One shouldn't get too "rpm happy". Valve float starts before you can actually feel it, like before the car noses over. It's like literally taking a hammer to your valve train. A 360 isn't a common high rpm combo, but I ran a W-2 360/727 in a 2,800 lb 2x3 chassis car with a 10.22/131 mph best, Started out shifting at 7200. Tried 6800 and it ran just as fast. Each combo is different, but that's my experience. More isn't always better/faster.
I know most people think of a 340 as a high rpm engine but 7000+ and actually making power and being happy there is not pretty normal if we're being honest. J.Rob
Totally agree-A stable, happy and RELIABLE valvetrain @ 7000+ is not all that common or easy. Most 340's I've tested are pretty much done @ 5900-6000--Will they rev to 7000 rpm if asked to--Yes most of the time. Will they actually keep you pinned in the seat all the way to 7000-7500? Not in my experience they won't. Thanks for the comments. J.Rob
All I'm saying is that I know PLENTY of people that take their 340s to 7,500 and all the up to 9,200 rpm reliably making power up there too
Oh, well I don't know anyone that does that around here-whether its a 350 Chev , 302 Ford or 340. Even our circle track stuff is NorthEAST DIRT Mods are limited to 7600RPM and they are all done by 6700-6800 rpm and lose about 75 HP when spun all the way to the limiter. J.Rob
yeah I realize that its very uncommon, I don't know these people in-the-face but I do know them online. .750 solid roller cam and very veryyyy expensive valvetrain helps the 9,200 rpm 340 live. Then again I did forget to specify that is a destroked 340
I think that’s because of the past yesteryears glory days. Now in everyone’s mind they all did that on a regular basis.
It kinda reaches the point of diminished returns. I know some friends personally who have some really quick race oriented stuff and never even see 6200. Some of the RPM talked about here is really unnecessary.
If you got to spin your motor over 6500 rpm especially 7000+ rpm to reach your peak hp goals your probably building too small of an engine.
Vic Bloomer ran/ runs his 340 around 9,000 rpm. 20 over 340 with iron production heads with 1.92 valves, aluminum rods, roller, yada, yada. Its been mid 9’s in a 67 Barracuda at 2700 ish pounds. He broke it few years back, think its back together now, should be out this upcoming summer.
I really don't understand some peoples fetish, or perceived need, to rev their engines beyond the point at which they are providing any return. I swear some people gauge output on sound, not empirical data. Why would you want to unnecessary risk your engine just for the thrill of saying you revved it to some number? Sorry, I don't get it. For perspective, my Superstock 340 with a very large solid roller, peaked at 6850RPM. I highly doubt many of these street engines are making power anywhere near that high. @RAMM this is not directed at your build, I think this is very cool and eagerly await the results.
It all depends on the situation. We truck pull which is basically a drag race with 35.000 pounds behind you. We run the engine to 85-8600 that way when the pan hits it falls into the power at about 7500rpm
