turbo stroker debate: Renix v.s. HO

[A-man930]

After reading around for a bit, I've stumbled on some information regarding the non-HO 4.0L motors, that I previously hadn't seen. I had automatically assumed that the HO was a better choice for my intentions, but as it turns out, maybe not.

 

First off, I will need a quick replacement for my current engine. Blow-by is bad, and I think I can hear the mains rattling at anything above 2 grand... I was looking for a HO to swap in, as I hear that it is a fairly easy transition from Renix to HO. I also intended to have the replacement motor's shortblock built turbo-ready stroker (although funds may not permit this quite yet :brickwall: )

 

Now comes the dilemma, I'm hearing that the pre-HO (Renix) 4.0 block is a better choice for strokers, and the only real advantage of the HO is the head/intake/exhaust/cam combo, which is interchangeable with any 4.0 or 4.2 anyways. This is supposedly because the Renix system utilizes a knock sensor (and since strokers like to ping...) My question now becomes: are there any issues/concerns that I should consider if I chose to use a Renix block for my turbo/stroker build? I would still have a variety of head castings/intakes/etc. to choose from, have the added insurance of a KS, and have one sitting in the garage ready to go... what to do!?

[Badger]

actually the renix's intake,exhaust ports are smaller and more restrictive then the HO

 

as for building a stroker turbo ,good luck on that one.you are bringing up the compression ratio close to the limits of pump gas with a stroker kit alone.so how do you plan on bring up the compression even more with a turbo?you only going to be running race fuel? going to get expensive.

[A-man930]

actually the renix's intake,exhaust ports are smaller and more restrictive then the HO

I realize this...

the only real advantage of the HO is the head/intake/exhaust/cam combo, which is interchangable with any 4.0 or 4.2 anyways.

as for building a stroker turbo ,good luck on that one.you are bringing up the compression ratio close to the limits of pump gas with a stroker kit alone.so how do you plan on bring up the compression even more with a turbo?you only going to be running race fuel? going to get expensive.

With pistons that are meant for FI...

http://www.hesco.us/shop.asp?action=det ... catId=7569

Among other things.

Here's a build thread that I've been following:

http://pirate4x4.com/forum/showthread.php?t=614289

[Badger]

i'll stick to what i said.its going to get expensive really fast.after reading most of that thread i see how he is doing it or getting away with it,using a dished piston to bring compression back down after stroking it.the stroker kit i have (but haven't used yet) is using 9.25 compression pistons so i'm already at the limits of pump gas.

[A-man930]

Oh no doubt it will be pricey... but it does seem as if it will work.

[Stumpy]

i've also heard that the Renix blocks have a higher nickel content(i think) and that its a denser block and holds up better.

[carnuck]

I want to do mine with LPG (turbo would be nice too as LPG is @110 octane and CNG is 130)

[zjrog]

I have a question about stroked/turbo'd 4 liter motors. Well, more like fuel injecotr/ECM questions. I have worked with the Chrysler turbo cars form the late 80s and early 90s, as well as prepared a V6 minivan for a turbo (that never got finished due to the van getting junked).

 

For Renix and HO were the injectors and ECM drivers high impedence or low impedence?

[MrShoeBoy]

Why is it that the older blocks are better? When I built my stroker several years back I was under the impression that you wanted a block from a 96 or newer because there was added material to help with NVH (noise viberation, harshness) and also the 96+ blocks came with a main cap girdle. http://www.angelfire.com/my/fan/selection.html

 

AARON

[A-man930]

For Renix and HO were the injectors and ECM drivers high impedence or low impedence?

I would not be able to answer that for you, I'm not really sure.

Why is it that the older blocks are better? When I built my stroker several years back I was under the impression that you wanted a block from a 96 or newer because there was added material to help with NVH (noise viberation, harshness) and also the 96+ blocks came with a main cap girdle. http://www.angelfire.com/my/fan/selection.html

 

AARON

I'm not really sure what exactly was done to the post '96 castings other than the addition of a stud girdle... Anyone?

 

The original reason I asked if using a renix-era casting would be better was because of there already being provisoins for a knock sensor machined into the block. After reading a bit more I don't think I'll be using one regardless, now I'm making sure there isn't some big reason to avoid the renix block, as I'll have one lying around already.

[FxRacing282]

i'll stick to what i said.its going to get expensive really fast.after reading most of that thread i see how he is doing it or getting away with it,using a dished piston to bring compression back down after stroking it.the stroker kit i have (but haven't used yet) is using 9.25 compression pistons so i'm already at the limits of pump gas.

you must have real crappy gas, my moms got a built 355 and she has 11:1 and runs pump 91

[Blue XJ]

i'll stick to what i said.its going to get expensive really fast.after reading most of that thread i see how he is doing it or getting away with it,using a dished piston to bring compression back down after stroking it.the stroker kit i have (but haven't used yet) is using 9.25 compression pistons so i'm already at the limits of pump gas.

you must have real crappy gas, my moms got a built 355 and she has 11:1 and runs pump 91

 

x2. My stroker is running 9.7:1 and it runs just fine on regular, but prefers mid grade. And my quench height isn't quite right either, its closer to .055". I could definately run regular if the quench was a little better.

[Badger]

i'll stick to what i said.its going to get expensive really fast.after reading most of that thread i see how he is doing it or getting away with it,using a dished piston to bring compression back down after stroking it.the stroker kit i have (but haven't used yet) is using 9.25 compression pistons so i'm already at the limits of pump gas.

you must have real crappy gas, my moms got a built 355 and she has 11:1 and runs pump 91

 

different motors can handle different compression ratios.i had a built 460 pushing 11:1 and making over 450 horse and that was on mid grade.

 

4.0's do not like to get above 9.5~9.7 or they start to have issues.what you might think is 9.7 in reality is more like 9.5~9.6 once you take into account of the head gasket thickness, ring landing area,and piston dish.

 

did you actually cc everything? from the head to the piston while in the block to truly figure out your compression ratio.or are you just taking a guess as to what you have based on parts used?

[LEAD_NOT_FOLLOW]

I'm running a supercharger on my 4.6L stroker. I don't have more than 15 mins on it with the blower as I'm still finishing up my engine management install to run it fully.

 

It is correct that the Renix blocks are stronger. They have an added ridge on the blocks that that HO ones do not have. My recommendation would be to run a Renix block with a HO head from '95 or '96.

 

I have almost 10K on my 4.6L without problems but I am also running upgraded everything in the motor. I dyno'd right at 290HP with the stroker and plan on breaking the 400HP mark with the blower.

 

If you have any questions feel free to PM me as I've done a TON of research and have 1st had experience with building a 4.0L.

 

My only question is why a turbo?

[A-man930]

LEAD_NOT_FOLLOW: Your builds totally rock by the way... why a turbo? Because turbos are better :D Much more tuning flexibility, no paracytic loss to get boost, and it will spool right where I want it to when sized correctly. Besides, I've wanted to do a turbo something for a long time now, and the 4.0 would sport a hairdryer quite well. I will definately need lots of advice on my build as it progresses, you will hear from me, lol.

[LEAD_NOT_FOLLOW]

The biggest problem with the turbo is location. Thier is not really any good place to put it. But what do I know, I spent like $1500 in everything to just get my blower mounted so I could shut my hood. :roll:

 

You have a few option, the best one would be a remote mounted turbo. But their are several draw-backs to doing this. The other location is on the drivers-side under the intake manifold. Problem is clearance and the issue with the steering. Lastly the option I would choose if I was going to do is is on the pass side around the ac compressor and bat. Get a bat. tray from a diesel XJ (moves it to the driver side) and ditch the AC all together with a pully from a non-ac XJ/MJ (kinda hard to find). Only problem with this option is running the piping to the intake (3" pipe is a REALLY tight fit over the valve cover). Than what do you do with getting the exhaust routed?

 

A turbo that will spool in the lower RPM range (what you want if you actually wheel it) will not produce much boost and heat up rather quickly. So you need to adress cooling the turbo and I'd recommend running a intercooler somewhere as well.

 

Anyways, you know how to get ahold of me. :brows:

 

P.S. I'm working with a vendor as we speak about making a supercharger kit available for the market based on my setup. We'll see what (if anything) comes of it...