1990 Jeep Comanche With S&J Balanced 4.7 Stroker Motor (Renix)
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- Опубліковано 24 сер 2024
- Quick video of my 1990 Jeep Comanche Long Bed 4.7L stroked, RWD, Auto. The truck has a little over 4k miles on the full build/stroker engine with a R.E.M. engine management system for the “Renix” electronics, 4:56 rear ring and pinion/locker. Iron Rock Offroad front lift with a Rusty’s 4.5” spring pack and Bilstein 5100 shocks. The truck has many more mods I will cover later, I haven’t seen anything on here about the S&J strokers so I just wanted to post this first initial video of it running! This engine has gobs of torque and works effortlessly when driving with a nice gain in HP and TQ. Love it so far!
Nice! A friend just picked up a 91 long bed 4x4 with a 4.0L HO. I have been dropping subtle hints about stroking it out to 4.7L.
Why did you stick with the Renix vs the HO? What crank? Scat or cleaned up from a 258ci? 12 counter weight or 6? Also what cam? The biggest issue I've seen with 4.0 strokers is wiping the cam lobes. Seems to be a very wide spread problem. Not sure if it's due to spring pressures, poor cam material, inadequate break-in period, not enough oil pressure, not enough assembly lube or wrong oil altogether. Not enough zinc in the oil?
Also what octane gas? Compression ratio?
Custom pistons? Keith Black? Or custom rods?
You can pickup another 20 or more HP if you swap to a 7120 cast head, horse shoe intake manifold, big bore throttle body, multi port fuel injectors (if you haven't upgraded them already) and dual electric fans.
www.sandjengines.com/promos/jeep-stroker-long-block-cherokee-wrangler-wagoneer-comanche-engine
The previous owner had the truck built to the way it is now with all receipts and documentation to prove it. I have receipts for everything including the S&J Renix stroker with less then 5k miles on the whole build. I don’t mind the Renix Jeeps, I’ve owned 6 Comanches and over a dozen Cherokees, many where the Renix so I know how to work on both and had 2 High Output 4.slow trucks. The biggest thing with the cams is enough assembly lube along with a proper break on procedure, if they are not broken in correctly it flattens out the lobes and will even cup the hydraulic Tappets in some cases. I just got adjustable Harland Sharp roller rockers to install and a comp cam, it’s running a barely upgraded from stock cam right now so I’m not getting the full potential yet. The head is ported with a 60mm throttle body and 24lb/hr injectors. It has icon premium forged pistons, scat 4.2 crank, etc. I posted a link to the website that tells you everything about the engines. I just run premium pump gas and it runs perfectly fine but it does like it when I mix some octane booster with the gas as well. 9.6:1 on the compression I believe so a little more then OEM, 9.3:1 is the recommended compression ratio for 87 octane or boost so I can always open up the combustion chambers a few cc’s to drop compression if needed. I got this truck because it has the barely broken in Renix Stroker already done and I am interested to see what I can make out of it. I have a pile of parts ordered for this already including the valve cover spacer for the roller rockers, all aluminum radiator and aluminum shroud with 3 e fans so I can delete the clutch fan and cool it with the triple electric fans. The stock stamped steel rocker arms and push rods really hold back quite a bit of power from all the friction and relying on adequate Lubrication getting to them. Strokers are hard on the pushrods/rockers as well so I can’t wait to get the Harland sharp 1:6 ratio adjustable roller rockers installed with a more aggressive came and new pushrods. I just want to see how well I can make a Renix 4.0 L run more or less. If I want to experience something crazy I just take my 5.7L Hemi swapped TJ for a rip! If that Renix stroker grenades in my comanche I will probably replace it all with a HO swap, I’m doing all I can to make it reliable as well as more HP & TQ. I have a REM Gen 5 engine management system in the comanche so the Renix isn’t as big of a deal with that.
When you order the 87-90 4.7 stroker from S&J the performance cam is optional, the previous owner decided to go with a cam that is close to stock so that’s the only difference from my motor to the build sheet on the sight with the internal parts list. That’s why I am going to swap the cam for a performance comp and then install the roller rockers and new push rods. I thought about upgrading to an aluminum head but it’s not that simple on the Renix since they are made to use the 91 and up intake & exhaust manifolds and throttle body. Think I’m going to just do the cam, rockers, and push rods with the aluminum radiator and electric fans plus some other odds and ends I ordered for now. Can always upgrade more of it later, I’m pretty impressed with the stroker using the Renix electronics as is though. Huge difference in torque and noticeable increase in HP. It just works effortlessly going down the highway, uphill, down hill, flat ground, it doesn’t care.
what do you think about these specs @comanche club
AMC Jeep Mopar 4.0L 288 C.I. L6 Stroker: 4.0L Block; Displacement: 4.7L/288 C.I.; Bore .040 - .060; Stroke: 3.906; Balanced rotating assembly; Firing Order 1-5-3-6-2-4; Compression Ratio: 9.3:1; Enginetech Main Bearings; Enginetech Rod Bearings; Felpro Performance gasket kit; Hastings Hypereutectic Dished Piston Rings; ICON Premium Forged Pistons IC944-040; Melling M-81A Oil Pump; SCAT Pro Comp Stroker Crankshaft 9-4.2L-3895 3.895" Stroke / 2.125 Snout .850 Pilot Hole; Horsepower 230; Torque 280 lb/ft typical; OEM-spec Camshaft-equipped (no computer reprogramming required), Performance Camshaft Available Upon Request