4.9l Six redline?
Post Fiend
Joined: Jan 2007
Posts: 7,021
Likes: 5
From: Almost Heaven
what happens when you float valves? I've taken my truck to 4,000 multiple times (I try not to).
Cargo Master
Joined: Jun 2002
Posts: 2,033
Likes: 32
From: Aurora,Colorado
I would think that the 4.9 could spin 4k without damage occurring.
Post Fiend
Joined: Jan 2007
Posts: 7,021
Likes: 5
From: Almost Heaven
Yeah, I would think so, as easy as it reaches 4K. So floated valves = permentant power loss?
Posting Guru
Joined: Dec 2008
Posts: 1,074
Likes: 1
From: Mass.
not permanent power loss, unless you break something which is likely at that high of rpm. the engine just basically loses power, you let out of the gas so the revs get down and your engine is back to normal however sustained amounts of time at high rpms with floating valves can cause serious problems.
Cargo Master
Joined: Jun 2002
Posts: 2,033
Likes: 32
From: Aurora,Colorado
I drove a telephone truck with the 4.9 years ago and if floating valves would hurt it-I would have found out about it. But I wouldnt suggest doing this. Just on fleet vehicles.
Post Fiend
Joined: Jan 2007
Posts: 7,021
Likes: 5
From: Almost Heaven
Postmaster
Joined: Jan 2009
Posts: 4,558
Likes: 2
The computer cant shut the engine RPM down when the driver downshifts. The computer can shut the engine down when upshifting-and it does it by cutting out the ignition. This way of shutting down the engine doesn't work when the driver downshifts-the engine can become a bomb all by itself-ignition or no ignition.
A bad excessively high speed downshift could killl an engine-or the driver may get away with it for several times and not know that he is overrevving the engine-because Ford didnt include a redline on the factory tach.
This is more likely to occur in mountainous terrain-where the driver is trying to use engine compression and no throttle to control the vehicle speed doing down the mountain.
Anyone that have operated a high performance motorcyle knows what a rev limiter does. Or low performance motorcycle for that matter. My old ST1100 limiter operated all of the time---very smooth engine and flat horsepower curve and low output (100 HP) meant that I was hitting it all of the time on Interstate onramps.
A bad excessively high speed downshift could killl an engine-or the driver may get away with it for several times and not know that he is overrevving the engine-because Ford didnt include a redline on the factory tach.
This is more likely to occur in mountainous terrain-where the driver is trying to use engine compression and no throttle to control the vehicle speed doing down the mountain.
Anyone that have operated a high performance motorcyle knows what a rev limiter does. Or low performance motorcycle for that matter. My old ST1100 limiter operated all of the time---very smooth engine and flat horsepower curve and low output (100 HP) meant that I was hitting it all of the time on Interstate onramps.
Postmaster
Joined: Jan 2009
Posts: 4,558
Likes: 2
Ok i see what your saying . After reading your post again your talking about down shifting to slow down with closed throttle . Lew
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Posting Guru
Joined: Dec 2008
Posts: 1,074
Likes: 1
From: Mass.
might be time for a fluid change, it sounds like shes slippin a little bit. but ive yet to drive an e40d that doesnt seem to slip alot and ive driven/ridden in about half a dozen. it does the same on my truck and ive been driving it like that for 2 years so i guess there just a little sloppy.
Laughing Gas
Joined: Dec 2007
Posts: 848
Likes: 1
From: Bethel Park, Pa
haha thats what this one guy said, every now and then it shifts a bit hard and he was like put up with it its fine, and well if my tranny blows out then its a perfect oppertunity to drop in a 5.0 with a 5 speed 
Post Fiend
Joined: Jan 2007
Posts: 7,021
Likes: 5
From: Almost Heaven
yup. when my tranny gets hot, it shifts so hard going in reverse or whatever that it feels like something is going to break. I really want to have my tranny rebuilt with a very firm shift kit. I honestly think my truck has the power to bark the tires going in second if the tranny wasn't so sloppy. when I had OE sized tires, after my gear ratio change my tranny did shift firm.. it was really nice.