Hemi Truck Club banner

2007 5.7 based 399c.i. stroker build

6K views 28 replies 8 participants last post by  Mrs.Studmuffin 
#1 ·
Greetings! This was a response to Chris's stroker build post, but I would like to post some pics of the progress and ask questions as problems come up. My son was laid off due to this whole "pandemic" scare, so I decided to kill two birds with one check - give him some of the experience I had as a kid and get my engine rebuilt at the same time. We are in the process of rebuilding my '07 5.7 due to a spun rod bearing. I had the engine rebuilt 3 years ago after I sucked some water into the intake driving through a puddle (turned out to be much deeper than I thought). Paid $2500 for the rebuild, and got exactly what I paid for - the cheapest crap parts money could buy and a quick engine slap together. One of the rod bearings on #3 piston slid under the other one and locked up the crank after chewing .026" off that crank journal. The crank and that rod are trash - I was going to do a 6.1 forged crank, but a stroker kit is similar in cost, so here we go!

The truck is a 2007 4dr 4x4 with a 6" lift and 35x12.50x18's that I bought 10 years ago with 36k miles on it. After much research and flip flop planning, I decided to go through Inertia for a Molnar 4.080 crank, 6.125 molnar rods, and CP Bullet pistons for a 399ci result. Inertia cam, king bearings, hellcat lifters and MDS plugs, Inertia tune (with my Diablo intune i3), custom Inertia pushrods, eagle heads (freshly rebuilt, stock springs and buffers per Stu, not ported or polished), .074" cometic head gaskets, LT headers (not set on this, as Stu @Inertia says they don't offer much gains over shorties, and I am running out of cash quickly on this build).

I spent all morning yesterday reading through all 176 pages of Chris's post. The information therein is invaluable to someone doing this swap! I have some questions. Stu told me I could make a gasket and bolt my pre-eagle truck intake to the eagle heads. I have done some port comparison, and there is about 1/4" protrusion into the intake flow on the head side. The o-ring gaskets in the intake don't match up with the sealing surface on the heads, so a gasket would be required. In order to get the full benefit of the heads with the cam, I really feel the need to use an eagle intake, and I have heard the eagle truck intake works the best for torque. That brings up the problem of the alternator and a/c compressor clearance. MMX has a kit to put a car timing cover on the block and comes with brackets for the alternator and compressor -I have not checked into specifics because it's $1000 and I cannot justify that when the intake is going to cost another $3-500. I'm pretty good at fabbing - I think I can come up with some mounts if I source a car timing cover. I just don't know where they need to be, as there are no pics of that setup I can find online. I did find a pic where someone cut the top bolt holes off the truck timing cover and made a steel plate to mount the alternator and compressor to, but it didn't look nice or reliable enough for me to pursue that solution.
Now that you are up to speed on my situation, here are my questions:

Chris:
If you had it to do over again, would you go the same route with the timing cover and LX accessories/water pump?
What injectors did you use for your build?
(Chris responded that he would absolutely do it this way again, so I purchased a 2005-2009 car timing cover last night for $60 on ebay)

Everyone else+Chris:
*Do I need to swap out my injectors since I will be increasing the displacement by .8l?
*Has anyone used the Holley Sniper intake? Will it clear the truck accessories and/or the accessory mounts on the truck timing cover?
*Does anyone know where to find some eagle valve covers, other than the junk yard? There are no eagle hemi's that I can find in my area. Only other option is Holley Sniper covers, and they are $420.
*How thick are the intake spacers offered by MMX? Is it enough to make the eagle intakes clear the coolant passage in the front of the block? Is there anything else currently offered on the market that will allow an eagle intake to be used on a non-eagle block with eagle heads? I don't want to use a carb - I don't want to modify my OEM FI other than injectors (if necessary).
*Is it necessary to upgrade beyond the stock throttle body when stroking a 5.7 to a 6.5?
*Does anyone have real world experience with a 5.7 based stroker, eagle heads, and long or short headers? Is there enough difference with the LT's to warrant a whole new exhaust system?
*Will eagle headers fit in my truck, or will I have to bastardize an expensive set to make them work?

I'm really looking forward to this build. I have wanted to do some engine mods to this truck for years, but never had the cash or the opportunity to do so. Now I am working from home, and I have some surplus cash... so here we go!
 
See less See more
#2 · (Edited)
Took some initial pics. The engine has already been pulled by my 21yr old son. This is the first serious vehicle work he has done. He's never really shown the same interest in turning wrenches I had, but I fear it is because I didn't provide enough opportunity when he was younger. We have the block on the stand right now. I set the eagle heads and the original timing cover on the block to see what options I had as far as intakes. Got the first of many shipments from Inertia yesterday - Carrillo pistons! What is it about fantastically machined aluminum parts that really gets the blood flowing?
 

Attachments

#4 · (Edited)
I'm not sure if it will be Inertia, or someone they work with. Didn't get that nailed down in the call with Stu. You're not the same Stu, are you? Seems like I remember Keith does some tuning? The point of this post is partially to share the best mechanical experience I have had with this truck, but mostly to try and benefit from the vast amount of knowledge assembled here. If you guys see me making a mistake or a flaw in my plans PLEASE correct me. Who would be best to tune this truck remotely? Would dyno tuning be better? I am in Greenville, TX so Inertia is a 4 hour drive. Pretty sure Jay Greene is fairly close as well.
 
#5 ·
Ebay seller just offered a discount on an 09-12 ram intake with fuel rails and injectors - $360. I was really looking at the Holley Sniper in bright finish. $140 difference in price (plus price of injectors for the sniper). Any thoughts on the choice between these two intakes? Keep in mind I am turning 35" tires, so torque is king here.
 
#6 ·
For a realistic comparison check the price for the injectors you want and the rails you will need for the Sniper manifold. For torque I suspect the oem truck manifold will out perform the Sniper. The Sniper valve covers do fit nicely with the taller valves and girders.
 
#8 ·
The injectors are one of my main concerns with the intake I choose. Do I need bigger injectors with the 6.4 stroker, or will the stock eagle 5.7 injectors flow enough to feed the bigger displacement? I apologize - while I fully understand the operation of a FI system, I don't understand how to size injectors based on displacement and intended use. This truck will never have nitrous or forced induction.

I found a couple of the post 2010 truck intakes with rails and injectors for ~$300. The only thing keeping me from jumping on them is the obstacle of the temp gauge bump on the front of the block and the thought of having to put new rails and injectors on whatever intake I choose. Yes, I would like it to look cool (Sniper) but more importantly I want function over form. I am not opposed to using a window switch to activate the runner solenoid on the newer intakes.
 
#9 ·
Most of the popular engine builders do alot of factory srt 392 upgrades with the original take off injectors available for sale. I would check with you favorite engine shop. Difinitively use a rpm window switch. Once set up you can forget about it. But I would install a led light to indicate when activate. Your tuner will scale the injectors when he tunes your engine.
 
#12 ·
What would be an acceptable replacement? 6.4L injectors? Is there a preferred brand, or will OEM do? The budget is already blown on this - might as well get what I need. I will be using an Eagle truck intake, so they will need to fit under the stock rails. I have been looking for replacements - everything is rated in lbs. I have never even researched aftermarket injectors or capacities. I am completely in uncharted waters on this one. Any info would be greatly appreciated.
 
#16 ·
Trying to remember what I used, believe it was SRT4 stage 2 injectors. Seemed it was around 55lbs. As I posted before a set of SRT 392 take off should work fine and save you a little money.
 
#17 ·
your Best intake option for what you are trying to do is going to be the 6.4 Truck intake see if you can get one with Rails and injectors Contact MMX 6.4L HEMI Intake Manifold for 5.7L RAM Upgrade Kit by MMX it's the Best bang for the buck , stay away from the Sniper intake , it's not going to help you at all, don't get me wrong, I've seen some great Power #s out of it, but it's intent is for those guys who Ring the crap out of these engines, the Sniper LOVES RPMs....not good for a truck with 35s....word of caution on those King bearings, their Quality Control has taken a Big stinking pile of (fill in your own 4 letter word for feces) in the last few months, Check and Check and Check again , I 've sent 3 sets back in the last month., the last set all uppers were 6.4 Hemi bearings, two of the lowers were Chevy LS bottoms(the LS is a narrower shell) the worst set was for a GM SB2 build....What a PHUCKING fiasco, as for the Molnar stuff A+
 
  • Like
Reactions: RecoilFreak
#19 ·
A few aftermarket tuners have PWM outputs. It would surprise me if a rpm window switch wasn't available with a PWM out put .
 
#21 ·
Ric3xrt - thank you sir. That's why I post here... To make use of everyone's experience. Conjecture is just that without experience. Worst case, I can lock the eagle ram intake into long runner mode. I'm not a eacer. I shouldnt have much need for the short runner configuration.

Now another question - are eagle injectors and pre-eagle injectors different lengths? Are they interchangeable? If not, I just wasted $150 on used SRT8 injectors.
 
#22 ·
Lets consider what a PWM signal does. It's output is 12v divided into pulses. Lets say 0-1000, 0 pulse, no output, as pulses increases more voltage is felt on the motor being controlled. If 12v is put to the motor then it is at it's max position whether it be a WG or manifold runner.
 
#23 ·
PWM allows precise positioning of a stepper motor as well as position feedback. If it's PWM, that tells me that either the short and long runners can be used in conjunction when in a gray area (like a mixer door on your HVAC) or that the ECM needs feedback on where the "mixer door" is positioned at all times. Since you can lock the intake into the long runner mode all the time, that is most likely what I will do. Thanks for all the feedback, guys!
 
#24 ·
What you said is correct, what I said is the motor can also be turned on/off by simply applying voltage.
 
#26 ·
A stroker motor with that cam as you have found out doesn't run properly on the stock tune. As already stated larger injectors and custom tune is needed. You will need to read Air Fuel Ratio (AFR) and Trims.. my recommendation is talk to Charged392 and get a startup tune. This will get you running..
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top