valve stem seal replacement at service

It's a must! It will also help keep your car from smoking at start ups and acceleration.

 

I am doing this the next major service on my carbed BB and should have done it at the last major service. I get a puff of smoke when I run synthetic motor oil so I run Castrol 20-50. I think the valve stem seals would correct this.

Did FOA offer a flat rate like the last time you did it and if so are you at liberty to divulge it?

 

I am doing this the next major service on my carbed BB and should have done it at the last major service. I get a puff of smoke when I run synthetic motor oil so I run Castrol 20-50. I think the valve stem seals would correct this.

Did FOA offer a flat rate like the last time you did it and if so are you at liberty to divulge it?

 

I didn't think the BB's had valve stem seals, and that was the reason for the puffs of smoke.
Perhaps I'm confused?

John

 

Puff of smoke can also come the car sitting and oil puddling from the bottom of the cylinders since they sit horizontal.

 

Ding, ding, ding...We have a winner!
This is the primary reason why all flat engine smoke, sometimes, on start up.

 

Relatively easy? That depends on your perspective.

Remove valve covers
Remove cams, buckets, shims and cam caps
Lock engine in place, so the flywheel/crankshaft can't turn
Insert compressed air in cylinder to prevent the valves from falling in
Using special tool and a degree of care, remove valve keepers (4 keepers/2valves/cylinder)
Remove upper valve spring retainer and likely springs
Remove old valve seal without damaging valve stems
Install new valve seal over valve without damaging new seal surface

(Or some variation of the above procedure)

Repeat x 24 valves

I'd estimate about six hours to do this...with the end result being the same. Seal wear on Ferrari engines isn't the problem. Guide wear is...So to replace the crappy uber-hard teflon-based, 1970's based technology, seals with the same seal is a total waste of time and money. (However, if the OE seals are found to be broken (i.e. in pieces), this is a viable excercise. Then again, replacing them with a viton-based BMW/VW seal may result in some improvement, presuming there's a problem with the seal to begin with.

All said and done, she'll still puff when she feels like it...

 

David,

When I run Mobil 1 15-50 (think I got the weight right) I get a noticable puff of smoke when I hit the accelerator after the car is all warmed up. When I use Castrol 20-50 no puff of smoke. I have always thought this was related to the valve stem seals.

I would really like to run the Mobil 1 synthetic since it apperas to have more ZDDP as oppose to the Castrol; reference Bill Badurski's recent Prancing horse article but the thing smoking upon acceleration drives me up a wall.

Have you ever replaced yours?

Drew

 

Dear Ferraristi,

....show off


Shamile

Freeze....Miami Vice !

 

Awesome !

 

Interesting.

IMHO:
I would think the stem seals are the same as 3X8 which are pretty nice quality PTFE parts with the nice dynamic clips. Do Ferrari's have a prob consuming oil thru the stem seals?

I just did my EO and didn't consider stem seals. The one component I neglected which bit me was the shift shaft seal. This $3 part was no fun to change with the engine put back in.

 

Drew,

Lots of ground to cover here...

First and foremost; my engine is fresh and not stock. Modern pistons with a great 3-ring design using the best possible oil control rings. Custom guides fitted, with a known .001" valve to guide clearance. The factory spec. is .0009-.0022". You're lucky to get .002" with a new factory guide and valve. BMw viton-seals...All rings hand fitted and end gaps verified. The engine leaks down on the worst cylinder a 1% now. Oil control is not a problem, regardless of the oil used.

Oil: Flat tappet engines need ZDDP. However, the EPA has for a while now been mandating lower levels ...as there is evidence of long term damage to cat converters. Most older Ferrari engines are of the flat tappet design, so ZDDP cannot be ignored. Personally I use...and have used for years Mobil 1 15W-50....as it has a ZDDP levels over 1100ppm. The minus is that the oil is thicker than it needs to be on a "cold start", which in theory increases engine wear according to a well-known "expert" on this board. However, oil analysis indicates otherwise. But...modern oil have improved dramatically and I'm seriously contemplating switching over to RedLine 10W-40, as I should have less potential wear on start up and more ZDDP, as well.

Old oil formulations/recommendations cannot be compared, apples to apples, to the newer synthenics. In the same breath, most of theses 5w-x and 0w-x "energy efficient" oils have dangerously low levels of ZDDP, so homework and calls to their engineering departments are in order.

Smoke: Simply stated-
>>On acceleration, rings
>>On deceleration (high engine vacuum condition), valve guides
>>In general, excess fuel dilution in the oil can cause smoke

Due to the Weber accel pump design, or lack thereof, fuel smoke on hard acceleration is not uncommon, nor a problem to be concerned with.

On a BB/TR, where the exhaust cams are literally "submerged in oil", some smoke is possibly even with known good guides. Ever notice the oil return galley inside the valve cover...and the 19mm hose returning the oil to the sump? We don't want excess oil hanging around in the head...

So, with the above thought in mind, imagine that you turn the engine off and one of the exhaust valves is open. Over time, by design, some oil could leak down the guide into the combustion chamber...and voila, on start-up, we'll have smoke. Or, in that we have a horizontal engine, splashed up into the liner (a normal condition)...and weeps past the dinosaur technology rings. Again, we'll have some some smoke, potentially.

As to Mr. Shaw-Wow's comments: No showing off here, my friend. Just trying to prevent folks from spending monies that really don't need to be spent.

Best,
David

 

Yes and no, but the newer materials used are a better choice.

http://www.ferrarichat.com/forum/showthread.php?p=138843888#post138843888

David

 

They are...all 8mm stems. The 4-valve cars use a 7mm seal, which is of a totally different design and material.

 

You mean 48?

LOL!

 

You've got two BB engines to do? LOL!

 

oops! I was thinking of my 512TR.

 

Dear Ferraristi,

No, no....you misunderstood.

It was a compliment to your vast knowledge and excellent explanation.

...are all the boxer girls this sensitive?


Shamile

Freeze....Miami Vice !

 

Thank you! May the Gods of fresh panties be with you....

Yep, we're a sensitive bunch...LOL!