Does anyone here have first hand knowledge or even an educated guess. The engine is stock rated at 188hp @ 4800 rpm, so I try to shift at 5000 rpm. A few times I have run it over 6000 and it was still pulling strong. Specs: 1951 F-1 truck, 264 with WCFB from a 322, dual exhaust, 3.96 gears, advanced timing an extra 5*, unknown cam (no markings corresponding to the original). This thing is fast and a blast to drive...I have even scared the sh...er snot out of some friends that were used to the old flathead. It even got 17 mpg on a 175 mile trip to a car show. I just want to whip as much performace as I can without blowing it up. Willie
Depending on the cam,,, I would say that about 6000 is right..... from what you say that Buford is pretty well sorted out....
:grin: :grin: :grin: There were some dyno runs done on 401's.....they maxed out at around 4800 rpm. I have a modified 425 that pulls to 6000 easy. Not worth going higher. 5500 is plenty on a stocker. Tom T is the expert here.... Concentrate on the torque, and forget about the 5500+ rpm hp. I bet you could improve the breathing with some 401-425 heads and some roller rockers!
I regularly ran my 264s to 6,000 rpm. A couple of times I twisted them until valve float. I never broke one. I love the now-rare 264s.
Actually , I did turn my first 401 up to 6500,,,, but it had pretty well leveled off at 6000 and wasnt making any more power.... not what you would want to do.... just did it a few times.... a shift at 5500-5700 is better....once the cam runs out of wind, you just as well shift.... Like walt says go for the torque,,, not the rpm.... some engines will do it , some wont... generally speaking, smaller cube engines will go higher than big cube engines... because of the mass....
Usually I see you posting how nailheads are torque engines and don't rev, but this thread is got people going over 6k!:Brow:
for a nail to go that high in rpm's i would think that it would put a terrible strain on the bottom end. you would need the cam but also some stiff springs. unless you are a pure racer i would never try that. remember the seat of the pants feel is torque. jmho jim
It is a strain on the bottom end, but the nail has a verrry strong lower assembly....no worries there, if every thing is assembled right.....
Thanks for all the replies. I will probably shift at 5000 and not worry if it pops up to 6000. 5000rpm in 2nd=50mph; 50mph in 3rd=2400rpm...2400rpm is the peak torque (256)...seems to be a good place to shift. Speaking of torque and shifting, there is no need to shift out of 3rd above 10mph. Willie
The main reason for my love of nailheads is the bottom end. I would be hard put to think of any V8 that is stronger. As a person a lot older and hopefully wiser then I was 45 years ago, I would not twist any nailhead to 6,000 rpm. They will do it, but as Doc has repeatedly said, nailheads are torque motors. You might as well use them the way that they were intended to be used.
A well built nailhead will actually rev to 6500,,,,, BUT after 5800 to 6000 it isnt making any more power it is just windmilling... i like to have the gov in the trans do my shifting,,, at 5800,,,, most all street driven hyd. cams are all done by that time any way.... A Buick factory rep told me that they did not recommend going over 5500....any way rpm is for small blocks, a torker is best.... torque is what actually moves a car... or truck... When I was a locomotive engineer the engines that i ran would run over 100 mph in about a mile.... but they only turned 850 rpm..... and had massive amounts of torque.... rpm doesnt move a car....torque does....brute twisting force.....:laugh:
Doc, You were a locomotive engineer? WOW!! Believe it or not, the first piece of self-propelled, powered transportation equipment that I ever operated (in 1949) was B&A ALCO D1A 466T #403! I also many decades later had the opportunity to be at the controls of a GP-16 for two hours. Awesome!
Yep , John, 28 years,,,, i have handled every thing diesel,,,,, no steam engines though.... there are 3 things a good engineer must know ,,, how to brake, how to pull without spinning and how to ''stretch'' a freight train....to stop the cars from rocking side to side... the biggest train that I have ever handled was 214 cars of wheat, 13 working locomotives, you did not do anything suddenly with that one.... in all my years I only got 2 knuckles and one drawbar....had a bunch of derailments,,,,the thing that took the most skill was running in these Tn. hills,,,,, like being on a roller coaster...crest over a hill, the cars take off , 20 lb air brake, bottom out , start pulling up the other side, no. 8 on the throttle, release the brake and hope we dont lay down going up the other side....loved railroading...hit 21 automobiles in my time,,,made good money...
Doc, Not to hijack the thread (they all say that before they hijack the thread), I saw a LI RR training film. One thing that struck me was that all engineer trainees were asked if they could deal with a fatal grade crossing accident. The train always has the right of way, but people are idiots. The training instructor said that the average LI RR engineer will have one fatal grade crossing accident in his/her career.
I was lucky, never killed any one in those and a lot of them were actually funny... because as you point out some people are stupid.... the first one that I hit was a big buick wildcat,,, that the guy had parked on the track and walked off and left to visit his neighbor.... I had 110 cars behind 1 switch engine and there was no way I could stop....
