Antique Racer Build On The Drawing Board!

[joeyputt]

Well been wanting to build this one for awhile and have decided it is finally time to get the ball rolling! I do a lot of custom building/fabricating but rarely get to my own projects and it is time for one! We have a family history of racing karts and I have always wanted to incorporate a racing briggs engine into our other passion, the motorcycle! It only seemed natural to build it into an antique racer similar to the old boardtrack bikes of yesteryear so here is the plan! We build 10,000 RPM briggs race engines and while one would be awesome on the bike I really always wanted to link up two of them togethor! So now we shall! The engine will be the old style flathead briggs blocks (yes like on your childhood kart!) fully ported and polished, decked head with fireslot, billet connecting rod, BIG cam (so it will just beat down at idle!), advanced timing, lightened flywheels, dual mikuni carb's (one for each engine) hanging on a handbuilt intake manifold, etc., etc., etc. Am handbuilding the hardtail frame as well as the front end, exhaust, fuel tank, etc. have not decided on the drive yet but am either going direct drive from the engines to the rear via a multi disc adjustable stall clutch like we run on the karts, or I may put a tranny in but have to decide before we start the frame...so need to make up my mind pretty quick! These engines are extremely loud and revvy! can not wait to get this going! Just thought I would share the idea! Here is a couple pics I drew up of the basic idea...

one more pic on the way...

[Guest]

Joe

looks like an interesting project, i bet you really going to enjoy putting it together, are you going to build the frame for it or try to find something.
i bet you can go to the swap meet at Barbers motorsports park in october
and find some stuff. you could use.
good luck on your project

jim
SLOCOMB AL

[Guest]

A little inspiration for ya. I love this little board track racer replica.

[crispy]

Keep us posted looks like a fun project

[joeyputt]

Bigger Jim you are only a few minutes from me if you are in Slocomb...yeah I am going to build the frame, actually probably build everything but the rims for the most part!

[joeyputt]

Deviant1...yeah man that is what I am after only with twin 10,000 rpm flatheads! adding the top view drawing now so you can see how I plan on routing the intakes and exhaust which I will build here...thought it would look pretty trick with dual mikunis hanging off the side!

[Guest]

well you have my attention, I can't wait to see it take shape!

[joeyputt]

here is one of the last kart engines I built and will be building a similar pair of to go into the bike except with much more attention to detail and mikuni carbs instead of the tilly...

[Guest]

My concern with your drawing for the carb intake tubes is this: with them being different lengths, you will never be able to sinc them right, also, the fuel tends to accumulate on the walls of long intake tubes and starve the motor, the more fuel that collects on the intake walls just makes the problem worse. This is due to the small atomised fuel particles in the air being reconstituted into droplets due to collection. I agree that it would be very cool to have two carbs mounted together like that, but you may want to make your design have equal length tubes with similar bends and be as short as possible!

[joeyputt]

Yes I have considered the different length tubes however that drawing is just a doodle and is not to scale and if I run them side by side there really is not much of a difference in length and have actually been thinking about running them staggered which would give them the same length tube anyway...these particular engines will run with different length or long tube intakes without puddling as they flow well over 700 miles per hour at just 6000 rpm on the flowbench...these engines will be good for around 10,000 rpm... jr drag cars use this same engine, many with longer intakes than I will be running with no problem...plus we are not going to street it, more of a shop/show play toy! I am educated in fuel systems and in theory your concerns are correct however these little engines are screamers and are not too finicky...

[Guest]

Yes sir...does sound like you know more about the subject than myself. I just wanted to make sure that this had been thought of....sounds like it most certainly has! I cant wait to see it, should be a real fun little ride for sure.

[joeyputt]

Trust me I did not mean to sound like nor was I saying I know more than you, I value all opinions and love discussing technical issues...man have you ever heard one of these engines run? they will twist up and are loud as hell but have an awesome sound to them! and they idle really radical too like a drag car!

[Guest]

I used to mess around on the strip a bit when I was a teenager. My Dad and I built a small block chevy with a 671 blower and shoved it in an 81 El Camino back in 94-95. We ran it a bit before selling it to someone who was better at driving it than us. At that time the Jr, dragsters were just getting started so I saw a few then, but don't really know much about them...arn't the based off of a simple briggs flat head design? Single cylinder?

[joeyputt]

yes, did you see the pic of the one i posted on this thread...? they are the regular old flathead 5hp like came on a childhood go kart or a tiller etc., we take them down to the bare block, throw the governors out, port and polish them cut the valve seats down, trim the valves down, and run them with heavier springs and you have to back cut the breather chamber with spring pockets if you run a real tall cam so they will not bind, face the lifter block for clearance and run a big cam and file the compression release off, billett connecting rod, deck the head and the top of the block for piston pop up, advance the timing with and offset flywheel key, header, etc. you can normally get around 6000-6500 with a stock machined and jetted brigs carb but they jump on up to 9500rpm plus with a tillotson carb or mikuni or similar...they come in both aluminum and steel bore dual bushing or bushing/roller bearing or double roller bearing crank configurations, a lot of guys like the double rollers, and that is probably what i will build the bikes engines out of but the old bushing bushing motors off of old tillers were the fastest engines we ever ran...i think the harmonic balancing in them is better and the crank stiffer...won lots of races with those engines! we run digital tachs/cylinder head instrumentation on them etc.

[joeyputt]

...forgot yes they are singlr cylinder 206cc...its funny when you go to the track and the jr drags with briggs 5 hp block are outrunning mustangs etc.!!! it always cracks me up

[Guest]

Hey Joey, I use to do a little Kart racing myself last year. I only raced for a year but I tell you, it was a blast. There is something to be said about whipping around a dirt track at 50-55mph with your ass about an inch off the ground. I actually need to have my engine freshened up.. Now I know who to call ..lol

[joeyputt]

Hey Twisted Noodle sure does feel like a lot more than 55 doesn't it! I have raced most every type of machine there is out there including bikes but nothing compares to the karts on an oval if you ask me! Got a killer extra kart I am probably gonna let go if you know anyone looking, full roller minus engine and is ready to win! Sure, we do stockers, limiteds, and opens...you running the flathead or the animal engine...? Be happy to freshen it up for you if you like when you get ready just drop me a line! where are you racing at? most of the kart tracks down this way have closed down...been thinking about just building an oval here to play on with the karts and bikes...gonna use two limited modified engines on the bike, what do you think...it ought to beat down! you ever ran a limited engine?

[joeyputt]

Check this out it tells about the 100+ mile per hour speeds, the wide open throttle and the no clutch no brakes boardtrack bikes of the 1910's 20's and 30's...!

http://www.motorcycle-usa.com/321/1460/Motorcycle-Article/Guts-and-Glory-on-the-Boards.aspx

[Guest]

Yeah it does feel like more than 55. I was running the flathead. Up north (NY, Niagara Falls) we have a class called the Outlaw. Little bit bigger cam, head work and such can be done. I first started with a road chassis on a dirt oval. didn't have it set up right and was sideways almost around the whole track. I got my ass handed to me but I've never had more fun losing before in my life. I was grinning ear to ear. After a while I got set up with a kart called "Slack" which was a popular local company. I did much, much better as the kart almost steers itself around the track. I haven't done any racing around here. It seems like there is mostly Lawnmower racing locally. Which is something I can't afford to get into right now with all my projects I already have... I would like to though.. lol I was going to get the kart out and take it for a beat in my development but the engine has been sitting too long with crap oil in it and I don't know where to get any Meth. I know Meth is popular here in the Wilmer area but I need the type you use as fuel.. lol

What do I think about 2 limited modified engines? Well, if you can get them sync'd, then hold on!!

I will definitely get a hold of you about my engine.

[joeyputt]

Cool just hit me up when you are ready and I will hook it up nice for you! I really do not think getting them sync'd will be too much trouble, lots of karters used to run dual engines on a posi rear back in the day but if it proves to be difficult I can always go with dual clutches...

[Sponsored content]