4.0 OHV max rpm

How high do you rev your 4.0 ohv engines? Any one going 6500rpm+? I took my engine past 6500, and I got a big end bearing failure as a result Back to the garage again, and hopefully I will find another crank.....

//Tobbe

 

[aldive]

I took my engine past 6500,

Pray tell, why?

 

[Willard]

I'm surprised it could make it up that far without floating the valves.

 

[briwayjones]

How high do you rev your 4.0 ohv engines? Any one going 6500rpm+? I took my engine past 6500, and I got a big end bearing failure as a result Back to the garage again, and hopefully I will find another crank.....

//Tobbe

You should have hit a limiter at about 4900RPM? Did you remove it?

 

[little x]

You should have hit a rev limiter

x2

 

[Rosscup]

i rev mine 3000 max why rev more the power drops off any high then that

 

[Joe Dirt]

I try to stay under 2,700- I like my Ex.

 

[techieman33]

His motor isn't exactly stock
http://www.explorerforum.com/forums/showthread.php?t=176114

 

[btimm86]

His motor isn't exactly stock
http://www.explorerforum.com/forums/showthread.php?t=176114

not a bit

 

[Hyde]

I hear a lot about this 4900 limit, My 91 hit 5500 regularly and my 93 hits the limiter at 51-5200

 

[Blacksheep Josh]

Yeah, even if I'm accelerating like a bat out of hell it'll shift between 4000-4500, and it's not comfortable by any means. with 260k miles, those valves are definitely hurting... sounds like they're rattling which is probably what someone called earlier "floating the valves".

I like the engine, plenty of torque to move it, but WHY rev that high? lol

 

[Texan01]

Mine hits the limiter at 5200 rpm. Tranny usually shifts around 4700 rpm though.

 

[Jakee]

Well, now you know the braking point. Set the rev limiter at 6499.

 

[Hyde]

Mine has 240,x... It doesnt make any death rattles or anything. Most of the time when I hit those kind of revs it is in 4lo First. Only once in a while on the street

 

[Tobbe]

It wasn't a big end, I assumed it was from investigations from the sparkplug hole.... The damages was very limited since the piston still was attached to the rod Just minor damages to the pistons, but the rod need a new bush though....

I've sourced another block which I am putting backtogether with stock 4.0 pistons and rods.......

 

[HahnsB2]

Nice, it really shouldn't have much of a problem around the 6k mark with what you've done, especially if you upgrade those wristpins.

 

[TBaker]

i take my explorer sport to 6 grand easy. i race all the lil ricers around my town and spank that ass

 

[briwayjones]

i take my explorer sport to 6 grand easy. i race all the lil ricers around my town and spank that ass

You have the SOHC in yours though.

 

[Tobbe]

Update,

the engine runs very well, a stock OHV bottom end, CR is 11.x:1, 18bars when doing a compression test. Put the rpm limit to 5200rpm, so it will last a while.... Finnally all the effort is paying off

 

[daan-o]

uhh my RPM gauge is all the way over under the MPH gauge.... didn't know this was possible!!! any body else do this??? i have the OHC 4.0 and my trans is slipping it happend during a slip. Before that though i would always may it out going through mud and stuff....