| Author | Message | ||
| Rick Reale (Rick)
New member Username: Rick Post Number: 5 Registered: 5-2002 |
Thanks for all the geat information and diagrams. The more I learn about ferrari the more I just love them, nothing compares in style or desighn. | ||
| Vincent (Vincent348)
Junior Member Username: Vincent348 Post Number: 195 Registered: 4-2003 |
This engine also ended up in the mondial t. | ||
| Rick Reale (Rick)
New member Username: Rick Post Number: 4 Registered: 5-2002 |
I was wondering, does anyone know why ferrari discontinued this engine design when they whent to the 355? I have noticed infact this engine was only used on the 348. What about the transmission, I do know the 355 had six speeds but was it basicly the 348 transmission desighn? | ||
| arthur chambers (Art355)
Intermediate Member Username: Art355 Post Number: 1474 Registered: 6-2001 |
Rick: As far as electronics, yes, also suspension, and the clutch went from a double disc to a single disc. The 1989-1990 had a 2.5 Bosch unit fuel injection, and the later ones 2.7. Major difference. The ECU had trouble, and we changed in, I believe 1992 for a more reliable unit, but still somewhat untrustworthy unit. The Syders, and 1994 and later TS and TBs had a different suspension, and that took a lot of the handling problems away. | ||
| Rick Reale (Rick)
New member Username: Rick Post Number: 3 Registered: 5-2002 |
Thanks for all the great information. Did anything mechanical change throgh out the years of the 348 from the TB,TS, and the spyder? | ||
| Jeff B. (Miltonian)
Member Username: Miltonian Post Number: 259 Registered: 12-2002 |
Sorry if this is overkill, but it's a good view of the timing chain and belt setup.  | ||
| Jeff B. (Miltonian)
Member Username: Miltonian Post Number: 256 Registered: 12-2002 |
This diagram gives a good view of the arrangement inside the 348 box, hope it answers your questions.  | ||
| Steve Magnusson (91tr)
Intermediate Member Username: 91tr Post Number: 1732 Registered: 1-2001 |
I think the two shafts at the bottom of the gearbox perpendicular to crankshaft axis are the main and counter shafts (i.e., the gearbox) and then the differential (the third shaft) is directly driven off the counter shaft which is below it. Judging from the illustrations in the '89 US 348 TB OM, the coaxial shaft returning from the clutch pack drives a shaft below it that has a bevel gear on the other end to transfer the power 90 deg to the gearbox main shaft -- wild! | ||
| Rick Reale (Rick)
New member Username: Rick Post Number: 2 Registered: 5-2002 |
Thanks for all the great information. Since seeing a cutaway view of the transmission I have one more question? There are two shafts that sit crosswise at a 90 degree angle from the main and counter shaft and are at the bottom of the transmission. What do they do, It almost looks like power from these two shafts go to a third gear/shaft and out to the half shafts. | ||
| Jeff B. (Miltonian)
Member Username: Miltonian Post Number: 255 Registered: 12-2002 |
Just got home and found out that the picture I posted shows only the oil pump chain, NOT the timing chain - sorry. The timing chain is driven by the same gear, off the nose of the crankshaft. The chain drives the "driven gear" (#1 in diagram) which has a keyed shaft running forward to drive the timing belt "driving gear" (#16 in diagram). So the timing belt is NOT driven directly off the crankshaft gear, to answer Rick's question.  | ||
| John J Stecher (Jjstecher)
Member Username: Jjstecher Post Number: 438 Registered: 1-2002 |
You are right above the oil pump it is chain driven I checked when I got home. I also checked my pictures from the 30k and it appears to me that the timing belts are driven by a sprocket mounted directly to the crank. They then loop up around the tensioners and then to the sprockets on the cams and then back underneath the water pump. | ||
| Rob Schermerhorn (Rexrcr)
Member Username: Rexrcr Post Number: 557 Registered: 11-2002 |
Oil pump is chain driven. That I do know for sure. Now I'm questioning my memory of the timing gears, it's been a while. | ||
| Steve Magnusson (91tr)
Intermediate Member Username: 91tr Post Number: 1725 Registered: 1-2001 |
Here's part of a cross-section drawing in the '89 US 348 TB OM -- shows (double-row) chain drive crank-to-t-belt drive sprocket shaft and (single-row) chain drive crank-to-oil pump shaft:  John S. -- The chains are "internal" so you wouldn't see them during a 30K service. Can you confirm your 348 t-belt is driven by a sprocket mounted directly on the crank snout? | ||
| John J Stecher (Jjstecher)
Member Username: Jjstecher Post Number: 436 Registered: 1-2002 |
When I had my 348 apart for the 30k there were no chains anywhere in the system. The cams and water pump are all belt driven off of the crank snout. The oil pump I am pretty sure is gear driven not chain driven but I dont remember I will look at my pictures later and let you know. But I am sure Rob knows as well. | ||
| Steve Magnusson (91tr)
Intermediate Member Username: 91tr Post Number: 1724 Registered: 1-2001 |
Jeff B. -- The only chain I can see in that illustration is one running down from the crank to the oil pump. Are they just showing the sprockets (and no chain) for clarity on the crank-to-timing belt drive sprocket arrangement? Can you post an enlargement of the area? | ||
| Jeff B. (Miltonian)
Member Username: Miltonian Post Number: 253 Registered: 12-2002 |
This shows the chain and belt arrangement.  | ||
| Steve Magnusson (91tr)
Intermediate Member Username: 91tr Post Number: 1722 Registered: 1-2001 |
Rick R. -- This thread has a jpeg of the "interesting" 348 cambelt layout (timing belt drive sprocket driven off crank snout -- but don't know whether chain or gear drive) at the very bottom: http://www.ferrarichat.com/discus/messages/112/32360.html | ||
| Rob Schermerhorn (Rexrcr)
Member Username: Rexrcr Post Number: 555 Registered: 11-2002 |
Gears. | ||
| Rick Reale (Rick)
New member Username: Rick Post Number: 1 Registered: 5-2002 |
Is there a primary timing chain or gear comming off of the crank shaft to drive the timing belt or is the timing belt driven directly off of the crankshaft? |