1998 550 Maranello "sorting" thread--DIY

Marks line up. Isn't that interesting?

 

Pete:

Why didnt you use the assembly marks to begin with, are they known to be off or you just wanted to check?

Are they also marks marking TDC and the cam drive gears?

 

OK, here is where I show i am a complete idiot.

Firstly Pete, thanks for letting me come over the other day. You really do some great work, but: What are the yellow and red marks in the pictures? I ask you guys not to laugh at me, but what are those marks, and what purpose do they serve? Thank you if your reply does not make me feel so stupid.

 

The only time I caught a motor that didn't line up was a Mondial 3.2.

 

So does mean that the assembly marks can in fact be used?

How many sets of marks are there?

Can the entire engine be "timed" with the assembly marks? (camshaft, and crankshaft gears)?

 

Depends on if you are happy with "Consumer Acceptable". The WSM gives a procedure to do it properly, I doubt they were just looking to fill up white space on a page.

 

Was the manufacturing tolerance just not there for the assembly marks to also double for timing and a single cam/gear dowel slot?

 

It is my theory that the "Cam Marks" were stamped when the blanks were still in a rough forged condition. Vig, to get the performance these engines give and still meet tough emissions standards, everything must be Perfect, close wont do.

I think the rough forged blanks were set in a machine where an indicator could find what was the center of the rough lobe and then stamped. The blanks were then put in the lobe grinder with this stamp as an index mark and then the cams finish machined. It is obvious that this mark was made Prior to heat treat and Parkerizing as it is of the same color and texture as the rough shaft itself. The stamps on the rear of the cams were made after the engine was timed but those look like they were done with a Battle Axe and are impossible to match accurately.

The intent is, and always has been, to have a mark that was close enough to allow assembly without bending the valves. I used to rate the cars as either a Mutt, OK or a Rocket when I would do the Pre Delivery Check test drives prior to an owner getting a new car, noting this in the cars file. One of my tests was if I could launch my Service Manager into the back of the seat with the 550/575's, while accelerating down the on ramp. IF I could firmly plant him in the seat it was "OK". If I slammed him into the seat and had him grabbing for the door handle... It gained Rocket status. Much can be learned when one has the opportunity to drive multiple examples of the same model in a given week. The difference.... Cam Timing. Of the engines sitting outside the dyno cells at the factory, the ones that did not pass, a few had leaks but the majority failed to meet the 'acceptable performance range' and had to go back and get "Re Timed".

For many... Close is good enough. Most often because they never had the opportunity to feel what "Exact" felt like. I liken this to FBB doing the blind GCK testing. I purposely shorted him the second stage of the kit because I wanted to know if there were enough subtle changes to justify the extra expense of offering it. A great car with no problems from the start...... yet a notable seat of the pants change with 'stage one'.... and again with 'stage two'....Opps, where did that come from?! You don't know what you are missing until you feel it. What does a Blueprinted engine with perfect timing "Feel like"? There is always a chance the engine timing is spot on with all 4 cams BUT as Pete has shown, only one of 4 cams is "exactly on the marks". You must visualize it from two different angles. Get the timing on ONE bank within spec, operating exactly like it was designed to and within the spec range... Great, that was "easy" but the work has only started. Matching the second bank to EXACTLY the same as the first bank is where the hard work is. Short of that you end up with one bank making all the power and the second going along for the ride. You have "spec" and then you have "match" OR... you have line up the marks, a crap shoot at best.

I suspect Pete will experience what I am speaking about BUT can he accurately express it in words that make sense to us? Doubtful, my Beta Testers have not been able to give me a single sentence description of the results. Pete did too many things at the same time to be able to identify what his results are primarily from but.... my bet is there will be smiles involved! What else matters?

 

We use the marks as a base to reassemble the motor off of. Even though most times it all ends up lining up you still have to go through the process to verify. Never assume, see it with your own eyes.

 

For the sake of discussion I just measured the F40 engine I am currectly cam timing. Leading edge of the cam mark and the leading edge of the cap mark.... trailing edge of the cam mark and the trailing edge of the cap mark.... 15 crankshaft degrees.

Take a few degrees off of either side and then it can be stated "There is a 11 crankshaft degree range where the marks 'Line Up'". Good enough for Horse Shoes....

 

That is believeable. On another thread I did the math on a 25mm and 36mm diameter shaft and 1mm wide cam scribe would yield 4* and 3* per line width. So what you say jives.

 

Pete, anxiously waiting for your posts. Sark

 

Pete, nice to see you back. I just found out today some oil dripping from bottom of right timming belt cover, asumming comes from cam seal. So I am wondering I should go head and follow your step by step work or get dealer to do the work. Sark

 

Pete,

The oil vapor control system is quite a kluge of weird plumbing. One of these days I would like to find a way to clean that up. I bet John would be all over that too.

 

I'm on it. (In between a few other things) I've got a blowby tank that I intended to cut up this last time home, but I didn't get to it. I suspect there's not much inside, as the blowby system really doesn't seem to work that well. My intake always has pooled oil in it when I open it up, as did Pete's, IIRC.

 

Last week I got a request to make a custom size of the SRI oil return hose we make for the oil drain backs on other models. If you get a chance, get me the ID's of the hose required for the 550's. I remember having to cut the crimps on the cam cover breather to replace those hoses in the past, but I do not have a late 12 cylinder in the shop at this time. If I am making one new size, might as well do a few new sizes when I meet with the engineers next week.

 

I'm on it! I'll email you some pictures with measurements.

 

Hey Pete:

I've been following for some time, exceptional work! One question: The paint color of the intake manifold appears to be more pure silver than the original color, which is an "off silver".

Cheers

Mark