The Stovebolt Site Forums The Shop Area Engine Shop Chevy 261 RPM

So this question has probably been answered numerous times, but I have done some googling and haven't came across a straight answer by really anyone. Was wondering what the top rpm of a chevy 261 would be? Took my truck to the track this past weekend and have a rev limiter that is set at 4300 but I'm about 20-50 feet from the trap and I'm hitting the rev limiter. Was wondering if I could take it to say 4500 and be ok? Motor has a 3/4 race cam and a fresh head that was just redone.

4500 should be fine, you may need more spring pressure, saying "3/4 race cam" really means nothing you need to know lift, duration, overlap, lobe centers etc. Or is this the one Patricks sells? I don't know off the top of my head, but there are guidelines for spring pressures/lift/RPM. You would have to look it up. According to California Bill, if you have a good balancing job, the stock rods are supposedly good for about 5000 RPM. Don't know as I would do it with the stock rods though.

How about for those of us with stock 261's, what's considered the sweet spot in the RPM range?

Guess I'm asking about the best useable point where its not lugging or past peak torque?

-Mike-

What year 261? there were slight differences over the years.

It looks to me it would be a little under 3,800 RPM for peak HP in 1958 with the stock/standard "high lift" cam shaft. The torque does not degrade quickly - this was a design goal/feature of 261s - good torque from relatively low to relatively high RPM (1,000-3,500 RPM).

My standard cam 261s revs/runs smoothly at 4,000 RPM (in lower gears) but I do not drive for distances at that RPM. 90 MPH is under 3500 RPM in my Suburban (3.55 rearend). 65 MPH is around 2,500 RPM.

Thanks Tim,

Mine's a 58 so the link for the graph should be spot on! Now I'll be able to determine optimal cruising speed for my truck though it will be a bit slower for a geared down Army truck. Once I get the tachometer hooked up I think I'll be looking at about 40 mph.

-Mike-

Thanks guys for the response and hopefully Mike you got your question as well. I did call up Patrick out in Arizona and he said I will be fine as well for 4500 rpm's or so, but just like any motor that is driven hard or on the track there is going to be more of a chance of it failing at some point. Thanks again, Jeff.