Magnum V-8 engines are great power producers. They offer lots of torque at low rpm and have a durable bottom end that can serve as an excellent platform for a workhorse engine or a high-horsepower racing powerplant. If you can overlook the horrific fuel economy, the 5.2L and 5.9L Magnum V-8 engines are generally likeable motors.
But if you're an owner of a Magnum V-8, you probably already know that it's not all a bed of roses with this engine. Almost certain head problems plague 5.9L (360ci) models, but 5.2L (318ci) owners should be wary as well. Heads are such a problem on Magnum V-8 engines that Dodge and Jeep dealers tend to keep them in stock.

1. The Cific C671 heads seem to be the solution for Magnum V-8 head woes. Ours came grease
The head problems usually lie between the valves. The extra pressure and power and the different stroke of the 5.9L engine tend to make it much more susceptible to issues than its 5.2L brethren.
Since we have a couple of these engines embedded in our fleet of vehicles, we've experienced more than our share of head gaskets blowing and heads failing. Our last pair to blow was on a daily-driver, and with 50,000 miles on the engine the temperatures were going through the roof and white smoke was blowing out the back-sure signs of head dilemmas. Our reliable engine masters at Jeeps R Us came to the rescue again, pulling our heads and sending them off to D&H Automotive Machine in Capistrano Beach, California, to see if they could be salvaged. But the report came back of numerous cracks in both iron heads.
With the recommendation of D&H, we tracked down a company called Cific International. Cific's heads are stock replacement on Magnum V-8s, but they've managed to thicken the metal around the water jackets and get more material between the valves. Having no prior knowledge of a simple head solution (save for a custom modified head) for the Magnum V-8 engines, we were eager to get our hands on a set for ourselves. It was a little uncharacteristic of us to rip something open and not modify it, but we resisted and kept ourselves from enlarging intake valves and popping in a lopey cam. Besides, "stock and working" is a great modification over "broken."
We were so close to having everything buttoned up when our true nature got the better of us. It couldn't hurt to add some more efficient roller rockers from Crane Cams (hey, the valve covers were already off) to our valvetrain. And the requirement for taller valve covers would give us an excuse to put some more impressive looking Mopar aluminum valve covers on our Magnum 5.9L.
Maybe we aren't so good at keeping things stock, but we sure do like the upgraded package that will keep our engine lasting longer and running a bit more efficiently.
-

2. With more material between the valves, the Cific heads are an improvement over a factor
-

3. Before going any further John VanBaalen of D&H Automotive Machine used one of our valve
-

4. D&H stuck the Cific heads in the washer and cleaned them prior to building them.
-

5. D&H washed and cleaned our original valves and springs after checking to make sure none
-

6. VanBaalen gently tapped each valve stem seal in place, making sure to seat them properl
-

7. With the valve stem seals in, VanBaalen pushed each valve into place (eight per head; o
-

8. With the valves in the heads, a pneumatic valve spring lifter was used to install each
-

9. With the heads off, Jeeps R Us did a visual inspection of the block and cylinder walls
-

10. Since the heads were already off, we couldn't help but add some Crane Cams roller rock
-

Crane Cams also sent us two adjustable pushrods to check out. If we were building a custom
-

11. Instead of the factory rockers, we decided to upgrade to some stock ratio Crane Cams B
-

12. Crane Cams provides an instruction sheet that tells best how to install the guideplate
-
-

13. Like we mentioned earlier, one modification can often necessitate another modification
-

14. Our valve cover answer came straight from Mopar, and gave our engine a new bit of clas
|
|
Crane Cams
1640 Mason Ave. Unit 180
Daytona Beach
32117
866-388-5120
www.cranecams.com
|
Jeeps R Us
3231 Laguna Canyon Road
Laguna Beach
CA
92651
949-497-9183
http://www.jeepsrus.com/
|
Mopar
P.O. Box 21-8004
Auburn Hills
MI
48321
800-992-1997
www.mopar.com
|
D&H Automotive Machine
n/a
949-493-5101
|
Cific International, Inc
n/a
800-891-8002
| |