Boxer engine out...

Hi Robert, nice work. One question, are you pulling the heads off? The reason I ask is because of the option to change the valves now before they cause you grief. The tight clearances makes me want to pull the heads and set the valve heights back to max spec and run the thickest shims I can for plenty of adjustment down the road so to speak.

 

I think you will find boxer owners will chime in here and tell you to pull the heads at this time. The clearance isnt so much the issue, why the clearance is tight is the question and when (not if) a valve head falls off, you will regret it because the cost can be staggering but a lot less now before it breaks. Of course its your choice but if you wait for it to break to go in a second time you will kick yourself.

 

I was going to ask about that...is there a way to visually inspect and confirm/deny sodium filled valves???? They may have already been changed.....

 

Head work will cost several thousand including gaskets, I wouldn't worry about it unless you think the seats or guides need replacing, if the guides are worn the valve cant dissapate heat as well and can break.

Its rare for a Boxer to have a sodium valve break more common for 308s as they rev higher among other issues perhaps including Flat 12s have better valve guides so the valves can dissapate heat or the oil circulates better in the guides keeping them cooler as well, its also interesting to look at the cam belts and tensioners path its fairly direct without much bends in the belt vs the 3xx motors, probably another reason cam belt failures are more rare on the Flat 12s.


How long do you think it took you to remove the motor all together?

 

Thanks for the great thread and pics Robin, as a boxer owner this is seriously interesting, i may attempt the engine out service on my car when its due and this all helps.
i have one question though, what have you used to cover your garage floor? It looks great.
Steve

 

Yes, what type of cleaner are you using to scrub the castings?

 

There's a Boxer on "the other site' that suffered a broken valve after engine service......pics are not pretty.

I was thinking of glyptol paint when you mentioned it....common in hi po applications to hasten oil drian back......

 

The boxer on the "other site" is also posted on this site and the engine had been rebuilt by a reputable ferrari engine builder that felt the valves were ok at the time. Skimping on that detail (for any reason) caused a lot of grief for the car's owner im sure. When my engine comes out, it will get valves so I can drive with piece of mind, thats worth the expense as far as im concerned. Im also not convinced it would be several thousands of dollars to do the top end but it would be if a valve head fell off, to each is own.

 

Lets add up how much it will cost

24 new valves @$50 each $1200

24 valve guides @$20 each $480

24 valve seats @$15 each $360

2 head gaskets @ $200 each $400


Machine work $1500?

I am adding up close to $4000 for new valves



And yes the 512BB on the other site suffered a valve failure after a full rebuild from Carobu Engineering who reused the valves and did a valve grind on them shortening the valves life further.

 

Guess you are right, let it drop a valve first then fix it cheaper......right?

You are getting it up the chute for machine work by the way and it might not need guides and most likely not seats either.

 

Glad I could help on the paint info.....listen I'm no expert, don't mean to imply such......I just try to be aware of the issues.

Absolutely correct the sodium valve technology is still applied in some engines to this day, so it may be best left alone. As far as I know both my 1977s are still equipped with them....

My understanding on my old 308GTBs is that disabling the air injection reduces the stress on them also. I think your reasoning is good, proper adjustment will insure good contact and heat transfer.

Valve guide work would only be indicated if excessive leakage and smoke was a problem. I think there is a better seal over stock some have fitted, but this was on older 12 cylinders. Never heard Boxers needing it.......

HTH...

 

No need to pull the pistons out, just do a top end job and plop it back in. Sodium valves are old technology and like any other engine part in a 24 year old car, they are 24 years old. They become brittle because of the heat cycles and age doesnt help. To me its a no brainer and there is no external test that can detect a valve that will break in 5000kms. If you decide to leave them in then I wish you luck because its not an "if" its a "when" situation just like a timing belt or any other wear item.

 

If you can get it done for under $1200 I would do it, you are getting a great deal on the machine work I hope they are good, it would be an expensive mistake if they messed up a head.

I would also check the springs as well, I think Ferrari has the guildes a bit loose from the factory so I would replace them as well.

 

Newman - I have enjoyed and learned a great deal from your posts over the years, but now must ask a question concerning your comments vis-a-vis sodium filled valves in Boxers.

If I understand correctly, there are 24 valves in each Boxer, and there have been approximately 3,000 produced (engineering approximation). Let's see, that means that there are 3,000 x 24 = 72,000 valves in these cars over an average of, say, 25 years. You suggest that the valves are prone to becoming brittle owing to hot and cold cycles, and that it is not a question of "if, but when." I commend you on your farsightedness, as it appears that none of your predictions have YET come true.

As has been attempted with the belt discussion, perhaps we should ask all the Boxer owners if they have experienced valve-stem failure. Anyone out there?

Please, no offense intended, merely healthy skepticism. I try to place more faith in automotice engineers and the value of experience. The Ferrari engineers who designed these engines stood on the shoulders of then 35 years of prior experience. Yes, mistakes are made, but they most often reveal themselves quickly. In summary, I am not rushing to change my valves.

Jim S.

 

Sodium filled valves may be old technology, but they are still being used today in high performance engines including the new Z06... http://superchevy.com/technical/engines_drivetrain/completebuilds_testing/0504sc_ls7/

 

*laughing at this line of thought*

Yes, Frank but they are NEW sodium filled valves in the Z06!!

ROTFLMAO!

I'm thinking of all the time I'd save, to trade in my Fcars on one and quit this chatroom.........LOL!

But I'd still have the hats, jackets, posters and room full of scale models going back to my original Hot Wheels!

*sigh*

Jim S.: lies, d@mn lies and statistics! Don't try to muddy this arguement with FACTS!

 

I dont doubt that sodium valves are still used, im sure they are made of a different metal though and lessons learned from the past might make them a better valve today. Like things from the past that failed such as the 4/6/8 electronic cylinder cancelling has now become the cats a$$. Same idea, better technology. A valve head falling off in a boxer engine isnt new, not a daily happening but then again, how many are driven out of the 2000 BB's built? How many have been replaced prior to failure and how many cars are actually left alive? Being in the trade myself, I feel my advice is sound and thought I would just voice it seeing as this is the purpose of the site - to help not misguide for kicks. Sorry for stepping on so many toes, I bow out of the thread now.

P.

 

Newman - don't bow out - your input makes us think. No offense was intended and I hope none was taken.

BigTex - you're right. What was I thinking? Facts... such a nasty way to settle an argument.

Newman - Your advice is sound. Who would argue with replacing valves. In medicine, however, we have a saying, "Above all, do no harm." The equivalent philosophy in auto mechanics is, "If it ain't broken, don't fix it."

What I am trying to convey is that the statistical likelihood of a 25-year old valve failing is less than a new valve failing. The latter will occur as a result of a manufacturing flaw, or an error in installation, or seat incorrect, etc. The real advantage of a 25-year old valve is that it has proven NOT to have a manufacturing flaw. Again, in medicine, we say that "...it has withstood the test of time."

This is different than normal wear that leaves the stem diameter less than specification, which would require replacement. However, in the absence of normal wear rendering the part terminal, I would not spend the money or time replacing perfectly good parts.

Jim S.

 

I share Newmans views on sodium filled valves having seen failures caused by the valve stem weaking from the inside. Metallurgy has made some giant improvements since those valves were manufactured.

 

Let us know how hard it is to remove the heads, I know it takes a puller on some to remove.