heads engine that weighs a factory-claimed 326 pounds (as compared to the 545 claimed for the SBC and the 413 for the 3.8 pushrod engine out of the minivan) and delivers 305 HP in stock form. As a comparison the “performance” SBC in the first-gen Camaro was rated at 290 HP. In the Sprint T with the SBC and a TH 350 transmission I was looking at just over 1700 pounds empty, with the Pentastar V6 and the 42RE transmission coming in at 1450 pounds but that 42RE transmission would be dicey for racing use. The later models used 6 and 8 speed slush boxen that would survive racing but also weigh considerably more, the 8-speed being strong enough for the legendary Hemi. The transverse version of the 3.6 would bolt to the 41TE transaxle in the mid-Bucket and take 87 pounds off the weight and rear axle, while adding more than 200 HP over the engine as it sits in the minivan. Do I want one? Not if I had to buy it from the dealer with a car around it. Would I take a similar deal as I got on the 3.8l pushrod engine, remove a derelict vehicle to remove the stuff I needed to make a car for free? Hell I would even pay for a car that got wrecked in the back as long as it wasn’t more than $1K to get the 305 HP version of the engine and then swap the FEAD (Front End Accessory Drive) for the transverse installation. I mean 200 HP more and 87 pounds less would I take that? Hell Yes I Would Take That!

So the reason for the walk was to get the 7/32” drill bit and the small tube of GOOP for the bike and Mini Sprint-T respectively. I logged 3.93 miles and 25 checkins on Map My Walk and M Plus Places respectively and burned a lot of calories in the process. The weather was perfect, just warm enough and just breezy enough with a high overcast so that it was bright but not blinding.

And I have to get the rest of the stuff I do offline done so I can go to bed, so I’m putting this post to bed first, then me.

Billed @€0.02, Opus the Unkillable