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Discussion Starter #1 (Edited)
Hey guys i have a few questions for you guys. First of all, I'm not the most knowledgeable person about Chevy 350's, I'd just like to pick some of your brains about this, because I know the knowledge on this site is unbelievable.

First of all the 350 I have is bored .040 over, the previous owner said it was 11:1 compression and 4bolt main. It has a comp-cams .507/.507 lift 292/292 duration. Comp-cams #12-213-3. The heads don't look like anything special, I haven't pulled the valve covers.
It has a Demon 630cfm 4 barrel street demon carb and roller rockers.

I haven't really reved this motor up, only to about 4,000rpm. It seems to be making alot of power. The previous owner said it was 400hp, although I don't know, the car really seems pull great once you rev to 3,000ish.

1)How high can I safely rev this engine and it stay together? 5500-6000ish?? Whats the safe-zone usually on an uknown engine. Or can you guys give me an approximate redline from these specs???


2) Lastly, the car has 3.73 gears and a muncie m21 tranny, hooker super comps and a world products dual plane intake. What do you think this car would do in a 1/4 mile, roughly
 

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If it truly is 400hp then with the proper tune and set up you'd have a low 12 sec car in the 1/4. As far as red line or shift points even a stock 350 in good shape can handle 6000 from time to time. Although without knowing the condition of the motor I wouldn't suggest much over that. I mean spinning it a time or two up to 6500 may be ok. As far as what you should actually shift at for a best et. is another story. You don't always want to shift at max. rpm. In you're case you probably will want to shift at a lower rpm because that's where your peek torque will occur. My dyno sim. CD is packed away already, but maybe someone else can chime in with an est. hp and torque curve to give you a better idea on a projected ideal shift point, or at least a good starting point for your first few trips down the 1/4. I can tell you a good friend of mine used to run an almost identical motor combo in his 70 Nova. Only real differences where he ran a Vic. jr. ,750dp, and 4.11 gears. And his best times of around 12.2X-12.4X came from shifting at 5900. Now keep in mind the bigger carb and intake ran the power curve up a little though to.
 

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Discussion Starter #3 (Edited)
The motor is relatively new, it was put together by the previous owner in 2001, with around 1,000 miles on it. Sorry I forgot to tell you guys that.
 

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400fbird,

Your 350 is very similar to the one in my current 1969. The prior owner had someone build the engine. I have a monster sized Autometer tach with a shift light. I hate that thing!! The guy was making it into a drag car before I bought it. He had a full spool in it. I saved it from being tubbed, backhalfed, caged etc. Your cam specs are nearly identical to mine. I think mine is .292/.292 w/ .524. I run 4:10 gears w/ a Super T-10 4 speed. The carb is a Holley 750 dbl pumper w/ mechanical secondaries. MSD 6AL box w/ MSD distributor. I think the compression is 10:1 or 10.5:1. This car is not as fast as my old 1969 which had a 500 HP 396 in it. However this car has some nice bolt on Edelbrock aluminum heads while my 396 had regular cast iron heads. Still hough I'd take my old 1969 over this current project turd anyday!!

I would say if your car can hook and it has 400 HP, then mid 12's like a 12.6 should be easily doable. My old '69 ran high 11's/low 12's on it's best day and that's if it hooked up. I used to race my friend's Suzuki GSXR 600 and that was a high 11's/low 12's bike.

As far as shifting you should be in your power band anywhere from 5,200-5,800 RPM's depending on your ignition, carb, heads, bottom end, rear gears. Mine likes the 5,600 RPM range although I've gone to 6,500 and it held. Don't go there!! The seller told me he had it built to hold at 7 grand. AGAIN, DON'T GO THERE!! I bought the car last summer but I hardly drove it since September as I've been working on it now for several months.

I'm not Mario Andretti or Dale Earnhardt Jr but 5,500- 5,800 RPM should be ok. I would say 5,600. It's scary but your '67 sounds alot like my current '69. I haven't taken mine to the track, but like yours it pulls strong around 3,000 RPM. Enjoy your car & Good Luck!!
 

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Forged internals..youll float the valves before you have spun it to high.
DO NOT DO THAT.
Cast internals.. stop around 5500 when racing, around 5k when playing on the street. Launch around 3500 and shift 1-2-3 at 5900 by then you should be close to tripping the light if it hooks good enuff...if the internals are cast let the engine idle after EVERY PULL to let the bottom end cool down enough or youll warp/twist the crank. JMHO thats what I would do.
 

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Warp/twist a cast crank?? Never heard a that one, wiskee??

Now BREAK, yes! cast crank if ran at the torque peak under a severe load for a long time, break indeed!! Like a Big Boat or a loaded Dump Truck pulling ALL the time..

I figure a cast bottom end should be good for 6 to 6500 OK, imho....

Not all the time mind you, but occasionally(Sp?)..

400bird,

What gas you running in your engine?? I ask b/c I DO figure at 11 to 1 you will want good gas in her............

pdq67
 

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Discussion Starter #7
thanks for some of the info guys. I don't really plan on abusing the engine. Probably keeping it under 5 grand. Just because I'm pretty cautious, I just wanted to get a ballpark range about this motor.

I'm still trying to learn, so any bit of info from you guys helps.

pdq67: I'm running 93 octane with no problems.
 

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just drive it cautiously at first, and just kind of keep pushing it harder as you get comfortable with it. you will learn it's limits and what it likes over time.
 

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Warp/twist a cast crank?? Never heard a that one, wiskee??

.......
I have seen a few cranks pulled that when looked at closely you could see the counterweights werent square with crank centerline, in-a-sence, we caught it before the break. Its actually kinda neat to see, all the main berings have a cool looking blue color.....

Diddo Novaderrik...as you drive it you will 'learn' its likes and dislikes. Chevy engines are real good about letting you know their likes and dislikes...
 

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Knock on wood, I've had good luck wih 350's, a 327 and a 396. My friends had good luck with 427's and the 454. I can't say the same for that piece of garbage 305 that was in my 1984 5.0 H.O. Z28. The cam went flat at 92 or was it 93k miles. I despise all 305's. The 305 is nothing more than an overpriced boat anchor. I also liked the Chevy 307. That was a reliable engine as well.

wiskeesour, I totally agree with what you said in post #5
 

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South Side, I take it you dont like 305's?
 

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I don't know about you guys...but I'm in the process of building my small block 350 bored out 4.030 and I'm plannin on having a redline around 7200 rpm's. You guys out there shifting your 350's at like 6000 and lower...what's going on guys? The 350 can hanlde more than that. However, I do have all forged internals and splayed caps so...maybe I'm a litle better off than most setups out there. Of course my engine will basically be built as strong and tough as the dirt track engines in many sprint cars pushing around 7500 and 8000 rpm's in their 358's and 410's. I don't mean to sound like an asshole just I don't know...if your'e gonna race a 350 and plan to win against competition...you need to shift a little higher than 6k. But yeah...even though my engine won't see too much drag time...it'll still be pushing around 7000 rpm even after I set the rev limiter on it.
 

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305`s have some great uses...if you need to hold a giant piece of paper still...if you have a really big kite that will pull you away...if you need a place to chain your dog...to tie behind the car at a ******* wedding...if you need something dragged to the bottom of the lake quick...(the wife didnt like that one...lol...)if cast iron ever becomes a desireable commodity...
 

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and ps, if your cam and intake wont support more than 5800 rpm, why would you go past that???just cause a motor will freespin to 9800 rpm doesnt mean it is making power tghere...just the contrary, you will lose power past your peak hp point...in addition, depending on valve springs used, the valves will float, and potential damage can occur at much lower than 7500 rpm..bigblocks rev much lower, generally, because they use much larger valves...heavier valve trains are much harder to control, so extremely large springs are used...much higher spring pressures are neweded to control valve float, so much better, and more expensive i may add, lifters are used...no matter what engine you run, a red line isnt where the engine will blow up...only where the engine runs out of "lungs"...spinning it up past that only increases engine wear unnessecarily...
 

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Again forged internals make about 2000rpm difference. Unless you are the only v8 2-stroke in the world.....7200 with forged internals is close to all a Chevy can take and still make power. Any harder than that you need to remove weight, I.E. the two rear cylinders. Believe it or not.
 

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Hey guys i have a few questions for you guys. First of all, I'm not the most knowledgeable person about Chevy 350's, I'd just like to pick some of your brains about this, because I know the knowledge on this site is unbelievable.

First of all the 350 I have is bored .040 over, the previous owner said it was 11:1 compression and 4bolt main. It has a comp-cams .507/.507 lift 292/292 duration. Comp-cams #12-213-3. The heads don't look like anything special, I haven't pulled the valve covers.
It has a Demon 630cfm 4 barrel street demon carb and roller rockers.

I haven't really reved this motor up, only to about 4,000rpm. It seems to be making alot of power. The previous owner said it was 400hp, although I don't know, the car really seems pull great once you rev to 3,000ish.

1)How high can I safely rev this engine and it stay together? 5500-6000ish?? Whats the safe-zone usually on an uknown engine. Or can you guys give me an approximate redline from these specs???


2) Lastly, the car has 3.73 gears and a muncie m21 tranny, hooker super comps and a world products dual plane intake. What do you think this car would do in a 1/4 mile, roughly

I had the same cam (Comp Cams 292) in my 327 +.040 and a few diff. sets of double-hump heads. I routinely revved mine to 6500 in 1st and 2nd gears. I did have ARP rod bolts. That's the unknown strength equation of your engine combo. In racing, my heads just didn't really flow up at 6500. I thnk you should stick to 6200 on that unknown engine.

Do you know what heads you have? If you pull off the valve cover, you should see it embossed there. I or someone else can try to look them up.

If you're engine, traction and gearing were dead-on, you'd have a 12 second car but I think realistically you'll find yourself in the 13's.
 
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