304 How much Horsepower?

Oldyeller

Very new to the forums but I've been around Jeeps for awhile. I've had this discussion with a lot of engine builders and never get a very straight answer. I'm running a 304 bored .030 over, Holley 670cfm TBI (2-bbl), 270 cam, edelbrock performer intake and headers. I know the heads have had minor work but I'm not sure what all has been done. I don't have the money to dyno it, so could someone give me SOME insight as to what kind of horsepower i'm making? I would just like a rough estimate based on someone's experience. And if you could give me some suggestions for improving my setup i would greatly appreciate it. This is all in a 76 CJ-5 Thanks, great board, really glad I finally found it. Yeller

jeepsr4ever

hmmm I would say 320hp@4800rpm

Oldyeller

wow, Higher than I expected, thanks for the quick reply.

fifesjeep

I wouldn't say that high... I'd say closer to 250-265hp max... Especially if you're using 8.5:1 pistons... Maybe in the 300's if you're running 9:1 etc..

jeepsr4ever

I dont know about that Fifesjeep. If you look at the graph here youwill see that a stock 304 makes 270hp with a .448.472 lift and a 204/214 duration with stock compression, stock bore and at 3000rpms. He is at .030 over making 309CI granted he only bumped up .01 in compression he is running a camshaft at .480/.480 lift and a duration of .224/.224 which would put his peak power in that range. If he had some port matching done or valve unshrouding he may be over 350 horse with a bump and a half in compression. I would say 310-320 is around what your running at.

Oldyeller

This site truly is amazing, I can't believe I've never come across it before. I'll be reading the archives trying to catch up, thanks again for the info.

Lifted79CJ7

Yup, MC is a like an Encyclopedia set of information on AMC engines. Welcome aboard Oldyeller!

pablorg

jeepsr4ever wrote
I dont know about that Fifesjeep. If you look at the graph here youwill see that a stock 304 makes 270hp with a .448.472 lift and a 204/214 duration with stock compression, stock bore and at 3000rpms.

Isn't this a TORQUE graph? :-|

jeepsr4ever

pablorg wrote
jeepsr4ever wrote
I dont know about that Fifesjeep. If you look at the graph here youwill see that a stock 304 makes 270hp with a .448.472 lift and a 204/214 duration with stock compression, stock bore and at 3000rpms.

Isn't this a TORQUE graph? :-|

:?: Why yes it is

I will have to look at some dyno sheets

Oldyeller

Didn't even notice, good eye. Let me know if you find those dyno sheets, I'd still like to know where I'm running. And I guess I can Hijack my own thread, so what should my timing be set at for the engine combination listed above?

tufcj

Use this formula to calculate HP. Torque * RPM ------------ = Horsepower 5252 So with the graph figure torque=270 @ 3000 RPM 270*3000/5252 = 154.23 HP @ 3000 215*5000/5252 = 204.69 HP @ 5000 Bob tufcj

fifesjeep

Figure,... a stock 304 from the factory pushes 125-155hp.... Changing the bore size +.030, with a decent lift cam, intake, Carb, exhaust... with stock heads, even with "minor work"... Getting an added 150hp is a decent task. But, with a little money mainly for the High Compression pistons and a smaller chambered head with decent valves to keep the flow up it'll push decent number mid 3's.... maybe more depending on the set-up. But then again here I am preaching to the choir... and probably to people that know more about AMC performance than I can even imagine. I'm still sticking with my numbers (250-265 max) :mrgreen: