Explorer/331 347 question

[chuck1022]

I think my previous question have shown I am not the most mechanical person...so here is another question.

When I floor my Explorer it runs up to almost 5000rpms and then shifts.

If I were to bore and stroke my 302 to 331 or 347.....how do you get it to rev higher when the computer shifts it at 5k?

Can you tune the ford factory computer to rev higher????

 

[73azbronco]

Depending on year explorer and computer, it may not run at all stroked to anything bigger than 302, with stock electronics.

Unsure of re-tuning factory tranny computer, But I know I have not heard anyone do that, they buy the aftermarket controller for the tranny they will be using for the job they will be using it for.

BTW, a stock 302 is hitting top end just over 5000 rpm, so I wouldn't "make" it go higher unless heavily modded.

 

[Tiko433]

Yes I remember hearing stock 5.0 Explorer you push it much past 5k it can float the valves. I have a 347 EFI with a AX 15 and when pushing it hard I shift at 5k . My tuner has a rev limiter set somewhere before 6k . I only found it a few times, it’s probably a good thing it was set.

 

[BanditBronco]

You can definitely build a 331 or 347 to rev higher than 5K, it just cost money. Most of your standard aftermarket top end kits/valvetrain components are rated for somewhere in the 5K range but they do make parts designed to rev higher than that without floating or exploding they just cost substantially more. If you are tuning an explorer computer for a 331 or 347, you can adjust the rev limit to whatever you want. Most off the shelf cams aren't going to show a ton of power past the 5500 mark even if it's a top end focused grind. If you want a high revving nascar motor then be specific with whoever is building your engine and what parts they spec. Most will tell you to trade torque for HP in a Bronco.

 

[Broncobowsher]

If it is just bore/stroke and you leave the rest of the engine the same (cam, heads...) the stock shift points will probably be just fine, maybe even a little high.
But if you do a performance build, you don't even need to bore/stroke, just leave it a 302, the factory shift points are likely to be off.

To change shift points you need to have a talk with your tuner. You will need a custom tune. And the tuner will need to know how to do transmission shift points as not all of them know this.