my 64 FI doesn't rev up very high. It has hydraulic lifters and i know those limit revs. I dont want to push it past the 4500 mark because it gets REALLY noisy with my chambered exhaust and sounds like its about the limit. The redline is 7000 so i know originally it had more to give. What RPM do you guys with solid lifters reach in the high horse small blocks?

 

What's the point of seeing how high you can turn your motor. Are you a masochist or what. After you hit the peak horsepower, usually governed by your camshaft, any more is just abusing your mill. Why? Most hydrallics peak out at below 6000, some 5000. Solids with a racing cam maybe 7500-9000max. I remember Grumpy Jenkens coming off the line at 9 grand, what a screaming small block, I think a 331, (327+.30), in a VEGA.

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

 

These are OLD engines and metal, don't abuse them. The times of leaving 100' of rubber on the road, and high rpm power shifts should be out of our systems by now. But Oh for the old days, when we didn't give a ****. Bill

 

around to the 'H in the letters TACH

 

6500 without blinking. could go higher I'm sure but I don't want to mess around.

 

Almost forgot -- one time my accelerator pedal got stuck under the edge of the carpeting and the tach went way past 7000 until the points bounced. It was bouncing around so bad I don't know where it ended up. This occured during a 1-2 shift (free revving when after the clutch was engaged) and scared the crap out of me. The engine is remains ready for more abuse.

Brian

 

i can always pull 1 RPS (rev per second) more than it takes to grenade any engine.... when i ran a gasser in the early 70s with modded 327s and 4 speeds i would always exceed the RPMs at the end of each season and blow the engine to learn it's limits (to learn the limits of any engine you must exceed them) this way i could see what failed an improve the build. most of the time at the end of the season it was just a bang.

i raced my gasser at the long gone Fremont raceway in NorCal. at the end of one season i revved the engine to the moon. the engine grenaded at the top of second gear. about at 70 1/3 way down the strip. it was by far the worst engine failure i have ever had, the car instantly filled with oil smoke. i could not see where i was going. everybody enjoyed the show (my gasser was built for traction-it NEVER burned rubber--it just did wheelies) i managed to get the car stopped and everyone had a good show.

of course everybody loved the blown engine episode, but they hated the 10 quarts of oil my engine dumped on the track.

autopsy, at my shop, a forged piston head seperatated from the piston skirt at high RPM. the top of piston slammed into the the valves. the piston skirt desintergrated, that loose rod was slinging around at 6 grand, it cut my engine in half, it was a wild ride...

 

I've had mine up to 3,800 RPM's, once.

 

I try not to run more than 7000 rpm. I have set the Rev limiter on the Ignitor III to 6900. In my past, I have been able to consistently run 327s and 350s well past 7500 without ill affects.
Back in the 70s, I launched my 62 Corvette at 8500 and shifted at 9000. When I took the engine out of the car a year later, it needed nothing. Sold it to another racer who dropped it in a 57 Chevy and ran 2 more seasons before a rebuild.
I've never lost a small block. Proper maintenance helps.

 

My little solid lifter 283 is good to 6,200 RPM which I passed handily after I first got the car and the accelerator linkage stuck in the incorrectly installed ignition shielding. A tough little motor.

I've left the Ignitor III at the default 5,500 RPM as that is more than high enough for my driving..

 

What are the cam specs? What heads are on the engine? What is the compression ratio? Do you know FOR A FACT that the FI unit has been properly dialed in? (FI units are quite capable of working to 8000 RPM)

It's quite possible you've got a poorly matched set of components that, taken together, limit your engine revs.

Jim

 

its not FI anymore, its the FI block.
it was totally machined and rebuild. now has a 64' holly on it

this is the cam he put in it but it was custom ground to be slightly larger the the 365 horse cam
http://performanceparts.com/part.php?partID=247293

hydraulic lifters

heads i believe are original, ported and polished

1964 winters aluminum intake manifold

The engine was defiantly done right. all work was done by Harris performance & Machine (i have the receipt). i have an engine blueprint with all clearances.

i just dont want 4500 to be my cars absolute limit. I want to be able to take it on the highway and not feel like the prolonged 3800 rpms is doing harm. (3.70 rear end)

 

What other failures did you see? An engine expert over on NCRS is warning about stock early connecting rods being unreliable.

I saw the same piston failure on production 396 hydraulic cam engines in 1969 on the Chevy durability test...with a similar result. The 396 block didn't break, they were tough, but only the opposite bank's cylinder head wasn't trashed. I did see a 350 block break in two...what a mess that made.

 

What makes you think 4500 is the absolute limit? What does it do over 4500?

If you're turning 3800 rpm at 70-75 mph, you have a 4.11 axle.

 

I never got that memo........

 

Now that's what I'm talkin' about!!

 

With a non-roller performance hydraulic lifter cam (such as the L79) and relatively new valve springs, 5800-6000 would be a normal limit. 5500 is obviously safer..............

Other lower horse camshafts may only rev (up to peak horsepower) in the 4500-5000 range.

But many other engine factors also contribute to a "rev limit". If you really want to determine what the engine can do (performance wise), and have faith in it holding up without catastrophic failure, then put it on a dyno.

Just note that hydraulic cams can experience valve float at their upper rpm range, and that float (where the spring can no longer hold the lifter in contact with the cam lobe) will result in lifter pump up, which can cause valves to contact piston tops with unpleasant results.

Plasticman

 

7,000+ and still pulling with my 70 LT-1 short block and Dart Iron Eagle heads.

 

Power band for a healthy L79 (327/350 hp) cam. Really no point in revving it beyond 6K.

 

LT-1 is a solid lifter engine. OP said he had hydraulics.........

Plasticman