302 Stroker question

[Scott B.]

If I stroke my 302 to a 331 (or 347) and run a mild/torque street-legal cam, will the 19 lb. injectors and factory intake manifold be able to supply enough fuel/air to spin the engine up to about 5000 RPM?

Obviously, I am building the engine for low speed/torque, but I want to have enough get-up-and-go while on the freeways.

At this point, I don't think I need the stroked engine - a 302 (306 since I will bore it) will be more than sufficient my needs. But, a little extra is always a good thing - however, I don't think I want to change the entire top of the engine.

Thoughts?

 

[Turdle]

OK
You know how when you are wrenching on a tough bolt, if you move your hand out further on the wrench handle the same amount of force will break the bolt free?
The same applies when stroking an engine. With the 347 you increase the stroke by .4" . This might not seem like a whole lot, but with the very same amount of combustion force you will increase the torque substantially.

This will result in not only more " get up and go", but also better fuel economy , since it will take less fuel to pull the same load.

However, there are some down sides which you must be aware of.

Usually the piston in a stroked engine is a bit shorter, location of the wrist pin gets tricky, be sure to get the right piston combo.

Also, since the piston is now moving farther in the same amount of time, it is moving faster. ( see, that's what she said)

Higher piston speed is both a good thing ( for torque and fuel mixing) but also comes along with faster ring wear. So, the rings travel farther, and faster. If you get good components it shouldn't be an issue as you are only touching the area of a 351w stroke. In other words that engine deals with the piston speed just fine fine.

The increase of bore (.030") will allow a stock diameter intake valve to unshroud , or " breathe" better. However, there is also going to be more intake volume, so stepping up the cam a tad will help.

When you get around to tuning, the magic will happen. Keep the vacuum higher and you will have a good torque motor. IMO

 

[Scott B.]

I understand all that.

Will the 19 lb. (orange) injectors be able to keep up?

And, how much tuning am I going to have to do?

 

[Turdle]

A 351 w has 19lb injectors stock. For this reason I say yes if you keep it mild and low RPM's