Hey guys, my cars been seeing the track occasionally during the summers and I wanted to know what RPM is about as much as a stock bottom end 350 could take before it's too risky. The car: 68 350, stock (unbuilt) Bottom end, rebuilt heads with big valves, TA stage1 springs, crower level3 cam and lifters, TA oil pump booster plate and regulator kit, Cast iron intake, HEI set at 13* initial 35* total all in by 2400, Mark Northcutt QJet, hooker headers, 2.5 exhaust, Trishield 9.5" converter, TH350, 3.42 posi. This will be my second season at the track. (I'm getting the fever I think) I typically spin it to 5300-5400 max. Is that ok? Too risky? Not enough?
Cool! What kinda times you running? 5300/5500 I think you'll be ok with the stock nut and bolt rods. I've spun my 350 with the capscrew rods to 6000, and prolly hit 7000 at least once at the track
Okay so I'm right where I should be, thats reassuring. Mark, My best is 14.2 but that was prior to me installing headers. I need sticky tires too, as I can't launch heavy on the throttle. I have horrible 60-foot times lol. My goal right now is to see those 13s!
No certain rpm or Hp level it’s all variable on the particular engine. Over 6000 rpm I would suggest forged rods and lighter pistons.
You should(?) be ok to 6,200 or maybe a little bit more if in the balance from the factory is on the better side of their wide tolerance.
Haha Yes! I did get mine up to just under 6k once but it was on accident, and scared the *+#* outta me
Try not to lose any sleep @ that RPM, if in you revved over 7,000, then that would be the time to be freaked out that your engine didn't explode!
I hit 6200 on the rev limiter with stock but all balanced engine with a 125 of nitrous does that make everyone feel better.
Keep at it Matt! You have the same rear gear as me, I'd get a set of MT DR's in 275-50-15 mount them on 15x8 rims. That's what I have, they ride AND hook AWESOME! I run 28 psi on the way to the track, then air down to 18 psi. I too was having severe traction issues with BFG's 245-60-15 TA radials. Get traction first, then go from there
I have the stock rods (with aftermarket forged pistons) in my '69 350 and spin it to 6200 more than I'd care to admit. I did have the balance checked on the rotating assembly when rebuilt though. I know I hit 7000 once when I was too busy looking to the right to make sure I still had a fender on the car I was running against rather than watching my tach, not a good feeling at all when I looked back at the tach! Seems to run it's best times shifting at about 5600, you can feel it pulling strong and it starts to drop off slightly before 6000.
before current engine setup was stock rods and 30 over pistons and all balanced. with the t/s d/p we would shift at 6500. when i made the s/p intake, we would shift at 7500 and go thru lites at 7500. hitting the wall day was 10,000. all that did was waste the rod bearings. didn't hurt the mains. build it right and the big things become little things. and i am still waiting for somebody to catch up to us abusing the 350........
From my CRS memory IIRC that 10,000 RPM hit the wall run was AFTER you installed the nascar take out rods in the engine in that car. Actually remembering back from your posts, you did the forged sbc 283 standard bore pistons that were 3.875" with the 1.889" rod journal nascar take outs with the factory stroke engine well before hitting the wall? The JB welded S/P intake you built went on the nascar take out rod build with the sbc 283 pistons. So in other words, get good rods in your engines and you won't have to worry about over revving it. You must have a dual plane intake on it, that's right about where those run out of air unless its heavily ported but still wouldn't be able to rev much higher with the power curve rising. Good rods, single plane intake and a cam that makes power past 6,000 would be the ticket on a sbb!(light pistons and a good balance job would help too)
Sorry to hijack thread, But what kind of RPM should the bottom end in my engine handle? my engine is balanced but with stock crank, rods, and stock style pistons(10.5:1 compression). engine pulls stong to about 5800/6000 rpm. TA roller cam, sp3 intake, Heads need ported but they do have the bigger valves, which is why I think its done at that RPM.
Yup, quadrajet carb, stock intake, stock points ignition, TA 290-94H cam, stock rockers, ported heads, TA headers, .030 forged pistons, stock rods, and stock crank. Have abused this engine for almost 20 years and it just keeps taking it!
Sounds like I need to take mine higher in the rpm range too. I shift it at 5000. I must trust the motor! and go for it. I run 14.6. Maybe if I stay in it longer I will reach your ET.
Here is mine with 8500 rpms and 22 psi of boost... stock rods with arp. blew the head gaske but no rod damage on tear down:
