Anyone know the nitty gritty of these engines? Talk about amazing. From what I've gathered they are limited to 358C.I. and a 4.185" Bore. What stroke do they usually run? CC of heads? Cam specs? Rear End Specs? How much do they weigh? Brake setups? Just any interesting knowledge of how these rears hold the 800hp and they can race for hours at 190mph.

-Corey

 

alls i know is the chevy guys run sb.2 18* heads. they have 12.5:1 compression. race weight is something like ~ 3650 lbs. i'm sure there is a web site somewhere that says all that stuff.

 

You live in Mooresville.. sign up for NT and find out

 

Mooresville? You are right in the center of it!

358 cubes with a 4.185 bore gives about a 3.253 stroke, or just about what a 327 SBC used. From pics I'v seen, combustion chambers are tiny (way under 50 cc?), so pistons may be dished.

Cams are flat tappet (no rollers). Engines twist to nearly 9500 if you can believe the TV telemetry ( I think it's accurate.) Metal valve springs are used. My guess is lots of valve lift using lots of rocker ratio (maybe over 2:1). They may be "lofting" valves in some applications. There is a good chance that a maybe a majority of the teams use the same cam company. Some design and grind their own, some don't.


Cup engines probably produce about 800 hp (nobody is really telling) in the high 8000 range with a power curve that stays quite flat on top. Interestingly, when compared to 900 hp, 19,000 rpm 181 cube NA Formula 1 engines, Cup engines have about the same piston speeds (one of the limiting factors in a engine), and just about the same torque per liter (or cubic inch) at power peak as the best F1 engines! That's in the 82-86 lb-ft per litre range. That says about the same level of engine airflow development technology in Cup and F1. Engine speeds on track range from about a 300 rpm band at Daytona and Talledega with the restricted (450 hp maybe) engines to about 3500 rpm band on short tracks and road courses. IMO, torque curves are tailored to the track and traction available.

Rear ends are basically 9 inch Ford, with reallly good oil coolers. Friction and heat are the big problems. My guess is everyone uses synthetic lube. They don't get the shock loads an 800 hp drag engine with slicks gives, so they last well. Obviously gear ratios vary from low 3's to high 5's or 6's depending on the tracks.

Allup weight is 3400 I think.

Brakes vary a lot from course to course. Biggest/best are for short tracks and road courses. With 15 inch wheels, rotor diameters are limited but width is not really. Cast iron rotors are required. Almost all the major international brake companies supply parts.

My $.02

 

THE NITTY GRITTY SPECS ON CUP MOTORS ARE PRETTY HUSH, HUSH. MY SUGGESTION IS GET ONE THE ENGINE BUILDERS IN MOORESVILLE DRUNK AND COME TELL US.

 

Good thought, but it would probably cost the victim his job.

My "spies" tell me guys from lots of shops often eat lunch together. Lots of shop talk as I understand. Bet it's tough to sort out the straight skinny from the bovine scat.

My speculation is that coatings, head/manifold flow (of course), and valvetrain parts and timing are the most hush hush info.

At first look, Toyota's (Craftsman) trucks are slow in Daytona testing. Sandbagging isn't unknown there, but I'd be very surprised if Toyota isn't very close on engine power.

 

Doubtfull you are going to get any cam specs on those motors. Nextel Cup stuff is flat tappet where the other series are rollers.

If you have the max bore then you have the minium stroke to get 358 cubes right? If you have one and you know it's a V8 you have the other.

Bret

 

i live in mooresville too, and its amazing to me that with all the nascar and racing technology around here no one has a bad a$$ lt1...n/a that is.

there are a couple quick blown lt1 cars around but nothing too serious on motor.


anyone ever seen a set of nascar brake pads....my goodness, they are like an inch thick...wow!

 

I know right! I'm only 16 though, so getting in a shop is a little difficult. I've been inside the Evernham shop, twice! It's so cool! Dang. I was talking to a guy about just helping out, pushing a broom, whatever and he walked me through to talk to the boss Oh well, like most guys he never returned my calls or anything

I know they run 6.XX at Martinsville. Comp Cams is always advertising with NASCAR so I imagine they supply a lot of the cams, but the cams are most likely a special grind. With 15" wheels, they can barely run 12" rotors, if that! 3600lbs is a little more than I was thinking. Hm. I talked to one of Hendrick's engine builders once and he said they varied stroke depending on track. If there bore is limited (4.185) then their MAX stroke would be 3.253. But if they used an lower stroke, still maintaining the 4.185" bore, they wouldn't be displacing 358C.I.

I'm debating NT. I've got 2yrs to figure it out

Anybody here work in a race shop around Mooresville or even know someone? Need some help doing little stuff around the shop?

-Corey

PS. Not too advanced but anyone have some real tips on getting a job at a shop? I've been dropping resumes off left and right but nothing yet. I just want to learn

 

Just bumping it up. Anyone have anymore info?

PS- I got the job at Evernham.
http://web.camaross.com/forums/showt...hreadid=214876

-Corey

 

heres the details

355 – 360 cubic inches Compression ratio 13:1 runs on “race” gas
Block: Race Prepped Chevy BowTie, 4 Bolt Mains, Splayed Billet Caps
Pistons: Forged Aluminum Alloy, J&E or equal, Bore 4.125
Crank: Billet Sonny Bryant, Stroke 3.335, 32-45 lbs. 1.88 to 2.1 rod journals
Rods: Carrillo or Lentz 6.20” H beam. Carr Bolts
Jesel Belt Drive Timing Set
ATI Balancer
Heads: SB2.2CNC Ported Aluminum Chevy Cylinder Heads w/ Del West 2.150 Titanium Intake Valves, 1.600 Titanium exhaust valves, Comp Cams triple valve springs, Titanium retainers and keys, Copper Berylium Valve Seats, Heads Flow 390 cfm @ .700 lift.
Cast Aluminum Chevy Valve Covers
Jesel shaft mounted roller rockers 1.70 to 2.00 ratio
Cam: Competition Cams Solid roller, 106 Deg. Centerline, Lift= .706 intake and .630 exhaust, Duration 324 intake and 332 exhaust
Lifters: Crower or equal, true roller lifters
Pushrods: CV or equal 3/8” * 9.050 * .080 wall
Wilson Intake manifold and Tapered 4 Hole Spacer 2.00" Part# 004150
Quick Fuel 850 cfm “Drag Carb”
Moroso or equal fabricated sheetmetal drysump pan
Oil System: dry sump, external pump Barnes or equal


i could tell you were i got this from...but then id have to kill you..then take your job


Rob

 

ohhh yea,....those heads are about 4 grand to put together =)

 

Yeah compression is actually limited to 12 to 1. The 18 degree head has been gone for some time. The GM SB2.x head is 11 degree intake and maybe 8.5 exhaust. The intake has some cant too. The cam specs are pretty common knowledge but as OldSStroker said the valvetrain and such that goes with it as far as the combinations that really work is very confidential and is a big player in turning over 9000 like they do now!

 

Not sure where you got your info, but don't bet your job on all of it being accurate.

No roller cams in Nextel Cup.

Bores are closer to 4.185 than 4.125 with strokes to get 358.0 max cubes.

Pushrods are probably a litttle more exotic than you mentioned.

Often cranks are built in house by the teams (billet).

My guess is there are literally hundreds of different cam combinations in use, with changes made daily (hourly?).

Don't forget coatings on almost everything, except maybe the driver.

 

Occasionally NASCAR will take the top finishing car of each make to the chassis dyno...generally rear wheel HP numbers are from 720-730hp with Chevy's and Dodges being pretty close last year and Ford down at the 705-710 range. Ford is getting a new head this year though to even them up.

I know Comp grinds most of the cup cams, all highly proprietary on the specs though.

As far as the rear ends go, they use differential fluid coolers. Usually they arrive at the track with dozens of ring&pinion combos already set up in removable carriers, so they can really split hairs in terms of gearing needs.

The superspeedway cars are really a breed apart, 4 dime-size holes in the restrictor plate under the carb limit them to about 450 hp.

Ryan Newman was winning races on fuel mileage last year because they ran 800cfm carbs. The dyno showed they only gave up 3 hp but it paid off, they won at least 3 events on fuel mileage last season.