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I'm working on an 86 deville and am replacing the camshaft and lifters. I was wondering if anyone could answer some questions;

1) What is the best way to "prime" the lifters? Chilton says one thing, some other sites say other ways. What do you guys think/do?

2) I have the complete engine gasket set, but I don't really want to mess with the valve springs/stems if it's not needed. They are a bit carboned, but don't look too bad. Can I get away with not changing the seals and leaving the heads assembled as they are, without having near future problems? From what Chilton says, I have to perform a bunch of part testing, take springs, valve seat concentricity etc. to be checked professionally. Chances are, not gonna happen.:cookoo:

3) I also wonder if I can get by without changing the pushrods, though common sense is telling me otherwise. The problem was that I found 2 of the lifters minus the lock rings, and everything above the plunger was floating around. (I did locate all the loose parts) Both of the rods to those lifters were scored just above the ball end on the lifter side. See pic.
http://img.villagephotos.com/p/2005-10/1089030/pushrod.JPG

Other than those marks, all the others appear straight and in good shape. I think there is no way those 2 could have been seated at all, but I couldn't tell because I removed the rods before I took off the intake manifold. Anyone ever seen that happen before or have a theory as to how that happened?

I guess also I'm just looking for any other quick tips to keep in mind when I reassemble this fine piece of machinery. I have searched the forums for months now and hate to ask questions if I can figure it out, but I haven't found much of what i'm looking for except the diagnosis posts. (Just like I hate to ask for directions):) This is the first time I've done this, so I guess I'll take all the advice I can get on this one.

Thanks in advance for any answers/thoughts.

Milk


p.s. Where is the outside temp sensor located? I am getting that error code, and figure it needs changing. Might as well do it now if it needs it.
 

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Put each lifter in a cup of oil (submerged) and push down on the plunger (use a push rod) with the lifter under the oil. That is really all that is required. The lifters will self-prime anyway so you really do not have to do anything. If you cannot push the plunger down that is good. Do not depress the plunger unless the lifter is in oil as that would force air into it.


The valve stem seals are likely fine. It would be OK to leave the valve springs alone.


The pushrods are fine. Reuse them.


It sounds like the rocker arms on the cylinder with the failed lifters may have come loose causing the failure. Did you unbolt the rocker arms from the support bar? If so, put the rocker arms back on the bar and install the entire assembly as one piece instead of bolting on the rocker arms after the bar is in place. The unit is designed to go on as an assembly. Individually assemblying the rocker arms after the bar is in place will likely strip the rocker arm bolt holes and/or break the rocker arm pivots.

Go back to the GM dealer and buy a new distributor gear for the distributor. That mates to the cam gear and you do not want to put the old used gear on a new cam. Install the new gear with a moly paste for breakin protection.

While you are at the dealer, buy a quart of GM EOS (engine oil supplement) and pour it into the crankcase in place of one quart of oil when you refill it. The EOS is heavily fortified for antiwear protection and will help the new cam break in correctly with no wear. This is important.

Use the heavy duty Delvac, Delo or Rotella oil in the crankcase. Cheap insurance against wear and the best oil for that engine.

Use the GM coolant supplement (sealer) in the coolant to prevent any coolant intrusion into the crankcase in the future.

If you are not putting a new timing chain and gear in....stop, go get one and replace the chain and gear when you reassemble. The cam gear in that engine had plastic teeth and the teeth will fatigue and fail. Even if it is fine now it will fail in the future so replace it.
 

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Discussion Starter #3
Chevelle, BIG thanks for the quick reply. I was a little worried about tackling those vavle stems. I already picked up a new timing chain set, that nylon didn't look too sturdy. Hey, I also removed the rocker arms as an entire assembly, so it looks like no problems there. I know I caught that info somewhere else on here. So I decided to heed the word... and the rotella is already waiting in the garage. I knew this project was coming for a while now and had picked up the bars golden seal tubes (2). I heard somewhere on the forum that that was ok too, but I think I would still like to use the tabs instead. Looks like all I need now is that distributor gear. I called a local gm dealer, and Ibelieve the price was about $85. I noticed oreillys has a few different ones for about half of that. 1 was ac delco, borg warner, and something else I forget. Do you think those are worth it? Anyway, when I get this thing back together and running, I'm posting a couple pics. Nothing fancy, just stock, but pretty near mint except for a headliner.

Now 1 final question. Do I need to adjust the valve lash, or just bolt on entire assembly and go?

Thanks again for the help

Milk
 

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That distributor gear is pretty finicky so I would personally go with the OEM part. The gear teeth are specially surfaced and the gear is tin plated for extra breakin protection.


No adjustment required for the rocker arms. Just bolt the assembly on, pull down the head bolt nuts that secure the bar evenly so as to not bend or stress the bar...i.e..don't tighten just one all the way down and then go to the next one, work each one down sequentially a turn at a time.
 

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i agree on everything but the pushrods.

by your picture they look rough, with quite a bit of material gone,
you have to remember pushrods are hollow thin-wall tubes.
i'd pick up two pushrods while your there.
better two pushrods than to pull the motor down again to replace them and whatever else if/when they break.
 

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Discussion Starter #6
Thanks to you both for the input. I definitely will put out a few extra bucks to avoid the hassle of redoing this stuff. Granted I took on this project because I got this car for a steal and I wanted to pull a motor sooner or later. (only thing left is self taught tranny work) Might as well be on a car that I really like and will keep for a long time to come. Ordering parts tomorrow am. I think I will go ahead with the pellets too, just for the principle of the matter. Thanks again.
Oh, and I don't remember who that is on this forum that is always like "junk it!" when it comes to the ht4100 and cam lobe problems, but I think this is going to be alright when I'm done, so i'm glad I didn't listen.:suspense: I'm the type that likes things original for the most part.

one more thanks,
Milk
 

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Chevelle gave good advice on the reassembly of the engine, but if you feel better replace the push rods. It's good peace of mind.

Absolutely replace that cam gear. Even the aftermarlet suppliers recommend using the new GM gear. It is a must.

The lifters can be placed into the engie without priming, but can be primed if you wish. Usually I just drop them all into a container of oil overnight and then install them.

Make sure you use camshaft pre lube on the lobes. The EOS works good for this, or you can purchase pre lube separately form GM or the aftermarket. Often a new cam will come with a container of it.

Mike
 

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The 4.1 engine did not have any cam lobe issues, per se. The cam lobes and lifters have proven to be able to run virtually forever given proper lubrication. Some of them did have an issue with coolant intrusion into the crankcase which lead to the crankcase oil becoming contaminated causing cam lobe wear from lack of lubrication. So, the point is, the use of the coolant sealant pellets is not a matter of principal it is a required item in the service manual and is necessary to keep any internal coolant leaks from contaminating the engine oil. It is important to use it for a fact, not a matter of principal.


If you check with the Cadillac parts counter they will list an intake manifold gasket "reseal" kit for that engine. It is not cheap but will allow the installation of the latest gasketing technology and fasteners as used by the later generation 4.5 and 4.9 engines. It includes all the intake gaskets and fasteners so it is worth the cost.

Look at the dowels in the block that locate the cylinder heads. They should be a "solid" tubular dowel, not a split dowel. The 86 should have the solid dowels but double check to be sure. If the dowels are split on one side replace them with the solid dowels available thru GM service parts. This is important.

Have you removed the pistons/liners/etc. from the block? The liners are loose pieces that simply slide into holes in the bottom of the block and are sealed with o-rings. If the liners are upset during dissassembly/reassembly and any dirt/debris/sediment gets trapped under the flange of the liner that seats to the block it will cause head gasket problems later as the liners will not all be at the correct height. If the short block has not been dissassembled you would want to clean around the bottom of the liners carefully and make sure that they are all seated completely if there is any chance that they were disturbed.

Only use the factory compacted graphite head gasket. Others will not live in that application. If you have an aftermarket gasket make positively sure that it is a compacted graphite (expensive) gasket or get the OEM one.

Be sure and follow the head bolt torqueing specs and sequence carefully. Same for the intake manifold. It is very easy to overtorque the intake bolts if you are not carefull. They require very little torque to install, particularily if you retrofit to the later model fasteners in the re-seal kit.

Along the ends of the intake manifold use a small dab of RTV in the corners only. Too much RTV or RTV along the entire seal will cause it to squirt out when the intake is installed. Just install the end seals dry and with no extra sealant...just a tiny bit at the corners.
 

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Hey man, those valve seals aren't that bad, and as long as the engine is down this far, why not attack them

When I did mine, I made a fitting that fits on to my home air compressor. It has threads on the end to screw into the spark plug hole in the head. When the air pressurizes the cylinder, it holds the valve in the closed position and you can very easily change the valve seals without removing the heads. You don't want to seal up your engine nice and end up with an oil burner in 2 years because the valve seals were never changed...
 

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I would have given the part number for the gear, but I can't locate it now.

Definatly use the GM intake set part # 3634742. It contains the latest impacted graphite gaskets, new spring washer bolts, a tap, the all important solid dowels and instructions.

It is up to you if you want to do the valve seals. It is easy now that the heads are off.

Mike
 

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CRAP!!!!!!! Now I'm getting frustrated. First off, Chevelle, I think this thing is going to run smooth when I'm done because of you and the others. I'm just going to go ahead and change those valve seals.

OK. Let's see if I can list all of this. I got the right distributor gear, the gaskets are good, and the dowels are the solid ones. There definitely was a coolant leak problem with this motor. 56k and 2 of the cam lobes were completely round. Most looked almost as bad. I don't see how this car was running at all to be honest. lol The part about the coolant tabs was that I already have the bars gold seal, but I think I will still go with the tabs anyway. (Hence the "principle" statement) I think I would just trust the tabs more.

Now on to my frustration. I knew about not disturbing the liners, but the # 4 cylinder liner lifted up when I was tightening the camshaft gear bolt. I just tapped it back into place, it was flush with the others, (with a plastic mallet) and started reassembly. Let's just put it this way, the intake manifold looks nice back in place.

I guess I'll be taking her apart again to replace those liner seals. If I have to mess with 1, might as well do all. Besides, I've got the seals for them.

I didn't want to go this far, but what about the piston rings? Should I even mess with those when I have the liners out? Of course if I see anything obvious, I'll dig deeper, but if not I'd like to leave them alone. I will say that what I've seen of the inside of the liners is nice and smooth/clean.

Some other snags that have me held up anyway; when reassembling the water pump to the timing cover, 2 of the bolts that nuts screw onto pulled out. They didn't damage the hole, just the fastener broke in 2 leaving a nice little star washer that fell inside the oil pan for me to disassemble to remove. I swear the torque wrench was set to 5 lbs!!!:bomb: I don't know if I can get new bolts to replace, haven't had time to call the local gm dealer yet, if not I guess I can (A) get some off a junker to replace, or (B) just replacing the timing cover.

Oh, and another thing, I can't believe how much sludge I've cleaned out of the oil pan and the under side of the intake manifold. Should this cause me to look at anything else while i'm in there?

When any of you wake up from this yawner of a post, #1 thanks for reading, and #2 thanks for replying.:D

Damn my love for mid 80's caddys and 3rd gen f bodies!!
Milk


Chevelle, do you work for GM? You're starting to gouge the sh!t out of my wallet!!! LOL
 
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