Dyno Death March! We Test 5 Jeep Cylinder Heads

We’re back with Newcomer Racing (http://www.newcomerracing.com)as they slam FIVE different Jeep cylinder heads across the dyno to see what works best. We’ve got a wide variety, from stock ports, to a fully hand-ported Edelbrock Performer cylinder head. This is the second of a two-part dyno testing series. Check out the first video where we looked at whether roller rockers help make power here: https://youtu.be/KWtfo4uT61E

Also, you can check out our complete build of Newcomer Racing’s budget stroker Jeep engine here: https://youtu.be/WlHrqhwojf0



30 thoughts on “Dyno Death March! We Test 5 Jeep Cylinder Heads

  1. what about the ProMaxx head ?? have you ever been able to test one of those? And what stock jeep head does the ProMaxx compare to? the 0331 or 0630 ?

  2. I have an ultra-low mile 92' Sahara (think Jurassic Park Jeep) and am considering a supercharger.
    Wow, what a test! I LOVE the no B.S.
    You earned another subscriber for this!

  3. oh wow u made 3xx hp sad , you would have less money in a ls swap than building this engine. and have more hp with a stock dead nuts reliable 5.3l add a cam and that lil 4.x is even further behind

  4. years ago I had a 4.0 mated to a 5 speed with grand ma first and a NP 205 transfer-case in a J 10. it was one of the most capable jeeps I ever owned and would still be in my garage except for the dread of all jeep owners it was built from a cheaper steel as american motors was nearing the end of it's life and was sold in Connecticut. needless to say when I got it it was a rust bucket but it had a very low mile 4.0 and the 5 speed I swapped in the 205 because I had a chance to get one and it was the best mod and the only one I did to the truck. I got 8 years out of it before it rusted back to the earth but the motor, trans and transfer-case went in to my little brothers 67 J 10 and still powers it to day that was over 20 years ago now and it's still his daily driver.

  5. why doesnt someone have the sense to build a crossflow head like the tunnel port heads that ford used to make? The 4.0 head is a design out of the 1920s.

  6. I'm not convinced the chamber design of the Edelbrock is an improvement. The loss of low end torque might be less to do with port design and flow, and more to do with the combustion chamber. It's hard to argue the weight savings and the bolt on power of the Aluminum head, but it's not the improvement I would expect.

  7. The last Ironhead, looks like it would probably have produced somewhere close to about 330 or better horsepower if it didn't have the larger combustion Chambers to allow for forced air you can. Maybe a slightly domed piston would have worked. That might bring you up into that 330 to 350 horsepower range. But that would have been really ideal and I don't think you had quite enough to him for that horsepower. Looks like the best head for the money was the stock Edelbrock. Just a little bit of cleaning of the ports, which most people can't do. Helps and not opening up the exhaust ports greatly would help in reduction of reversion. Which could cause issues down the road with the coking up the intake.

  8. Wow. This is NOT an engine that you can just throw a head at and expect a good return. I knew it was a dog, but WOW. Really makes a case for electric conversion if you want to see a notable difference.

  9. when you run a side mounted four barrel carb the primaries face the intake valves, how about testing the four bangers (2.5), the throttle barrel injection manifold is way too small, but the electronic (four injectors) has a better runner design, the throttle body , will bolt on and you plug the four injector ports, the four banger jeep also had a twin cam cross low head

  10. Great video. Some very impressive numbers. That torque is awesome. Exactly what u need in a trail rig, low revving 4.0 or in this case 4.5. People that bounce these engines off the limiter rode the short bus as kids.

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