Slow Car Fast

[matmospheric]

Hello there.

I have been considering a streamliner project for some time, and I've decided to pull the trigger. The CAD has reached a point where I'm happy to start cutting tubes and spending money. I wanted to also start a build diary on here so I could post progress and hopefully get some constructive feedback on the project.

I'm building a streamliner car with a 500cc (K class) engine. Naturally aspirated gas, though we may explore a turbo and methanol later.

I've always enjoyed hot-rodding slow cars with small engines. So naturally, it seems like a fun project to take the smallest engine class and try to go as fast as possible. It's more fun to drive a slow car fast than to drive a fast car slow; so why not take the slowest engine class and make it go as fast as possible.

I'm an automotive engineer with some experience racing and fabricating, but I also understand the value of experience and I know these things are often much more difficult than they may seem. So I humbly present my design, and hope for a constructive and fun conversation that will help me navigate the unknowns and, more importantly, the unknown unknowns.

I'll post some more detailed photos later this week and dive into some design specifics.

[Stainless1]

What tank is in front of your feet... the best answer is probably intercooler water... not fuel... sealing one firewall is hard enough....

Have you spent time looking at other liners and talking with the guys running them....

Oh and most don't think 200 MPH is a slow car... all the K records except fuel are over 200... maybe small motor car fast
Looking forward to seeing your build

[matmospheric]

It is a water tank. I?ll be running lines back to a water/water heat exchanger for the engine. I?m hoping I can run those lines inside the frame tubes.

I have chatted with a few of the streamliner guys walking around at Bonneville this year and at El Mirage in October. I stopped by the Bockscar and talked with someone (maybe you?) about the 18? tires. I have lots of pictures and lots of answers, but still many questions.

[racergeo]

   

   An excellent first post and explanation of your project. you already won me over by having your front roll cage hoop tie into the lower frame rail. Half the cars you see that have been coming to Bonneville for years have that wrong.  Oh that's right your an engineer

[Stainless1]

If you talked to an ugly old tall guy with a big hat then yea... that was me.... 

What 500 motor are you thinking about using...

I'm not a fan of open frame tubes at the salt, but lots of folks have them.... just flush them well and watch for rust... with that said, we used the frame tubes of Bockscar for water when it was a K streamliner.  We sealed them up when it was converted to Lakester 5 years later.  When I cut the tubes open to stretch the car a foot 15 years after that they were surprisingly clean... some light rust dust but no pits.   

[DallasV]

Hello there.

I have been considering a streamliner project for some time, and I've decided to pull the trigger. The CAD has reached a point where I'm happy to start cutting tubes and spending money. I wanted to also start a build diary on here so I could post progress and hopefully get some constructive feedback on the project.

I'm building a streamliner car with a 500cc (K class) engine. Naturally aspirated gas, though we may explore a turbo and methanol later.

I've always enjoyed hot-rodding slow cars with small engines. So naturally, it seems like a fun project to take the smallest engine class and try to go as fast as possible. It's more fun to drive a slow car fast than to drive a fast car slow; so why not take the slowest engine class and make it go as fast as possible.

I'm an automotive engineer with some experience racing and fabricating, but I also understand the value of experience and I know these things are often much more difficult than they may seem. So I humbly present my design, and hope for a constructive and fun conversation that will help me navigate the unknowns and, more importantly, the unknown unknowns.

I'll post some more detailed photos later this week and dive into some design specifics.

I guess that would be running on Jim Burkdoll's 33 year old record with the Bluebird. Best of luck to you, Looks like you're off to a great start.

[Rex Schimmer]

Really like your concept, looks like you might be thinking about having the rear part of the chassis bolt on to the front as I see you are showing rectangular and square tube for the rear of the chassis. Don't be afraid to add some extra length behind the driver as it will fill up pretty fast and a little longer wheel base is always good for handling. Looks like it is going to be flat bottomed, much easier to fab.

Looking forward to you making your ideas into steel, keep it coming you will get lots of help from the people on this site.

Rex

[matmospheric]

What 500 motor are you thinking about using...

Currently looking at using a BMW S1000RR motorcycle engine with valve rockers removed from two cylinders. I might pull the pistons and con rods and add a dummy weight to balance the crank, but I'm trying to keep it as simple as possible for the first iteration, and pulling rocker arms is super easy. That should get rid of the pumping losses in those cylinders.

...looks like you might be thinking about having the rear part of the chassis bolt on to the front as I see you are showing rectangular and square tube for the rear of the chassis. Don't be afraid to add some extra length behind the driver...

Not bolting, I'm welding it all around, it's just easier to mount things to rectangle tubes so that's what I'm going to use in the rear. I have designed a laser cut junction between the round tubes and the rectangles. There is currently lots more room than I think I need, which will probably mean I'll just barely have enough!

[jacksoni]

Be sure to leave some extra space above the head in the cage area. Helmets are getting bigger, need clearance by rule above and on the front bar. As drawn, is the cross bar over the knees supporting steering shaft/instruments and such have the ability to swing up? if not you cannot get in and out, in my opinion. You need space for knees, feet to slide forward to clear your head under and in front of the cage. You will need to mock that up with a real driver some way. Been there, done that. (I made mock up with  plastic pipe and still ended cutting cage for more space eventually). And I also did the reduce displacement thing by taking pistons out and using bob weights. Works.

[Stainless1]

Matt, if we talked tires did I let you jump in to try it for size?  We do that a lot unless we are busy...
As Jack said, be careful to build something you can get in and out.  Your cage looked plenty big for helmets but I'd leave more room between you and the tank... maybe put the tank in front of the wheels in the nose.

Swing away steering and dash
Did you see or talk to Curt Huntoon, car 717, H/BFL.... he has a great swing away dash and steering set up.  He is in Sparks, NV ProtoFab is his company... Not that far from you... bet you could set up a meet and see what he has and how it was done.   
Are you trying to make 2022?  if so I can tell you you're already behind the power curve... LOL 
He will be at SpeedWeek... me too
see ya on the salt 

[matmospheric]

Be sure to leave some extra space above the head in the cage area. Helmets are getting bigger, need clearance by rule above and on the front bar. As drawn, is the cross bar over the knees supporting steering shaft/instruments and such have the ability to swing up? if not you cannot get in and out, in my opinion. You need space for knees, feet to slide forward to clear your head under and in front of the cage. You will need to mock that up with a real driver some way. Been there, done that. (I made mock up with  plastic pipe and still ended cutting cage for more space eventually). And I also did the reduce displacement thing by taking pistons out and using bob weights. Works.

I had a friend 3D scan me with all my gear on, and I designed the cage to have 3/8" clearance from my helmet from all sides after adding in the SFI roll bar padding. I'm hoping that will be enough. The cross bar that the controls mount to will indeed flip up. There is a cross bar in front of that near my shins that will be stationary.

Di you have any pictures of your bob weights? I was planning on clamping around them with a two-piece aluminum clamp that is the same weight as the heavy end of the connecting rod. I'll retain the con rod bearings under the clamp to maintain the same oil pressure.

I wanted to float this by as an initial design for front suspension. I have both wheels connected together so that when one tire bumps up, the other does as well. I also have it designed with one shock and spring. It seems like this meets the intent of the rule (each sprung wheel needs a damper) although it could be interpreted as "each wheel" needs its own damper even though there is one spring and they are connected together.

I wonder if this suspension approach has been tried? Looking for any feedback, Thanks!

[jacksoni]

"Di you have any pictures of your bob weights? I was planning on clamping around them with a two-piece aluminum clamp that is the same weight as the heavy end of the connecting rod. I'll retain the con rod bearings under the clamp to maintain the same oil pressure."

I don't. It was 1982 and that engine and parts long gone. Was a donut of steel machined to take a rod bearing with proper clearances for oil etc. If my memory of balancing things is correct you want all the big end rotating weight and half the reciprocating weight to make a proper bob weight (if you are balancing at 50%). If your parts are light enough, aluminum might be ok. Just is what mass do you need and what density is the material to make the size work.

[Stainless1]

I don't think the 1 shock will work... it didn't work in 1984 when we put a Honda motorcycle inside the Bockscar... frame, swingarm, everything but the steering head and forks. That means it had a single rear shock on the swingarm... We added a couple of pinto shocks between the pillow blocks that held the axle and the frame.  You can run it by the tech chair in the rule book, but that rule has been there since at least 1978... my oldest rulebook.

The swingarm front or rear is not that odd.... you will want to design in movement limits... and one more shock
Here's a couple of pics of one guys idea...

[matmospheric]

I have an idea for a rear axle that I wanted to post here and see if anyone had feedback on. It's somewhat similar to some designs I have seen, so I'm curious if anyone has experience and constructive feedback based on experience.

I have two axles I can have cut down to 8" long and re-splined up to the bearing landing. I can slide these into an internally splined steel sleeve that is split open along one side. I'll then clamp an aluminum sleeve around the steel sleeve to clamp down onto the splines. The steel sleeve and the aluminum sleeve will be connected with a machine key. I can then bolt the sprocket onto one side of the aluminum sleeve and the brake disc onto the other side. Four bearings, two on each side, will be pressed onto the bearing landings. I'll also have two bolts, one on each side, going all the way through the sleeves and the axles as an added security.

I'll have a swingarm that grabs the bearings and attaches the whole thing to the frame. The swingarm will rotate up and down, but both sides will be connected so if one wheel goes up, the other one does as well.

This is certainly way overbuilt for my ~100 horsepower engine, but it seems secure and I have all the tools to make it. I'm also trying to build in future capability to this streamliner in case I want to switch to a faster class in the future.

Let me know your thoughts.

[Stainless1]

Matt, we use something similar on the lakester. Our axles are keyed, no splines... they are clamped and have a thru bolt as a safety to keep them in place.  They work great.  I know you are looking for a narrow solution. 
Just a question or two... do you have room for the chain based on the drive from the motor or are you using a jackshaft to get the chain in the middle.  Have you considered putting the chain outside the tires giving you the ability of having the tires close together, thus making the back of the car narrower.... chain on one side, brake on the other, both outside the tires. 
I included a pic of our lakester rear... much like you have drawn, a center section and 2 axles... just a little wider and more spread out than you would want on a liner.  The outer housings are where we have the bearings.