bigmack

yea this is my first race motor and i got these heads in a trade so i'm running them for now, i had a 355 but it was just a 10 to 1 motor and i shifted around 6500 rpms. the 383 is about 12 to 1 and last year i was so scared to shift it over 6800 because i didn't want to blow it up. but the car ran ok at 6800 rpm's but i never try it any higher and it's killing me to know lol!!!

zipper06

If you have a good balanced rotating assy, 7500 is not dangerous if you have the proper clearance's and the cam is still pulling at that RPM. I know with the .624/.624 roller i had with track 1's it was finished about 7200. I've ran a .630/.630 roller with better heads and it would pull past 7500 RPM's. It all depends on how good your combo is and where the peak torque is. If it slows down by shifting at the higher RPM, then obviously the peak torque range is lower. Heck i had a friend running a Nikens and Brown 292" motor that used to come out of the hole petal on the floor 10,000 RPM's and shifted at 8800. Dam car ran 8.80's @ 2350 lbs.

Bottom line if you have the good parts, try the higher shifting points, if it runs faster stay with it, if it slows down just drop the shifting points, your motor will tell you.

JMO

Zip.

bigmack

yea i baby this motor all last year and it's got all good parts in it. like i said i never shifted that high before and was just a little scare. but i can't wait to get it back out there. i just wonder what it would have ran at the higher rpm's i'll keep you guys posted.

cepx111

No harm in that, babying a motor that is.

I still get the willys everytime my BBC is reving into the 7's - lotta metal slinging around in there, anything could happen.

I'll be the first to tell you I love going fast, but at this point I'm all about motor longevity too, all the things I've done to my set-up in the last 6 months have been about lowering RPM's and making the motor/trans/car more efficient & more consistent.
Fast isn't always consistent, unless you run in a heads-up class or you just want to 'go faster' (been there done that) there is really no point in it if you run bracket races, other than it's fun and it gives you a starting line advantage (opponent red light/bad light/mistake)


Buddy of mine runs a 3rd generation camaro, nice roller cammed 383, all forged/balanced internals, he never rev'd it past 6200 (shift) as long as I've know him.
The motor is very capable of reving way into the 7k range, but no matter how hard people try to convincing him to it - he wont.
The motor is going on it's 6th season this year - the only thing he's done to the motor > routine maintenace.

Lots to be said about going fast, reving it to it's peak every pass definetly puts more undue stress on a motor but bottom line you gotta do what "you" want to do.
My buddy? He's happy running middle 670's
I'm happy running 560's, that is, if the converter tweak, (tighter) makes it any faster!! :lol:

So you gotta ask yourself, how fast do you want to go?



Cp

bigmack

yes that's it i keep telling my friends that's running in the low 9's high 8's i don't want to run that fast if i get it down in the mid 10's this year i'll be happy i'm making a couple of changes this winter hopping it will put me where i want to be. but you know what they said, yea right mack lol!!!

JEFF69Z28

SHIFTING MY 406 AT 7000-7100 ALL DAY.

bigmack

track opens feb, 27 at edgewater in cincy hope to have the car out testing and see how it likes more rpm's. jeff what kind of car you have the 406 in.

fullspeed383

hey bigmack i shift my camaro at 7200 and it's got a 383 in it and it runs 10.70's all day long.

bigmack

well i forgot to update you guys, well i did some work over the winter i deck the heads put new valves and springs in and install the larger cam well my best time so far is 6.83 @ 100 and 10.74 @ 125. shifting at 7200. but i think the car is faster i call ptc about my converter and they tell me i'm running a 3000 to 3500 stall converter a street/strip converter for 373 to 410 gears and i need more stall. man now i need a converter if anyone have a 5000 to 5800 turbo converter for a 3200 pound camaro let me know.

JEFF69Z28

86 SS MONTE CARLO 3165 WITH ME IN IT BEST PASS 10.27 @ 130 MPH.
AFR 210'S,SOLID ROLLER CAM 260/264 @ 50,688INT/678EXH,SUPER VICTOR PORT MATCHED,PRO SYSTEMS PREPARED 850 HOLLEY,TURBO 350,4.56 GEAR.