Thread: engine rpm

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i am building a 49 ford. i amm putting in a hot 496 b.b. chevy .the carhas been back-halved,has 4:56 gears,4-link auto with 3500 stall.will this gear work on the street o.k.?car will weigh about 3500 l.b.what kind of r.p.m.s will the engine be turning at 55 m.p.h.?what e.t.s can i expect to be running in the 1/8 mile???

Your going to be going through alot of tires With that kind of torque and those low gears you'll probably be burning rubber in 3 of your 4 gears. I don't have a laptop to figure your time but at 55 you;ll probably be turning around 3,000RPM/s

With that combination you should literally be able to watch the fuel guage going down as you drive. $$$$$$$$$

will this gear work on the street o.k.?

Only if you're a glutton for punishment.

what kind of r.p.m.s will the engine be turning at 55 m.p.h.

Need to know your tire diameter, but assuming a 30" tire, a little over 2800 RPM. With that stall speed, I suspect your transmission will be slipping. Not a good thing.

IMO that much stall in a converter on the street, like Jack said, is going to spend most of it's time slipping and building up way too much heat in the transmission.... Converters over about 2500 stall should probably best be left for quick trips at the dragstrip and cooling between rounds, not street cruizin'.

I have a similar setup only 100 fewer ci. (402ci, 3500 stall, 4.56:1 rear, 3400 lbs) RPM will depend on size of your tire. With 31" tire, I'm turning 3000 at 55. Also depending on the tire, you may run out of gear at the traps in a 1/4 mile. I'm spinning just shy of 6000 at 100mph at the finish line on a 29" slick. I have no idea what your e.t. will be without knowing how much power you're making or where you're making it I'm at 13.2s with a much smaller engine, but unless that 496 is built to spin to 7000, I would recommend a taller gear like a 3.90:1 for 1/4mi racing

Edit... I see you're doing 1/8mi racing... in that case 4.56:1 is probably a good gear. And as Dave mentioned above, you can expect HOT trans temps driving around town or on the highway for any distance from the converter. I have a 30 mi drive to the strip and it can get real hot in the summer.

what stall do you recomend for the street?

you're stall should be matched to your cam specs... if you have a serious cam, you will need a high stall.... the heat comes with the territory. For a street/strip car, there are always compromises. I'm planning to add a trans cooler this year, hopefully that will help get more heat out. You have to ask yourself whether you want a street rod you occasionally race or a race car you occasionally cruise and make the appropriate compromises.

thanks! my first hotrod at 39!just wanna do it right.no car buddies where i currently live,so,looking for fellow car friends,and all advice i can get!!