4.7 to 5.7

[kontrolled]

I Currently own a 2008 4.7L 6 Speed Manual truck and i love it i couldnt ask anything more but around 70% of the time it sounds like the engine has a horrible knock and i was just simply wondering what could go wrong or how to trouble shoot it... and if worse comes to worse and i have to replace the engine will a 3rd gen 5.7L hemi simply be able to replace my current 4.7L or what other adjustments would have to be made along with that engine replacement?

 

[Redtruck-VA]

More than a few folks have done it. Now with that said, if you are counting on someone else to do the work then I don't think it will make financial sense to do it. I would recommend researching everything involved and when you are comfortable with doing the swap then proceed. A 6 speed hemi running a cable drive throttle body would make for a great project truck.

 

[kontrolled]

i'd like to just point out i'm more worried about the incredibly loud knock and trying to get that figured out to me it sounds like a cylinder is hitting the valve cover and the last time i hear that it was in my 4.3L V6 S10 that ended up blowing up on me just crusing down the highway and it would be a disaster if that happened to me in this truck

 

[Redtruck-VA]

Most mechanics can readily tell you what a loud knock is by the speed of the knock compared to engine speed. Is it a solid knock that varies with revving the engine? What's the oil pressure? Does it go down at idle? Can you tell if its in the bottom of the engine or top. Half speed knock points at a lifter. Post up a video or take it by your shop. As you have stated from your past experience knocks indicate something is seriously wrong and usually tear themselves loose in short order.

 

[kontrolled]

the knock speeds up with engine speed but i only really notice it as i start off and get going.. the knock will then syncronize with normal engine/road noises at higher speeds of 50-70 MPH.. but from inside the cab it sounds like its coming from the top of the engine i'll have to get out and inspect it more myself when its doing it but its harder to tell with it just being myself

 

[Redtruck-VA]

the knock speeds up with engine speed but i only really notice it as i start off and get going.. the knock will then syncronize with normal engine/road noises at higher speeds of 50-70 MPH.. but from inside the cab it sounds like its coming from the top of the engine i'll have to get out and inspect it more myself when its doing it but its harder to tell with it just being myself

If you have been driving it much at 70mph then I'd guess it isn't the bottom end probably valve train related. Good luck...

 

[HemiLonestar]

More than a few folks have done it. Now with that said, if you are counting on someone else to do the work then I don't think it will make financial sense to do it. I would recommend researching everything involved and when you are comfortable with doing the swap then proceed. A 6 speed hemi running a cable drive throttle body would make for a great project truck.

I don't think anyone has done it with that new of a CAN bus truck plus manual trans. Having the stick shift would be cool. Might be able to use the hemi PCM from a 2500 manual trans.

 

[Redtruck-VA]

I don't think anyone has done it with that new of a CAN bus truck plus manual trans. Having the stick shift would be cool. Might be able to use the hemi PCM from a 2500 manual trans.

Good point, hadn't thought about it using the Can Bus. Do the newer 4.7's still use cable drive TB?

 

[HemiLonestar]

08 and newer 4.7's use fly by wire, whether that same system is adaptable...?

Sent from my HTC One using Tapatalk

 

[kontrolled]

*Update*

I spoke to some good mechanics that havent steered me wrong before and they said that just simply replacing my engine with another 4.7 maybe be cheaper in the long run than the whole guessing and checkign weather or not a certain issue is whats actually wrong with it.

Thoughts?

 

[HemiLonestar]

Would definitely be cheaper and easier to throw another 08+ 4.7 in there and see if that is the issue before trying (hoping) to make a hemi swap work.

 

[kontrolled]

that in mind if i just stay with the 08+ 4.7 would it even be worth it to go to a 5.7L simply because the 5.7 only puts out 30HP more wouldnt it jsut be more cost effective to keep the 08+ 4.7L and just chip/upgrade it to where i want then wa-la i have a 5.7?

 

[HemiLonestar]

Neither the power potential nor aftermarket/factory support is there for that engine really. Yeah, 310hp is only 35 shy of a stock 3rd gen 5.7, but with the money you pour into it, you could amp up a 5.7 a helluva lot more. Since you have a stick you're ahead of the game with not worrying about transmissions. I don't know how custom tunable the 08 4.7 PCM is; if it is you can do head work and hotter cams. Better gears (are you 2wd or 4wd?) with some form of LSD will help alot. Also a better exhaust system. First thing is to get it running right before modifications. All the mods I listed will put you with a stock hemi most likely; start those mods on a hemi (even a small cam like a 260 is good for about 30hp right off the bat) and only forced induction or nitrous will enable you to keep up.

 

[kontrolled]

I understand ill never be as powerful as a 5.7 with the same mods but I think it'd be cool to roll up on a stock 5.7 and at least catch him off guard... But what do you mean I already have the advantage by having a stick? I'm sorry if I seem ignorant I am just only privy to my truck not having experience with other models or options

 

[HemiLonestar]

The 545RFE's seem to be good transmissions overall when the truck is left stock (with a few notable horror stories I've heard), but tend to not last when you start upping the power (hence the reason Redtruck is looking at an A518 swap). You have a manual trans, no crap**** factory programming to deal with.