4.0 Roller Cam

[89 MJ]

I saw that Newcomer Racing has come out with roller camshafts for 4.0s. Not at all cheap, but sure beats having to build an engine with a flat tappet cam twice with the poor quality of new flat tappet lifters. Looks like they have the same offerings as their flat tappet cams. 

 

For anyone interested:

https://www.newcomerracing.com/store/p49/Billet_Roller_Cam_and_Lifter_Kits_4.0_4.2_Jeep_AMC.html#/

[pizzaman09]

This is exciting.  Hopping up the 4.0L is on my future endeavors list.  

[ghetdjc320]

Best mod I’d like to see for a 4.0 from the aftermarket is a flow through head 

[TurboedMJ]

I'm sure hoping he'll come out with a video soon about a 1500 hp 4.0... you know he's experimenting with that new roller cam lol. 

Edit: just saw on the website that the first cores are arriving in February and then dump testing will begin. Excited! 

[AZJeff]

47 minutes ago, ghetdjc320 said:

Best mod I’d like to see for a 4.0 from the aftermarket is a flow through head 

That’s kinda hard to do with an in-line pushrod engine.  You would basically have to revamp the design to OHC to make room for the exhaust ports/runners.

[pizzaman09]

6 hours ago, AZJeff said:

That’s kinda hard to do with an in-line pushrod engine.  You would basically have to revamp the design to OHC to make room for the exhaust ports/runners.

It's been done on other platforms.  Aftermarket flow through heads are a common upgrade for the old Austin A series engines used in vintage Minis and many other old British cars.  You are right though, it involves engineering a new head from the ground up and would be very expensive, also probably not very popular as all out horsepower for racing isn't super common for Jeeps.

[ghetdjc320]

There have been 4.0 roller cams before (e.g. 505 performance). A flat tappet can work fine if properly setup with the right springs along with some decent oil for it. Biggest issue I've seen is with the lobe width on aftermarket cam blanks. The 2229 mopar cam had the full width lobes as did a few others. I ran the comp 235 cam for upwards of 40K miles with zero issues and that was with the narrow little lobes on that cam. Just need proper oil and break in.

[89 MJ]

1 hour ago, ghetdjc320 said:

There have been 4.0 roller cams before (e.g. 505 performance). A flat tappet can work fine if properly setup with the right springs along with some decent oil for it. Biggest issue I've seen is with the lobe width on aftermarket cam blanks. The 2229 mopar cam had the full width lobes as did a few others. I ran the comp 235 cam for upwards of 40K miles with zero issues and that was with the narrow little lobes on that cam. Just need proper oil and break in.

The other problem I have heard a lot about is with flat tappet lifters. It sounds like quality has gone down a ton in the last four years. That said, I wouldn’t be afraid to slap in an NOS flat tappet cam. 

[ghetdjc320]

Just now, 89 MJ said:

The other problem I have heard a lot about is with flat tappet lifters. It sounds like quality has gone down a ton in the last four years. That said, I wouldn’t be afraid to slap in an NOS flat tappet cam. 

Grab some Johnson lifters. They make quite a few options for AMC engines that work great 

[89 MJ]

4 minutes ago, ghetdjc320 said:

Grab some Johnson lifters. They make quite a few options for AMC engines that work great 

That solves that problem!

[75sv1]

I don't think Johnson make lifters for the 4.0L any more. I nabs some off of EBay. Have to look closely on some US brands or made ones. They'll be marked Johnson. Not sure of how many I have. Not a lot. I did get some SPI (???). Made in Mexico. I could tell the surface was not very Spherical Radius. It was splotchy. I do measure similar parts at work. After a while you can look at the surface an tell. 

     Some sources say a Roller Cam is worth say 35 additional HP. Also, the cam sprocket with Torrington bearings worth 8 hp. 

[ghetdjc320]

2 hours ago, 75sv1 said:

I don't think Johnson make lifters for the 4.0L any more. I nabs some off of EBay. Have to look closely on some US brands or made ones. They'll be marked Johnson. Not sure of how many I have. Not a lot. I did get some SPI (???). Made in Mexico. I could tell the surface was not very Spherical Radius. It was splotchy. I do measure similar parts at work. After a while you can look at the surface an tell. 

     Some sources say a Roller Cam is worth say 35 additional HP. Also, the cam sprocket with Torrington bearings worth 8 hp. 

I can't imagine a hydraulic roller cam worth that much more on a 4.0 than a flat tappet cam with the same grind. Maybe 5hp at some ridiculous rpm?? Solid roller, perhaps??  Thats a bummer if hylift-johnson isn't making them anymore. I see Mopar ones are still available though.

I'm not sure if they actually have them in stock but here is the elusive mopar performance cam: https://www.moparpartsgiant.com/parts/mopar-camshaft-engine~p4529229ac.html Normally comes with the lifters as well. 

Seems like there is less and less for the 4.0. It's bitter sweet, I've had so many Jeep straight 6's. But I will say, they are really hard to get much bang for your buck when upgrading.

 

I feel the 87-95 4.0 cams are great overall. Bump up your compression and do any mods that will keep your intake velocity high to take advantage of that short 197 duration. Regearing and shedding useless weight off of Jeep's helps a ton (pun intended) and is probably one of the best improvements to drivability for the money. 

[75sv1]

It will be interesting if and when Newcomer post dyno results. I hope they post some of the lower lifts. One of the main advantage of a roller cam, is that it can have more aggressive ramping. I do see in some LS posted dyno run, that the lower lifts stay about even with the higher ones, till the higher RMPs. I get annoyed with some claiming XXXHP. At what RPM? 

[89 MJ]

24 minutes ago, 75sv1 said:

I get annoyed with some claiming XXXHP

Agreed. I couldn’t care less that it makes 500 hp at 7000 rpm. I want to know how much hp, and more importantly, how much torque I’m making between idle and 4000 rpm, where my vehicles all live. 
 

I drive a newer 4cyl vehicle when I’m at school. The darn thing doesn’t make power until after 4000 rpm, so I feel like I have to beat on it to keep up with traffic. I much prefer my I6s for daily driving.