Forum: HoseHeads Sprint Car General Forum (go)
Moderators: hosehead

I'm struggling to believe all these big horsepower figures being shouted. The track record at the Grove is 5 years old. The engines all sound and look the same on the straights. They don't sound even as good as the strong ones did 8 or 10 years ago. Underfinanced cars often set fast time. Everyone is within a few tenths. If the "good" stuff is making close to 900, everyone must have about 900. I often hear stories of various engines several years old doing great things. If great strides have been made recently, how can a 6 or 8 year old piece even compete?

The hopeless desire to outrun Bud Grimm's Fords is 
why central PA became the toughest place to race on 
the planet. Even the KING couldn't run with Casey 
Luna's Fords on a tacky track. It's a crying shame 
that current car owners failed to notice.

Here is a question I've been pondering for sometime now and maybe Kelly can answer this....

I noticed on Kinser's car a week or so ago that he consistantly turned it 9200 RPM. Why don't/can't they turn them tighter? I watch the telemetry on the NAPCAR races and these guys are turning damn near 10,000 RPM with a damn flat tappet cam for 500 miles! What gives? Is it the difference in compression between a "gas" engine and one burning methanol?

Provisionals, Fuel Stops & 
Rubberdown Tracks Suck! ©

A lot of times when you hear horsepower numbers, they are "corrected" numbers on the dyno. Most of the time when you have a new track record, a few factors a present. Most of the time you have "very good air" (low humidity, cool temps, and high? barometric pressure). Track conditions have to be able to handle the power with minimum (optimal) tire slippage. I'm sure some of the motor pros on here can tell you more about the corrected parameters.

Numbersusa.com 

What gets me is the rules in unlimiteds state 410 c.i.d now a days you are seeing guys spend just as much on a set of heads as they did for a whole engine even 10 years ago??? where will it end and what steps will be taken to cap the engines to make fair competition. When you go to the races and your under the stands or have your back to the track you can hear the difference in the ring of the motors from outlaw to regulars. And what really floors me is that really there is not really a such thing as bad equipment these days yet there is a huge gap from the weekend racer to the racer that races at least 3 nights a week. You used to be able to say that it made a difference to race all week but I think equipment is much better and prevelant with the traveling series. Another mystery in the engine department is qualifying motors, Why is it at the end of the year or over the winter many of the top teams sell engines that a person is warned they could be illegal possibly in the 430 cid range. I will agree with the post before, why have rules if you cant enforce them. I will say in Nascar i cant stand the restrictor plate races but it does bunch up the pack and cause them to race I have noticed in sprint car racing you have to have a huge jump or good luck on that first lap cause there is no such thing as letting the pack spread out and making your move like the good old days of racing, it almost seems like high speed hot laps where cars are 5- 10 bumpers apart and follow the leader racing. What happend to the big inverts and the come from behind races the fans love to see?? I wonder if they will ever do anything to the rules on engines

Horsepower is mathematical function of torque times a given rpm.  I believe the formula is hp=torque*rpm/5252.  Lets say you have two engines that both make peak torque of 650 ft lbs. the only difference being one makes it at 5500 and the other makes it at 6000, the one that makes the 650 ft lbs at 6000rpm will make more horsepower.  If you do the math, the engine that makes 650 peak torque at 5500 will make 680.69 hp at that rpm, where the engine that makes 650 peak torque at 6000 rpm will make 742.37 hp at 6000 rpm.  Anytime you can increase the rpm at which the engine makes peak torque you will increase the peak hp.

Of course there is a down side to this, especially in our sport of direct drive sprint car racing. 
There is  no clutch, stall converter or transmission to enhance the driveability of the engine.  So in order to have an engine that takes off on starts, restarts and to run under part throttle in traffic or dicey track conditions you must be willing to give up big hp gains for driveability.

That is why you might see old 820hp technology win against 900 hp engines.  Due to the configuration of the racing surface, especially dirt, a smoother running more controlible engine may out perform a stumbling, explosive tyre frying high rpm killer hp engine.

Hope that makes sense.

Mark Burch, Lincoln NE

In English please. lol

closest I can figure, some folks have a dyno that will show 110 HP even BEFORE they hook up an engine to it LOL LOL L:OL

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Duane Davis

Laser Engraving 
641-751-7777
101 N Center
Marshalltown, Iowa 

nodust is pretty close to what goes on with the dyno's. Some engine builders choose to inflate their numbers to sell engines. Sometimes though they just have inflated numbers and don't know it. Horsepower numbers sell engines.

Here are a couple reasons a outlaw engine will have trouble turning 10,000 RPM.
1. An outlaw engine usually has around a 3.800 stroke on the crankshaft where a nascar engine uses around a 3.335 stroke. Since the outlaw engine has a longer stroke it is going to be harder on the rotating assymbly then a nascar engine.

2. Outlaw engines use a IR (individual runner) injection system. A nascar engine uses a plenum type intake using a carburetor.

3. Outlaw cars use a direct drive that hooks the engine to the rear end. No transmission.

4. Since they run more gear ratio to get the higher RPM it makes part throttle control harder at lower speeds for a outlaw car. Nascar cars don't require a lot of throttle control at lower RPM they just put it to the floor and they also are running on a smooth surface.

5. Money

Horsepower does not always win races. But it sure helps when you time in.

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Mark pretty much summed it up in his post.

Pizzadude said in the very last line of his post, "I wonder if they will ever do anything to the rules on engines." Somebody did and it's called ASCS. As far as the 410 ranks go who knows what will happen in the future but something needs to be done rather quickly, but then again we've been saying that for a few years now and I haven't seen any progress yet in the engine department. Instead we've been concentrating on tire compounds and widths and wing dimensions.

Dyno numbers? Sticky subject. Yeah we as well as other engine builders around the country hear them all the time. I guess it's just something we have to deal with, it's been going on for years. Like my dad has always said: "it may say 900 horsepower on their dyno, bring it to Bixby and let's put it on our dyno."

If police radar can catch a tree on a calm day at 118 mph, I am sure a dyno can get at least 200 hp without an engine lol

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Duane Davis

Laser Engraving 
641-751-7777
101 N Center
Marshalltown, Iowa 

Responding to Wesmar your right on about how they are concentrating more on tires and wings, and as far as engines you guys build some of the baddest ass motors around so your pretty up to snuff on these issues, dyno and RPM's someone mentioned the other day there is now 6 pages of rules about wings, and about 3 pages of engines concerning the 410 class??? does make you scratch your head a bit but even though ill get a nasty post or two I say hell with the wings if they are becoming so controversial. Without wings there of course is the safety factor, but honestly watching how fast some of these winged warriors are getting around the track id have to say the safety factor almost is an even split from wings to wingless. Wingless cars though not as fast are cheaper on tires, fuel, and lets face it they dont need the big horses under the hood to win, they usually run in a pack and swap posistions quite frequently, On the other hand as a kid I witnessed many of the fatal crashes that pretty much mandated wings at Knoxville so as far as safety i beleive in the wings, but then again with the wing cars they dont like tacky tracks, you gotta have a big horse under the hood, plenty of tires and fuel, and spare engines, and more and more they are becoming follow the leader races and the wings have so much downforce it uses up motors pretty regularly. I know they are my opinions but have heard many of my friends that drive and own race cars around the country, and as a fan I hear some of the same complaints.

As far as the dyno sheets read I know a few guys that build and they always smile and say they can make a motor read whatever you want

I agree.......  if we need that many rules for the wings, and are so worried about every minor tweak on them, let's just get rid of them!!!

Thanks guys on the info. I never realized that the NAPCAR engines ran such a short stroke, that explains a lot.

One last question for Mark or Kelly. How much more room is there for head improvement on a 410 engine? Will there always be something to be found flow wise?

Provisionals, Fuel Stops & 
Rubberdown Tracks Suck! ©

I am kind of out of that loop at this point in time. Kelly can probably answer that better than I can. My opinion is that unless they put some kind of rule in place to limit cc's or valve angles it will never stop. And, even if they build something better or not....if someone is winning with it others will follow suit regardless if it is a better product or not....right Kelly?

MB

Mark is right again. Although I will say that we haven't seen any major changes for that matter in the cylinder head technology for about maybe 2 years now? I think were at a stalemate at this point, BUT just when we think were done along comes something else................lol.

Like Mark says in his last line - "monkey see monkey do"

Monkey Saw, MOnkey Did, now Monkey Fast

Jocko's Tee Shirt lol maybe a Karl KInser quote?

Save your butt, get a colon screening TODAY

For complete line of Sponsor Awards check out 
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Duane Davis

Laser Engraving 
641-751-7777
101 N Center
Marshalltown, Iowa