Cam drive-gear bearings..engine remove?

It's definitely doable. I've done it a couple of times. Unfortunately the posts with most of the pix are currently off-line in the old fchat archives. Also did it to JWise's car more recently (both w w/o pulling the engine, guess we needed the practice.) There's a long writeup on it, but the pix are also off-line.

Short version:
Remove the sump cover, then remove the oil pickup tube & double-nut the pickup tube studs off. Will need a good basic set of auto tools, plus: Snap-On 'short' 12-point 1/4" drive flex socket w/ 14" & 12" 1/4" drive extensions, a 10mm wrench with about 3/4 of the box end ground down very thin.

Then remove the studs going up thru the sump's front lip into the timing cover's base, again double-nutting them.

CAVEAT: If you can't get just one of the oil pickup, or the timing cover base, studs out, then you have no choice to pull lthe engine(been there too). Luckily most of the time this doesn't happen, so the odds are in your favor.

If all goes well, it's a 3 to 4-day job, but for a 1st timer, it'll probably take 6 days.

If the timing cover stud boss hangs up on the WP, you'll have to either pull the WP, or else trim the intersection with a hacksaw blade.

Most of the rest is pretty straightforward. Feel free to post more questions to this thread as you go along. Also send me eMAIL & I'll give you my phone # & talk you thru if necessary.

 

Are you sure it isn't your girlfriend in the next seat??? :

hth,
chris

 

Are there any upgraded bearings for the cam drive & tensioner bearings??

It lseems fairly clear from the 4.1 engine post that the bearings are a "bit" under-engineered, or at least, under-speced.

Can anyone out there list better quality bearings #s for the early carbed 308's???

Just looking down the road, so when i do the belts, i will have all of the necessary parts.

thanks,
chris

 

I'm not convinced that the OEM bearings are badly under-spec'd. The early carb'd 308s had the bearings in-board of the seal. Big advantage: Both bearings are open frame & lubricated by engine oil. Disadvantage is that the outer bearing is set about 5 or 6mm inwards from the cam drive gear rathar than being right up against the gear. Also, I think the outer bearing may be slightly smaller than in the later cars.

However, to the best of my knowledge, no one with an early carb'd car has reported a cam drive bearing failure on Fchat or FerrariList.

The newer design was to put the outer bearing outside of the seal & depend on it's factory lubrication. This mounted the bearing right up against the cam drive gear. Best possible location for radial force transfer into the housing with minimal twisting moment. Believe that the bearing was somewhat larger as well. Subsequently the later QVs & 328s came with an even larger outer bearing.

IMHO, the reason we're seeing these outer bearings fail is that the factory lubricants are drying out & breaking down after 20 years more or less.

When doing JWise's car I talked with a tech who worked for the MA Ferrari dealership from '77 to the late '80s. Said he didn't remember them having a single timing bearing failure. Was surprised we'd run into them.

As to 'better quality' bearings, I took the factory bearings to a local bearing supply shop. They said that the SKF bearings were SKF's top grade of bearing. BTW, bearings have constantly improved over the years. Tolerences, alloys, hardning methods, lubricants of today are significantly better than what was available in the 1970s.

About the only practical way to utilize a 'better' bearing would be to do some significant redesign & machining to accomodate an even larger bearing, unfortunately, this would include machining the block, the timing cover, and most likely making a new shaft with it's integral gear! This seems to be what the 408 guys are doing.

Both the NSK & SKF web sites have a lot of good technical tutorial material on bearing selection/application trade-offs, etc. I really like NSK's 'Handbook' section, especially the explanatory chapters:
http://www.tec.nsk.com/Handbook.asp?menu=1,0,0,0&PageID=/TypesAndFeatures/IndexTypesAndFeatures.html

Spent a lot of time researching them when my timing drive bearings went a few years ago. Decided I couldn't do better than the original bearings.

 

My 77 308 has the earlier design with the oil seal on the outside and this failed after the previous owner had new belts fitted at a dealer.

I did a write up (http://ferrarichat.com/forum/showthread.php?t=14913) but as the photos have gone missing I'll send you an e-mail Mark.

As Verell says, it is possible but there is no guarantee that something won't hang up and force you to remove the engine. I was lucky and managed to do it in-situ. Personally I think it's well worth having a crack at it in the car unless you want to remove the engine for other reasons.

Richard

 

Mark,
I wanted to do some basic service on my 81 gtsi (belts, bearings, w/p etc.) and decided to remove the engine.
With all the help from this forum, it was an easy job and a very complete one.
Every part of the engine was cleaned/replaced/repaired short of taking the heads off.
I have no previous experience on the subject and a moderate collection of tools.
Taking the engine off, may be a slightly longer job but I feel that the return/pride/knowledge return is very high.
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I had a rear bank outer bearing fail. I have heard the inner ones rarely go bad? Are you sure the growling noise is coming from there. I had a chattering sound at idle and after much research and work turned out the engine was idling to low making the transfer gears chatter. The idle should be at 900-1000rpms mine was idling fine but at about 750-800 causing the noise after I increased the idle it miraculouly dissappeared!!!
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Gianluca,
Pls tell us what you used to get your engine so clean.

 

errr. That's just Paint Verell!!

Painted engines tend to look good for a short while and then very scruffy soon after.

The best method is thorough cleaning using solvents etc, and some light bead blasting on components that can be cleaned easily internally (not heads or blocks).

 

Verell,
I scrubbed down with parts cleaner and use Rub 'n Buff. Not too difficult at all.

Ferrarifixer,
It is not paint. Rub 'n Buff appears to be a metallic powder in a wax binder.
A very small amount will cover a large area.
To my surprise, it does not look scruffy at all after time goes by. Not only it retains the look but it can be refreshed by simply going over with a rag.

Many people here have used it and they know how great the stuff is. for those who have not yet tried, do yourself a favour and buy a tube to try. You will be simply amazed.

Any art store sells it in their picture frame department. 3-4 $ a tube.
The tube of the stuff is very small. About 2 tubes to do every single part on your engine.

 

I love Rub&Buff
Great stuff, and cheap too.
Don't use it on Suspension components, it is not rust proof so it appears $hitty after a while. On aluminum engine though, it is hard to beat.