Best guess on Max. RPM for 360?

[CJ5]

I have purchased a book on Holley Carbs. I thought since I run one and have little experience with carbs maybe I'm not to old to learn. I have actually learned alot already. Anyway, you can use a formula to determine which carb is best for you motor. Basically its Cubic Inch x Max. RPM divided by 3456 = Carb CFM. This will give you a general requirement. You have to take into effect the effeciency and other factors but this gets you in the general area.

Looking at a basically stock AMC 360 what would you guys figure is the maximum RPM for this motor? I am sure there is a curve effect and I assume they mean at the top of the curve and not before explosion smile.gif . Any thoughts?

[Lindel]

Your rpm limit is going to be near 4000, give or take a 1000. Valve float is the limiting factor for these motors.

Even with an Edelbrock Performer/1406 carb, mine won't turn much over about 4000. However, with a 4x4, the main focus isn't high revs, and big hp, it's low revs, and high torque.

Unless you're building one for mudding, exclusively, don't worry about the high end rpms, and throw a holley 600 w/vacuum secondaries on it.

[CJ5]

Thanks Lindel,

The 360 in the CJ is used for semi-hard offroad and daily driving. I figured 5000 for top RPM so I was close.

I got the holley book to learn more about carberation in general and also how and what to trick. I wanted to double check what I got was appropriate. It is with the exception of the mechanical secondaries. I have since learned what you said and that is for off road your better off with vacume secondaries. Oh well! But I did get a 650 CFM Carb (4150 p/n O-4776-c). Its also a double pumper. Not sure I needed that now either. I am in the process of decideing which power valve I need. I was thinking running with my vacume guage hooked up in the cab and monitor my vacume under different circumstances. This should give me the info I need on power valve size. Either single opening or a dual opening.

So, I got long winded. Thanks.

[CJ5]

BTW Lindel, notice in my sig I'm looking for a FSJ project? I wanted specifically a '79 Cherokee Golden Eagle.....you got one! That is by far (IMHO) the best looking model they made. A friend had one in high school when they were new. We tried to tear it up and couldn't. I was/is the baddest. Let me know if you ever run across another. BTW, can you get new stickers for them, in case I ever find one?

[Lindel]

The standard tranny will buy you some leeway on the carb, so you might not be bad off. You'll want to adjust the secondaries so that they only open up on the freeway, and not on the trail somewhere, that could be embarrassing, and dangerous, all at the same time.

You'll most likely never use the secondaries, unless you turn high rpms on the highway, and then you'll feel it more in the wallet, than anywhere.