FE Guys: 6,000 RPM

[Bernica]

C'mon guys, who is running their big block in the 6+ RPM range? And if you are, for how long?

[undy]

6K rev limit for my KC Pond 482.

Short of a very light weight rotating/valve train assembly...or... with a solid flat tappet or solid roller 6K is about the limit.

[mdross1]

Have to say motor was built to spin near 6k, what few times have had to use it's capacity too busy keeping an eye on things to look down at the tach.Certainly not afraid to do what it takes to get the job done.Talking only drag racing conditions have not had the priviledge to get out on a road course yet other than what we do up here in the country.
Honestly that is part of the reason why big blocks are such a good choice for me,never get sick of having the big grunt all the time.

[flipscobra]

I know you have to have a rev limiter because mine will hit the rev limit before a cat can lick his butt.

[Ron61]

The horsepower on mine topped out at 6300 RPM but I have the rev limiter set at 6,000. The engine is old and I don't need to be driving it at high speeds anyway. Especially with the original tires on there and they are 44 years old. When I blow it out I do so in 2nd or 3re gear so if one of the old tires does explode I won;t be going so fast and tear the car up.

Ron

[Clois Harlan]

My 427 C.O. .015 over consistantly turns north of 6000 RPM. However, unless you build your engine right I would advise against pushing that 7000 RPM window. I did at Texas Motor Speedway about 6 years ago and it scattered bits all down the front straight away, starting at the end of turn 4. Now, saying that I will say that particular engine that let go had a legitimate 4000 race miles on at the time it let go. I believe I got my moneys worth out of that build. I sleeved the block and sold it to a guy in Austrailia for $600. Most of the rest of the engine is on my current build (heads, roller rocker arms, intake, carb, MSD Dist. etc). Crank, cam, one rod and 7 pistons, and all the valves and push rods were trashed

[Cobra #3170]

7200 to 7500 regularly engine is chipped at 7800 peak power is @ 7500. Carrillo rods, Moldex crank, Ti in and Ex. Solid roller Crane cam. 500 HP at 4500 rpm, you have to RPM them to make any real hp.

[patrickt]

My "weak sister" FE glides right by six grand without batting an eye. SCAT "short stroke" 4.125, Wiseco pistons, solid flat tappet, Ersons, Blue Thunder intake, Edel heads, aluminum flywheel, rev limiter set at 6400, and I bounce right off it when I'm not paying attention. I think it would do that all day with no ill effects.

[Bernica]

For me, at 6K in 4th gear with a wide ratio toploader and 3:31 rear end, I end up having all kinds of things on my mind. Like tires blowing, windshield folding in my lap, flying parts etc. Just need to find enough safe roadway. A better cardio workout than a treadmill when you're done though!

[FWB]

Originally Posted by undy

6K rev limit for my KC Pond 482.

Short of a very light weight rotating/valve train assembly...or... with a solid flat tappet or solid roller 6K is about the limit.

agreed on the solid cam and roller......but factory valvetrain and bottom is fine up to 6500.........lots of dragstrip time with factory parts in the past. at one time factory nut and bolt rods and valvetrain were all there was to use unless you had very deep pockets.

if running a dual plane manifold, your done at about 6200 anyway. why make more noise when the "go is gone"

[Rick Parker]

Lets talk about Dick Smiths 198 MPH...........

[FWB]

you like to talk Rick....go ahead......we all sit on a tack waiting for your responses anyway

[JBCOBRA]

422 Motorsports
Some of these guys come out of the hole at 9500 rpm's

[601HP]

427 @ 0.030" over.
Ford forged crank with stock 3.78" stroke.
22# aluminum flywheel.
H-beam rods.
11.0 to 1 compression ratio.
Single plane Tunnel Wedge.
Solid roller cam, .639" and .667" lift. 252 & 262 duration @ 0.050".
Crower lifters.
Erson roller rockers.
KC Stage II heads, 2.25" int. valves with 570# springs.
I nail it at about 4,000+.
MSD limiter trips at 7,000. I go there often.

4-speed Toploader.
3.70 9" rear.
Billboards.
8.5 ish mpg.

I shift my Toyota Yaris at less than 3,000.
42 mpg.
David

[Cobra #3170]

Originally Posted by Rick Parker

Lets talk about Dick Smiths 198 MPH...........

198 MPH = 17424 ft/min
29" tire D. x Pi = 91.1"
91.1 / 12 = 7.59 ft/ rev
17424 / 7.59 = 2296 RPM at the tire
2296 x 3.31 (Rear end ratio) = 7599.7 RPM (engine)

Tire diameter is assumed, could be taller, a 31 " tire = 7120 engine rpm

[Rick Parker]

The point I was hinting at (thank you FWB) was that although Dicks car was not a stroker as many of you are discussing he didn't achieve the claimed speed at Daytona of a 198 MPH by adhereing to a 6000, 6500 or even a 7000 rpm limit. At the WSCB a few years ago I had the opportunity to have Dick and one of his engine builders at my dinner table. One of the main questions I had was how they did it. He said they were running Firestone tires which were a little taller than normal. He felt they grew 1 inch in diameter speed (?) He didn't remember the gear ratios but said they pushed the engine to extreme RPM levels but only in 4th gear and used the brakes for slowing the car not the engine, (no downshifting). I'll let you guys do the math.

[dcdoug]

My old school standard bore and stroke 427FE with Lemans rods and TRW pistons (valve train is modern though) will easily rev past 6,000, but I try not to go past that and have my rev limiter set at 6,300.

[gsharapa]

Mine will go 7,200 but made peak HP at 6,800. It was built to take the HP band and tork up higher with solid roller, T&D shaft mounted roller rockers, aluminum flywheel etc. I wanted it to spin faster and knock down some of the tork down low since these cars are so light and mine even a bit lighter with carbon fiber body and all aluminum motor. Keith Craft did a great job with this one....

[Morris]

Originally Posted by Cobra #3170

7200 to 7500 regularly engine is chipped at 7800 peak power is @ 7500. Carrillo rods, Moldex crank, Ti in and Ex. Solid roller Crane cam. 500 HP at 4500 rpm, you have to RPM them to make any real hp.

Ditto and we hold it there on the corners on the NASCAR tracks....

Pulls like a freight train......

[rpatton3]

Dick Smith's car was not a dry sump engine, was it? This was a mechanical marvel considering the big windshield. What horsepower would be required to do this 198 MPH miracle?