Who on here is the go-to for discussing a stroker build?

[sierradmax]

Several years ago, I purchased a used long block along with a Magnum Powers Supercharger. #4 and #5 were burned up so the intent was to bore & stroke the motor, building it with low compression for boosted application. The motor was sent to a local machine shop where the engine was machined, built, & blueprinted into a 4.7L using the following parts:

05 Block
SCAT 9-4-2L-3895 forged 4.2L crankshaft 3.895" stroke
SCAT 2-ICR40L-6125P forged rods 6.125" long
ICON IC668-040 forged pistons 3.195" bore
Edlebrock performer aluminum head
Harland Sharp 1.7 rockers

I lost the cam specs but I recall the compression ratio being computed at 8.9:1. After much reading, I think my plans will change from a boosted to naturally aspirated motor. Am I better off revisiting the engine build to raise the CR? Who's the go-to for 4.2L-4.9L strokers so I can wrap my head around my potential mistakes? Desired goal is around 330 lb.ft. and 280 hp.

 

[macleanflood]

@Woodrow just did one.

-Mac

 

[Woodrow]

@Woodrow just did one.

-Mac

Mine was bought, not built (Golen 4.6L) and I installed it in 2021. My engine has a ‘92 block and 7120 casting head. According to Golen, this specific engine made 284HP at 5200 RPM and max torque was 323ft.lbs. (with over 300 from 3000-5200RPM) at the crank on their engine dyno. Stock 1997 4.0L numbers are about 180HP and 225ft.lbs. at the crank. The stroker uses 24# injectors instead of 18# stock. Compression is 9.5:1. Here is the cam profile:

Here's the stock 4.0 vs 4.6 chassis dyno (stock tune in ECU for both)

So, chassis dyno numbers are less than predicted based on engine dyno but about a 25% bump in HP and TQ. I've been happy with it but I do plan a tune at some point.
Edit: @SkylinesSuck and @Rickyd are probably much better resources for someone building their own stroker than me.

 

[Rickyd]

Run your parts list and goals past russ pottenger. You can find him on jeepstrokers and probably Facebook

I didn't get notified by your ping for some reason woodrow

 

[Chris]

Run your parts list and goals past russ pottenger. You can find him on jeepstrokers and probably Facebook

I didn't get notified by your ping for some reason woodrow

Hasn’t Blaine been waiting well over a year for his stroker build from Russ? Maybe I misheard.

 

[jeepguy03]

+1 on Jeepstrokers, spent hours reading on there lots of knowledgable folks over there.

 

[Rickyd]

Hasn’t Blaine been waiting well over a year for his stroker build from Russ? Maybe I misheard.

Longer than it took me to get everything i needed from russ. And some other builds I know of.

Regardless, i would trust russ for a solid recipe.

 

[Chris]

Longer than it took me to get everything i needed from russ. And some other builds I know of.

Regardless, i would trust russ for a solid recipe.

No doubt, from everything I've been told, Russ is the man!

 

[sierradmax]

Run your parts list and goals past russ pottenger. You can find him on jeepstrokers and probably Facebook

I didn't get notified by your ping for some reason woodrow

I did call and speak with him. He's suggesting I change the cam and pistons and measure deck height. At that point, I'm re-balancing the crank and it just might be better to start from scratch.

 

[Rickyd]

I did call and speak with him. He's suggesting I change the cam and pistons and measure deck height. At that point, I'm re-balancing the crank and it just might be better to start from scratch.

10.5:1 and a nice big cam?

Which cam?

 

[sierradmax]

He didn't say.. We continued talking and said I might be able to use the pistons that are in it and chose a different head gasket to raise my CR. But, Russ mentioned I need to figure out deck height first.

 

[Rickyd]

I somehow missed the part where it's already assembled. Yeah,it could be worth trying to mill the head for compression or run a thin cometic head gasket.

The nice thing about lower compression is being able to run stale 87 octane from rural places. Mine wants premium,especially when it's warm out

 

[LJBean]

Russ was a huge help on my stroker build. His custom dish pistons were key to dialing in CR. I'm running 87 octane with no issues, and that's what I asked for.

As far as the original question on the go-to for stroker build recipe, Russ is your guy. Oh, and I didn't have to wait a year for my order. Russ was pretty prompt.

 

[GoldenGorilla]

I'm in the planning stage of a build but reading the sources mentioned alot. Your build sounds like a solid recipe. Might be a little below your target, but close. Unless you have concerns about something with the build I'd run it as is and see if you are happy with it as is. However to hit your target numbers you probably need to have it decked a bit, change to a thinner head gasket and/or change the piston for a shallower dish. Clegg and Newcomer only recommend the forged Icon pistons with boosted applications because they require a bit more wall clearance for thermal expansion and that makes them a bit more likely to encounter piston slap. But it doesn't automatically mean you'll have issues.

To really get it right, you're going to need to have the ECM tuned. You'll find some recommendations on jeepstrokers. It makes the difference between those topping out at 280hp and going higher. You also need to know the flow specifications for the 24lb injectors as well as the fuel pressure in your system. You'd think a TJ is a TJ, but almost every year is different. I was talking with Keith Newcomer the other day about some questions on some of his components and he indicated that the fuel pump would also need to be upgraded to support those HP ranges you're talking about. If you don't have a wideband O2 installed, you'll need one to get WOT dialed in, preferably that can feed into HP Tuners prolink to make logging simpler. I wanted to use a system that could simultaneously output wideband and narrowband signals in an existing upstream bung, but Chrysler uses an indirect method to check sensor readiness on start that wouldn't work and I couldn't find a way to squeeze an extra sensor in above the mini-cats. You can still get a meaningful reading between the mini-cats and main cat though.

I've been tinkering with HPTuners on my own to have it figured out when the time comes. Which is an option if your jeep is currently running as you can get some good baselines with your ECM now. Assuming your jeep is an 05 or 06 like your motor you'll have some advantages in tuning with the NGC3 computer over the JTEC+.

 

[MikeE024]

Hasn’t Blaine been waiting well over a year for his stroker build from Russ? Maybe I misheard.

My understanding is that buying parts from Russ is very different than trying to get him to build a motor.

 

[GoldenGorilla]

Also regarding injectors, the fuel pressures are higher on most TJs, particularly the later ones than the pressures the injector flow numbers are rated/advertised at, so you need to offset for that. 24lbs is typically going to flow a bit closer to 29lbs at later TJ stock pressures. The stock injectors spec'd in my '04 is 20.5lbs/hr at standard pressure, but at the pressure Jeep uses flow at 24lbs/hr and the factory tuned for that. These things are all over the place which is why you need to get it tuned. It'll be close enough with a 24lb for closed loop to calculate, but open loop will need adjustment.

The HP Tuners forum Dodge channels are unfortunately not that helpful. Too many people trying to sell their services gatekeeping and shutting down people trying to figure it out themselves (unless you want a burbble tune on your hemi Callenger). And unfortunately Chrysler isn't open about their systems as GM is making it all a bit harder. I want to tune mine myself because I want to be able to maintain it myself.

 

[Coalcracker18]

@sierradmax Both names were already mentioned here but I'll add my two cents. Russ and Newcomber, I had Russ speck me out a stroker a few weeks ago it does take him a few days to get back to you but he is very busy and of retirement age. I had another friend of mine who had a race car shop who is now retired look his build sheet over and was very happy with his choice of parts and liked the look of his work. He sent a bunch of pictures with his email, the only thing he he wanted me to change was to use Newcombers' Billet roller cam. I'm still waiting to hear back from Russ on the cam selection for my build, he said that he has another client that is asking for the same recommendation at the moment on a new build.

 

[Rickyd]

use Newcombers' Billet roller cam.

Do it! I want one but I don't want to be the guinea pig here.

 

[machoheadgames]

Hasn’t Blaine been waiting well over a year for his stroker build from Russ? Maybe I misheard.

He’s been waiting something more like 3 or 5 years. But, Russ doesn’t typically build motors. I think he agreed to build it for Blaine but that comes with “you’ll get it when I feel like it” which sucks. Typically you get your pistons and such from Russ and then get it built somewhere else.

 

[LJBean]

Do it! I want one but I don't want to be the guinea pig here.

Still trying to figure out why one would spend the $$ on roller for what is basically a tractor engine, but maybe I'm missing something.

I'm hearing a lot of opinions about jumping to an LS swap as opposed to stroker due to the comparative cost vs. performance. I'm happy with my stroker, but I think roller cam would push it out of reason.