Track Tac

Backyard Engine Builders

PD Power said:
No one can explain, on a forum, what to do to your engine. Whatever anyone says, there is always a lot more.
You likely should go about the business of engine building, backyard, front yard, or garage, with the same sequence as you would, if you wished to become a heart surgeon.
You would not start out by cutting out someone's heart, and trying to figure out how it worked.

1st thing you do is study, then study some more.....as to how engines work. Look up (Google has lots of this stuff) about air and fuel flow, and their relationship.
How do cams do, and how do you make choices between them.

Take a machining class at a local vocational hi-school. That is a basic necessity.
You will need a valve grinder, mill, lathe, geared hone, measuring tools and other "stuff"and plenty of patience.


Engine building is not a hobby.....and a hobby is not engine building. Engine building requires considerable knowledge of the makeup of material, a LOT about
air and fuel flow, and their relationship to compression, bore/stroke ratio's and a ton of other stuff.

This is not "easy" stuff. Well....I've got to go now, cause I need to close a deal on another, larger lathe than I currently use.
Oh yes....did I mention a sizeable investment in tooling? It IS satisfying tho. Go for it!!
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What?! Yeah, its a hobby - period. I ain't gettin paid for it so...

Anyway - ignore the pessimism in PDs post - its a whole lot of fun - just take the tolerances seriously and you will learn lots!
 
My observations are: The best way to find out how important chassis set up and tires are is to ask a question about how to improve engine performance.
 
PD Power said:
You likely should go about the business of engine building, backyard, front yard, or garage, with the same sequence as you would, if you wished to become a heart surgeon.
You would not start out by cutting out someone's heart, and trying to figure out how it worked.....You will need a valve grinder, mill, lathe, geared hone, measuring tools and other "stuff"and plenty of patience.
Click to expand...
If that is the case my oldman must be a rocket scientist with a degree from the School of Hardknocks and a bodyman MSO. Maybe that's where I got the drive to go on to engineering and a PE license.

alvin l nunley said:
I purchased a new Mc91, set the timing and put it on my home built kart with my home made pipe and header. There was a regional race that weekend. I ran Reed Heavy.
I ended up with 2nd place.....straight alky and Super Klotz.
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Oh yea....My dad builds a very mean Mc49, that we both run regularly in the VKAs..straight alky with Klotz on the old rear engine karts. I'm running a converted Max Torque clutch to fit on my crank from a Mac 250 saw, that first thing Jim Donovan said to us was "what did you do to my clutch?" He now builds clutches for the 250 and 200 saw Mc49 conversions. We have built some very stout 5.3s for the VKA saw class, next season. He built one of his own chassis back when I was kid. Today we build our own chassis for running on ovals in the modern karts, nothing better than winning a track championship and many races with your own home built chassis.
 
Everything that you need to know about building a clone is here on Bob's. Just make a book out of it. Will you get secrets? No of course not. Why should someone reveal what they worked hard to find? In time with study and dedication you can find your own secrets. Will you tell everyone? Hardly.
If you enjoy building - go for it - study and breathe engines. You can find everything you basically need right here. Send your machine work out. How dedicated are you to the rest of your racing, chassis tires, etc. The engine is a vital part - not the only part that needs tweaked.
 
Talking to an engine builder, a welder or a rocket scientist require the same amount of concentration.


... :)
 
read read and read.... find any info you can and read it!!! I started a bought 4-5yr ago building these clones... came from 2 stroke dirt bikes and stock car v-8s... a lot is the same but a lot is different too... the best I can say is get a motor and start... you got to start some where at some time... wish you luck!!! if you need a hand feel free to ask... i'll help with what I can and if I cant and if I cant ill try to point you to some one who can...
 
You definitely have to start somewhere. Most of your commercial builders were once backyard builders. Jimmy's book is a great place to start. Engine building requires a lot of well rounded skills. Understanding of machining, combustion, air flow, fuel mixture, etc....and the more you learn the dumber it makes you feel. Engine building is great at the backyard level or working in it 8-5.
 
Here is one for the story on engine building in the backyard. Last night we raced in the RWYB class and it was all 2 strokes except my clone,,, I built it my self. yes ordered parts online and did all the metal moving and grinding myself also..Yes I have knowledge of engine building and have done quite a few V8 motors for street and strip... You can do it yourself.. In heat 1 my clone finished 3rd outa 5 in the RWYB class and in the main finished 4th outa 5.. and this was with a 15yr old straight up Coyote kart with a weight min of 370,, we rolled across the scales at 450 as we had so much lead on the lt rear to keep it from bicyling.....,,you can compete with the big engine builders... they buy there hi-po parts somewhere,, learn the assembly proccess......knowledge is king,,,,,
 
top fuel bbq: "knowledge is king" .... that is the truest statement made. you don't have to have all the machines and tools in the world. but you have to have the knowledge to know what to do. everyone starts out as a backyard builder. some may not ever get beyond this stage, others sink a small fortune to get every last drop out of a clone....and still get beat. i remember a team that i help when i lived in mississippi....built all thier own engines on the floor of the shop...only did minor stuff to the heads and bottom end....other than that it was all r&r with performacne parts. they raced against late models with gaerte engines and the like....they didn't win not one feature all year long....but they were consistently in the top five and they scored a track championship without winning a race. why? because for all they did to the motors, they were consistent...while others dropped out with thier high dollar motors and scored DNF's, they were consistent and finished every race.....

anyone can do the same thing...build them ourselves and be consistent. with that being said....if i was running for national points or one of the national events? i'd look to dover power or one of the big name engine builders...because at that level, you need every ounce of horsepower that you can get!!! but for my level at my home track? i'll suffer with consistent finishes......and a engine built within my budget!!
 
What are you needing help with mikey56? You know i build mu own and i dont have alot of money in them and you see how they run.
 
My first clone motor was a used up old motor off of a pressure washer that had a bad pump. Bought it from a guy for $20 on a classified. My goal was to take the thing apart, down to every piece that it was, clean it, hone it, refresh it, put the "add on" racing parts in it, and see if it still ran after I was done. I threw it on my kart chassis that I bought for another $200 on a classified, and went to the track for my first ever race. I didn't even have a tach and was running on dryrot tires. I had 2 goals; not get lapped and not finish last. I accomplished those goals, even though I would have been lapped if the race was 2 more laps and I finished next to last.

This year I am running good. It's my second season. I'm solid mid pack, with an occasional push for place (took a third in a race this year). I'm always on the prowl for people selling used clone motors on the internet, because that's all I have used. I buy them, refresh them, throw my "engine builder" name on the blower housing, and have no regrets. Reading Bob's I have learned tips and such to building a better motor, but I have never had a professional touch any of my hardware. The fun for me is running what I built, and the icing on top is finishing ahead of someone running a pro built motor.

I make a good living, but the day that a motor costs me $600+ is the day that I hang up the racing suit. I now have 4 motors and easily have less than $800 in all of them. I buy used tires and run with an older digitron. I love this "hobby"
 
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