I have followed NASCAR for many years and I am scratching my head over some of the new engine rules. I’m an engine guy so I will focus on the new NASCAR engines coming into this season’s competition, and I will compare them to the other previously introduced engines from Toyota and Chevy, by make.
Toyota: Toyota entered NASCAR racing in the then Craftsman Truck Series during the 2002 season and was forced to develop a completely new engine just for NASCAR.
It was a completely clean sheet design, as Toyota didn’t offer an overhead valve (OHV) engine. The production Tundra has all overhead cam (OHC) engines. An early rumored was that GM gave this engine design to Toyota when they were working together in the 1990s.
The visual similarities between the early Toyota engine and the R07 are extremely close. The first version Toyota engine has a bore spacing of 4.47”. It was extremely competitive in all the venues it ran.
A little known fact is this engine was required to use a smaller carburetor spacer to reduce horsepower last season. In 2008, a newer version of this engine was introduced in cup to match the rules and it will later be used as the basic engine in both Nationwide and trucks.
Chevrolet: For the 2007 season, Chevrolet brought a newly designed engine to Darlington to replace the SB4. The R07 engine was designed from the ground up from a supposedly clean sheet, but it bears a big resemblance to their LS-series of production engines.
It also shares similar dimensions and architecture with its LS sibling. It uses six bolts on the main caps, four bolts on the maincaps and two side bolts into the caps through the extended bulkhead skirts.
The previous SB4 engine used a version of the factory small-block design that had be around since 1956. The heads on the SB4 were designed with a better valve angles but retained the Siamese style ports and their limitations of the factory head.
The head design gave a marked advantage to the older Ford and newer Dodge engines.
Ford: Ford introduced its new NASCAR race engine, the FR9 at SEMA earlier this year and will phase it into the cup cars over the 2009 season beginning with the Roush team. The FR9 will eventually filter into the trucks and Nationwide cars in the next year.
Ford’s present NASCAR engines are all production-based on the old 351 Windsor and 351 Cleveland engine designs. The new engine will no longer resemble the older engine and actually looks a whole lot like the new Chevy R07 externally.
Dodge: Dodge is introducing their new R6P8 engine with Penske during the earlier part of the season. They will phase out their older R5P7 with the other teams as the season continues.
The new engine is no longer based on a production engine, but unlike Chevy and Ford the earlier R5P7 engine, that had such a horsepower advantage over the older Chevy and Ford engine was based only loosely on a production piece.
The block was similar to the LA/Magnum series engines, but the heads were of a newer non-production based design more closely related with a Ford head with spaced intake and exhaust ports.
The factory LA/Magnum head uses Siamese ports on the intake and the center two exhaust ports.
Now that we have the initial information on each manufacturer’s engine, we need a basis of data for comparison. The common data on all the engines are based off the rules NASCAR is now requiring for all new engine design. Production based engines will no longer be used as a basis.
Engine Block and Crank Assembly: The engines will be of a high Nichol content iron block with a maximum of 4.125” bores on a 4.5” bore spacing and deck height will be fixed at 9.0”. All engines have a 3.25” stroke and a maximum bore of 4.185”.
The mains will incorporate the new Chevy R07 layout of four bolt mains and two side bolts on an extended bulkhead skirt. Rods have a minimum weight of 525 grams and pistons have a minimum weight of 400 grams.
They have a raised camshaft location no more than 6.125” above the crankshaft to improve valvetrain dynamics and 2:1 roller rockers.
Competition Cams from Memphis, TN. manufacture all the camshafts for NASCAR and depending on the track, duration and lift is different within NASCAR maximum specs. NASCAR allows only solid flat tappet camshafts that limit cam lobe ramp speeds.
All tappet bores will be the same size at .825” and valvetrain angles must fall within NASCAR specs. The new engine block has taken the best of all the current engines.
What always made the Dodge engine so strong was the camshaft location and lifter bore size. Both measurements are included in the new design.
Heads: Heads for the engines will be the largest area for teams to explore an advantage. The heads will be made of aluminum and use six head bolts per cylinder. Each head will be manufacturer exclusive to their engine and of the canted valve design.
The heads will have a maximum valve size and port diameters, but port radius and profiles are left to the engine builder’s discretion. Combustion chamber size will be fixed, but the combustion chamber shape and design will be open for exploration.
The best heads available on the older engines were the ones on the Ford. Ford and Doug Yates designed an improved head loosely based on the 351 Cleveland and used the canted valve alignment.
This made for better engine breathing at higher rpm, thus more power. All of the new heads use huge tapered ports and canted valves, using the best ideas of the Ford designs. Chevy fans, please don’t start sending me things about the old big-block engines.
The Ford Cleveland designs were in response to the big-block Chevy on the 385 Ford big-blocks and the design idea filtered down to the Cleveland. The current NASCAR designs are worlds ahead of even the best of anyone’s canted valve heads regardless of the manufacturer.
Induction and Ignition: Intake manifold layout is fixed and all engines will use the approved Edelbrock intake manifold.
The intake port volume will be a fixed volume, but some radius modification is allowed. The carburetor will be the NASCAR approved Holley 830 CFM unit.
Modifications are allowed as to metering, jetting, accelerator pumps, and fuel distribution. Distributors on all the engines will now be in the front of the engine and will use the approved MSD ignition box.
Comparisons: With the new policy of equalizing the field, NASCAR has basically told the manufacturers to develop a spec engine for the upper series. As you can see all the engines have the same specifications and when compared together, they all look alike.
The horsepower between the engines are minuscule and yet the overall cost per engine is considerably more. With engine builder modifications, an engine can be tuned to produce more power at a given rpm and that is where a good tuner will make his money.
Some drivers like more power lower in the power band to pull the 3,500-pound car off the corner and down the straightaway. Other drivers want more power midway down the straightaway and less off the corner to reduce wheel spin.
Evaluation: The idea by NASCAR was to even the playing field and reduce the overall cost of the engines. They accomplished in one aspect, equalizing the competition, but on the reducing cost aspect, NASCAR has dropped the ball.
The current engine package runs in the neighborhood of $75,000 whereas the new engine will be sold for more than $110,000 estimated. My problem with all of this is simple.
NASCAR is moving further away from the original concept of Stockcar. They have decided to produce a complete fendered racecar and that isn’t my idea of a Stockcar.
As a fan, I would prefer the requirement of a stock block and head based engine with full fuel injection. The engine must be offered in a current vehicle and will be allowed to run whatever valve setup the factory engine uses. That would allow Ford and Toyota to develop its OHC engines that are currently powering their street trucks.
It would also allow Chevrolet to develop its LS engines that are used in their cars and trucks, and allow Dodge to do the same with the Hemi. It would be beneficial to the big three as well as Toyota and hopefully the developing technologies would be trickled down to our street engines.
I would also encourage the use of alternate fuels or possibly a hybrid system similar to what is currently being run in Formula One.
Conclusions: What we will have in NASCAR is a spec engine to go along with the spec COT body. The chassis on all NASCAR cars are virtually the same today, so what will differentiate the different makes?
I can see in the near future the attempt to do the same thing in the upper levels that NASCAR has done in their lower divisions. The push to a single type spec engine made by a non-manufacturer and the body will close behind in that push.
We will finally see the non-manufacturer fan friendly car similar to an IRL racecar. This might be exciting to some, but to an old fan growing up cheering for his favorite brand, it is a hard thing to swallow. Stockcar racing show represent the concept of racing car similar to what is offered by the factory, not an IRL car with fenders.
The cost of these engine will also have another unseen effect. As they become mandatory to meet tech the small team owners will fall quickly to the wayside. We will have only the mega-buck teams very much as has happened in the IRL and Formula one.
This will not be better for the fan at all, but will remove one more group of fans that love the small guy. I for one can see little good about the COT or these new engines. In fact it really worries me that NASCAR is moving further away from its roots and more to a race series that will fall on its face.
Spec cars are not exciting and I only hope NASCAR will come to its senses before it is too late.