On the '92 FB (stock 305), I am surprised the redline is only 5000. Is this a common sbc number?

Weren't most 2nd gens ~5500 or better? Different animal, but my old Pontiac factory redline is 5750 with the 400--and Pontiacs were built for low rpm power/torque. It just doesn't make sense to me. Was it limited because the 305 didn't make any power anyway so there was no point pushing the revs, or could it really only handle that speed?

Just curious, nothing I want to change. It hardly ever spins over 2k driving.

Thanks

The low output engines like the 305 TBI (with any trans behind it) and the 305 TPI + auto trans combos both used the "peanut cam" in them which just won't breathe any higher than that. They all got the 5000 redline. The higher output engines like the 305 TPI with manual trans or 350 TPI had at least a mild performance cam in them from the factory and the stock tach redlined at 5500.

You can read about the various year engine options and other little things like why your tach redlines at 5000 instead of 5500 over at Thirdgen.org where they have year-by-year listing of available engine, transmissions, rear end ratios, a little bit of stock cam information and what changed from one model year to the next. It's actually kind of a fun and informative read if you start in 82 and go all the way up through 92.

Any push rod motor will have a fairly low redline... Having all those parts flying around much higher will definitely cause problems, not to mention valve float.

Any push rod motor will have a fairly low redline... Having all those parts flying around much higher will definitely cause problems, not to mention valve float.

My pushrod engine (SBC) comes close to 7K RPM, and it isn't even anything wild.

Thanks Damon,
I have read some of the stuff over there, but I have so far resisted joining. We have a much more active community here (and the older cars are better/more fun).

Camaroz: That was my point. I know about the old technology limits but I always thought 5500-6000 was normal, 5k just seemed stupid. I just didn't know if they put in such a weak valvetrain that it would not work higher--designing the entire system for the low rpm, low power motor or if it could rev more and there was simply no point.

Full throttle shifts with the automatic are @~4k, btw, so they were staying low on everything. There really is no point to these motors except reliable 150,000 mile slow speed use and good mileage (for most, but not this one--I'll save that gremlin for another thread).


Cmonson--yeah I knew it shouldn't take much. Just surprising how much things changed in the last 40 years. From high power high rpm, to low both, and now back to high again... (stock, I mean)