Random stupid thought of the day

[holyford86]

I have been throwing around the thought of putting solid lifters in a 2.9. I was wondering what everyone thinks of this. I figure that it would require a different cam to work correctly. I imagine power gain would be minimal at best. My thinking was that you don't need oil for the lifters to "pump up" so even with the craptastic top end oiling if properly adjusted it would seem to me that they would be quieter than your typical 2.9. I'm not planning on attempting this unless I can find a concrete answer to the question, but its more or less the wandering of my mind. Thoughts?

 

[LittleHorse]

the biggest thing that would put me against it was the fact that you'd have to do periodic valve lash adjustments. It's bad enough on my bike with just 4 valves, I don't care to do it for 12.

That, and my 2.9 doesn't clatter. I had a Nissan 3.0 with some lifter clatter, I got rid of it with a procedure that involved cleaning the hell out of them with gasoline, and filling them back up with oil to test their function. They usually have some sort of check ball that's supposed to let oil in but not out. If it gets stopped up and can't close, the lifter goes flat and will clatter.

 

[RustedRanger]

Yes you have to get a solid lifter cam also. From what I have read here at TRS a lot of the time its worn cam bearings that lose some of the oil pressure to the top end. Mine clatters at idle but goes away when I rev the engine. My 87 cost me $500 and I have around 600 more in parts in it so I can't see doing much more but driving it,once I get the running rich taken care of.

 

[Jason]

the biggest thing that would put me against it was the fact that you'd have to do periodic valve lash adjustments. It's bad enough on my bike with just 4 valves, I don't care to do it for 12.

That, and my 2.9 doesn't clatter. I had a Nissan 3.0 with some lifter clatter, I got rid of it with a procedure that involved cleaning the hell out of them with gasoline, and filling them back up with oil to test their function. They usually have some sort of check ball that's supposed to let oil in but not out. If it gets stopped up and can't close, the lifter goes flat and will clatter.

Valve lash adjustment isn't so bad. It only takes me 1.5 hours on the Bandit, and that's 16 valves and a large valve cover removal.

 

[Beastly88]

If you guys come up with a solution to it LET ME KNOW my 88 clatters like you would not believe some days and others it will only clatter for a short time then quit

 

[UrbanRedneckKid]

Doesn't the 2.9 have shaft mounted rockers like the 4.0?

I didn't think you could adjust lash on shaft mounted rockers...

 

[Psychopete]

I didn't think you could adjust lash on shaft mounted rockers...

They are adjustable on a 2.9L.

I think it's an interesting idea, solid lifters are kind of noisy anyway, I wonder if it would be worth while in the long run? That valve lashing would get annoying pretty quick if you run the motor pretty hard..

Pete

 

[LittleHorse]

Valve lash adjustment isn't so bad. It only takes me 1.5 hours on the Bandit, and that's 16 valves and a large valve cover removal.

I guess it depends on the vehicle...I don't like doing bucket shims because you have to buy the shims...some vehicles have a threaded adjuster built in so it's an easy adjustment.

It also depends on how big of a job it is to remove the valve cover. The inline 6 BMW's and Datsuns I've done it on aren't bad, but it's no fun to be tearing the whole car/bike apart in a race against heat transfer to get the lash measurements and adjustments done while the engine is still hot.

 

[holyford86]

I know that the craptastic 2.9 top end oiling is due to the cam bearings "bleeding" oil. Adjusting the valves wouldn't hurt my feelings at all. I drive the truck about 12k miles a year so I'm guessing that I wouldn't have to adjust the valves much more than once a year. Would it be possible to use 2.8 lifters and have someone grind you a custom cam? Or is it more involved than that?

 

[Jason]

I guess it depends on the vehicle...I don't like doing bucket shims because you have to buy the shims...some vehicles have a threaded adjuster built in so it's an easy adjustment.

It also depends on how big of a job it is to remove the valve cover. The inline 6 BMW's and Datsuns I've done it on aren't bad, but it's no fun to be tearing the whole car/bike apart in a race against heat transfer to get the lash measurements and adjustments done while the engine is still hot.

What bike are you doing that they have to be done hot? I have owned 35 + bikes and all had to be checked/adjusted cold.