I have a 1999 challenger (twin 787's) and both of the head pipes are leaking pretty good, the guy i bought it from tried to epoxy or jb weld it, well anyways both of them are leaking in at least 2 of the notorious spots, i was wondering what other skis (xp,gtx etc...) or if any of the 787 head pipes will fit the challenger application. im taking it to a mechanic to take them off and weld as long as they are not too far gone, but if it would be better to replace them, what all will fit? Thanks Im sure someone knows this!
Well, I ain't Dr. Honda, but if you don't mind, I'll set you up.
Your model 787cc in your boat uses part #274000161, which runs about $846 bucks. I've seen this pipe for sale in the $600 range, but you'd really have to look for it.
The models and years you can cross with are: 1999 Challenger 1800, 1996-97 XP, 1997-98-99 SPX, 1998-99 Speedster, 1996 Challenger, 1996-97 GXS and the 1996,97 GTX.
Hard to believe the JB didn't hold. Makes me wonder if they used the right stuff. I have a head pipe on my 97 Challenger that I used the high strength JB weld on. That was about 4 years ago and it's still doing good. I admit, the best fix is to have it welded, but aluminum welding doesn't come cheap. Also, welding a "cast" aluminum is brittle and will sometimes crack under heavy vibration.
The key to using the JB weld is preperation. I used a Dremel tool and cleaned out all the area to be bonded. Then, I used a piece of aluminum screen to cover the area. After I covered it, I put a thin application on, let it dry. Then, I lightly sanded and put a second application on.
These water leaks of the head pipe are common. The water used for cooling circulates around between the inner and outer part of the pipe, pre-heating the water before it enters the cylinders. The chemistry involved in this is, when the water heats up, minerals leach out and adhere to the metal. Over a period of time, it begins to insulate the inside walls. The sodium chloride (salt) is what does most of the damage.
Good luck, hope you can find or fix yours. Remember, the water pressure on this area of the pipe, really isn't that great. So, if you want to try the JB again, make sure you do a really jam up job on cleaning and exposing fresh aluminum, so you can get a good bond. I know, before I paid that kind of money, I'd do the JB weld fix again. To get 4 years out of my fix, I'm o.k. with doing it. But, I also own a MIG machine with aluminum and carbon steel wire.