SC'd 4.2L Stroker

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I am contemplating dropping in a sleeved 4.2L stroker block into my FX and I am trying to figure out what all I will need to do in order to make it a smooth running, reliable mod. I want everything to look stock in the end, but put out around 400-500hp and equal tq numbers to the wheels.

I want to put a roots or whipple style blower on it, and the stillen sc would obviously be the easiest option, but I don't know if it has the capacity(pressure/flow) to create that much power on a bigger engine. Supercharger as opposed to TT for simplicity and low-end torque for occasional towing.

obviously it will need larger injectors and a larger fuel pump. Will I need a piggy back fuel management or can it be tuned with the stillen/stock ecu?

I saw that rookie has some hardened gears in his tranny and I think I will be in the same area as he is with power so this might be necessary. I am not looking to create a race vehicle, but more of a Porsche Cayenne turbo competitor. Basically I want the same numbers that the Porsche puts down and I want to have the reliability you would expect from it too.

Any suggestions, ideas that could help me put this together?

Thanks,
Justin
 
First of all Justin, welcome to the Scene.

I have been pondering for some time about what options out VK45 have for FI. There really is not any for the VK engines. Nevertheless, I did reifly speak with rookie and he did point me in the right direction of what is possible with the VK45 engine.

Do you have an FX35 and want to drop in a VK45 engine or have an FX45?

This makes alot of diffrence in what direction you want to take..
 
Berto, that engine has nothing to do with VK's

That is still a VQ35DE, bored and stroked to 4.2L.

If it's a VK45, stroking it would give more than 4.5L :tongue:

I was going to reply to this topic, but I honestly don't know much about either. I never was too interested in the low output Stillen, but it is EXTREMELY reliable compared to the other FI options for the VQ, and I was just never baller enough to give the 4.2L motor (from GTM) a shot. Instead I have like a 3.54L built motor :wink:

Your setup, for what you are after, seems like a flawless plan. You're not asking for a whole lot of power out of the Stillen, but at the same time you're gonna get what you need from the combination of the two (stroked + SC'd).

As for fuel/engine management, I would go with a completely stand alone for what you're after. That was what first came to mind with your intent. The reason being is that you can't get the same tune with all units, and that is why you pay the premium. The Haltech Platinum and HKS Fcon VPro are the only 2 engine management units that I'd recommend if someone's not on a budget. Heck, I'm on a budget and still may go with one of those two.
 
Goodluck man! it will be the first 4.2 stroked engine in an FX, i wish you all the luck.

i believe i replied to your thread on the .org about this, its starting to make sense to me now. you will have a larger power output due to the bigger engine, and the stillen kit (even though it doesnt give a ton of power) will add on to your 4.2 and give you a good amount. you will have a very strong engine with the most reliable F/I kit available....sounds goooood!
 
I don't think the M62 will support those power levels, the 5.7L Stillens use the MP112 and they might be making the power you're talking.

Not sure which stroker kit you're looking at but pricing it out in my head I'm pretty sure the GTM 4.2 stroker is over 9k in parts, before assembly and removal and re installation of the motor. This potential route could cost over 25k.
 
rookie said:
I don't think the M62 will support those power levels, the 5.7L Stillens use the MP112 and they might be making the power you're talking.
Click to expand...


Thats the main thing I was worried about with the Stillen kit. I sent them an email, hoping to find out if one of the larger superchargers can be bolted to the manifold.


rookie said:
Not sure which stroker kit you're looking at but pricing it out in my head I'm pretty sure the GTM 4.2 stroker is over 9k in parts, before assembly and removal and re installation of the motor. This potential route could cost over 25k.
Click to expand...

The assembled shortblock costs ~9k, SC kit costs ~7K, installation ~4K, stand alone ECU, etc etc,

Porsche Turbo ~95K, FX35 ~40k

I dont know, I like the idea, but I could come across something else in another month, theres no telling.

Thanks for all the response!
 
RFS 1k
Big injectors 650-1k
Stand alone 3-5K
Transmission work 3-5k
Random misc costs another 3-5k

I'm in no way tryng to discourage you, the stroker is the part that is above and beyond what I would have in the mix. With the Stillen as part of the equation it would be difficult for me to consider the potential costs for somehting that could possibly not make enough power. The Stillen heat exchanger would need to be upgraded to maintain efficiency.
 
rookie said:
I'm in no way tryng to discourage you, the stroker is the part that is above and beyond what I would have in the mix. With the Stillen as part of the equation it would be difficult for me to consider the potential costs for somehting that could possibly not make enough power. The Stillen heat exchanger would need to be upgraded to maintain efficiency.
Click to expand...

In order to build an engine capable of supporting that much power reliably (from what I have read) I will need to have rods, pistons, sleeves, etc. I figured that the additional cost of a stroker kit would be reasonable since it would allow me to run a more conservative tune and still make the same numbers, adding to the longevity of the motor.

I saw a 350z with the same stroker kit and TT pushing something like 770hp to the wheels at 20psi, 550hp @ 13 psi. Is it unreasonable to think that 10 psi on a supercharger would make in the range of 450-500whp? perhaps less hp and more torque due to the difference in efficiency between TT and roots SC?



thanks for all of the help, I am relatively new to these motors and appreciate all of the advice/criticism.
 
The 4.2 stroker from what I know is a reliable set up. Heat from the boring has been an issue which is addressed in a few ways.

The CFM from the GT30s of the APS Extreme kit are probably well above what the M62 can do. Not sure if you've ever seen the heat exchanger on the stillen manifold, but it is relatively thin.

For the power you're looking for a centrifugal supercharger is probably not ideal. A big single could be ok but the lag is probably not what you're looking for in power delivery.
 
I saw on a few sites for mustangs that the M90S is used for their 4.6L applications. I'm not sure of the comparability between a v8 and a stroked v6, but it seems as though this supercharger would be sufficient for my application. Would that be a reasonable assumption?

Stillen wont write me back, does anyone know if the Stillen FX35 kit could be easily modified to fit the M90? Could it be a simple matter of cutting the center section of the upper manifold and welding in an adapter plate??

To improve cooling, perhaps a spacer could be added to the manifold and another intercooler could be sistered to the existing one...

thanks,
Justin
 
I think the M90 is better sized for our motor. Not sure the details as to why the M62 was used instead of the M90 but with the hood clearance issues Zs have it must have been the better route for Stillen.

The Stillen manifold would need to be modified to deal with the additional heat involved with the larger blower.
 
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