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I'm at a complete loss for words (Broken valve springs) sad smiley

Posted by Earendil 
I went to give my baby some spring time love, oil change, valve adjustment, etc. I even went to look at the wrecked E30 I keep talking about, got all excited about it, took pictures... Now I can't bring myself to even talk about it.

When I went to do the valve Adjustment, I noticed one of the intake valve springs had what looked like a loose O-ring. I know nothing about valve springs, so this was obviously just an initial thought. I poke at it some more, and it appears my spring has turned into about 5 different "rings". I check all my other springs, and find one other intake valve spring is twisted, and broken in at least one place, maybe two. I searched around for bits of spring or metal and came up with nothing. The cams and other moving bits under the valve cover appeared undamaged. My car ran as well during the oil warm up as it has the entire last year...

I'm trying to find info on what broken springs mean. Unfortunately most of the information out there pertaining to valve strings revolves around the idea of getting newer stronger ones to handle engine modifications. I can't find a single "how to" out there, either official or a forum post. Does this mean my engine is toast? Any chance my valves survived? I can find places to purchase new springs easy enough, but I wouldn't know what to do with them if I did.

I know nothing about this part of my car, and the lack of internet info has me worried sick for my baby. I'm kind of prepared for the worst right now...
I didn't even drive her home from the friends house where I was doing the work. I got a ride, and just left her there sad smiley
Any advice or kind words the community could offer would be great.

-----------------------------------------------------------------------------------
1989 - E30 - M20 - Manual. Approximately 270,000 miles
2000 - E46 - M52TUB28 - Manual. Approximately 110,000 miles

The 325i has double valve springs. Since you could see the broken coils, it is likely that only the outer ones have broken. That would also explain why your engine runs fine.

Replacing the valve springs shouldn't be too big a job and can be done with the head on the engine. You just need some special tools.

The engine is not toast; yet. Get the springs replaced(all of them) and you should be good to go for many more miles smiling smiley
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Archeo-peteriX
The 325i has double valve springs. Since you could see the broken coils, it is likely that only the outer ones have broken. That would also explain why your engine runs fine.

Peter, if you were here I might just kiss you! Since getting home to internet resources, I have read about these double springs, which I hadn't noticed before. I can't imagine how the outer spring broke in at least 4 places (on the worst spring) and the inner spring didn't disintegrate right along with it. I'm not exactly shy of higher RPMs, especially living in the mountains here.

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Replacing the valve springs shouldn't be too big a job and can be done with the head on the engine. You just need some special tools.

Now that I know this is a doable shade tree mechanic job, I'll do a bit more looking around the internet for info. Without anything turning up right away, I was afriad if wasn't a DIY sort of job. Perhaps it's just an uncommon one?

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The engine is not toast; yet. Get the springs replaced(all of them) and you should be good to go for many more miles smiling smiley

When you say all of them, you mean both inner and outer for all 12 valves? It would be my first instinct, where one fails more will. But that'll cost an awful shiny penny...

Thanks again for the quick response, Peter. I may actually sleep tonight now smiling smiley

-----------------------------------------------------------------------------------
1989 - E30 - M20 - Manual. Approximately 270,000 miles
2000 - E46 - M52TUB28 - Manual. Approximately 110,000 miles

Yep, those high revs do have a price. The springs fatigue at high revs because the frequency of the valve action gets to the natural frequency of the spring and it surges making the coils touch each other. This causes a contact spot that starts a fatigue crack. New springs, both inner and outer for all valves is the answer. Not the cheap ones either. The better ones will be shot peen treated all over with a fine media that puts the surface of the spring in compression so it will not crack.

Bob in Everett
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Bob in Everett
Yep, those high revs do have a price. The springs fatigue at high revs because the frequency of the valve action gets to the natural frequency of the spring and it surges making the coils touch each other. This causes a contact spot that starts a fatigue crack.

Interesting. I suppose combined with that could be the shear age of the engine its self? smiling smiley

New springs, both inner and outer for all valves is the answer. Not the cheap ones either. The better ones will be shot peen treated all over with a fine media that puts the surface of the spring in compression so it will not crack.
Bob in Everett[/quote]

This raises a good question. What do the "better ones" buy me exactly? More high revs, or more revs (read: miles) total? I don't think I need springs that will last me over 100K miles. With the miles she has, I'll feel incredibly blessed if she goes another 100K without throwing a rod through the hood. However if the cheap ones do not handle higher revs, well, that just won't do. Perhaps some people think revving high is cruel and unusual punishment for an engine. I think of it as love, with moderation of course smiling smiley
Do you know the answer to that question?

Are springs like these okay? Certainly there are some pretty high performance ones out there that cost more than my car is worth, and I hope those were not what you were suggesting smiling smiley

-----------------------------------------------------------------------------------
1989 - E30 - M20 - Manual. Approximately 270,000 miles
2000 - E46 - M52TUB28 - Manual. Approximately 110,000 miles

Yes, do the whole works. They are all the same age so it does make sense to replace them all now rather than as they break.
rkj
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Archeo-peteriX
Yes, do the whole works. They are all the same age so it does make sense to replace them all now rather than as they break.

And don't forget, these motors really don't like living on redline, they have weak rockers that love to crack. Keep the motor in a good power band and use your gears.

The four bangers are more rev happy.

Rick
So, a couple hours of research later I can find no info on how to replace the valve springs. The Bentley also has nothing. All I seem to have figured out is that I need a spring compression tool, but besides that...?
Has anyone here actually done this themselves, or did y'all just stay at a holiday inn last night? smiling smiley
If anyone wanted to help walk me through this when the time comes, that would be awesome. But that is probably at least 2 weeks off.

Right now I need to know what else should be replaced when I do this. Usually when you replace a large metal bit, there are smaller metal bits, and sometimes rubber ones, that should be replaced at the same time.
For your easy reference, here is the RealOEM picture [www.realoem.com]

I have also read that the head bolts should be replaced if they are the "old type" hex heads, because they tend to snap off. The "new" Torx ones are better. Thoughts? I've never read this before.

Basically I'm trying to scope out a parts list and a price tag on this adventure. I'll be attempting to balance available funds with the cost of time. i.e. if I'm already tearing things down this much, what else could I do, and what else should I do.

Thanks everyone!

-----------------------------------------------------------------------------------
1989 - E30 - M20 - Manual. Approximately 270,000 miles
2000 - E46 - M52TUB28 - Manual. Approximately 110,000 miles

rkj
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Earendil
So, a couple hours of research later I can find no info on how to replace the valve springs. The Bentley also has nothing. All I seem to have figured out is that I need a spring compression tool, but besides that...?
Has anyone here actually done this themselves, or did y'all just stay at a holiday inn last night? smiling smiley
If anyone wanted to help walk me through this when the time comes, that would be awesome. But that is probably at least 2 weeks off.

Right now I need to know what else should be replaced when I do this. Usually when you replace a large metal bit, there are smaller metal bits, and sometimes rubber ones, that should be replaced at the same time.
For your easy reference, here is the RealOEM picture [www.realoem.com]

I have also read that the head bolts should be replaced if they are the "old type" hex heads, because they tend to snap off. The "new" Torx ones are better. Thoughts? I've never read this before.

Basically I'm trying to scope out a parts list and a price tag on this adventure. I'll be attempting to balance available funds with the cost of time. i.e. if I'm already tearing things down this much, what else could I do, and what else should I do.

Thanks everyone!

Tyler, Baby

To start of with I would never do this job with the head in place, I would always do a head gasket, head bolts and the rest with the head off. That way you don't have to tear your hair out doing a simple job, but, beware of simple jobs; they can get mighty big in a hurry.

Once you have the head off you can check things out; like walls, tops of pistons and all kinds of good stuff. My friend did this job in place (he had four broken rockers from one over rev!) and it was a nightmare.....

Rick
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rkj
Tyler, Baby

To start of with I would never do this job with the head in place, I would always do a head gasket, head bolts and the rest with the head off. That way you don't have to tear your hair out doing a simple job, but, beware of simple jobs; they can get mighty big in a hurry.

Would you suggest to me, if you knew I could not point to "the head" and am going to run off to wikipedia to try and figure out precisely what it is? I'm not kidding...
I'm good at research, I'm good at figuring things out, and I know how to use a hammer. This has taken me to the far corners of my car, but not inside the engine yet!

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Once you have the head off you can check things out; like walls, tops of pistons and all kinds of good stuff. My friend did this job in place (he had four broken rockers from one over rev!) and it was a nightmare.....

Rick

So might you suggest taking everything apart, checking everything over, and then ordering all the parts that I think I need? Because my car has to live outside, having the engine in pieces causes me to worry about contaminating it with dust and water. Though I suppose I could get inside the engine, notice that everything is on the verge of snapping, and just give up on the engine all together... though I try not to think of that possibility sad smiley

-----------------------------------------------------------------------------------
1989 - E30 - M20 - Manual. Approximately 270,000 miles
2000 - E46 - M52TUB28 - Manual. Approximately 110,000 miles

Hmmm, I know on a small block Chevy, you merely pump the cylinder up to 60psi with a sparkplug air attachment, that holds the valve in place, use the valve spring removal tool to take off the cap, replace the spring and seal, replace the cap and you are done. Not sure if it can be done on an E30.

alan
rkj
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Earendil
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rkj
Tyler, Baby

To start of with I would never do this job with the head in place, I would always do a head gasket, head bolts and the rest with the head off. That way you don't have to tear your hair out doing a simple job, but, beware of simple jobs; they can get mighty big in a hurry.

Would you suggest to me, if you knew I could not point to "the head" and am going to run off to wikipedia to try and figure out precisely what it is? I'm not kidding...
I'm good at research, I'm good at figuring things out, and I know how to use a hammer. This has taken me to the far corners of my car, but not inside the engine yet!

Quote

Once you have the head off you can check things out; like walls, tops of pistons and all kinds of good stuff. My friend did this job in place (he had four broken rockers from one over rev!) and it was a nightmare.....

Rick

So might you suggest taking everything apart, checking everything over, and then ordering all the parts that I think I need? Because my car has to live outside, having the engine in pieces causes me to worry about contaminating it with dust and water. Though I suppose I could get inside the engine, notice that everything is on the verge of snapping, and just give up on the engine all together... though I try not to think of that possibility sad smiley

Okay, I think I know what you're saying; as far as motor work goes, you're a rookie (if I'm wrong correct me) and you think being out in the open would screw the innards of the motor while it was apart.

Okay, first things first; at this point, given your higher mileage I would strongly advise you to pull the head off and have a good looksee inside. IF, and that's a big if, you could sneak the new springs in with the motor together you would need a compressor (just to name one tool)so you can charge/pressurize the cylinders so the valves don't fall into the cylinder while you're changing out the springs ect.

You just did a big ugly job with your driveshaft etc.

If you can do that you can do the head, be warned though, you'll come face to face with all kinds of stumbling blocks; that's why you're here, with us, guys that have been doing this for awhile now (I'm 65 and have had my own restoration business since 1962.... no cracks, I can disappear easy B)

There's a lot of people here that are very competent too so have Faith.

Next, doing all this outside is not the best but with a little extra work and prep it's totally fine and doable.

On the other hand, if at this point you're thinking about upgrading to something newer and with less mileage/headaches- now a good time to make that leap.

So Tyler, if you're feeling froggy, leap..... If on the other hand you want to further yourself and the car- go for it, no matter how you go about it smiling smiley

What can happen?, you fail?.... so what, failure is the best teacher you'll find anywhere!

Rick
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alanrw
Hmmm, I know on a small block Chevy, you merely pump the cylinder up to 60psi with a sparkplug air attachment, that holds the valve in place, use the valve spring removal tool to take off the cap, replace the spring and seal, replace the cap and you are done. Not sure if it can be done on an E30.

alan

With the E30 M20 engine, the rocker arm rods have to be removed so that the rockers can be removed. That makes space for the valve springs to be removed.

The spark plug/air attachment works fine.

The hardest part of doing this job with the head on the engine, is getting the rocker arm rods out. They have to be pulled out the front of the engine and that requires the radiator and the cross piece behind it being removed.

Either way, it is a major job that just takes time.
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rkj
What can happen?, you fail?.... so what, failure is the best teacher you'll find anywhere!
Rick

I'll respond to this little section for now, because it encompasses a lot on my mind.

My E30 was a great college car, because it didn't need to be reliable, and working on it catered to what I had, which was time and not money.
Now I have a job and require a more reliable vehicle, only have slightly more money, and a lot less time.

I'm all for tinkering with my Engine until I either fix it or break it. The hard part is knowing whether I should pay $400+ for engine parts and tools that may go towards a car I'm not able to fix. If I had another vehicle this would be an easier decision. I had intended to get another car in the next 6-9 months so that I could retire the E30 as a weekend car, and in time perhaps a track worthy car. But this has new development has forced my hand earlier than when an easy and confident decision can be made on my part.

So, I need to work all that out before I can decide about whether I am or am not willing to do brain surgery on my car, which I think I am smiling smiley

As always, advice, prodding, and general life musings are welcome. Derail the conversation as much as you like at this point. If it comes down to a valve spring repair I'll start a dedicated thread to that endeavor. But a solid decision from me on a course of action is going to be a week or two off at this point...

-----------------------------------------------------------------------------------
1989 - E30 - M20 - Manual. Approximately 270,000 miles
2000 - E46 - M52TUB28 - Manual. Approximately 110,000 miles

And more than ever, thanks for the encouragement. I've never come so close to losing my baby. It's hitting me harder than I thought sad smiley

-----------------------------------------------------------------------------------
1989 - E30 - M20 - Manual. Approximately 270,000 miles
2000 - E46 - M52TUB28 - Manual. Approximately 110,000 miles




Edited 1 time(s). Last edit at 02/23/2010 02:00PM by Earendil.
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Earendil
I'm trying to find info on what broken springs mean.

since no one else's advice has been very useful, i'll chime in.

broken springs "means" you need to swap in an S52. simple as that.


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Earendil
I've never come so close to losing my baby. It's hitting me harder than I thought sad smiley
Chin up. It ain't dead yet.

Borked valve springs are not a terminal engine condition.

Replacing the valve springs is way easier if the entire cylinder head is first removed. But of course that means removing the cylinder head, which in itself is a nuisance because you'll need a new timing belt, head gasket, and head bolts, etc.

The problem with trying to do this without first removing the cylinder head is that you need to push down on the valve springs to compress them far enough to remove the valve retaining collets from the end of the valve stem. But as you push on the spring the valve will drop down into the cylinder. So you need something to hold the valve up while you're pressing down on the spring. You can use compressed air in the cylinder, or use the rope-fed-through-the-spark-plug-hole trick, to hold the valve in place. But you will still need some sort of tool to safely apply enough pressure to compress the valve spring.

The cheapest generic valve spring compressor available from Sears presses against the bottom of the valve and the top of the valve spring. For that, the cylinder head has to come off.

See photos here: [80-75-156-107.colo.gravityinternet.net]
or here: [www.bigboomblog.com]

That first website pops up a warning that their security certificate has expired. Don't know why they even require a secure site anyway. Just accept the warnings. Their photos are better than the second site.
Plan-B:

There is a tool, " Universal Overhead Valve Spring Compressor ", that will let you compress the valve spring from on top, without removing the cylinder head.
The spring quality and life get back to that RPM thing. As I pointed out previously, the high speed gets to the natural frequency of the springs and they "surge" which means there is a wave motion going back and forth at the same frequency as the rocker arm hits the end of it. This causes impact of the coils against each other and stress concentrations, then fracture. The shot peen treatment is to put the surface into compression so a crack will not initiate at the surface. Higher force springs will have a higher RPM capability but put higher forces on the cam. High RPM will also fatigue the rocker arms and break them too. The higher quality these parts are, the longer you can rev to the right side of the tach before having to go back for more parts. The stock springs work pretty well to most peoples taste but you have to decide how much fun you can afford. The stock rocker arms will also fail eventually at the high RPM. One enemy is the removal of the rev limiter on performance chips. The stock chip will try to protect your engine but an over rev on a downshift can really mess things up.

The spring manufacturer should be able to tell you what the RPM rating is for the springs you buy. The mass of the rocker arms makes a huge difference too.

Bob in Everett
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daniel
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Earendil
I'm trying to find info on what broken springs mean.

since no one else's advice has been very useful, i'll chime in.

broken springs "means" you need to swap in an S52. simple as that.

Haha. I told myself that if I put enough work into the body before the engine goes, that I'd put a different engine in there. However I haven't put enough work into the body yet ;-)

-----------------------------------------------------------------------------------
1989 - E30 - M20 - Manual. Approximately 270,000 miles
2000 - E46 - M52TUB28 - Manual. Approximately 110,000 miles

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Ferdinand
Replacing the valve springs is way easier if the entire cylinder head is first removed. But of course that means removing the cylinder head, which in itself is a nuisance because you'll need a new timing belt, head gasket, and head bolts, etc.

Humm... yes.... tell me more about the "etc" you speak of. smiling smiley

Okay, so I'm still trying to work out the difference between the two methods for replacing the springs.

As I understand it...

1) Don't remove the head, do it in place.
This would involve finding a method to keep the valves from dropping into the cylinder. I'd also need a spring compressor that can be used to compress the springs with the head in place. Is it as "simple" as that?

2) Remove the head, do the work on a tabletop someplace?
This includes a lot more work, a lot more precision, and a few more parts. Larger payoffs, because I can check out the inside of my engine?
I'd still need a spring compressor, right? For this I think I'm looking at getting answers for three categories:

A) What do I need to replace when I do this?
- Head Bolts
- Head gasket
- Timing belt (needed to do this one anyway. already have one ready to go)
- ???
- What about cleaning/machining parts? What does this usually cost?
- Spring compressor, torque wrench, anything else tool wise?

B) What should I replace when I do this?

C) What could I replace if I find $500 on the street?


Last question, for those in the know:
Take a stab, a wild guess, a statement for which you can not be sued over, at what you think each method would take time wise.
Or, if even that is scary, give me a time ratio between the two methods. I'm still struggling with not having a frame of reference for this kind of work. I'd never done a drive shaft, but I could look at a tutorial and get a pretty good idea what it would take me, because I knew how to use a wrench and a hammer smiling smiley

-----------------------------------------------------------------------------------
1989 - E30 - M20 - Manual. Approximately 270,000 miles
2000 - E46 - M52TUB28 - Manual. Approximately 110,000 miles

rkj
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Bob in Everett
The spring quality and life get back to that RPM thing. As I pointed out previously, the high speed gets to the natural frequency of the springs and they "surge" which means there is a wave motion going back and forth at the same frequency as the rocker arm hits the end of it. This causes impact of the coils against each other and stress concentrations, then fracture. The shot peen treatment is to put the surface into compression so a crack will not initiate at the surface. Higher force springs will have a higher RPM capability but put higher forces on the cam. High RPM will also fatigue the rocker arms and break them too. The higher quality these parts are, the longer you can rev to the right side of the tach before having to go back for more parts. The stock springs work pretty well to most peoples taste but you have to decide how much fun you can afford. The stock rocker arms will also fail eventually at the high RPM. One enemy is the removal of the rev limiter on performance chips. The stock chip will try to protect your engine but an over rev on a downshift can really mess things up.

The spring manufacturer should be able to tell you what the RPM rating is for the springs you buy. The mass of the rocker arms makes a huge difference too.

Bob in Everett

Hey Bob

It's been my experience that these race worthy rockers and valve gear are pricey, can be very pricey actually. In all my years with the M20 (in a few different forms) it's an easy thing to get your head around sensible shift points that make breaking valve gear almost a non issue. Tyler, you listening?

Rick
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rkj
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Bob in Everett
The spring quality and life get back to that RPM thing. As I pointed out previously, the high speed gets to the natural frequency of the springs and they "surge" which means there is a wave motion going back and forth at the same frequency as the rocker arm hits the end of it. This causes impact of the coils against each other and stress concentrations, then fracture. The shot peen treatment is to put the surface into compression so a crack will not initiate at the surface. Higher force springs will have a higher RPM capability but put higher forces on the cam. High RPM will also fatigue the rocker arms and break them too. The higher quality these parts are, the longer you can rev to the right side of the tach before having to go back for more parts. The stock springs work pretty well to most peoples taste but you have to decide how much fun you can afford. The stock rocker arms will also fail eventually at the high RPM. One enemy is the removal of the rev limiter on performance chips. The stock chip will try to protect your engine but an over rev on a downshift can really mess things up.

The spring manufacturer should be able to tell you what the RPM rating is for the springs you buy. The mass of the rocker arms makes a huge difference too.

Bob in Everett

Hey Bob

It's been my experience that these race worthy rockers and valve gear are pricey, can be very pricey actually. In all my years with the M20 (in a few different forms) it's an easy thing to get your head around sensible shift points that make breaking valve gear almost a non issue. Tyler, you listening?

Rick

i.e. don't let the rev limiter tell you when to shift? B)

Actually, the entire idea behind a "sensible" shift point is somewhat laughable, right? The depends entirely on the car and the driver smiling smiley
I'm sure my grandmother thinks a sensible shift point is around 2K rpm. Of course, she never got her license, so...

I rarely get close to red, and have only hit the rev limiter 3 times. That said, I know where the power curve is, and "spirited" mountain driving sees me between 3K and 5K on the rpm dial.

In any case, the current stock springs have lasted me 3.5 years, 40-50 thousand miles, plus whatever the previous owner put on them. If I only replace the springs, and keep my current driving habits, my money would be on a different component breaking before a spring does. But maybe the springs really are the weakest link by a long shot?

-----------------------------------------------------------------------------------
1989 - E30 - M20 - Manual. Approximately 270,000 miles
2000 - E46 - M52TUB28 - Manual. Approximately 110,000 miles




Edited 1 time(s). Last edit at 02/24/2010 04:52PM by Earendil.
rkj
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Earendil
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rkj
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Bob in Everett
The spring quality and life get back to that RPM thing. As I pointed out previously, the high speed gets to the natural frequency of the springs and they "surge" which means there is a wave motion going back and forth at the same frequency as the rocker arm hits the end of it. This causes impact of the coils against each other and stress concentrations, then fracture. The shot peen treatment is to put the surface into compression so a crack will not initiate at the surface. Higher force springs will have a higher RPM capability but put higher forces on the cam. High RPM will also fatigue the rocker arms and break them too. The higher quality these parts are, the longer you can rev to the right side of the tach before having to go back for more parts. The stock springs work pretty well to most peoples taste but you have to decide how much fun you can afford. The stock rocker arms will also fail eventually at the high RPM. One enemy is the removal of the rev limiter on performance chips. The stock chip will try to protect your engine but an over rev on a downshift can really mess things up.

The spring manufacturer should be able to tell you what the RPM rating is for the springs you buy. The mass of the rocker arms makes a huge difference too.

Bob in Everett

Hey Bob

It's been my experience that these race worthy rockers and valve gear are pricey, can be very pricey actually. In all my years with the M20 (in a few different forms) it's an easy thing to get your head around sensible shift points that make breaking valve gear almost a non issue. Tyler, you listening?

Rick

i.e. don't let the rev limiter tell you when to shift? B)

Actually, the entire idea behind a "sensible" shift point is somewhat laughable, right? The depends entirely on the car and the driver smiling smiley
I'm sure my grandmother thinks a sensible shift point is around 2K rpm. Of course, she never got her license, so...

I rarely get close to red, and have only hit the rev limiter 3 times. That said, I know where the power curve is, and "spirited" mountain driving sees me between 3K and 5K on the rpm dial.

In any case, the current stock springs have lasted me 3.5 years, 40-50 thousand miles, plus whatever the previous owner put on them. If I only replace the springs, and keep my current driving habits, my money would be on a different component breaking before a spring does. But maybe the springs really are the weakest link by a long shot?

Sensible shift points are when you're keeping a motor under power, that doesn't mean running at five grand for any length of time, I guess you have to learn things like this the hard way, maybe after you put your car back together you'll have a better idea.

Be clear on one thing Tyler, the rockers are the weak link on these motors, my moto is (not only with my thirty) is grab another gear and keep in the meat of the power zone; as soon as you see that needle head toward 6 grand pull another gear, quietly and safely spinning smiley sticking its tongue out

It's so hard to relate to young guys about things like this, its usually a waste of time till you guys get into your own motors so you can gain respect and knowledge/wisdom... sorry if that sounds like a lecture, just trying to give you a little wisdom smileys with beer

Good luck, Rick
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rkj
Sensible shift points are when you're keeping a motor under power, that doesn't mean running at five grand for any length of time, I guess you have to learn things like this the hard way, maybe after you put your car back together you'll have a better idea.

It's quite possible to learn things the easy way. Who said anything about staying at five grand for any length of time?

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Be clear on one thing Tyler, the rockers are the weak link on these motors, my moto is (not only with my thirty) is grab another gear and keep in the meat of the power zone; as soon as you see that needle head toward 6 grand pull another gear, quietly and safely spinning smiley sticking its tongue out

Aye, that's what I said I do smiling smiley

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It's so hard to relate to young guys about things like this, its usually a waste of time till you guys get into your own motors so you can gain respect and knowledge/wisdom... sorry if that sounds like a lecture, just trying to give you a little wisdom smileys with beer

I bet you find it even harder to relate when you presume to know how I drive just because I'm a male in my mid 20's B)
Like I said, spirited driving sees me between 3 and 5. What this means is that if I want to accelerate with the intention of shifting, I take it up to around 5 or (depending on the gear) past that before shifting down so that I arrive back within the start of the power band. When staying within a single gear and driving aggressive/fun, I'm closer to 3k. When driving to work or to the movies with the girlfriend, I rarely go above 2.5K.

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Good luck, Rick

Thanks smileys with beer

-----------------------------------------------------------------------------------
1989 - E30 - M20 - Manual. Approximately 270,000 miles
2000 - E46 - M52TUB28 - Manual. Approximately 110,000 miles




Edited 2 time(s). Last edit at 02/24/2010 06:03PM by Earendil.
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Earendil
Humm... yes.... tell me more about the "etc" you speak of. smiling smiley
You do own a copy of the Bentley service manual, don't you?

If not, buy one immediately! It is the best investment I ever made in do-it-yourself repair work. The Bentley will explain everything.

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Earendil
Okay, so I'm still trying to work out the difference between the two methods for replacing the springs.

As I understand it...

1) Don't remove the head, do it in place.
2) Remove the head, do the work on a tabletop someplace?

I'm more of the mind, if it ain't broke don't fix it. If this were my car, I'd try to replace the valve springs without removing the cylinder head. But even that's not as simple as it sounds because you still need to pull the rocker shafts out to get at the valve springs. And I suspect that's not easy to do with the engine in place.

Removing the cylinder head is a whole lot of extra work, with the certainty that you'll end up replacing a lot more stuff than you had first intended. But it is the "proper" way of doing this job, and you'll have the satisfaction of knowing it's done right.

Either way, be sure to study all the steps involved by reading the Bentley manual before diving in there blind.
Yep, I have a very well used, torn, oily, but still in one piece bentley. I know I looked in there for information specific to removing the valve springs and found nothing. I'll look the whole section over as soon as I go back to my car, and see if what that says about removing the head makes sense to me. Thanks for the reminder though!

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1989 - E30 - M20 - Manual. Approximately 270,000 miles
2000 - E46 - M52TUB28 - Manual. Approximately 110,000 miles

rkj
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Ferdinand
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Earendil
Humm... yes.... tell me more about the "etc" you speak of. smiling smiley
You do own a copy of the Bentley service manual, don't you?

If not, buy one immediately! It is the best investment I ever made in do-it-yourself repair work. The Bentley will explain everything.

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Earendil
Okay, so I'm still trying to work out the difference between the two methods for replacing the springs.

As I understand it...

1) Don't remove the head, do it in place.
2) Remove the head, do the work on a tabletop someplace?

I'm more of the mind, if it ain't broke don't fix it. If this were my car, I'd try to replace the valve springs without removing the cylinder head. But even that's not as simple as it sounds because you still need to pull the rocker shafts out to get at the valve springs. And I suspect that's not easy to do with the engine in place.

Removing the cylinder head is a whole lot of extra work, with the certainty that you'll end up replacing a lot more stuff than you had first intended. But it is the "proper" way of doing this job, and you'll have the satisfaction of knowing it's done right.

Either way, be sure to study all the steps involved by reading the Bentley manual before diving in there blind.

Replacing the valve springs and pulling the cam etc is a hassle with the head on the bench, I usually have my machinist do it. Good luck doing it in place eye rolling smiley
I remember on my 325iX I had no rev-limiter (LPG converted). Being unaware of the rocker issues (and young and stupid), I overrevved (as in 1000 rpm beyond the start of full red on the scale) it often, without ever breaking one. I guess you need some amount of luck at times. I may consider myself to have been lucky as the valves didn't float either.
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Ferdinand
Plan-B:

There is a tool, " Universal Overhead Valve Spring Compressor ", that will let you compress the valve spring from on top, without removing the cylinder head.

Perhaps what I'll do is go this route, and not remove the head. I need to do the timing belt too, so I can get a lot of "stuff" out of the way on the front end. This leaves me only needing to buy a spring compressor, an adapter for my air compressor to pressurize the cylinder, and a torque wrench, which I should own anyway. I think everything else I would have gotten for the timing belt anyway (or already have).

If I go this route, the worst that can happen is that I end up having to remove the head, right? Assuming I don't do anything blatantly stupid (which is a pretty big assumption), I'm not risking any additional damage to the car? Only damage to my knuckles and psyche?
I know it won't give me the same respect/wisdom with regards to my motor, but it might have to do for now smiling smiley

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1989 - E30 - M20 - Manual. Approximately 270,000 miles
2000 - E46 - M52TUB28 - Manual. Approximately 110,000 miles

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