Max RPM of a 565 BBC

[overdriv]

Hello, this is my first post and want to introduce myself. My name is Phil, I live in central Illinois. I have a 87 Z28 on the half shell, building it to do a bit of racing. I have a 565 tall deck BBC with eagle rods, eagle crank, JE pistons, Profiler heads, Dart intake. I plan on a 1050-1150 Dominator on E85. It has Rehyr-Morrison 420-116 cam, Isky roller lifters, Smith Bros pushrods???, Next-Tec springs and T&D shaft mount 1.7 rockers. I have no real idea how much HP it has. My desktop dyno puts it at 790 @6500, I suspect a bit more.

I bought the engine from a RED racer, says it has 60 1/4 mile passes. I have not taken it down yet but plan to pull the pan and take a look at a few bearings.

My question is; what is a safe RPM to turn this engine? What do you guys with big tall decks turn?

[supernova]

It depends on what the heads flow. The R-M cam you have will spin the motor to the moon but the heads may limit the rpm. 7000-7200 is a good place to start for that combo. If the heads are good (which they probably are) the motor may like to spin higher but testing will tell you more about that.

Here's Reher-Morrison's web site: http://www.rehermorrison.com/rmEngines.htm

[ytnova]

Like supernova said, it will depend on the cam/cylinder head combo. Being a tall deck will have no bearing on what rpm you should spin it. Mine is a short stroke, long rod, big bore combo 522" tall deck that I turn 8500.

[overdriv]

Thanks for the insight guys. I know the race RPMs will be determined by the head/cam/CR, etc. What I'm concerned with is the max RPM the rotating assembly will reliably handle. Long life of parts is what I'm interested in.

My desktop Dyno says 790hp@6500, 682tq@5500. The only fuzzy numbers were the head flow#s. I took their flow numbers on their new heads, but mine are older and probably aren't as good. But they have been ported, so I'm told.

[supernova]

Thanks for the insight guys. I know the race RPMs will be determined by the head/cam/CR, etc. What I'm concerned with is the max RPM the rotating assembly will reliably handle. Long life of parts is what I'm interested in.

My desktop Dyno says 790hp@6500, 682tq@5500. The only fuzzy numbers were the head flow#s. I took their flow numbers on their new heads, but mine are older and probably aren't as good. But they have been ported, so I'm told.

I wouldn't trust the desk top dyno. Use for reference only. R-M has a 565 on alky with the same cam thats in your motor and it makes a lot more power than the desk top dyno shows you. There motor has Dart pro 1 355 heads on it and makes over 900 hp.

I have several dyno programs and use them to help but I don't take them as the last word. They get close but only a true dyno run will tell you the truth.

The motor I have is a 525 ci (tall deck, 4.310 bore * 4.500 stroke) with 12.1 compression, Dart Pro 1 325 heads fully ported, a much smaller cam (.716 lift) and made over 800 hp. no nitrous. Just the size of your motor with that cam should make more power than my motor. I would say at least 40-50 more hp. than my motor depending on how efficient the heads are.

As far as rpm's go, I wouldn't spin the thing to 8200. You will probably find that 7000-7200 will produce plenty of power and is a safe rpm for the components that are in your new motor.

If that isn't enough run it on gas and put the juice on it.

[overdriv]

Thanks for the insight guys. I know the race RPMs will be determined by the head/cam/CR, etc. What I'm concerned with is the max RPM the rotating assembly will reliably handle. Long life of parts is what I'm interested in.

My desktop Dyno says 790hp@6500, 682tq@5500. The only fuzzy numbers were the head flow#s. I took their flow numbers on their new heads, but mine are older and probably aren't as good. But they have been ported, so I'm told.

I wouldn't trust the desk top dyno. Use for reference only. R-M has a 565 on alky with the same cam thats in your motor and it makes a lot more power than the desk top dyno shows you. There motor has Dart pro 1 355 heads on it and makes over 900 hp.

I have several dyno programs and use them to help but I don't take them as the last word. They get close but only a true dyno run will tell you the truth.

The motor I have is a 525 ci (tall deck, 4.310 bore * 4.500 stroke) with 12.1 compression, Dart Pro 1 325 heads fully ported, a much smaller cam (.716 lift) and made over 800 hp. no nitrous. Just the size of your motor with that cam should make more power than my motor. I would say at least 40-50 more hp. than my motor depending on how efficient the heads are.

As far as rpm's go, I wouldn't spin the thing to 8200. You will probably find that 7000-7200 will produce plenty of power and is a safe rpm for the components that are in your new motor.

If that isn't enough run it on gas and put the juice on it.

Thanks Supernova, that's the kind of info I needed. I'm full aware of the limitations of the desktop dynos. I just use them to do what ifs and see what changes do to the output. Like I said, the heads are the only specs that I don't have concrete numbers on. And that's where the power is.

Thanks again.

[supernova]

By the way, welcome to Drag Stuff. It's a great place.

[Moparious Maximus]

I would guess you will run out of power before you would ever hurt that motor, we run a 4.5 X 4.5 572" mopar, I shift it a 8200 and go through the traps at 8400, if I go over 9000 my valve train gets pissed off.

When we ran it NA, the HP dropped off right after 7500.

I know its not a chevy, but a big motor is a big motor, I dont care what kind it is.

[overdriv]

By the way, welcome to Drag Stuff. It's a great place.

Thanks, I've been reading and got more to do here. So much great information from guys that's been there, done it. I hope I can contribute.

[overdriv]

I would guess you will run out of power before you would ever hurt that motor, we run a 4.5 X 4.5 572" mopar, I shift it a 8200 and go through the traps at 8400, if I go over 9000 my valve train gets pissed off.

When we ran it NA, the HP dropped off right after 7500.

I know its not a chevy, but a big motor is a big motor, I dont care what kind it is.

Thanks for your input. You have the greatest name for a car I've ever seen, IMO. I think I seen you run at Midstate Dragway last year?? I remember the days when all cars had names displayed with pride on the side of the cars. Nowaday, it's just sponsor names, and I understand that too.

[427belair]

What sized runners are your heads? If you used the flow # off the new heads, I think you will be a bit off, as those are cnc ported with a brand new design and are really killer heads. Im not saying that your heads arent good, Im just saying Darrin Morgan really know his stuff. Depending what your heads flow you shouldnt have to shift at anymore than 74-7500rpm as your probably making peak H.P. around 68-7000rpm.

[CDR Performance]

Hello, this is my first post and want to introduce myself. My name is Phil, I live in central Illinois. I have a 87 Z28 on the half shell, building it to do a bit of racing. I have a 565 tall deck BBC with eagle rods, eagle crank, JE pistons, Profiler heads, Dart intake. I plan on a 1050-1150 Dominator on E85. It has Rehyr-Morrison 420-116 cam, Isky roller lifters, Smith Bros pushrods???, Next-Tec springs and T&D shaft mount 1.7 rockers. I have no real idea how much HP it has. My desktop dyno puts it at 790 @6500, I suspect a bit more.

I bought the engine from a RED racer, says it has 60 1/4 mile passes. I have not taken it down yet but plan to pull the pan and take a look at a few bearings.

My question is; what is a safe RPM to turn this engine? What do you guys with big tall decks turn?

Like everyone else said depends but, for your eagle crank and depending on the rods and rod bolts a safe rpm is 7500 or less. Good luck on the project.

[FARRIGNO]

your combo is like mine i have a 565[not a tall deck], with eagle rotating assembly,and bmf 350-heads, like your dart 355,s, mine made max hp @7400rpm,but i shift it @7800-rpm .your eagle stuff should handle 8000 rpm all day long.fwiw.