What's your redline set at?

[ZOMBEAST]

shift @ 6800 out the back 7500

What does this mean?

I don't bother with the light or the tone. I just observe the gauge. I would like to bump the actual limiter up out of the way. I hit it pretty good twice the first couple of weeks I had the car. Since then I've only just barely touched it once.

 

[skyhighsd]

He shifts at 6800 and goes thru the traps on the 1/4 at 7500

 

[SlowSVT]

shift @ 6800 out the back 7500 .... i will let you know when it breaks

this will be its third season.


shitty fuel systems and missed gears and riding the limiter eat rods

good clean shifts dont unless drive like a tow truck !

Revving a highly stressed blown 5.4 that high is more like a roll-of-the-dice. It's not the number of seasons your doing it but more like "how often" and "how long". You may never have a problem or have a catastrophic one but it's rarely anything in between. Take my word for it, your bottom end is not having fun in that realm. 7500 rpm's on a long stroke motor is risky business. Better rods would be a good investments for where you are playing

 

[BlownShift]

Revving a highly stressed blown 5.4 that high is more like a roll-of-the-dice. It's not the number of seasons your doing it but more like "how often" and "how long". You may never have a problem or have a catastrophic one but it's rarely anything in between. Take my word for it, your bottom end is not having fun in that realm. 7500 rpm's on a long stroke motor is risky business. Better rods would be a good investments for where you are playing

he's not having fun if he's not breaking something

 

[09Troublemaker]

shift @ 6800 out the back 7500 .... i will let you know when it breaks

this will be its third season.


shitty fuel systems and missed gears and riding the limiter eat rods

good clean shifts dont unless drive like a tow truck !

:bs:

sorry I aint buying that...7500 cmon...who you kidding:nonono:

 

[03cobra#694]

:bs:

sorry I aint buying that...7500 cmon...who you kidding:nonono:

anytime you want to come to the track ......


137 with 345/35/18s had to raise limiter when i had 305/35/18s with the

4.56s


think about it I shift at 6800 every gear and run out the back

it sees 7000+ for less than a second , its probably not above 7000
until after the 1000 ft marker ... i am going to look at the data log.

i believe you guys are right , thats why the NEW long block is just about done .... maybe one more week waiting on cams .

thanks JEFF

 

[03cobra#694]

he's not having fun if he's not breaking something

GEEZ .... dont give away all my secrets ......:dw:

 

[whitecobra2387]

ford raised the limiter on 2010 gt500 to 6250rpm so if ford is doing it. I dont see why we can take it a little higher :banana::banana::rockon:

 

[Finaltheorem47]

I dunno, its simply a 5.4, a big brother to the 4.6 in the modular family. They aren't comparable to pushrods, in fact pushrods are not a good comparable engine.

It has always been my understanding that OHV's like to rev higher than pushrods. I want some more concrete evidence as to why these engines cant rev high. I have read a long debate on another forum where they were arguing it was because of piston speed, but eventually people agreed that the piston speeds aren't increased enough to warrant a problem.

 

[chuckstang]

ford raised the limiter on 2010 gt500 to 6250rpm so if ford is doing it. I dont see why we can take it a little higher :banana::banana::rockon:

Umm, the 07-09 is 6250 as well

same redline

 

[chuckstang]

I dunno, its simply a 5.4, a big brother to the 4.6 in the modular family. They aren't comparable to pushrods, in fact pushrods are not a good comparable engine.

It has always been my understanding that OHV's like to rev higher than pushrods. I want some more concrete evidence as to why these engines cant rev high. I have read a long debate on another forum where they were arguing it was because of piston speed, but eventually people agreed that the piston speeds aren't increased enough to warrant a problem.

My tuner said the same thing, its an OHV engine, it loves to rev, he gave me the go ahead to go to 6800 all day long.

We ran it there on the dyno and I believe he is saying that only because the A/F ratio was spot on and still making power but a good A/F ratio is not going to stop a rod flying through the block

 

[Carbd86GT]

I dunno, its simply a 5.4, a big brother to the 4.6 in the modular family. They aren't comparable to pushrods, in fact pushrods are not a good comparable engine.

It has always been my understanding that OHV's like to rev higher than pushrods. I want some more concrete evidence as to why these engines cant rev high. I have read a long debate on another forum where they were arguing it was because of piston speed, but eventually people agreed that the piston speeds aren't increased enough to warrant a problem.

Pushrod motors also use OHV's (Over head valves) oke: Its the engines that use more than 2 valves per cylinder (1 intake, 1 exhaust) that usually like to rev as they can fill the cylinders with more air, more efficiently. The Lethal car suffered the broken rod syndrome from Horsepower + RPM. They way I see it, just because you rev it to 6500+ rpm and are making good power doesnt mean your engine WILL blow up, but the chances are much greater. After looking at our stock rods, I am AMAZED that even they can handle over 600 rwhp @ 5500 rpm, they are thin as hell!

 

[Blaine]

My tuner said the same thing, its an OHV engine, it loves to rev, he gave me the go ahead to go to 6800 all day long.

We ran it there on the dyno and I believe he is saying that only because the A/F ratio was spot on and still making power but a good A/F ratio is not going to stop a rod flying through the block

I'm sure our engines love to rev. Just the rods didn't get that memo.oke:

 

[mullens]

I'm sure our engines love to rev. Just the rods didn't get that memo.oke:

:lol:

 

[SlowSVT]

I'm sure our engines love to rev. Just the rods didn't get that memo.oke:

Untrue!

No long stroke engine likes to rev! Both the 5.4 and the 4.6 are long stroke engines. It's not just a matter or using HD rods. Beefey rods weigh more and you will get diminishing returns adding more mass there.

Why didn't Ford push the bore spacing out of us? :cuss:

Short stroke engines will just tolerate revs better and longer.

 

[Finaltheorem47]

Pushrod motors also use OHV's (Over head valves) oke:

Excuse me, I'm not sure what I meant when I said that, but you still understood, in essence, the point I was trying to get across.

Untrue!

No long stroke engine likes to rev! Both the 5.4 and the 4.6 are long stroke engines. It's not just a matter or using HD rods. Beefey rods weigh more and you will get diminishing returns adding more mass there.

Why didn't Ford push the bore spacing out of us? :cuss:

Short stroke engines will just tolerate revs better and longer.

Less torque and efficiency maybe? oke:

I don't claim to know anything about these engines, but I feel this thread is a good opportunity to try to uncover the answer to some questions that are not asked about these motors.

Hypothetically, if it's the rods as suggested above, would a built block be able to rev to lets say 7500 without fear of throwing a rod?

At 6k rpms, the inertial load on the rods as they change direction is something crazy like 8,000 lbs I read somewhere. But is the problem with the engines simply the rods? Is that all we have to fear? Would changing to better rods combat this problem?

 

[sharke]

Excuse me, I'm not sure what I meant when I said that, but you still understood, in essence, the point I was trying to get across.



Less torque and efficiency maybe? oke:

I don't claim to know anything about these engines, but I feel this thread is a good opportunity to try to uncover the answer to some questions that are not asked about these motors.

Hypothetically, if it's the rods as suggested above, would a built block be able to rev to lets say 7500 without fear of throwing a rod?

At 6k rpms, the inertial load on the rods as they change direction is something crazy like 8,000 lbs I read somewhere. But is the problem with the engines simply the rods? Is that all we have to fear? Would changing to better rods combat this problem?

I remember reading there are problems with crank balance and harmonics at that point as well

 

[09Troublemaker]

I'm sure our engines love to rev. Just the rods didn't get that memo.oke:

:lol::lol:

 

[rlhay2]

My tuner said the same thing, its an OHV engine, it loves to rev, he gave me the go ahead to go to 6800 all day long.

And with your luck, you believe him?!?!?:bash:

 

[mullens]

Sorry gents but the mod motors are OHC (cams on top) , not OHV. Yes most 4v OHC motors like to rev but not one's with a 4.1" stroke. The stresses on the rods and pistons at 6800 RPM are tremendous. Our 4.6 little brother can pulls some revs with only a 3.5" stroke and relatively low piston speed and reciprocating mass.