69 replies to this topic

[xczach]

I noticed that pro motors are now gaining 10+ hp on stock engines. My question is, outside of the machining of the block and cylinder head, what is done to increase the power in a legal way?

[Dan Cooper]

If you can get an engine builder to tell you that, i sure hope you do sales for a living!

[William Bonsell]

Maybe 10+ on a '99, but doubtful on a 1.6....A dyno tuned decent stock 1.6 with a good original head, a Springfield Dyno exhaust , flowed injectors and a SP Induction, should be able to make 118 or so corrected HP. Doubt that a pro build 1.6 will make much more than 125. If I am totally wrong about this, I would love to be corrected and pointed in the right direction. I know I am down on power a bit, but not as much as I had thought. It really is more about who's the pilot!

Bill-

[Rob Burgoon]

Well, legal is a funny word. Basically they will do anything that makes more power can't be proven during a teardown. That's what we call tech shed legal. No doubt part of it is picking a matched set of pistons, a matched set of con rods, and so on. Then anything that has a range will be right up against the extreme that makes the most power.

Finally, I believe Race Engineering (shameless sponsor plug) has a flowbench for flowing cylinder heads. They could buy a few dozen and find the ones that suck the least.

[dstevens]

Finally, I believe Race Engineering (shameless sponsor plug) has a flowbench for flowing cylinder heads. They could buy a few dozen and find the ones that suck the least.

I thought they benched them to find the ones that suck the best.... I'd bet RE isn't the only SM building with a flowbench. It's a pretty common piece of engine building equipment.

[dstevens]

I noticed that pro motors are now gaining 10+ hp on stock engines. My question is, outside of the machining of the block and cylinder head, what is done to increase the power in a legal way?

It comes from taking the undercoating off the bottom of your tub.... (sorry, bad joke from another thread)

Short answer, in addition to what the others have posted, are knowledge and attention to detail and working the spec to the last thousandth. They know what it takes to wring every little last bit out and still be legal. It takes a lot of work and experience and it's not likely anyone will share more than general info with someone they don't know.

[Glenn]

Its the smoke........when it leaks out they QUIT running.

[LarryKing]

Would you rather have 118 HP or 125 HP?

[David L]

There is nothing legal about pro built motors, lets all be clear about that. It is cheating without getting caught.

Permitted engine maintenance includes the replacement,

but not modification, of external engine and engine

systems parts. No balancing, blue printing, lightening,

polishing, or other modification of moving parts of the

engine is permitted. All parts in the engine must be stock

Mazda OEM parts unless specified in this rule set. For all

Mazda part numbers in these specifications, superseding

part numbers are considered equivalent.

[Glenn]

There is nothing legal about pro built motors, lets all be clear about that. It is cheating without getting caught.

Permitted engine maintenance includes the replacement,

but not modification, of external engine and engine

systems parts. No balancing, blue printing, lightening,

polishing, or other modification of moving parts of the

engine is permitted. All parts in the engine must be stock

Mazda OEM parts unless specified in this rule set. For all

Mazda part numbers in these specifications, superseding

part numbers are considered equivalent.

You and the clown best buddies?

[James York]

There is nothing legal about pro built motors, lets all be clear about that. It is cheating without getting caught.

Permitted engine maintenance includes the replacement,

but not modification, of external engine and engine

systems parts. No balancing, blue printing, lightening,

polishing, or other modification of moving parts of the

engine is permitted. All parts in the engine must be stock

Mazda OEM parts unless specified in this rule set. For all

Mazda part numbers in these specifications, superseding

part numbers are considered equivalent.

Explain what exactly the builders are violating in your GCR qoute please? And you know this how?

[David L]

I knew this was coming. First off I am not bad mouthing anyone, just stating the obvious or so everyone thinks. It clearly states in that paragraph that i took directly from the gcr that balancing and blueprinting is not allowed. I can not say with 100% certainty that pro builders are doing these things because I am not in their shops but from what I have heard and seen and know this is what you are paying for. Picking the best set of pistons is balancing wether they are factory or not. Again I am not saying there is a way to stop it, or tech it or even saying it should be stopped just saying that under the rules it is illegal.

[David L]

I like the clown

[David L]

And I also don't hold pro motors against anyone. Hell if I had the money I would have one

[Glenn]

I knew this was coming. First off I am not bad mouthing anyone, just stating the obvious or so everyone thinks. It clearly states in that paragraph that i took directly from the gcr that balancing and blueprinting is not allowed. I can not say with 100% certainty that pro builders are doing these things because I am not in their shops but from what I have heard and seen and know this is what you are paying for. Picking the best set of pistons is balancing wether they are factory or not. Again I am not saying there is a way to stop it, or tech it or even saying it should be stopped just saying that under the rules it is illegal.

Do we REALLY want to go down this road again, and again, and again..........................................

[tony senese]

Permitted engine maintenance includes the replacement, but not modification, of external engine and engine systems parts. No balancing, blue printing, lightening, polishing, or other modification of moving parts of the engine is permitted. All parts in the engine must be stock Mazda OEM parts unless specified in this rule set. For all Mazda part numbers in these specifications, superseding part numbers are considered equivalent.

For those of us who can't see a size 8 font....... heheheheheh.

BTW, I think balancing MAY apply to matching weights of pistons rods etc, but I think reducing the weight of things like the crankshaft and flywheel by aggressive balancing.. (read drilling lots of holes) is/was the bigger issue.

[LarryKing]

Sorry David L, I and many others ranted against this 6-7 years ago. You are right, pro motors violate the intent and the GCR/CCR but SCCA and NASA choose to turn a blind eye. Are you familiar with the phrase "pissing in the wind"?

Woulda, shoulda, coulda spec'd sealed crate at the class's inception. That F'n genie done bought a condo in Miami and retired.

[Glenn]

Sorry David L, I and many others ranted against this 6-7 years ago. You are right, pro motors violate the intent and the GCR/CCR but SCCA and NASA choose to turn a blind eye. Are you familiar with the phrase "pissing in the wind"?

Woulda, shoulda, coulda spec'd sealed crate at the class's inception. That F'n genie done bought a condo in Miami and retired.

Yeah and he cant even give it away today

[Jim Boemler]

I like the clown

Thanks David, although I think you're taking this one too far. I think there's a perfectly legitimate "builder" function, within the rules. Essentially what that means is doing a very careful rebuild -- much more so than a normal machine shop would do. I think parts matching (without modification) is perfectly legal (my own opinion), even though it does operate to optimize the engine balance.

I do agree that any machine work to improve balance, as well as polishing, would be illegal. And frankly, I suspect a lot of it goes on. But that doesn't mean that having a pro build you an engine is inherently illegal.

[tony senese]

+1 on the clowns wise words