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tech questions


Del Harris

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If you are 10 mph faste in the corner, you are going to be 10 mph faster, if not more, going down the straight. Like JC said, find corner speed and you will find straight away speed. And if he can get in the gas fasster than you, he is going to be much faster.

Exactly.... How much corner speed is 2% (59% vs 57%) left side worth? I think the 2bbl and the crate are pretty close in horsepower but the advantage is in the leftside weight which helps with corner speed not to mention the ability to use the outside groove.

 

What do you guys think is a realistic horsepower range for the 3 engine combinations crates,2bbl and open ?

the rules seem to imply there's not much difference in a 2bbl and the open motor( 1% penaly) but a lot of difference between the 2bbl and the crate(2% penalty). I like the way the rule allows for different engines which means more cars can compete with existing equipment,but I think the difference in performance on the track deserves a second look to see if the rules are really an equalizer, as intended or an advantage for the crates.

 

I also want to say JC,Michael,and David have this thing figured out, and I don't want to take credit away from the job they are doing because they work hard and their efforts show on race day.That includes being smart and taking advantage of everything the rules offer.My congrats to all of them.

 

Well lets see just off the tp of my head last year THR, HMP, Red River and CC had a few different winners

 

Mark Chrudimsky 2bbl option

Tuffy Hudson 2bbl option

HE Nauman open motor option

J.C Umscheid Crate Motor option

John Heil 2bbl motor option

Ralph Burris Jr 2bbl option

Hanna Baker 2bbl option

Justin Long crate motor option

Ian Webster 2bbl option

 

These are just the ones off the top of my head, looks to me like a little of everything won. I also remember being in tech last year when the comment was made "Damn one crate, one 2bbl and one open motor"

 

Also remember when Joe Aramendia, Casey Smith, Tuffy Hudson, John Heil and my self ran the #5 then #15 car for Raymond 2 years ago it was a 2bbl option until it exploded with Tuffy driving it at THR. I wanna say John, Joe and Myself all won with it that away also. Alot has to do with getting everthing to work together wether its a Lat Model, truck, Modified or an eco stock! Which we will have one of those debuting next week!

 

Again, Call if youd like!

J.C Umscheid

817 783 7383

512 496 0195 cell

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I have been told by a reputable source that for every 1% of leftside is equivalent to about .1 of a second on the clock. The biggest advantage as far as that is concerned though would have to be that the rigt side tires are going to stay a lot cooler which in theory should be able to make ithe car more consistant.

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I asked this earlier but never got the answer......Modracer what car are you with? Just like to put a face with the name.

 

I have been told by a reputable source that for every 1% of leftside is equivalent to about .1 of a second on the clock. The biggest advantage as far as that is concerned though would have to be that the rigt side tires are going to stay a lot cooler which in theory should be able to make ithe car more consistant.
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I race in the USMTS series so you probably wouldnt know me.

 

 

USMTS doesnt even have a left side rule, I know this becuase I help a guy that runs USMTS. What car you with? If some one would really do some work and get the left side and all the percentages right on one of your cars it would fly on a dry slick track or when the track starts to take rubber. Why dont any of you guys run a sway bar? They are easy to take on and off. Did you know Lonestar Speedzone has a Dirt section for guys like you? You racing in the Houston area in a couple of weeks?

 

Good Luck,

J.C Umscheid

817 783 7383

512 496 0195cell

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If the rules are made by the rules makers in houston and every seems to agree for the mods that the multiple engine combinations make since I wonder why they do not make since for the pro lates the same people are teching both classes why not let the pro lates run 2bls and really increase the car coounts.

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Maybe this will put the GREAT VALVE COVER CONTROVERSY to rest.

 

In 1938 a study conducted at the University of Belgium, Brussels by Dr. Gerhard Litzinger on the effect of

Oscillating Paddles in a closed chamber produced interesting results.

The entire paper is much too long to go in to here but here is the gist of it: Taking his study and interpolating

it to rocker arm (paddles) and valve covers (closed chambers) it basicly shows that at engine speeds up to

3000 rpm the rockers are moving down then up at 25 times per second (tps). They have no trouble displacing

the air in the stock valve cover. However at speeds greater than 25 tps the air becomes compressed above the

rocker. At 35 tps measurable pressure is created just above the rocker. This pressure then doubles at 40 tps then

quadruples at 45 tps then increases at a factor of 10 at 50 tps which equals 6000 rpms.

In effect what you have is 16 tiny air compressors working aganist you. However his study showed that by increasing

plenum volume ( TALLER VALVE COVERS) the efffect could be canceled out. So by using steel or aluminum taller

valve covers you then get rid of parasitic drag internally freeing up horse power to use. Your rocker arms " think"

you have pulled vacum on the crankcase.

I know this sounds like bull but try this- this is an exagerated example but you can get the idea.

Fill a gallon bucket and a bath tub with water. Now stick your hand in the bucket and move it back and forth rapidly

-now do the same with the bath tub. Which one made the bigger mess. Still not convinced ?

The 1948 Harley Davidson motor was called a knuckle head. It had closely cast aluminum valve cover thingies that

looked really cool when polished. In 1949 they changed to a large stamped steel cover that became known as the

pan head. The pan head engine-same cu in same cam same pistons produced approx. 4hp more than the knuckle head.

Was it because of the larger volume valve covers? you decide.

I'll leave you with this thought that the professor so aptly put at the end of his paper on this subject.

 

WENN SIE SCHRAG SIE MIT, VERWIRREN SIE MIT STIERSCHEIFE !!

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Can someone with the knowledge comment on the expense and maintenance cost associated with each engine the initial cost to obtain a competitive engine for each?

Crate Motors: 604's- I am assuming around 6k to 7500 for a competitive crate motor with rebuild costs around $2500 to $3500? Is this accurate?

 

2 barrel motors: I have been told 10k+ all depending on whats done to the motor. If one had a good sbc 350, what would it costs to build a competitive 2 barrel motor, carb to pan?

 

With regard to the Pro Trucks, are the 602's crate motors similar in costs to a "built 305" if built within the rules?

 

I know the estimates associated with the above can vary but I am trying to compare the costs of a competive motor between the Pro Late Motors, TSRS motors and the Pro Trucks.

 

Thanks for the input.

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I know I am not one of the front runners, since Ive only been in the mods for one race, but I have less than 8k in my 2 bbl. Its a stout motor, but I went with it because I had most of the parts. With the rules written the way they are, the way to go is with the crate. I am not sure of the cost of the extra work you can get done on a crate but that added $$$ ontop of the upfront cost of buying the eng was out of my reach. I guess it depends on what is easiest and in your budget for you.

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I don't have a dog in this discussion, but if the Left side percentages were even for all classes of engines do you think

there would be more participation from other cars? At Houston there was a pretty good field of cars. It seems the Goodyear tire is certainly a great equalizer when it comes to grip. My guess is the same cars would be winning that are winning now. Now if SAS was still around I might have a different opinion.

 

Just food for thought.

Mel

Edited by Mel
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The problem most promoters do not understand is that there is a huge amount of 2bl parts around and a racer can use out of his inventory or buy up pieces as he go along. Kind of like the old cadillac song, "one piece at a time". Were as with a crate you have to buy it all at once and then send it off for blessing even before you race it. Just like 61 said it was out of his price range. Another thing is that to correctly tech a crate you almost have to have a borascope to look into the heads and cylinders(like I have heard ASA does) I am not aware that the tracks in texas running crates have this equipment. How do they tech the crates in Houston just for imformation? Unfortunately I believe the whole crate issue is a monkey see monkey do, where some national series does it and so it must be good for local racing. Or in some cases several of the better funded teams who like to travel want to run their equipment locally but because of the local rules sometimes they cannot and talk the track into doing it. Which ends up alienating the majority of the racers for the minority. With the way the economy is right now would it not make more since for the sanctioned bodies to help the local machine shops, who in turn sometimes help sponsor racers instead of funneling dollars to some out of state shop or one or 2 regional shops. Unfortunately with the turnout like houston had it is going to be hard to convince them they need more car count by equalizing a 2bl motor. Also it really sucks having to listen to crate running on the chip, versus the sound of a highly tuned motor without a chip.

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It funny that when we had the #5 car on the speedzone for sale we never once got a phone call..........just incase anyone is wondering I did have my engine pulled and teched last year infact they(HMP and the tech inspectors) dynoed it. We enjoyed pulling it out of the car for you guys that evening!!! AND WILL DO IT AGAIN! But this time would like to get paid for our time and expenses........ Or how about you just buy the thing and put it in your car so that I can get a new one and wear you out with it all so.

 

Quit whinning and go to work on your racecars.

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It funny that when we had the #5 car on the speedzone for sale we never once got a phone call..........just incase anyone is wondering I did have my engine pulled and teched last year infact they(HMP and the tech inspectors) dynoed it. We enjoyed pulling it out of the car for you guys that evening!!! AND WILL DO IT AGAIN! But this time would like to get paid for our time and expenses........ Or how about you just buy the thing and put it in your car so that I can get a new one and wear you out with it all so.

 

Quit whinning and go to work on your racecars.

 

 

We were working on the car, :lol: and we know you pulled the motor in Houston, we were there all night too. :o Don't think we are accusing you of anything wrong we admitted right up front, you ( the 5 car and the 42) are doing a good job of wearing us out already and it is because you have great eqiupment, a lot of talent and hard work. yYu have already stated some other cars have won races in the last few years but you must admit the left side weight is a huge advantage I noticed PASS has similar engine combinations for their SLMs and there is only a 50# penalty for the 2bbl (11:1) option and all cars including the open motors run 57% LS and as statedin another thread this really seems to work for them. I don't know the answer but I think its worth looking at to see how much difference the 2% will make on lap times. I didnt get any response to my question about horsepower differences but I am assuming the crates are between 400hp and 420hp the 2bbls may be 450hp to 500hp and the opens maybe 550hp to 600hp which like I said before would make the 2bbls and the crates closer to each other than the 2bbls and the open motors.

 

I would think this difference ( the leftside weight) would be more noticeable on the 8 inch tires than the 10 inch tires but again this is just my opinion.

 

We are planning to continue working on the car and use the front runners times and finishes as a goal, so we should be able to close the gap a little.I think its our job to analysis everything about the car and whats holding us back even if it means questioning the rules. I think you are right in defending your accomplishments and I think the rules makers are to continue trying to make the rules as equal as possible. I noticed PASS has adapted their rules a few times over the last few years.

 

Good luck in Houston.

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