Box Stock

Rebuilding Clone

D

danbol45

New member
Hi Guys,
So me and my brother are having an interesting conversation. We are both running in a blue plate clone class at our local dirt track but we have differing opinions on the build for our engines. He is taking his clone engine to a local builder, which i think he is paying way too much for, and i am rebuilding my clone engine myself.
We are using the standard AKRA Box Stock rules. I am saying that Speed and HP depends on the Flywheel and carburetor. I am using a Dyno PVL Flywheel and a Ru*ing Carb with a .34 main jet. The only thing he knows about his engine is that is has a billet Flywheel. His builder will not give him the specs are tell him the parts he has used, except to say they are legal parts. His builder is telling him he can 2 more HP out of his engine, so almost 8.5 HP based on the flywheel and other components.
So i just want to get different thoughts on this!
 
jet is to small pm me ill tell ya what you need to know we have plenty of engine buisness. pm me







42 years racing and building engines in the karting industry
Clone engines best and cheapest racing in years
Bullet Motorsports
205 270 9772
 
danbol45 said:
Hi Guys,
So me and my brother are having an interesting conversation. We are both running in a blue plate clone class at our local dirt track but we have differing opinions on the build for our engines. He is taking his clone engine to a local builder, which i think he is paying way too much for, and i am rebuilding my clone engine myself.
We are using the standard AKRA Box Stock rules. I am saying that Speed and HP depends on the Flywheel and carburetor. I am using a Dyno PVL Flywheel and a Ru*ing Carb with a .34 main jet. The only thing he knows about his engine is that is has a billet Flywheel. His builder will not give him the specs are tell him the parts he has used, except to say they are legal parts. His builder is telling him he can 2 more HP out of his engine, so almost 8.5 HP based on the flywheel and other components.
So i just want to get different thoughts on this!
Click to expand...

Im having a hard time believing any builder is going to get 2+ HP out of any AKRA legal engine over another AKRA legal engine. Also, speed comes from more than just the carb and flywheel. Cam, timing, jetting, tolerances, coil gap, head, all this comes into play when your talking about speed and power. Most builders would agree that most of your power comes from the carb and the head, and attention to detail plays a big role in that. I also agree than .034 is too small of a main jet, you need at least a .036 or .037 main jet and .022 to .026 low speed jet, this is if you are using the aftermarket air filter adapter instead of stock airbox. Also, are you guys using the 3/4" weenie pipe or big pipe? Id like to add that typically plate engines run a .039 main jet, they run more on the rich side.
 
Another thing, when you start with a 6.5hp clone with the governor intact, yes you have 6.5hp, but once the governor is removed and exhaust, air filter, timing, and cam changes, you are more around the 10hp range instead of 8.5 like you said. Unrestricted engines would make more than 10hp in box stock
 
Sorry. i am using a .38 main jet and a .22 low idle jet. I am running a Dyno CL1 cam. My brothers has a BSP2 cam. Not sure on the carb. We both are using weenie pipes.
 
"His builder will not give him the specs or tell him the parts he has used, except to say they are legal parts." ..... and he's paying for this? sorry...(my own opinion) if i'm paying the bills for this engine, then i want to know what all he's doing to it. i will never say someone is cheating unless i know for sure, but lots of things can be used to say that it will be legal. he (your brother) may be paying a premium price for take off parts (good stock parts that have been removed from a new stock engine), lesser quality parts, or stuff that he (the builder) has laying on the floor of his shop. i mean no disrespect to any engine builder (including this gentleman), but again....if i'm paying, i want to know. i'd listen to guys like weddle racing, screamnclones, dynodon, youngengines....and a lot of others engine guru's on here. i'm building my own engines based on thier advice and what posts they have on various engine components....they won't lead you wrong.....

again, it's my own opinion, but what's so secret about what he's doing to the engine? most engine builders have thier own way of doing things, but i don't think that any of the major builders would tell you basically to mind your own business as long as it's legal....something just doesn't sit well hearing that....
 
I tell everyone there are no secrets to building an engine. Just paying attention to detail and getting the specs as close to legal as possible. I never not tell someone what I did to their engine they pay the bill they deserve to know. That way there are no hidden secrets if someone else should take the engine apart to check my work
 
and that, my friend, is why i trust what you've explained to me about what i'm doing....because you are a gentleman....thank you!!!
 
"I am saying that Speed and HP depends on the Flywheel and carburetor."
Flywheels do not make HP.
The mass of the flywheel will let the engine accelerate more quickly or not. But there is no HP gain.
A heavier flywheel may make you run deeper into the corner because when you let off the gas it keeps the engine spinning a little longer and give you better times, but if you ran as deep into the corner w/a lighter FW you could get out of the corner faster and beat the heavier FW engine.
But no extra HP.
Air flow, compression, a/f ratio, ring seal make HP.
 
Here are the specs from the puter on the best Blue plate I've ever dyno'd.

Engine # 39217
Class Blue
Pipe Bradley G #2
Head 109/.280
Springs RaceCity
Installed Height 19/21
Valves 2.44
Flow Intake
Seat Height INT 0.008
Seat Height EX 0.013
Head Gasket 0.01
Flywheel ARC/39 deg
Coil 0.075
Cylinder Clearance 0.005
Piston Spec Std
Comp Ring 0.007
Middle 0.015
Oil nice
Rod 0.005
Cam Cl-2
Crankshaft 126
Cam Crank C/L -0.0008
Sump Cover Clearance 0.001
Dowel C/L 0.003
Block Pulse Assembled 7.47
Carb # 39217
Main 0.037
Pilot 0.028
Air #1
Air #2
Air #3
E-Tube 2-.029
Flow Air
Flow Wet

Evause
WWW.racingcarb.com
 
Racingcarb.com said:
Here are the specs from the puter on the best Blue plate I've ever dyno'd.

Engine # 39217
Class Blue
Pipe Bradley G #2
Head 109/.280
Springs RaceCity
Installed Height 19/21
Valves 2.44
Flow Intake
Seat Height INT 0.008
Seat Height EX 0.013
Head Gasket 0.01
Flywheel ARC/39 deg
Coil 0.075
Cylinder Clearance 0.005
Piston Spec Std
Comp Ring 0.007
Middle 0.015
Oil nice
Rod 0.005
Cam Cl-2
Crankshaft 126
Cam Crank C/L -0.0008
Sump Cover Clearance 0.001
Dowel C/L 0.003
Block Pulse Assembled 7.47
Carb # 39217
Main 0.037
Pilot 0.028
Air #1
Air #2
Air #3
E-Tube 2-.029
Flow Air
Flow Wet
Click to expand...
'That'...my friends equals a $1000 motors-worth of data...:)
 
In the above, I do note the 'Dowel C/L 0.003' listed. Is this referring to the wrist-pin/piston off-set(?) and that is what the piston-direction 'arrow' was all about? If so....:)
 
Racingcarb.com "This C/L is the distance between dowel hole locations, I use ground pins with a tight fit to check all blocks before putting alot of time in them."

Wow ! And people wonder why the cost of a clone is so high.
There's a wheelbarrow load of work that goes into blueprinting an engine.
Interesting.
 
This should help clear up kinda what I'm looking for

OD Grinders 003.jpg
This is the flathead drawing on just the sidecover, my clone drawing has alot more detail on the sidecover and block. :) Hope this helps with all the questions most have

Evause
www.racingcarb.com
 
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