How do NASCAR engines make 750+HP?
Suspended Sponsor
Joined: Oct 2004
Posts: 371
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From: Just outside of Palm Springs Ca.
Don't kid yourself, there is tons of technology in the N.A.S.C.A.R. world. The alloys and materials used for diffrent components are incredible and the cylinder head and camshaft technology is ridiculous. Remember, most of us here are most akin to the roller cam, these engines run with a flat tappet camshaft with nearly 1" of valve lift and still manage to spin over 9000RPM for what might as well be an entire day. Believe me, there is some technology there for sure. We build some pretty bad little engines for our local circle track guys and even a Super late model is a pretty impressive piece, making 450ish HP from 360" through 2 1.5" holes in the restrictor plate is a pretty tricky process!!
-Bryan
-Bryan
Originally Posted by DanO
And nobody mentions F1 cars?
If you want to be amazed by engine technology take 3.0L NA (183 cu in) and put out 900+ hp and pushing 20,000 rpm
Its all about optimizing all of the components to work together. You can actually design engines to create over 100% volumetric effiency without forced induction.
Not to be a stick in the mud, but nascar engines do not have the enigneering power (and $$) behind them like F1. But the nascar rules prevent technology from filtering into the sport of carburation and 9" rears... (zzzzzz)
If you want to be amazed by engine technology take 3.0L NA (183 cu in) and put out 900+ hp and pushing 20,000 rpm
Its all about optimizing all of the components to work together. You can actually design engines to create over 100% volumetric effiency without forced induction.
Not to be a stick in the mud, but nascar engines do not have the enigneering power (and $$) behind them like F1. But the nascar rules prevent technology from filtering into the sport of carburation and 9" rears... (zzzzzz)
Staging Lane
Joined: Dec 2003
Posts: 95
Likes: 0
From: Hayward, CA
Originally Posted by Torkman15
Wow OVER 100% volumetric efficiency would mean you would have to stop every once in a while to drain some fuel out of the tank right?
Teching In
Joined: Jan 2004
Posts: 31
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From: Toledo, OH
Nascar engines are very efficient engines, between the cam timing, and alot of R&D in headers/exhaust scavenging. They are limited to carb size, and they make alot of power with a small carb. I had a friend that worked at a nascar team engine shop. They dyno'd one of the engines with my 1050 CFM Braswell Dominator, and it only gained 15 HP across the board. For almost double the airflow capability, it wasn't a huge gain in power.
TECH Enthusiast
Joined: Apr 2005
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Originally Posted by Torkman15
Wow OVER 100% volumetric efficiency would mean you would have to stop every once in a while to drain some fuel out of the tank right?
volumetric efficency = how much air is placed in the cylinders vs. actual displacement of engine
Originally Posted by Louis
The cams are expensive! On the order of 1000$+ for just the cores 
The lobes are welded to be able to withstand the abuse they take 
The lobes are welded to be able to withstand the abuse they take I do not believe the 12:1 is the limit on comp. I think it is much higher. The engines do not make 750 hp with the restrictors in the carbs. The information about the 1050 carb making 15 more hp is not even close to correct. One of the top teams bolted on a larger dominator (unrestricted) on one of the cup cars and the speed went from 178 to 230 and that was without tuning the carb to the engine. Those cars are incredibly aerodynamic and will go 200 mph with 500 hp. I have read that the exhaust systems are so good that they get a very good pull on the intake charge because of the vacuum effect the exhaust creates. They are not as complicated as F1 but probably have more tricks applied, do to the same basic engines for past 30 plus years were as F1 rule changes make them start over every decade or so.
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just to give you guys a taste, in one of our schools project motors. Romco late model series motor. (Bowtie block and bowtie heads, 390 cfm carb, carillo rods, custom cut JE's 9:1 compression) spinning to 9000rpms makes 604 hp on the engine dyno. It is basically a mini cup motor. Cup cars do not run near the 13 or 14:1 compression ratios like they used to. I believe 12 to 1 is where they are at now.
Teching In
Joined: Jan 2004
Posts: 31
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From: Toledo, OH
12.00:1 compression ratio is the limit in the rule book. The 15 HP gain was on a dyno engine, using a stock Edelbrock SB2 intake with the dominator adaptor. No carb tuning, with it setup for my drag car. The cars can go alot faster than 200, but the body template and spoiler rules for the races limit them.
Originally Posted by Full-Force
Dont forget the NHRA pro stock trucks ran basicly the same engine except 2 dominator carbs on a sheet metal intake and made over 900hp.
Damn right! Those were some IMPRESSIVE motors!
Originally Posted by ChucksZ06
I do not believe the 12:1 is the limit on comp. I think it is much higher. The engines do not make 750 hp with the restrictors in the carbs. The information about the 1050 carb making 15 more hp is not even close to correct. One of the top teams bolted on a larger dominator (unrestricted) on one of the cup cars and the speed went from 178 to 230 and that was without tuning the carb to the engine. Those cars are incredibly aerodynamic and will go 200 mph with 500 hp. I have read that the exhaust systems are so good that they get a very good pull on the intake charge because of the vacuum effect the exhaust creates. They are not as complicated as F1 but probably have more tricks applied, do to the same basic engines for past 30 plus years were as F1 rule changes make them start over every decade or so.
The Cup motors are on par if not more complicated in some areas compared to F1 motors, actually they are suprisingly similar.
F1 rule changes force the teams to change the motors yearly. Over the last 4 years they went to unlimited engines per weekend, to one engine per weekend, to one engine for 2 weekends to now dropping displacement from 3.0L to 2.4L. Not to mention the little things in there like rules on the materials used in the motors and the banning of variable length intake manifolds.
Them Pro Stock truck motors also tried to run the Splayed Valve heads, what junk they are.... that's why the Little Chief heads were designed.
Bret
TECH Fanatic
Joined: Jun 2002
Posts: 1,979
Likes: 3
From: Upstate NY
Originally Posted by DanO
And nobody mentions F1 cars?
If you want to be amazed by engine technology take 3.0L NA (183 cu in) and put out 900+ hp and pushing 20,000 rpm
Its all about optimizing all of the components to work together. You can actually design engines to create over 100% volumetric effiency without forced induction.
Not to be a stick in the mud, but nascar engines do not have the enigneering power (and $$) behind them like F1. But the nascar rules prevent technology from filtering into the sport of carburation and 9" rears... (zzzzzz)
If you want to be amazed by engine technology take 3.0L NA (183 cu in) and put out 900+ hp and pushing 20,000 rpm
Its all about optimizing all of the components to work together. You can actually design engines to create over 100% volumetric effiency without forced induction.
Not to be a stick in the mud, but nascar engines do not have the enigneering power (and $$) behind them like F1. But the nascar rules prevent technology from filtering into the sport of carburation and 9" rears... (zzzzzz)
Look at the BMEP at power peak rpm for F1 (183 cu.in.), NASCAR Cup (358 cu.in.) and Pro Stock (500 cu.in.) engines. You might be surprised how close they are, and which has the highest.
BMEP (Brake Mean Effective Pressure) is a good measure of how much an engine gets out of the air it pumps. IOW, it indicates how much torque the engine gets to the flywheel from each cubic inch of displacement. Because hp = torque x rpm (and a conversion factor of 1/5252 to get the units correct), it's very important to get the highest torque/cube and then go for rpm while not losing much torque/cube as you up the revs.
Of course doing it at near 20,000 is much more expensive than doing it nearer 10,000.
On The Tree
Joined: Oct 2003
Posts: 150
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From: harrisburg PA
Comparing a ps/t motor to a cup motor is well...kinda like comparing a new c6 to a vw bug. Cup motors by design are technology limited. The effective teams are spending more money using the power they have, and making it durable, then trying to make more. You can make all the power in the world off of the plate, but if you are racing restricted, all bets are off. If you are racing in a bowl, all the power does little good, while recovery is king.
Imagine how fun nascar would be if they could use un-restricted 500" P/S motors....I might actually watch then!
Dennis
Imagine how fun nascar would be if they could use un-restricted 500" P/S motors....I might actually watch then!
Dennis
Originally Posted by airflowdevelop
Imagine how fun nascar would be if they could use un-restricted 500" P/S motors....I might actually watch then!
Dennis
Dennis
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Joined: Aug 2002
Posts: 3,726
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From: Fort Collins, CO
Originally Posted by Full-Force
Dont forget the NHRA pro stock trucks ran basicly the same engine except 2 dominator carbs on a sheet metal intake and made over 900hp.
Its called unlimited R&D budgets. When I first went to work for Stef's we had just finished 3 x R&D pans. These were for testing only and not legal by todays standards but they were built to help understand other things going on. Cost was $9000. They aren't scared of failure down there so they will try stuff, even if it is off the wall.
Even the oil pan has specific guidelines that we must follow or the pan is deamed illegal. 1/8" of an inch more depth can mean more power.
Sweeping engine rule changes will take place in '07. Stay tuned.
Even the oil pan has specific guidelines that we must follow or the pan is deamed illegal. 1/8" of an inch more depth can mean more power.
Sweeping engine rule changes will take place in '07. Stay tuned.