Tech Rules For The 2020 REC Dyno Contest

Tech questions that don't fit above forums

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gmrocket
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Re: Tech Rules For The 2020 REC Dyno Contest

Post by gmrocket »

swampbuggy wrote: Fri Dec 13, 2019 3:19 pm This may explain what Greg means by the way he has written the rules. I "think" this is what he means or lets say this is the way i would personally interpret what he wrote. If you filled the port with a liquid, just as if you were ccing, the area that the liquid displaces is the area in which you can do whatever, you can not do anything beyond where the liquid is. :?:
Nope, so wrong ...

Why would you even think that?

It's the ports casting wall thickness that limits the dimensions.

See the explanation on going beyond that into areas where oil, coolant or atmosphere are discovered.
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Re: Tech Rules For The 2020 REC Dyno Contest

Post by FC-Pilot »

gmrocket wrote: Fri Dec 13, 2019 10:31 pm Isn't exhaust pipe always O.D.?

If not, show me where it's the I.D.
My point is this, if the outside is supposed to be 3” then it did not specify what the ID was supposed to be. At that point I would use what ever wall thickness I needed to get the dimensions I wanted. Or I would create a merge collector that had an external dimension that pacified the tech inspectors demands.

I am just a back yard hack, but after reading these rules there are a thousand questions I would ask an official before I started my build. I would be looking to take advantage of any area I could (just as my competitors would be) and I would not want to get thrown out if inspected so I would address an official before starting my build. In honesty, with all the gray areas I see in the rules, it would be fun to be there to see what really intelligent people might do that would be even more forward thinking than I am. That is why I enjoy this site.

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Re: Tech Rules For The 2020 REC Dyno Contest

Post by Joe-71 »

The question was why 400" limit class and no cubic inch divider. My answer was correct in that all three engine types must be between 400 and 410 cubic inches, so no cubic inch divider. That limits folks to buying aftermarket blocks with best main bearing sizes, best crankshafts, best heads, best intake manifolds--etc. Like I said all "cookie cutter" engines for those with deep pockets. Joe-JDC
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Re: Tech Rules For The 2020 REC Dyno Contest

Post by swampbuggy »

Isn't exhaust pipe always measured O.D. ? Engine headers are manufactured from "tubing" which is measured at the O.D., typically 16 GA. which has a wall of .060 to .065" so when one is figuring tubing flow/size and I.D. they must add .125" to that to get the O.D. when ordering.
Pipe is measured at the I.D. , and the O.D. will vary with the wall thickness/ schedule number
Tubing is measured at the O.D. and the I.D. will vary with wall thickness/ gauge number. Hope this helps somebody who reads. Mark H. :)
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Re: Tech Rules For The 2020 REC Dyno Contest

Post by swampbuggy »

Sorry guys wrong thread, my mistake. Mark H.
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Re: Tech Rules For The 2020 REC Dyno Contest

Post by swampbuggy »

Ignore the above statement about wrong thread, it IS correct thread. Thanks Mark H.
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Re: Tech Rules For The 2020 REC Dyno Contest

Post by gmrocket »

swampbuggy wrote: Sat Dec 14, 2019 10:28 am Isn't exhaust pipe always measured O.D. ? Engine headers are manufactured from "tubing" which is measured at the O.D., typically 16 GA. which has a wall of .060 to .065" so when one is figuring tubing flow/size and I.D. they must add .125" to that to get the O.D. when ordering.
Pipe is measured at the I.D. , and the O.D. will vary with the wall thickness/ schedule number
Tubing is measured at the O.D. and the I.D. will vary with wall thickness/ gauge number. Hope this helps somebody who reads. Mark H. :)
Exhaust piping is measured by its O.D., like I said

The rules are correct and clear.
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Re: Tech Rules For The 2020 REC Dyno Contest

Post by Gregory »

apm wrote: Thu Dec 12, 2019 8:44 am Hi Greg
I'm based in Australia and would love to try and compete in the competition with an Australian based Holden engine , I put this to the organizers of engine masters 2 years ago for the iron headed class but never got a response, could you let me know if an entry would be considered with this engine ?
Thanks
Tell me more about the Holden engine and the specs you would use.
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Re: Tech Rules For The 2020 REC Dyno Contest

Post by gmrocket »

Joe-71 wrote: Sat Dec 14, 2019 12:31 am The question was why 400" limit class and no cubic inch divider. My answer was correct in that all three engine types must be between 400 and 410 cubic inches, so no cubic inch divider. That limits folks to buying aftermarket blocks with best main bearing sizes, best crankshafts, best heads, best intake manifolds--etc. Like I said all "cookie cutter" engines for those with deep pockets. Joe-JDC
why cant you use a stock block? why would you need the "best" crank when there are plenty of cost effective choices? same with best intake and best heads? do you not modify anything ?

what particular make were you thinking you cant do without deep pockets? maybe we can help
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Re: Tech Rules For The 2020 REC Dyno Contest

Post by Walter R. Malik »

gmrocket wrote: Sat Dec 14, 2019 10:35 pm
Joe-71 wrote: Sat Dec 14, 2019 12:31 am The question was why 400" limit class and no cubic inch divider. My answer was correct in that all three engine types must be between 400 and 410 cubic inches, so no cubic inch divider. That limits folks to buying aftermarket blocks with best main bearing sizes, best crankshafts, best heads, best intake manifolds--etc. Like I said all "cookie cutter" engines for those with deep pockets. Joe-JDC
why cant you use a stock block? why would you need the "best" crank when there are plenty of cost effective choices? same with best intake and best heads? do you not modify anything ?

what particular make were you thinking you cant do without deep pockets? maybe we can help
Personally, looking over those rules as they are written, a Trick-Flow "High Exhaust Port" head with a "World Products" intake manifold would be best on a Ford 351W small block; and pretty easy and inexpensive, too.
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