Started my 4.7 Stroker build today.

[old_man]

I have enjoyed following this thread. I built my 4.7L Renix stroker back in 2000. Being a gearhead and engineer, I was very careful to pick the right components and get the quench height where I wanted it. I have seen tons of strokers come and go. Most blow up because of not getting the tune correct. The best thing I did was spend some quality dyno time at the beginning, but I fought it over and over. There is no way I would run a stroker without an ARF gauge. Most strokers I see are running way too rich or way too lean. With my setup, I get 21mpg on the highway and 18 highway pulling my teardrop. Back in the day, it dyno'd at roughly 300hp and 325 lb/ft. of torque. Now at over 250k miles, the power is down a bit. The compression is still great but I think the cam lobes have worn over time.

[bajabronco]

Originally Posted by -PigPen-

Is there any data on the stroker output prior to the tune? It would be interesting to see how much power is left on the table without getting a tune.

If I remember correctly, it was 207hp. Initially we couldn't do a lot of tuning because of fuel delivery. The top run during the first tuning session was 212. So I guess if you look at the HP tuning delta from base run with the new stroker, and what I tune ended up with was around 20hp, More importantly Chris worked on getting the air fuel ratio dialed in across the complete throttle and RPM band to optimize performance as well as make it reliable.

[cal]

Originally Posted by CMNCHE

How much did this 80 RWHP cost? To me this doesnt seem very cost effective.

At what dollar value would you consider a 50% increase in power to be cost effective?

[jrowell]

Originally Posted by CMNCHE

How much did this 80 RWHP cost? To me this doesnt seem very cost effective.

After having a taste of the power difference a stroker provides, there is no way i'd go any other route. I'd take out a good running motor to drop one in. It's so much more fun to drive.

[hexdmy]

Originally Posted by -PigPen-

Is there any data on the stroker output prior to the tune? It would be interesting to see how much power is left on the table without getting a tune.

It's important to think of the tune or “tuning” as not a way to squeeze every last hp, but to make sure the vehicle will run well and stay running well. I find that people think a "tune" will fix everything, however I typically spend as much time, if not more time, diagnosing and repairing various issues than I do actually tuning.

There are instances where you can get away without a tune, and still have a safely running engine, but you need to make the effort and be savvy enough to verify and know that everything is working properly: mixture, fuel trims, ignition timing, etc. are all within an acceptable range. Just one example: someone contacted me about tuning a stroker build installed in their off-road rig. He said it "ran ok" but felt that it should make more power and wanted a tune. He confirmed that it had a high flow pump installed as well as 24 lb/hr injectors. I told him I could help but insisted that he check the air fuel and fuel pressure first. He was reluctant to do this, and it took a bit of persuading on my end, but in the end he fitted a wide-band and sure enough the truck was running extremely lean at wot and even at part throttle, checking the fuel pressure, it was somewhere around 30 psi, less under load, due to a problem with the fuel pump install.

That example above is not the exception to the rule, that is the norm. The owner of that rig was driving it around without any concern, yet I can say with some confidence that the engine would not have lasted too long if he had kept driving it that way. Long story short, don’t be lazy or cheap, and if you think tuning is a farce or “not worth the money” then you need inform yourself on how to competently evaluate things for yourself, and finally don’t fall into the “Dunnin-Kruger effect” category, which happens far too often unfortunately.

[bajabronco]

Originally Posted by CMNCHE

How much did this 80 RWHP cost? To me this doesnt seem very cost effective.

For me, the 50+% increase in HP was totally worth it. When I looked at other options - mainly a supercharger or a LS swap, they would have more problems with smog, put out less power and or were more complex and expensive. I considered a supercharger, and looked at the one by boostedtech - and even at its high boost configuration, it put out less power than a stroker config. It also would have been a supercharger on an old engine, heat is a problem with forced induction if you don't have an intercooler, and would have never passed CA smog. It didn't seem worth it for the $4100.00 price tag. I considered a LS swap as well, I actually have a buddy who is in the process of doing one. It was a tempting option for sure, since I love V8's, but in talking to people who have done the swap, they are complex, and end up costing a lot more money than you expect. Of course there is a way to actually smog a LS swap in CA, but it is a complex process and you need to jump through a lot of hoops to get it done. One of the great things about the stroker is that it just drops straight in. I didn't need to wire anything, change my exhaust, modify any brackets, radiator, AC, coolant or tranny lines etc. It just drops in place of the stock 4.0.

[Anak]

Originally Posted by bajabronco

For me, the 50+% increase in HP was totally worth it. When I looked at other options - mainly a supercharger or a LS swap, they would have more problems with smog, put out less power and or were more complex and expensive. I considered a supercharger, and looked at the one by boostedtech - and even at its high boost configuration, it put out less power than a stroker config. It also would have been a supercharger on an old engine, heat is a problem with forced induction if you don't have an intercooler, and would have never passed CA smog. It didn't seem worth it for the $4100.00 price tag. I considered a LS swap as well, I actually have a buddy who is in the process of doing one. It was a tempting option for sure, since I love V8's, but in talking to people who have done the swap, they are complex, and end up costing a lot more money than you expect. Of course there is a way to actually smog a LS swap in CA, but it is a complex process and you need to jump through a lot of hoops to get it done. One of the great things about the stroker is that it just drops straight in. I didn't need to wire anything, change my exhaust, modify any brackets, radiator, AC, coolant or tranny lines etc. It just drops in place of the stock 4.0.

This makes sense to me.

I now live where an LS swap would be easier than Kali on account of the smog requirements, and I still think a stroker is a better option.

I love seeing what others have done with LS swaps. They are awesome. But from a practicality perspective the stroker looks like a better option for me. Change a few priorities and that picture shifts. It comes down to the individual. There is a place for each.

[IslanderOffRoad]

Originally Posted by Anak

This makes sense to me.

I now live where an LS swap would be easier than Kali on account of the smog requirements, and I still think a stroker is a better option.

I love seeing what others have done with LS swaps. They are awesome. But from a practicality perspective the stroker looks like a better option for me. Change a few priorities and that picture shifts. It comes down to the individual. There is a place for each.

Agreed. I was going back and forth on it myself a few months back before I decided to punt and just replace my head for now.

If I had an automatic (or wanted to switch to it) the LS swap might have made more sense. But with the pricey adapters needed to mate it up to the NV3550 it killed the cost savings on the engine. And while they are reliable, you've still got an engine with miles on it and depending on how you bought it, some ambiguity of how it was treated.

I'd be more willing to take that risk on a street/strip toy than something I'm driving out to the middle of nowhere to wheel.

[twinhauler]

I am still waiting for a timing chain, so I can get my 4.6 built. Your performance sounds great. I am gonna be super happy with more power hauling the heavy pig around.

[CMNCHE]

Originally Posted by cal

At what dollar value would you consider a 50% increase in power to be cost effective?

He gained 80 RWHP....so stock he had 40?

[cal]

Originally Posted by CMNCHE

He gained 80 RWHP....so stock he had 40?

That would be a 200% increase.

Stock XJ's with an AW4 put out about 140 RWHP.

[sidewaysstarion]

Math is hard, especially when you're trying to justify not building a stroker.