VWandDodge,

I got to side with Steve on this one. I too had to replace my heads, and my truck has never seen a drag strip either. The only mods on it are a cold air intake, and an exhaust setup. Nothing more. When I did the cylinder heads in September of '05, I worked with a mechanic on it at his shop. We called several machine shops (in various states including Nevada, Utah, and Idaho), and also called a number of wrecking yards (also in Nevada, Idaho, and Utah). They all said the same thing about the cracking between the valves. Mine were cracked hardcore and were not fixable.

The biggest problem(s) I had with removing and working on the timing cover were having to lower the oil pan (removal is not necessary), and getting a new front main seal to go in. But I would definately pull that cover and replace the timing chain. The slop in mine was quite.............noticable. A double roller fits in nicely and kudos to Mopar on this one, no pressing of the crank sprocket is necessary. Very easy to install and worth it if you are going in the engine that far.

Good luck!!

 

Thank you for the insight. Where did you get the double roller rocker timing chain? I found a 6-vane aluminum water pump at Summit for cheaper than the one listed above. I am also looking at rebuilding the heads myself. I could use the experience. If I'm going to spend the money at Summit, I might as well make it worth my while.

 

I got the timing chain from one of the parts joints here in town (we only have 2, Napa and the other one). The timing chain I got was made by CLOYES and has stock, advance, and retard settings. When I installed it, I left it at the stock setting.

 

The 1992-1998 factory Magnum cylinder heads do have a cracking problem from intake valve seat to exhaust valve seat across the ridge.

I have read maybe 30-40 post from Ram owners whose cylinder heads ended up being cracked
and some did seem to be just 'regular' truck owners who were not racing or chasing horsepower.

I have also read posts from older Mopar guys who were searching for Magnum style heads to put on older LA style engines and in the junkyards these guys found that the majority of the cylinder heads from 'totalled' trucks ended up showing cracks when they were magnafluxed. Many of these cracks are shallow enough that they have not yet penetrated the cooling jackets - but they grow with time.

I don't have the numbers handy but I believe there are at least three different factory Magnum cylinder heads, each with a revised casting number.

There is also the Mopar Performance RT cylinder head that has larger ports. In the advertising for the MP RT cylinder heads they mention that it has a revised alloy and is supposedly less prone to cracking.

Those Hughes HD Magnum heads are cast in Austraila from a design originally from New Zealand.
Unlike the factory Magnum cylinder heads they have seperate hardenedd valve seat inserts.

The original Magnum cyl heads had the cast metal near where the seat was to be machined electromagnetically heated and hardened - there is no seperate insert that is pressed in. Some believe that improper hardening of the cast metal is what starts the cracking, and that does make sense.

 

While we're on the subject, where is a good source for a transmission rebuild kit? I'm betting that the Lucas additive is what's causing my transmission growl. I found another web space devoted to transmission myths and problems/symptoms. One discussed how additives can cause the transmission to slip, not to mention the wrong fluid. I'd like to clean my system and run the ATF-4 as Chrysler now advises. That is, of course, after I rebuild the tranny.

 

Here's one place that emphasizes price:

http://www.bulkpart.com/Merchant2/me...gory_Code=A518

Here's another that is regarded as having the best knowledge:

http://www.dieseltrans.com/dodge/index.htm

reading about some of their classes is worthwhile:
http://www.dieseltrans.com/phpBB/viewtopic.php?t=33

 

Will the diesel links be good information for my 42RE?

 

42RE? aint it a 46RE?

if your doing headwork yourself.. look at some RR's free up some hp and mpg and are more durable then the stock steel stamped ones

did you decided to pull the motor or doing the work in the engine bay? assuming engine bay b/c your a tiny dude (no offense)

while your rebuilding that tranny get you a transgo shift kit,,, itll improve shifting and prolong the life on the tranny

goodluck with all those projects!

 

I'm sorry. I must have my transmissions confused. I believe the gas engine is mated to the 46RE, as you stated. I'm trying to find someplace I can get the rebuild kit and shift kits, but I'm coming up dry.

BTW - the tiny dude response No worries. I can scramble around in that engine bay with no problems. Sometimes it pays to be svelt


Well, damn. I just called a local shop today and they said Magnum heads are prone to cracking like you all stated. I'm going to pull the heads and have them checked, but I'm debating on whether I should get the replacement Magnums (with the hardened seats) or if I should go with RT heads. I use the truck occasionally, so I don't see the added expense of R/T heads if they are $800 for a pair.

 

cool. looked like fun. to bad im going to have to do that this weekend. [8D] anyone think i should have the intake a crap polished?