Need guidance on a stroker recipe.
Posted: April 12th, 2013, 5:49 pm
I have a 2003 TJ Rubicon with a totally stock 4.0 that is still under 50,000 miles, and I have never had an engine problem other than one throttle position sensor. The Jeep is on 33's with stock 4.11 gearing and an NV3550 5-speed transmission. There is maybe an extra 400lbs in armor and mods on it now.
I want to set it up for towing. The trailer will be around 1000lbs loaded. The idea is prolonged expedition use including driving to Alaska and back. I plan to constuct a lightweight but roomy trailer using fiberglass and aluminum, and having a rooftop tent. The trailer will have a couple of fuel cells either side of the axle containiong a total of 40 extra gallons of gasoline to extend my range, by refilling the main tank.
It is already the case that with a heavy load of camping gear, or high altitude, or anything but the gentlest of slopes, I have to drop down to 4th, and often to 3rd gear, to keep the speed up. I expect this will be a lot worse dragging 1000lbs of trailer.
Through certain - irregularities - in some sports cars I used to own, my Jeeps get picked for special attention at a "test only" station, every time. Not just my Wrangler, but the wife's 2001 WJ as well. However I solve my problem, I'm gonna have to pass California emissions testing. Today the engine runs really clean and the history of the three smog tests I have had is that they all showed emissions around 20% of the limits.
Telntatively this is the plan:
1) Re-gear the Jeep from 4.11's to 4.56's or 4.88's. I have not decided which yet, but I do plan to keep the stock Rubicon lockers. I do plan to stick with the 33's.
2) Build or buy a stroker motor, keeping the stock motor as a known good spare. I'm not especially price sensitive, and I could buy a HESCO or Golen long block. But I want it to look stock, work well with the stock exhaust and throttle body, and pass smog by a comfortable margin. I don't mind putting Premium fuel in it. I note multiple stroker recipes here but I don't know which one comes closest to my needs. Although I have never done a Jeep engine, I did build a 2.0L 186hp Alfa Romeo engine a few years ago (it passed everything except the underhood inspection).
3) I understand that there are some practical difficulties tuning the 2003 model year, but I don't know the details. Looking for some input on this as well.
I want to set it up for towing. The trailer will be around 1000lbs loaded. The idea is prolonged expedition use including driving to Alaska and back. I plan to constuct a lightweight but roomy trailer using fiberglass and aluminum, and having a rooftop tent. The trailer will have a couple of fuel cells either side of the axle containiong a total of 40 extra gallons of gasoline to extend my range, by refilling the main tank.
It is already the case that with a heavy load of camping gear, or high altitude, or anything but the gentlest of slopes, I have to drop down to 4th, and often to 3rd gear, to keep the speed up. I expect this will be a lot worse dragging 1000lbs of trailer.
Through certain - irregularities - in some sports cars I used to own, my Jeeps get picked for special attention at a "test only" station, every time. Not just my Wrangler, but the wife's 2001 WJ as well. However I solve my problem, I'm gonna have to pass California emissions testing. Today the engine runs really clean and the history of the three smog tests I have had is that they all showed emissions around 20% of the limits.
Telntatively this is the plan:
1) Re-gear the Jeep from 4.11's to 4.56's or 4.88's. I have not decided which yet, but I do plan to keep the stock Rubicon lockers. I do plan to stick with the 33's.
2) Build or buy a stroker motor, keeping the stock motor as a known good spare. I'm not especially price sensitive, and I could buy a HESCO or Golen long block. But I want it to look stock, work well with the stock exhaust and throttle body, and pass smog by a comfortable margin. I don't mind putting Premium fuel in it. I note multiple stroker recipes here but I don't know which one comes closest to my needs. Although I have never done a Jeep engine, I did build a 2.0L 186hp Alfa Romeo engine a few years ago (it passed everything except the underhood inspection).
3) I understand that there are some practical difficulties tuning the 2003 model year, but I don't know the details. Looking for some input on this as well.