Mike

4BD - nice option also that would probably get good fuel mileage. I will have to start another engine swap thread so this one stays on topic about valvetrain and doesn't get cluttered with swap ideas. haha Happy New Year to you too Moses, thanks for the great tech, Mike

Thanks for the detailed and quick reply Moses, very interesting tech. I think you're right it is probably multiple worn parts making clattering together. I am looking forward to tearing down this engine one day and seeing how it looks/checking the wear. This is Mike at MCE Fenders (MCE Mike on Facebook) and this is the lime green Jeep in our photos. (Also emerald green before it was painted) I've owned this Jeep since I was 16 in 2000. You are absolutely right, this is a testimonial for this engine. I am absolutely amazed at how problem free and durable this engine is. Since it doesn't have much power, and had larger than stock tires on it since ~60,000 miles, this engine spent a lot of time at full throttle and/or high RPM. It has had 31s and 4.10s for a few years, 33s and 4.10s for about 6 months, 33s and 4.88s for a few years, and has been on 35s with 4.88s since 2008. I could also go on about all the times it spent revving high in the snow, breathing dust in the Moab and PNW silt, and it has overheated a few times due to a water pump and electric fan issue. I always just kept the oil changed. I am probably not going to do an engine swap for a while - just not enough time right now and focusing on other Jeeps and the company, but am collecting ideas on what to do. I am definitely leaning towards a small V8. I don't want a huge powerhouse, I rather have reliability of the entire Jeep rather than a HP number on paper. So was thinking a Vortec 4.8 or possibly a 5.3. From the research I have done, the Magnum 5.2 and 5.9 are the "easiest" swaps for my TJ electrically, so those are also on the drawing board. One other idea is to try 505 Performance's new 2.5L stroker kit and head. (2.7 and 2.9 options) But I am still researching this. While the sound and power of a V8 is fun, keeping the light 4 banger but adding power might also be fun. In '08 I swapped the AX-5 for an NV3550 with junkyard parts, and bolted on a NV241-J to that. So I am thinking they will be fine with either option. The front axle is a high pinion 30 out of a Cherokee. This would probably be fine for the stroker 4 cyl. option, but probably need replacing for the V8. This Jeep doesn't have a rear axle at the moment, but it will probably get a D44 when I have time to get to this project. Too many options, haha! Mike

Good info, thanks. Here's an odd one I have been trying to figure out for years. I bought the Jeep at 57,000 miles ('97 TJ w/ a 2.5L), and now it has about 200,000. So I am assuming now it's worn out and am just going to swap it out. But, this is what it has done for years: First cold start of the day, it is quiet. After about 30 seconds or a minute of warming up, I can hear a valve clatter/tapping noise starting. It did this until the engine was up to temp, then would go away as long as the engine stayed running. If it sat for a while and cooled off, it would do it again until warmed up. This never impacted the engine's performance or drive ability, so I never really worried about it. But, in the last year of driving it, the noise would appear at about 30 seconds or 1 minute of run time, but would stay once the engine warmed up. It would be quieter once warm, but definitely audible. It almost sounds like a diesel. This Jeep has sat now for about a year and a half, but I am going to revive it this winter, as well as do another build on it. Also plan to swap the engine for something else, but will always be curious as to what was making this noise. When I have a chance, I am going to tear the engine down and see if that shows anything. It definitely doesn't sound like a rod knock, and is coming from the upper part of the engine. So I am assuming it is something in the valvetrain.