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Sat Nov 07, 2009 2:43 pm

So we got the bus on the road, took it down to the gas station. It was running great for maybe the first 3 miles, then I started hearing this clicking sound... long story short, the rocker arms had come loose from the studs and were wiggling around in there. After some samba detective work, I found out that we had used the wrong gaskets under the rocker arms.

My heads have the indentations for the o rings, but following the idiot's guide's advice, we installed some thicker ring gaskets, that had totally shredded in there, leaving my rocker arms untorqued. We disassembled the rocker arms, pulled out the pieces of gaskets, and inspected things. pushrods looked a little banged up around the edges, but still straight.

We assembled the assembly with the o ring style gaskets and the engine turns like it should, the valves go in and out, everything seemed okay, but when I went to adjust the valves, I could not get a feeler gauge in there. I unscrewed the valve adjusting studs all the way, and took them out, still couldn't get the feeler gauge in. it seems the valve stems are sticking out too far.

Apparently, the thicker gaskets had held the rocker arms out far enough for the whole assembly to work, but with the proper gaskets, the valve stems are just sticking out too far.

The pushrods and rocker arm assemblies are the same ones that were in there before the rebuild. We had the heads rebuilt, and have new cam followers. Maybe the cam followers are thicker than the olds ones, causing the pushrods to stick out too far? Or perhaps something to do with the rebuilt heads?

The bus was running great before the rocker arms came loose. Would it be okay to just space the rocker arms out with some shims or something?

Sat Nov 07, 2009 3:14 pm

I'm guessing this is a type 1 motor?

Sat Nov 07, 2009 4:17 pm

Type 2 - 1600. I distantly remember the new cam followers being thicker on the cam side than the old ones, and the gaskets we had on while the bus ran for a few miles were quite thick, practically temporary self-destructing rocker assembly shims.

Sat Nov 07, 2009 4:28 pm

those big (black?) o-rings I think are the ones that go inside the case between halves if they came in a kit. I believe the small white ones are the ones that go under the rocker arm supports. Someone who has recently rebuilt a T1 motor chime in please to verify if this is correct.

Sat Nov 07, 2009 4:41 pm

We used the 6 big black O-Rings between the case halves on the six studs, and instead of using the 4 small O-Rings beneath the rocker arm assembly as we were 'sposetah, we used fat cylindrical ones (which John Muir told us to use!). Also, the big O-Rings for between the case halves would not have fit into the depression around the rocker arm studs in the heads!

Sat Nov 07, 2009 6:38 pm

I am willing to bet a considerable sum of money when you put it back together the far end of the pushrod landed on the edge of the lifter, instead of inside it. loosen up the rocker assembly, and jiggle the pushrod till you can get it to drop further in the motor. this is so easy to assemble on the engine stand, and surprisingly hard on a milk crate/in the car.
I have made this mistake 3 times in a month now, so I am feeeling pretty good that is our only issue.

Sat Nov 07, 2009 7:06 pm

I have taken the rocker arm assemblies on and off twice. I went through it again, making sure the pushrods were seated properly in the cam lifters. I'm really starting to think the lifters were just thicker than the olds ones.

Sun Nov 08, 2009 1:18 am

Uvula wrote: following the idiot's guide's

Bingo!!! Trash that sucker. It won't help you at all but will get you in trouble instead. Possibly it already has. Get the Bentley service manual and for what you have been doing it is a must that you get Tom Wilson's engine building book. Evidently you don't have them because you were refering to the idiot book.
So if you have new lifters evidently the engine is a total rebuild. Who built it? An experienced builder? Reason I ask is that working with deck heights, setting compression, and head work can affect your valve clearance issues like you are asking about. Was anything done to the heads other than valves and guides? Any flycutting or machining?
Lifters thicker on the cam side like you say have nothing to do with your issues.
There are no spacers, shims, or gaskets between the rocker arm stands and the head. It is a solid metal to metal bolt down.
Yes, either the white cylindrical seals or the right O rings fit into the recesses in the heads. But they totally squish down into the cavity and do not space the rocker arm assembly outward.
You must completely back out all the valve adjusters whien putting on the rocker shaft assembly. Otherwise all the valve pressure will not allow you to get the rocker shaft down and correctly torqued.
There is absolutely no difficulty when installing the rocker shaft assembly to get the pushrods properly seated in the lifters and rocker sockets. when you start sliding the assembly onto the studs rotate all the rockers down so they are in contact with the pushrods. Then slide the assembly all the way on. A little wiggling and rotating the pushrod lets you know they are right.
Couple questions- You have stock aluminum pushrods and not steel? And you evidently have stock valve adjusters and not swivel ball or swivel foot?

Absolutely for sure throw John Muir away. Get Wilsons book and study it. You have mentioned a few things that suggest other problems.

Sun Nov 08, 2009 12:09 pm

I have the bentley, I use the idiot guide too because he goes way more into detail about how to actually do stuff. I will get the tom wilson book.

I rebuilt the engine, it's my first one, and I didn't do anything about compression or deck heights. I got the heads rebuilt, but didn't ask them to do anything special to them.
The o rings are the little ones that fit down in there and don't make a difference in how the assembly is spaced.
I got new cylinders and pistons, everything stock. the pushrods and rocker arm assemblies are also stock.

What have I mentioned that suggests other problems?

Sun Nov 08, 2009 12:32 pm

when you tighten the rocker back on, tighten it evenly. DO NOT tighten one nut all the way then the next etc. Start with the side that sticks out the most. You should be able to spin the pushrods a little and wiggle them before you begin to be sure they are in the lifters correctly.

Sun Nov 08, 2009 3:26 pm

I have tightened it evenly, like you say sgkent.
If no one will tell me why throwing a couple of shims under the rocker arms is a bad idea, I will try it...

Sun Nov 08, 2009 3:50 pm

The question is why do you need to? Why do you not have sufficient gap? What is not stock or normal? Heads sitting closer to the case would do it. That's why I asked about setting the compression ratio. You mentioned possibility of longer lifters. I have never heard of longer lifters although that would cause your problem. As soon as you get Tom Wilson's book please closely review it and compare it with all the work you did.

Sun Nov 08, 2009 4:24 pm

well, we noticed that the part of the lifter that is wider, on the cam side is definately thicker than the old ones. I don't know if the insides where the pushrods sit are or not, although it seems possible. It's the only thing I can think of. I will order the book now...

Sun Nov 08, 2009 10:36 pm

they just are thicker on the foot, they will sit the same height in the cup. a picture is worth a thousand words ya know.

Sun Nov 08, 2009 11:14 pm

Quote: definately thicker than the old ones

probably because they were new and not reground lifters.

What about the case, did you have where the barrels sit, and the heads surfaced when you did the work? This would also bring the rocker arms closer to the cam.

Another possibility is that the shop ground the seats really deep and the valves so that they now stick out farther. All of these things may be combining to work against you.

Who did the machine work?

Mon Nov 09, 2009 10:24 am

if it was fine w/ the wrong gaskets in there, when you replaced them taht is when your problem started. I really think that the pushrods simply are not in the cup in the lifter. I am familiar with the thicker foot lifters, they do not affect geometry that much.

Mon Nov 09, 2009 10:46 am

SGKent wrote:

What about the case, did you have where the barrels sit, and the heads surfaced when you did the work? This would also bring the rocker arms closer to the cam.

Another possibility is that the shop ground the seats really deep and the valves so that they now stick out farther. All of these things may be combining to work against you.

Who did the machine work?

I'm not exactly sure what you mean by the barrels. I did grind the surfaces of the cylinders and heads with valve grinding compound to make sure they seated well, but I don't think that would have caused them to sit that much further down. There were copper gaskets between the heads and cylinders also, which I put back in, so that should be the same. there are very thin paper gaskets between the cylinders and case, which I didn't notice taking out when I took it apart, but it shouldn't make that big of a difference anyway.

I'm thinking that it is probably the shop's work on the heads making the difference, because nothing else I have done has changed anything that much.

The machine work was done by a shop in pensacola fl, that had a "vw guy". I asked him about machining for a full flow filter, and he didn't know what I was taking about, so... yeah.

Anyway, if that is what is causing the problem, I can just throw some shims in there right?

fusername wrote: if it was fine w/ the wrong gaskets in there, when you replaced them taht is when your problem started. I really think that the pushrods simply are not in the cup in the lifter. I am familiar with the thicker foot lifters, they do not affect geometry that much.

The reason it was fine with the wrong gaskets, is because they were much thicker, and they actually held the rocker arms out, not resting against the heads. they were acting as a spacer in between the heads and rocker arms. This problem was simply masked by the thicker gaskets, untill they shredded into teeny tiny little pieces and the rocker arms were allowed to sit against the heads (and flop around all crazy too).

Mon Nov 09, 2009 2:23 pm

You should really do some research on rocker arm geometry. By your description yours is way off.

This will cause your valves to wear out way faster and will reduce performance as your valves won't be getting full lift.

The basic problem is that you are using something that moves in an arc (the rocker) to push something in that moves in a straight line.

With correct geometry the rocker is pushing perfectly straight on the valve stem at half lift. Before half lift it's pushing up on the valve just a bit. After half lift it's pushing down on the valve just a bit.

The way your geometry is now the rocker is always pushing down on the valve stem as it's pushing in. This side loads the valve in one direction and wears the valves and stems out fast. It also gives you less valve lift because you the rockers aren't as close to pushing straight against the valve as they could be.

Using shims is one way to adjust. But in your case I don't think it will be enough to do it right. You probably need shorter push rods.

This adjustment is almost always done with the engine out of the car.

Mon Nov 09, 2009 2:55 pm

Uvula wrote:
I'm not exactly sure what you mean by the barrels. Cylinders

I did grind the surfaces of the cylinders and heads with valve grinding compound to make sure they seated well, goodThere were copper gaskets between the heads and cylinders also, which I put back in, Not good. T-1's don't use copper gaskets there. You lapped the cylinders and heads for a good seal, they mate with each other with nothing in between.

Anyway, if that is what is causing the problem, I can just throw some shims in there right? Hang loose until you get, and study the book. Find and fix the real problem if it needs fixing. Depending on what the real issue is, it is apt to Bite you down the line. Then all your good work might have been in vain.

fusername wrote: I really think that the pushrods simply are not in the cup in the lifter. No! Go grab a lifter and a pushrod and try to simulate it. You can't. If a pushrod was hung up on the end of a lifter the pushrod would be out about 5/8". You wouldn't be able to even get the rocker arm assembly installed.

I am familiar with the thicker foot lifters, they do not affect geometry that much. Doesn't affect geometry at all.
the thicker gaskets, There are no gaskets involved. A gasket is a gasket. A seal is a seal. Just giving you a picky harassment.

Mon Nov 09, 2009 3:17 pm

josh wrote: Using shims is one way to adjust. But in your case I don't think it will be enough to do it right. You probably need shorter push rods.

This adjustment is almost always done with the engine out of the car.

Yes, good geometry is real important.
Spacers and special length pushrods go along with non stock and performance parts. And pretty much needed with swivel adjusters. If he is stock the problem is elsewhere. Spacers would not be needed.
Yes, builders set the geometry when building the engine. But it can sure be done while in the car. Only deal is laying on your back :lol: .