Landracing Forum
Bonneville Salt Flats Discussion => SCTA Rule Questions => Topic started by: Harold Bettes on February 08, 2008, 07:11:03 PM
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Hey Experienced Dudes and Dudettes, :-D
In the impound area, how is the stroke of the engine measured? By a long reaching dial indicator or a dial caliper? :?
If they pump the engine instead of mechanically measuring the displacement, how close do they figure that is even with using temperature calculations? :roll:
Inquiring minds just wanted to know. 8-)
Regards to All,
HB2 :-)
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I guess I'd like to know, too. The engine I'm building is going to be within a few cc's of the limit for my class.
Where's the cheating line? If I set a record, will I need to pull the head?
Thanks for bringing this up, Harold.
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Just don't get into a big hurry to get to impound let things cool down. It is much easier to take things apart when they are cooled off. Its like going swimming things shrink when they cool off. Brian #7796
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At Bonnville and El Mirage last year my engine was measured with a calipers (graduated C clamp). At Bonneville they came up with 496cc. At El Mirage a month later they came up with 494cc. Maybe it cooled a bit more at ElMirage.
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Well like most things in the SCTA........ It depends.........
On the car side if/when you make it to inpound they will take some general information from you about your engine. One of the questions will be "whats the displacment?". If you look in the '06 rule book on page 10 1.H it say's if the displacment is not within 3% of the upper OR lower class break the engine can be measured with the SCTA's swept volume checker thru a spark plug hole. Example, let's say you have a small block chevy & you claim 302 ci. Well it's tear down time for you as this is too close to the limit for the air pump. It's up to the competitor to bring any "special" tools that might be needed to measure your engine, say from the bottom or through a spark plug hole.
The scooter guys use fluids, direct measurement, etc.
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if your bike has the sparkplug in the center of the bore tech has a tool to check bore and stroke if not you pull the head willie buchta
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They measured my busa motor with the "expanding caliper" deal. They measured 1299cc....the motor was 1299....doesn’t get closer than that.
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"NASCAR" style.
Mike
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"NASCAR" style.
Mike
Oh, I see. One guy doing the work and three others standing around and watching. :-D
Reminds me of municipal workers fixing potholes in Milwaukee.
Oh, that was cruel. It probably doesn't behoove me to pick on the tech inspectors BEFORE I show up with a car.
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Reminds me of municipal workers fixing potholes in Milwaukee.
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I am trying to finger out if the guys that 'plug' the potholes with asphalt frosting during the summer are the same ones that are finding them with the front end loaders?
beep beep beep....diesel grrrrrrrerrrrrrrerrrrrr BANG the house shakes and the cat flees!
what part of the city are you in Midget? I live on the unfashionable side of the river
Mark
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Show up with a drilled head bolt or some way to "seal the motor" I believe they will some times seal it and let you continue to run and not take your motor apart until later in the meet.
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Steve, while that might work for the car guys, the bike tech folks advise against it in the strongest terms. See the note, for instance, taped to the bike tech trailer wall: "Set a record today? Get your engine measured today!"
A good reason to follow through on this is because they can't/won't measure a blown-up engine. If you set a record and have your motor sealed without being measured, then break it later in the event -- no measurement, therefore not even that first record after all.
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You must be kidding!
Tell me again what happens and why if the engine blows up on a backup run but still has measurable parts the size can't be verified. :roll:
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You must be kidding!
Tell me again what happens and why if the engine blows up on a backup run but still has measurable parts the size can't be verified. :roll:
I'm gonna go with ... cause their measuring caliper thingamabobie might fall into the hole you just blew in the side of your engine.
Or... when they try to fill it with fluid it just keeps leaking out the side! :-D
Anything else you want to know Jack, just ask! 8-)
:evil:
Deb
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You must be kidding!
Tell me again what happens and why if the engine blows up on a backup run but still has measurable parts the size can't be verified. :roll:
I'm gonna go with ... cause their measuring caliper thingamabobie might fall into the hole you just blew in the side of your engine.
Measuring a blown engine is kind of like counting hanging chads.
I think about it in these terms - to verify records, you want to be able to consistently confirm, from one entrant to the other, the exact size of an engine. The methods are already established. And while I have no doubt that most of us could come up with a fairly accurate measurement of a blown engine, the established procedure would have to be modified or compromised to allow for a deviation.
But to modify the procedure for ANY reason, regardless of how noble the intent, would always raise questions as to the fairness of the results.
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Or think about the time when Scott Guthrie set records with a four-cylinder bike, of which two of the four cylinders were different from others. If that motor had blown up and the destroyed one was small -- the engine would have measured, using only the big ones, as too big for the class.
Not a common instance,but it has happened.
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I know Jack Costella blew his 50cc single to the point of nothing left to measure for a bore.
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You must be kidding!
Tell me again what happens and why if the engine blows up on a backup run but still has measurable parts the size can't be verified. :roll:
Read again
Try again.
You might want to dwell in the meaning of "BLOWN UP" and "MEASURABLE".
There is a reason the FIA and FIM both require measurement of every bore and stroke that was used for the power package also.
Anything else is just blind faith.
The key is to be smarter than the cheaters and make sure they respect the the difference.
If the cheater is smarter than the person certifying the measurement, the other entries are being cheated as well. :roll:
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Goodness Guys! :-D
Wasn't looking to cheat orto catch any unnecessary grief :evil: IF I was fortunate enough to end up in impound, I just didn't want to be blindsided by non-logical things. :roll:
If a guy is pretty close to the displacement limit, and they use a caliper to verify the stroke, there might be a problem there. My assumption is that they use a dial caliper for verification of both bore and stroke. If that is the case, then it is very easy to miss the correct bore by a couple of thousandths and certainly probable that the stroke would be missed by more than a couple. Some strokes just don't dwell very long at either TDC or BDC. :-o
SO, what I think I am hearing (reading) from responses so far is that it is far better to be a few inches shy than right on the limit. Which is somewhat of a recounting of most of my adult life! :lol:
Regards to All,
HB2 :-)
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Precisely ! :-D
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For someone as cagy as you and with the vast experience you have including that at SuperFlow, if I were the tech guy, I would really look very carefully, not only at cid but anything and everything else I could possibly be aware of.
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in the motorcycle class you can be over your cc limit by a .020 over bore in vintage i think its .050 --a set of calipers is what is always been used on my bike what you have to watch is that they subtract the distance from the top of the piston to the top of the cylinder if they dont it will add to the stroke my engine is 984 cc i run in the 1000 cc class im under by 1 cu in my plug isnt in the center of the bore so i have to pull the head o well willie buchta
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SO, what I think I am hearing (reading) from responses so far is that it is far better to be a few inches shy than right on the limit. Which is somewhat of a recounting of most of my adult life!
ahem.... :-o
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HB2 and Dr. G -- Don't worry -- that "few inches"...is measured from the ground.
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HB2 and Dr. G -- Don't worry -- that "few inches"...is measured from the ground.
to which I have to paraphrase the old one about the two men sitting at the end of the pier.....dangling , as it were..." the water is cold".....................................................
" and deep!" :mrgreen:
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Oh darn. I forgot about the impound. I Hope to be ready for ECTA/Maxton in April. My motor is a de-stroked Chevy 305. CID is 254.7 cu in. I guess that is to close to the 260 cu in. upper limit in E class ?
Does ECTA have you tear down ? (mmm I am going to need some tools,, LOL )
The Body just made it here, the chassis should be done this week. Once they meet, I gotta get the Roll Cage built. Is the halo bar the preffered way for the front loop?
Thanks
Charles
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Dyno & Harold. Just because an engine is within 3% of the limit does not mean it will be always torn down. The pumps are sent back periodically for calibration. Yes it is checkable and can be done. During the last 7 or 8 years I've been doing them I have found with the proper training you can get very very close to the cubic inch diplacement of the engine. Even if a competitor is well with in the limit I pride myself on getting the engine to pump what it truely is. Internal engine temperture is a large factor in the procedure, We have an exact % factor for each degree. The list is with the pumps. When the engines cylinder air tempature is found and the pump properly used it will be correct.
If you are close it maybe to you advantage to bring whatever is necessary to remove a cylinder head. The valves must be made inoperable for the pump to function correctly. OHC guys please take note. If you remove the timing belt and your pistons can hit the open valves we cannot pump you engine. Good Luck..........................JD
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JD, I REALLY don't want to upset the apple cart but......
Wasn't the rule changed to +/- 3% to keep someone who had an engine at the maximum upper (or lower) limit from moving into the next displacment class? I understand the pump can be very accurate as we used it many times in the past during my SCCA Trans-Am days and several SCTA records but the point is to make sure someone doesn't run in the wrong class. I wouldn't want to tear down if I could help it but we need to stay consistent, there are more than a few classes that would easily have higher records if the lower class could run in the upper class ( I know Jack, shame on them) but it's how we do it.
My point is if you're within the 3% limit you need to be torn down............or change the rule to ??? JMHO
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Fluid displacement is going to be more accuate than pumping air any day if it is close. :wink:
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Charles,
I believe ECTA goes by the honor system and they believe you are running whatever size motor you claim to be running...no tear down.....no fun cheating and noy getting caught.
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ECTA is a little different animal in that it is a short weekend event and the entries need to quickly scatter to the winds and back to a real job when the meet is over.
That doesn't accommodate the ability to seal the engine and have it additionally measured later because the travel distance is so great.
As their events mature, they will add more scrutiny but for now it suits their purpose.
In the early days of SCTA, engine type was the deciding factor and size was less important.
Of course if you went too fast, regardless if the type of motor, they just bumped you up a class and that was that.
I guess if you want to cheat, you can, but you have to consider at what expense.
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During the last 7 or 8 years I've been doing them I have found with the proper training you can get very very close to the cubic inch displacement of the engine.
Just shows ya how easy it is. After 7 or 8 years you finally get close!
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BRUTAL :-D
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JackD, I hope by reading my post you did not get the impression that I wanted to cheat. Being new to this I just wanted to know the rules. I read the engine size/class as being literal. So when E class says up to 260 cu in. I have had designed a 254.7 - 255 cu in small block chevy,,, That is only 2% under. I have every intention of setting a record, but being very very rusty on engine tear down myself, I Just wanted to know if they "always tore you down" if you run good and/or are within 3% of the limits? I am not concerned that I will be oversize as I will be exactly the size I state. Just with the time involved and my limited motor skill. I asked so as to be prepared to ave the motor builder come with me.
Hope that explains why I asked... cheating never entered into it.
Charles
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...........So when E class says up to 260 cu in. I have had designed a 254.7 - 255 cu in small block chevy,,, That is only 2% under. I have every intention of setting a record, but being very very rusty on engine tear down myself, I Just wanted to ................
Actually it is up to 260.9999, so you have almost one more cubic inch to work with,
Sum
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Summ, I stand corrected... see I told you I am new at this... I will now only be at 97.5862 % ( 254.70 / 260.9999 = .975862 )
Just have been informed that my crank and heads will not be here until about March 15th... It's going to be close making Maxton in April,, I will be there for sure, but my Vicky may not be ready.... Gosh... I am crossing my fingers all works out for April..
Summ are you going to make it in April ?
Charles
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.................Summ are you going to make it in April ?
Charles
No, I think it will be crowded with the Hot Rod deal and I hope to run my truck, so I'm now planning on the May meet. Hope you are there with your car. Sounds like a nice car,
Sum
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Summ, yeah the Hot Rod Top Speed Challenge is in April,,, I am trying to get my car done. I think you are right however, May will be less crowded and give us each a chance to make more runs.
Take care.
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I only made reference to the honor system that works well enough for them.
I prepared a 258 inch V-6 that was direct measured for an SCTA, 200 Club, and an FIA record all in the same week at Bonneville.
The next event was at the salt also and the person that was verifying the club record on that same car used an air pump.
He instructed us on what to do to prepare the engine and was not aware of the requirement to disable the valve train.
I knew better, but followed his directions exactly.
As you might imagine the pump declared the motor to be substantially smaller that it really was.
I waited until he was done and quietly went over the proper method with him and you can bet he was a lot more attentive to detail than he demonstrated to me after that.
RELAX :-)
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Because of Dean's SA answer I'll being going to private messages from now on....However Jack will continue with all the correct answers..Good Luck All.............................JD
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Because of Dean's SA answer I'll being going to private messages from now on....However Jack will continue with all the correct answers..Good Luck All.............................JD
"Can't take a joke and keeps on kicking." (me)
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JD---how in the world will we know who to root for ??????????---I have decided to root for JR Johnson---divorced my former driver ts when he decided to drive a JAP car :-D 88-48
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Because of Dean's SA answer I'll being going to private messages from now on....However Jack will continue with all the correct answers..Good Luck All.............................JD
My humble apologies to you. I, like Jack, like to have some fun here. Nobody is dinging your skill. I appreciate all the work you have done over the years.
Note to everybody: If Jack opens his mouth you KNOW it's somewhat tongue-in-cheek. If I open my my mouth it definitely is.
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Yeah Dean but you step on yours. :-D
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You will have to excuse Glen, he is old, and retired to Utah.
What more can I say ? :-D
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I do have an incurable case of foot-in-mouth disease!
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if we could get a air pump on that we could check for the proper displacement sorry dean willie buchta