1990 2.9L Top End Overhaul - Parts Sources and other Insights

[PetroleumJunkie412]

Free floating rockers and improved cam bearings both fix and prevent future problems.

 

[PetroleumJunkie412]

Also, the oiling thing isn't as severe as people think.

In my experience, the lifter tick originates from soft cams. Theres some photos in my build thread that show how soft they really are.

Also, to fix oiling issues, check and clean out your rocker shafts. Valvetrain oiling relies on shaft bores being clean. They usually are not.

 

[MikeG]

So that's it? No machine shop work needed?

 

[Demersus]

I read somewhere a recommendation to use hollow push rods and to drill out the adjusting screws to allow the trapped air to escape from the lifters. But that was a post from like 2007 and I have yet to find any additional info on that. Otherwise, you can get a high flow oil pump, and you are correct about newer style cam bearings that have a groove around the outside to help improve flow. I've also read that you can drill the oil passage a bit larger. But that's also an older recommendation and maybe the newer cam bearing style is sufficient. There are so many threads, and so many different opinions....

Otherwise, what PetroleumJunkie412 says seems correct. As for oil, yes, don't go above 10w30, and probably stick with 5w30 or even 5w20 in colder climates. As well, my experience with synthetic oil was that is just leaks more. I recommend sticking with dino, but that's arguable as you will likely read. This is an old motor design, so specs are not nearly as tight as newer engines.

 

[Demersus]

Yes, I have also read about using free-floating rockers. But that was just recently, so I don't quite understand it yet. But I am researching that also. From mine, I just want reliable performance and decent fuel mileage, and to keep it from wearing out too soon. I made a lot of mistake at first, so working to correct those now.

 

[PetroleumJunkie412]

The legendary 2.9 Free Floating Rockers

Ok engine experts, here's the newest dumb thing I'm cooking up. I successfully recreated the 2.9 phenolic intake spacers. Now I want to recreate the Sven Pruitt / Pat Kunz "free floating rockers." I got my spare heads and rockers back. Finally. This should be as easy as measuring the gap...

www.therangerstation.com

 

[Demersus]

View attachment 50463

The legendary 2.9 Free Floating Rockers

Ok engine experts, here's the newest dumb thing I'm cooking up. I successfully recreated the 2.9 phenolic intake spacers. Now I want to recreate the Sven Pruitt / Pat Kunz "free floating rockers." I got my spare heads and rockers back. Finally. This should be as easy as measuring the gap...

www.therangerstation.com

Oh yes, this seems to be the best route for my needs. Thanks again for all the info and insights. Now I wonder though, if I should replace my rockers and arms in the process, in case they did wear such as described in the write up you linked.

 

[MikeG]

That looks easy enough. Just some tubing plus lathe work. How's it wearing?

 

[PetroleumJunkie412]

That looks easy enough. Just some tubing plus lathe work. How's it wearing?

@Nez'sRanger is running them. My pistons and rods are out for fitment atm.

 

[Nez'sRanger]

@Nez'sRanger is running them. My pistons and rods are out for fitment atm.

They're still going strong! I think I mentioned it in a previous thread, but they didn't fix the ticking for me... I think the cam bearings are really bad. I've yet to check the free floaters, but I'm about to change the oil in prep for our lovely PA winter, so I'll let yinz know if I have aluminum shavings in the oil pan or filter.

 

[Demersus]

I spent a few months in Pittsburgh back in late 2017 doing some contract work. I had forgotten the term "yinz"! Brought back some memories, but I did not forget the Dec/Jan weather...
But when you mention the "free floaters", do you mean the fabricated aluminum spacers?

 

[Nez'sRanger]

I spent a few months in Pittsburgh back in late 2017 doing some contract work. I had forgotten the term "yinz"! Brought back some memories, but I did not forget the Dec/Jan weather...
But when you mention the "free floaters", do you mean the fabricated aluminum spacers?

Yes, my dad and I machined them out of aluminum stock on his lathe.