207 replies to this topic

[Johnny D]

The second engine sent to race builder makes more power.

 

Reason, OEM specs just mean that the parts are within the spec tolerance. Race builder selects parts that are within the tolerance but also matched to themselves.

 

Second reason, professional engine builders are not constrained by the rule that says if it doesn't say you can....you can't.

 

True.

J~

[Bench Racer]

Which engine best conforms to 9.1.7.C.1?

c. Crankshaft

1. The stock Mazda Miata crankshaft must be used with

no modifications except for machining to allow the use

of main and rod bearings as allowed in 2 below. Shot

peening to stress relieve the crankshaft after machining

is permitted. The following table lists the permitted crankshaft

for each model year and the minimum weight (not

including pilot bearing or hardware).

 

Model Year Part Number Minimum Weight

(kgs)

90-93 (short nose) B617-11-300          26.5

90-93 (long nose) B6S7-11-300A         26.5

94-05 BP06-11-300D                           35.6

[B(Kuch)Kucera45]

King Hiro I had a pro motor built back in 2009 and then I redid it a couple of years ago myself and I ended up with an extra 2.5 hp and 2 TQ .

I can't explain it but when I rebuilt it I used all brand new parts from mazda I mean all new, pistons,rods,bearings,rings,valves,pumps,ect...and I didn't do anything else ( no machine,grinding,porting,ect...) just a rebuild. So I couldn't give you a for sure answer.

Ps. The dyno numbers I used was a fresh rebuild on both and no break in time. Then I did them both after a couple of race weekends and they still had the same results.

[Tom Sager]

One more time, with feeling. I'm not talking about junkyard engines or even necessarily budget builds.

 

Question: Two brand new crate motors. One gets sent to a Mazda dealer to be disassembled, measured and reassembled to exact oem specs and procedures. The other goes to (pick a name) professional Spec Miata engine builder for whatever their standard build procedure is.

 

Which engine makes more power?

 

Which engine best conforms to 9.1.7.C.1?

 

We don't race or rebuild crate engines any longer.  Most of us are racing with rebuilt engines from old street cars.  We have a well defined set of rules for the rebuilding process.  Those rules allow some machining of some parts.  The rules are designed to make the engines both reliable and very similar in terms of power (when the rules are followed).  Using an experienced and meticulous engine builder costs a little more but has 2 benefits, better reliability and better power.  This may not be true 100% of the time but the odds are better that one will reap these benefits by using an experienced Miata or race engine builder.  

 

There's always the sealed engine argument (but many won't like that if suddenly forced to pay $6K for a rebuilt sealed certified engine) so our class operates on rebuilt engines.  Until then we have tight rules which give everyone the same opportunity and the rules also don't require racers to use rebuilt engines.  Our class offers choice.  Run an old tired engine if you like, rebuild it yourself if you like or buy an engine from your rebuilder of choice.   

 

My experience has been that buying a professionally rebuilt engine is quite cost effective (best bang for the buck) when you consider performance and can amortize the expense over 3-4 seasons or even longer if you are only the occasional racer.  

[FTodaro]

 

My experience has been that buying a professionally rebuilt engine is quite cost effective (best bang for the buck) when you consider performance and can amortize the expense over 3-4 seasons or even longer if you are only the occasional racer.  

Plus it gives you someone to call when things go wrong. If i had to pay an hourly rate for all the time and phone calls of my builder over the last 5 years on the questions and problems i come up with, i can say I got the motor for free. The support is more valuable than the motor.

[Alberto]

  

 

My experience has been that buying a professionally rebuilt engine is quite cost effective (best bang for the buck) when you consider performance and can amortize the expense over 3-4 seasons or even longer if you are only the occasional racer.  

 

 

Maybe that's true but consider that a "pro" motor is about $7k while your garden variety used, NA SM can be purchased for around that price or a wee bit more...

 

You won't be going for a national win with that car and motor but it gets people on track and racing.

[FTodaro]

I was expecting some type of an announcement does anyone know when a statement will be or is supposed to be released? Wheel?

[James York]

I was expecting some type of an announcement does anyone know when a statement will be or is supposed to be released? Wheel?

 

I thought today was the BOD meeting.....  But my memory is not as good as it once was...

[wheel]

The CRB presented a package to the BoD in Topeka on Saturday.  The final minutes and Fastrack should be up momentarily. 

 

wheel

[Johnny D]

https://www.youtube....h?v=klcLK-sNhRM

 

J~

[Chris70]

And ???????

[Bench Racer]

And ???????

Momentary may be within many different time frames, minute, hour, day, week, month, year, you get the picture.

[Johnny D]

https://www.youtube....h?v=wMQXDHGUQxM
J~

[Mike Collins]

[ECOBRAP]

[Tom Sager]

[Johnny D]

Honestly what are you guys expecting ??

SMAC/CRB already made their recommendations.

 

BoD could change things up but it's a little late in the season.

Sounds like Parity testing is going on, but I don't think it for 2015.

 

Yes the fat lady needs to sing (no not Lisa) and they need to tell us, but I'm not expecting much.

But I've been wrong before.

J~

[FTodaro]

Honestly what are you guys expecting ??

SMAC/CRB already made their recommendations.

 

BoD could change things up but it's a little late in the season.

Sounds like Parity testing is going on, but I don't think it for 2015.

 

Yes the fat lady needs to sing (no not Lisa) and they need to tell us, but I'm not expecting much.

But I've been wrong before.

J~

If i recall someone smarter than me posted that they can make parity adjustments any time though the year. Not sure that has to be done by 1/1/15. So they could say starting May 1, 2015 your new wt or plate is x as long as they give you some time to react to implementation of the new rule.

[Johnny D]

Yep Jim I think. And yes, this could drag on to the next Fastrack.

 

But (for parity) Pretty sure the 99 can't be choked down anymore so the balls in 1.6's court.

 

So I don't think were changing heads, boring out, shaving down, change carbs on 1.6's or anything.

 

I was hoping at 1st that parity was going on, but it looked like they were just looking at heads which is a long ways off from making a Parity rule change IMO.

 

IDK, like I said I've been wrong before.

J~

[Johnny D]

Parity adjustments meaning RP and weight only, that's it, if BoD agrees to the CRB recom, today.

J~