| Author | Message | ||||||||||||||||||||||
| Steve Magnusson (91tr)
Intermediate Member Username: 91tr Post Number: 1857 Registered: 1-2001 |
Graphs are working OK for me now. | ||||||||||||||||||||||
| Ted Gage (Tedmac)
New member Username: Tedmac Post Number: 23 Registered: 2-2003 |
Performance/advanced cam timing - step-by-step http:www.tedgage.net Version 2 is available on the link. I've attempted to capture all of your comments. If anything was missed, it was inadvertent. I�ve resized the charts. They work for me. I have no idea why some cannot see them. If you are still having a problem with them, please send me details (a screen shot would do nicely: Alt-Printscreen, then Shift-Insert captures then inserts the active window). I think I've figured out timing using the dowel holes in the cam and pulley. This has been added to the write-up. I found it to be useful in calibration when the desired setting was only a degree away, with difficultly in seeing difference in dowel holes alignment. Thanks for the inputs. | ||||||||||||||||||||||
| Ted Gage (Tedmac)
New member Username: Tedmac Post Number: 22 Registered: 2-2003 |
Thanks guys. Input appreciated. I'll update and release V2 soon. FYI, I've had an "Aha!" regarding the cam pulley dowels. In V2, I'll describe the indexing methodology used (I believe it's correct). | ||||||||||||||||||||||
| Verell Boaen (Verell)
Member Username: Verell Post Number: 823 Registered: 5-2001 |
Terminology clarification: Ferrari documentation consistently (308 GT4 FSM, 308 GTSi/GTBi FSM, 328/308 QV FSM Supplement, and the corresponding owner's manuals )use the following terminology: 'Camshaft Drive Gear' or 'Camshaft Driving Gear" for what's commonly called a 'Cam Pulley' in F*Chat posts. (Until it's the directions tell you to "install the 4 pulleys'...(sigh). 'Cam Gear' seems like an acceptable short form. 'Drive Gear', 'Driving Gear' less frequently 'Timing Gear' or 'Timing Drive Gear' for the smaller gear that drives the cam belts.(Until you get the actual figure illustrating how the timing drive system fits together, then suddenly it's a 'pulley'! 'Driving Dowels' are the pins that go thru the holes in the Camshaft Drive Gear' and into holes in the Cam's flange to provide fine timing adjustment. 'Idlers' are what's commonly called tensioner pulleys. I was about correct someone once & checked the manuals in time to avoid embarassing myself. re: Torques The 328/308 QV Torque specifications sheets are a little more clear than some of the other documentation: Securing Pulleys to Camshafts (12x1.25 thread) 70Kg-M (72 Ft-lb) Securing Timing Belt Driving Gear (17x1 thread): 12N-m(86.5 Ft-lb) | ||||||||||||||||||||||
| Steve Magnusson (91tr)
Intermediate Member Username: 91tr Post Number: 1854 Registered: 1-2001 |
Ted � What�s not to like? Very well done! (but the graphs aren�t showing up now). Being 308-less, I�m not the best person to comment on the exact hardware/procedure details (e.g., QV vs carb), but I do have some comments (in no particular order or importance): 1. Try to use consistent nouns -- what you call the �Cam timing gears� I believe would be called �Cam pulleys� in most F documentation. 2. Give a definition/description of what you�re calling �lift� -- my take is that in this document by �lift� you mean: Lift = measured motion of the bucket/shim caused by the cam lobe acting thru it�s normal operating clearance� 3. On the �Background� page � A. Note that the table is an �intake� example. B. 43 ATDC should be 43 ABDC C. Selecting the �lift� (as defined above) that gives the specified duration to be the endpoints for the calcs/settings is A-OK, but using any equal lift points (and the corresponding duration for those lift points) can be used as the endpoints to calculate the �center� and do the setting. To illustrate you could add a column, �Calculated Center�, to the table on the Background page as shown below:
4. �Calculating 308 GTB/S cams to Euro specs� page � add the appropriate ATDC, BTDC, BBDC, or ABDC to each degree value in the table. 5. �Remove the timing gears� page � rename to �Remove the Cam Pulleys� as noted above. 6. �Mount the cams� page -- Change �Be sure that the crank is set to zero degrees (TDC)...� to �Be sure that the crank is set with piston #1 at TDC...�. IMO wouldn�t hurt to restate that (for the stock condition) all 4 cam marks should line up with their corresponding mark on the cam cap when piston #1 is at TDC (IME sometimes this gets confused -- i.e., people wrongly think that the 5-8 cam marks should line up when piston #5 is at TDC.) 7. My belief is that the �Nut, pulleys to camshafts� torque spec of 11 Kgm is for the BOLT holding the cam pulley to the camshaft, and that the 13 Kgm torque for the �Timing belt driving pulley� is for the ring-nut holding the driving pulley down by the crankshaft. Feel free to use or ignore as you wish  | ||||||||||||||||||||||
| Verell Boaen (Verell)
Member Username: Verell Post Number: 817 Registered: 5-2001 |
Ted, re: 'multiple entry points' I think you're on to something. It might be appropriate to setup hot-link paths thru the procedures, with a series of questions to guide the person thru the links. It also struck me that the procedure you're documenting is pretty advanced. I'd classify it as 'performance/advanced cam tuning'. The novice just needs to be guided thru the basic factory recommended process which is aligning his flywheel on the the PM1-4 mark, and using the cam-cam cap marking lines to align his cams. Some of the things you've come up with like using a piece of belt on a rigid plate to hold the cam gears in place would still apply of course. A 2nd varient would include doing a basic valve clearance service while the cam covers are off. I may be helping another FChat member do a belt service on his QV later this summer. If it comes off, It'll be a great opportunity to get the photos & capture the basics. BTW, someone else was asking about sealing the cam covers up. Here are some prior threads on the topic. Note that as one of the threads progresses I change recommendations as I gained new 'experience' (which is what you get when things don't turn out as planned): http://www.ferrarichat.com/discus/messages/256120/65844.html http://www.ferrarichat.com/discus/messages/256120/103720.html Most of the time the belt service procedure is done in the car by pulling the passenger side wheel & wheel well. The access to the area is much better than you'd think until you've done it. It's not wide open, but you can reach in & get at everything. For comparison, you have much better access to everything than you have when doing the belt service on a Dodge Stealth. Talk about tight quarters! Having the car on a lift really helps as you can adjust it's height to fit what yo're doing. However, just getting it up as high as you can on jack stands is sufficient. re:"Damaging o-ring when installing the cam bolt" Know this all too well. Somewhere in the archives is my 'frothing off at the mouth' when I got ticked off at the dealer's mechanic's inability to eliminate oil leaking onto my cam belt. When I went in, I discovered that all 4 cam bolt heads were at the center of 6-pointed star oil streak marks. All of the o-rings were hard as a rock, & 2 were nicked/broken. After that I've done all my own service. | ||||||||||||||||||||||
| Ted Gage (Tedmac)
New member Username: Tedmac Post Number: 21 Registered: 2-2003 |
Thanks Verell, Supposing we create a list of procedures in the parts & service links (or wherever), we might end up with sections like: Maintenance teardown Valve work Cam timing Belt replacement Reassembly� and so forth. When you complete writing the teardown segment, we could adapt each segment to correlate to the other. I've read some of your earlier postings such as how to get the A/C compressor of out the way. These don't need to be in the archives... they need to be in a readily accessible section. In my case, the engine is out of the car. I suppose one could perform the precise cam adjustment described with the engine in the car, but I expect it would be rather tedious due to limited access. If you were to attempt this activity with the engine installed, taking off the RR wheel and wheel well might help. �It's a lot easier to deal with the cam gear bolt by breaking it loose with an air wrench while the original belt is still...� I agree. I�ll take a look at updating the section so that the technician can do the work at the best time. There�s a number of �entry points�. More on this later. �It's very important to point out the o-ring that seals the cam gear bolt head, and make the point that it must be replaced each time the bolt is removed..." I�ll add this in your words with your permission. I also found out that it�s easy to damage the O-ring if it�s not seated fully on the bolt and gets pinched in the groove. The cam clamp input for the QV is useful. Perhaps the thing to do here is to include designs for both the 2V and QV cam clamps in the methodology if you�ll go ahead and design the one for the QV. Unfortunately I don�t have access to a 308 QV but I�ll take a look next time I�m at Norwood�s. �The procedure needs to take the person through the process of installing & sealing up the cam covers. This is where most novices get into trouble...� I�ll confess to not being up on all the tricks to this. Perhaps we can get a volunteer or find something definitive in the archives. There�s a navigation problem using the processes depending on the individual technicians issues. I guess what I�m proposing is that it appears that it would be extremely useful to tomorrow�s Q&A�s to go ahead and try to post some tried and true methodologies. These probably should be accompanied by typical workflows. Finally, I�d like Steve Magnusson to weigh in with an opinion. | ||||||||||||||||||||||
| Verell Boaen (Verell)
Member Username: Verell Post Number: 812 Registered: 5-2001 |
Ted, Nice start on a write-up. You asked for feedback, so here are some initial tips/suggestions: - The write-up's starting point, & procedure to get there is a bit vague. It seems to start with the cam covers, timing belt, cams, tensioners, etc. already removed from the engine. It's also unclear as to approximately where the engine initially should be (ie: on PM1-4 mark which is supposed to be TDC, and is usually very close to it. - I was going to start my version of the write-up of the procedure with everything fully assembled. ie: Start it with removing the passenger side wheel well liner, progressing thru removing the A/C compressor, alternator, belt covers, cam covers, etc. - It's a lot easier to deal with the cam gear bolt by breaking it loose with an air wrench while the original belt is still in place & under tension, & the engine is in 5th gear with the park brake engaged. The belt keeps the cams from rotating. - It's very important to point out the o-ring that seals the cam gear bolt head, and make the point that it must be replaced each time the bolt is removed. Also, a bit of non-hardening sealant like Locktite PST, or Hylomar smeared on the o-ring & the 1/4" or so of the threads next to it ensures that the bolt won't leak. Many times cam seals have been replaced when the only problem was that the cam bolt o-ring was leaking. - Tool you document for locking the cams in place cannot be used with a quattrovalve engine. There's only about 7mm of space between the cam seal & the cam gear flanges. It's so tight that you can't see the index pin holes in back of the cam gear mounting flange. Makes everything a lot harder. The reason there's a lot less space is because the cam seal mounting region of the quattrovalve engines is made significantly differently from the 2V engines. The QV engine has a groove for a large o-ring machined into the head/cam cover surface area where the 2-V cam seal sits. A large aluminum ring with a stepped down neck with a matching o-ring groove is retained by the o-ring. The cam seals are then mounted in this large aluminum ring. The effect is that the seals are mounted in what is the space between the 2V cam seals & cam gear mounting flange. Also, in the seal-cam gear flange gap, the QV cams aren't round. They have a hexagonal cross section with rounded corners. What's even worse is that the sides of the hex aren't flat, they're rounded inward. A simple 2-bar clamp like you show for the 2V engine can't be used with a QV engine. I've been working on designing a tool that will pick up the hexes & lock the cams, but haven't needed to build it. The old thin piece of cardboard (business card, matchbook cover...) under a cam cap is adequate, but a bit risky for an inexperienced person. - The procedure needs to take the person through the process of installing & sealing up the cam covers. This is where most novices get into trouble. Things like properly & carefully trimming the gaskets so they seal the head-cover joint at the seal edges (even-worse in a qV, is sealing around the o-ring at the corresponding joint. I've run out of time, but will post more suggestions when I get a chance. | ||||||||||||||||||||||
| Gianluca Chegai (Gianluca)
New member Username: Gianluca Post Number: 5 Registered: 5-2003 |
Works for me although on the "Cam timing specifications for the 308 " I can not get any pictures. Thank you for the very informative post! Gianluca | ||||||||||||||||||||||
| Ted Gage (Tedmac)
New member Username: Tedmac Post Number: 20 Registered: 2-2003 |
Sorry about that. It works here, but I'm inside the network. I'll try to test with an outside user. Is everybody having this problem? | ||||||||||||||||||||||
| Andrew A. Illes (Andyilles)
Junior Member Username: Andyilles Post Number: 77 Registered: 10-2002 |
Ted, None of your website links seem to work... I get a monkey. | ||||||||||||||||||||||
| Jay Morris (Jm3)
New member Username: Jm3 Post Number: 18 Registered: 10-2002 |
"Thank you" would be an understatement. | ||||||||||||||||||||||
| Ted Gage (Tedmac)
New member Username: Tedmac Post Number: 19 Registered: 2-2003 |
As a follow-up to the previous thread "308 Cam specifications - European", I've finished a draft step-by-step process for setting any cam timing on the 308 2-valve. The process is possibly applicable to the QV. Included are a summary analysis of the cam timing design and factory specs, a derivation of 308 GTB/S cams to European specifications, info on special tools, and a step-by-step methodology for setting any cam timing. Developing the methodology, cylinders 1-4 took about a week, fumbling around for the process. Cylinders 5-8 took 35 minutes. Your constructive comments, suggestions, corrections, et.al. are appreciated. The draft is available at: http:www.tedgage.net There's a lot of pix so it may not be for the bandwidth challenged unless you're really curious. It's fast on DSL. |