2.9 Top End replacement advice

[eightynine4x4]

1989 A4LD 4x4 2.9

Hey all,
Considering doing a top end replacement / rebuild and have a few questions about the 2.9..

To preface this, I already “want” new heads because I recently replaced both exhaust manifolds and never got perfect / permanent connections for new manifolds due to all of the drilling out of bolts / holes i had to do. Very long job and should have just pulled the heads and would have saved myself several rough days.

What id like to install:

-new Promaxxperformance heads, loaded with valves and springs
-new rockers/shafts, pushrods, lifters, etc.

Questions:

Do new valves that come installed in new heads need to be lapped first? Or are all the mating surfaces supposedly flush from factory?

Does a new camshaft need to be installed when replacing all of the above? From my understanding the other top end components need to stay related to each other whenever replacing stuff. But I’m replacing all of the upper moving parts. Is any cam wear going to be compensated for the lifter pre load adjustment? Or do I need to also install a new camshaft?

Are my head bolts likely to be as difficult to remove as the manifold bolts? My manifold bolts were about as difficult as I could imagine. Fully rust-welded you could say. I think maybe 2 out of 12 unscrewed, the rest were a major drillout project each. Am I likely up against the same beast with the head bolts? Or are they more protected / lubricated and/or not as rusty or welded?

Thanks!

 

[franklin2]

The valves and the seats are already machined, no additional work is necessary.

You do not need a new camshaft. Actually, from what I have been reading the past few years, I highly recommend you do not change the camshaft, they have been having a lot of quality control problems with a bunch of different manufacturer's aftermarket camshafts. You can re-use the old lifters with the old camshaft, I would not use new lifters with the old cam if I could help it. You can get new pushrods or use the old ones. I see no problem using the old pushrods on the new rockers. When you get it all together, you will have to do the routine of turning the engine over by hand, and setting the lash for each valve.

The head bolts should come right out, though if I remember correctly they had a weird bolt head. I want to say you might need a female torx socket. I replaced my heads also, with ones from that company on ebay. I broke every bolt off on the exhaust manifolds, but I figured they could worry about that since I had to turn the old ones in for a core. But I am sure they just use the valves and various other parts, and put that in the new thicker head castings.

Make sure you buy new head bolts, I think they are torque to yield. Again, going by my memory and it fails me sometimes.

 

[eightynine4x4]

The valves and the seats are already machined, no additional work is necessary.

You do not need a new camshaft. Actually, from what I have been reading the past few years, I highly recommend you do not change the camshaft, they have been having a lot of quality control problems with a bunch of different manufacturer's aftermarket camshafts. You can re-use the old lifters with the old camshaft, I would not use new lifters with the old cam if I could help it. You can get new pushrods or use the old ones. I see no problem using the old pushrods on the new rockers. When you get it all together, you will have to do the routine of turning the engine over by hand, and setting the lash for each valve.

The head bolts should come right out, though if I remember correctly they had a weird bolt head. I want to say you might need a female torx socket. I replaced my heads also, with ones from that company on ebay. I broke every bolt off on the exhaust manifolds, but I figured they could worry about that since I had to turn the old ones in for a core. But I am sure they just use the valves and various other parts, and put that in the new thicker head castings.

Make sure you buy new head bolts, I think they are torque to yield. Again, going by my memory and it fails me sometimes.

Thanks for the info! Good to know about the cam shaft!
I actually did a lifter preload adjustment this summer. A number of the pushrods gave almost zero resistance when lightly pushed down with one finger. Some were firm. I’m not too thoroughly educated still but it seems like some of my lifters are completely collapsed or messed up. I was still able to tell where the top of the lifter was supposed to be and it would just barely hold up the pushrod in that spot, and thus I was still able to do the adjustment with the rocker arms in the right spots. But it seems like my lifters truly have issues, not just speculating that they might. So that’s why I’m planning to replace them and I figure replacing the rods and rockers all at once makes sense to keep them even. Does that sound right?

 

[franklin2]

Putting new lifters on a old camshaft can be iffy. That will be a lot more work also, since you will have to pull the intake off.

Do you have a lot of lifter noise (ticking)? When the engine is running, the lifters should pump up and take that slack out. Just some of them are bleeding down more than others.

If you have a vendor that you trust that will get you a good replacement camshaft, go for it and do that also.

 

[gaz]

@eightynine4x4 ,

When I did my first 2.9l top end I had unservicable push rods, rocker, valve seats and valve seals. I bought a new improved performance camshaft from Delta Camshaft of Tacoma Washington for under $200. If I had understand regrinds then I would have done that instead.

I believe the answer to your question depend on how much improvement in performance you expect. The heads I used were aftermarket prepped with valves and springs; I had a performance valve job done on them and would not do it any other way...time and money permitting.

 

[eightynine4x4]

Thanks fellas,
Yeah I have ticking, which I could live with, but what’s worse is the valve train health in general. I get ultra ultra rough starts but it always smooths out after a long steady warmup which makes me think the bottom end is just fine. Also I get decent mileage and pretty good power once warmed up, except for up long hills. I’ve been down many attempts to solve the clammer and roughness, from fuel to oil to spark to vacuum to air, but am starting to think I just need to refresh the whole valve train.

And because I already have sketchy connections at my manifolds due to manifold-head bolt drama, I’d love to have new heads.
Im also starting to suspect I have a small coolant leak. So I would like to do a headgasket at the very least, and I‘d still need to inspect the heads.

I stumbled upon this clip below, which at 44:22 (when he revs it) happens to sound EXACTLY like the clammer in my engine upon startup. Earlier in the video he was working on all sorts of valvetrain issues, like bent rods and stuck valves and dislodged rockers, and his engine was doing all the same kinds of sounds and behaviors my engine makes during bad startups. It was like a bell going off for me, I was like hey I know those exact shakes and rattles!

 

[eightynine4x4]

Another sample below at 22:20. This is how my engine sounds during its roughest starts.
Mine smooths out over a few minutes. But it starts out just as bad sometimes. Like a metal clacking combined with a miss or even multiple misses. He improves it by opening things up and addressing several poor valve conditions. So this is leading me to thinking maybe I need to refresh the valves / head and rest of valve train. Or at the very least, take it all out including heads, do a full assessment of all parts.

 

[franklin2]

Have you verified you have the improved heads? In this article it shows how to tell what you have. If you have the old style heads, I would definitely replace them.

Ford Ranger/Bronco II 2.9 liter Engines

www.therangerstation.com

 

[eightynine4x4]

Have you verified you have the improved heads? In this article it shows how to tell what you have. If you have the old style heads, I would definitely replace them.

Ford Ranger/Bronco II 2.9 liter Engines

www.therangerstation.com

Yes, I have the 89TM. Here’s a pic of my rocker assembly and you can see the larger rectangular support block under the shaft mount. Bonus, you can also see one of my hex nuts I had to use to make the connection from manifold to head, after drilling out the holes.

What is the issue of using new lifters on an old camshaft? And would a reground camshaft mitigate this? Obviously this is a whole extra disassembly step that brings me practically to pulling the engine for a complete rebuild.

I think the most logical thing to do is pull my valve covers again and turnover the starter while observing the rockers to see if anything looks wonky or slow or sticky. This is what he’s doing in that video and the symptoms in that video are absolutely spot on to my engine during some warmups. I have not stumbled on any other video of this behavior until I found that one by accident.

 

[gaz]

@eightynine4x4 ,
I understand if your valve train components are no longer servicable but if they are have you tried adjusting the preload on the hydraulic lifters ..)

When the lifter preload is properly set, a 2.9l will sing the sweet silent song of maximum performance!!

 

[eightynine4x4]

@eightynine4x4 ,
I understand if your valve train components are no longer servicable but if they are have you tried adjusting the preload on the hydraulic lifters ..)

When the lifter preload is properly set, a 2.9l will sing the sweet silent song of maximum performance!!

Yep I went through that this summer, under the excellent guidance of RonD. It DID seem to make some improvement in the performance after it’s been warmed up, but I did a number of things to help at the same time. But like I said, my most glaring issues are almost entirely during warmup. And it’s beyond just oil flow or viscosity changing from warmup temp. It’s big time misses and lumps, not just ticks. This is why I’m so curious as to the condition of my whole valve train. It sometimes even yo-yo’s up during the first few revs, like starts at 300 rpm and takes a couple seconds to get up to idle, sounding like it’s stuck. Happens during summer too, not just cold weather. All of this points me to parts literally being sticky or faulty. It would be great news if all the parts were serviceable and just need a thorough cleaning and maybe drilling for oil flow restoration.

 

[franklin2]

What is the issue of using new lifters on an old camshaft? And would a reground camshaft mitigate this? Obviously this is a whole extra disassembly step that brings me practically to pulling the engine for a complete rebuild.

Like any of the other parts, the old lifters have made their "home" on the old camshaft, wearing together. New lifters will have to wear in to the old cam. This can work, but there is some risk also. A dab of moly grease on the bottom of the new lifters would probably be a good idea if you do it.

 

[gaz]

@eightynine4x4 ,
Another action to consider while your valve train is apart is to increase the top end's oiling potential.

Disassemble the entire rocker arm, thoroughly clean the inside (it is likely caked with sludge). There are oil holes in both the arms and the rockers. Drill the orifices one drill index size larger, chamfer and deburr.

 

[eightynine4x4]

Well I’ve ordered a set of the Promaxxperformance heads. I’ve checked with some others who’ve bought these heads and they’ve mentioned that the included hardware works well. Hoping that the valves won’t need to be lapped, but if they do that’s not a huge problem.
I’ll be inspecting everything as the parts come out and determining what can be kept. But it would be nice to just start fresh with everything.
Anybody have any thoughts about quality of things like rockers, rocker shafts, push rods, and lifters? Might end up getting Melling of everything but there certainly are cheaper options out there. Just not sure what’s trustworthy.

 

[eightynine4x4]

Like I mentioned earlier, while putting in the Promaxxperformance heads I might just go ahead and replace the rockers, shafts, rods, and lifters. My valve train has been subjected to so much violent commotion, for who knows how many years before me, that I worry some parts are slightly warped or worn and it would be nice to start fresh. Maybe I’ll attempt to restore all lifters to good working order so that they match the cam wear. But I’ll have to assess this after opening it all up.

Thinking of going with Melling across the board since it seems like a trustworthy brand.
However on Rockauto the rod length spec for Melling is 5.242” where as on all the other brand rods it is 5.429”. That’s a pretty big difference, getting near 1/4”. I suppose this would be compensated for when setting pre load with the rocker bolts, but turning those bolts is no joke and that’s a lot of added cranking, and also it worries me that I might even run out of thread to do the pre load. It also concerns me that it’s putting the arms at a less efficient setup for the arms-to-valve/springs contact to have the arms angled that much.
Anybody think the Melling length is ok?

@PetroleumJunkie412 @Ron D