| Author | Message | ||
| Gerrit Visser (Gerritv)
Junior Member Username: Gerritv Post Number: 92 Registered: 6-2001 |
Just as another data point, page 148 of the current version of XJS Book describes the problem Jaguars have on their V12's. In common with Ferrari is 2 Marelli distributors and catalytic convertor fires. URL is http://www.jag-lovers.org/modelindex.php3 . The book also shows a nifty circuit for detecting single bank ignition failures. | ||
| magoo (Magoo)
Advanced Member Username: Magoo Post Number: 3113 Registered: 2-2001 |
Exactly. | ||
| Paul Newman (Newman)
Member Username: Newman Post Number: 432 Registered: 12-2001 |
Mitch, I like your theory regarding the distributor/ignition setup but its flawed. The dual distributor setup is not for multiple points to increase dwell/coil saturation, it is for emmissions. The multiple points are used for two different timing setups to reduce hydrocarbons for the northamerican consumer as well as the other countries that require it. You just cant fit 4 breakers inside one distributor. My car has a single distributor with 1 breaker per bank and revs to 8000rpm. Its also performs better than the dual setup and is easier to time. | ||
| Paul Newman (Newman)
Member Username: Newman Post Number: 431 Registered: 12-2001 |
Yeh Magoo, I wont bother anymore. | ||
| magoo (Magoo)
Advanced Member Username: Magoo Post Number: 3111 Registered: 2-2001 |
Paul, I also feel that there is a better way to speak to others when they ask for help here on the F.C.. No use in us trying to spare Mitchells feelings. Seems like he likes it as it is. So let the chips fall where they may. | ||
| Mitch Alsup (Mitch_alsup)
Junior Member Username: Mitch_alsup Post Number: 137 Registered: 4-2002 |
(1) The reasons for dual coils (and points where applicable) is that Ferrari engines rev higher than other cars. Back when cars used coils and breaker points, the only way to get 8 to 12 plugs to fire at 7500 RPMs was dual coils (many times with dual distributors). Older breaker point single distributor American hot rodded V8's had terrible problems getting more than 6000 revs out of the ignition system. Fiat 124's often used dual breaker points and coils for a moderate reving 4-banger. With modern capasitor discharge and optical timing of the ignition, the need for multiple breaker points has past. Not so with coils. Coils take a certain amount of time to saturate the magnetic field, and if you fire a coil faster than its staturation time, the spark becomes weak. The greater the number of cylinders and the greater the number of revs the harder it is for a single coil to do its job. Modern motorcycle engines have gone to a coil per plug (15,000 RPMs) just to get an adequate spark without burning up the coils. (2) The flat plane crankshaft allows the inlet and exhaust pulses to be timed "better" so that harmonic resonances in the inlet and exhaust tracks can be converted into power. This also enhances the "sound" of the Ferrari engine. The cost is addes vibrations in the V8s (just about 4X (peak excursion) and 2X (RMS) the vibrations of the split plane cranks. Flat cranks are also stronger than split plane cransk, and can be ballanced with lesser amounts of counterweighting. | ||
| Paul Newman (Newman)
Member Username: Newman Post Number: 426 Registered: 12-2001 |
I guess all Im trying to say fatbilly is you are WRONG!!! when you explain certian facts to us on this topic. And I didnt misunderstand you, you came across loud and clear. | ||
| David Jones (Dave)
Member Username: Dave Post Number: 302 Registered: 4-2001 |
Billy, I just thought you might like to add these couple of trinkets to your database..... You may think I have no clue as to what I am talking about, But...... Not all Ferrari cars have ECU's, Cats, or dual distributors...  A 308GTB cutaway from 1976  and page 76 from a 308GTB owners manual | ||
| Mitchell Minh Le (Yelcab1)
Member Username: Yelcab1 Post Number: 350 Registered: 11-2001 |
Billybob, As I said once before, your technical contribution is always appreciated on this "Technical Forum." I certainly appreciated your technical help. Lord knows my knowledge of all things Ferrari is very small and I rely on the combined knowledge of this community to work on my car. What others observed to be "judgment" is not always so appreciated. | ||
| magoo (Magoo)
Advanced Member Username: Magoo Post Number: 3110 Registered: 2-2001 |
Billy, I think I speak for a lot of guys here when I say that we all welcome your knowledge and "constuctive comments." It is the way you say it as to berate the guy and you give the impression that you are the final word on the subject. Here on the F.C. we have a number of guys who are very knowledgeable and probably more so than yourself. They offer help but don't put the person down they are trying to help. I guess what I am saying is that if you know the answer to ones problem, be humble and don't try to impress everyone. I'm certain your respect in future comments will be appreciated by everyone here on the F.C.. Regards, | ||
| magoo (Magoo)
Advanced Member Username: Magoo Post Number: 3109 Registered: 2-2001 |
Exactly Paul, If you look back in these post you will see I did the same thing. Then I was corrected. So yes I think Billys approach was somewhat wrong in the way it was said but then, "To each his own." | ||
| billy bob (Fatbillybob)
New member Username: Fatbillybob Post Number: 29 Registered: 8-2002 |
Well All, It seems to be gettin a little hot! First line of my post is " I am not trying to put you down". Facts is facts. I have no problem with Michtell's intellegence it is the method of execution. There is a huge difference. I understand the reason for FC however, would any of you want to buy a Ferrari from someone who used one as an experiment. Sure you need to learn somewhere but this can also be done without creating any mistakes by really taking the time to think things out. Ferrari is does not make great manuals like chevy. Ferrari does not build cars like Nissan. Logic to Ferrari is directly proportional to what parts they have on the shelf today. Anyone who has played with Ferraris for a long time knows this. Therefore, you have reverse engineer what they do using sound mechanical principals. I have no theory on the cats just facts. Other car don't burn up like Feraris. Other cars don't have unsophisticated kluges to shut the ECU's down when cats get hot. All 8's and 12's Ferraris use a dual system. Each iteration of the US 308 to 360 use dual distribution systems in the form of dual distributors or DIS ECU's etc... The reason for temp probes in the cats with exhaust ECU's is to shut down one side when things get hot. If you have significant miss in a single ditribution system such that you run the risk of fire in the cats the car runs so bad that you shut it down or the ECU fails to run the car in all but the limp home mode. Ferrari systems run so strong that if 1 bank is dead the car still runs fine at all but seat of the pants acceleration runs. If fact you pull the plug on one side and I bet your mom would drive the 308 and think everything is just fine. Paul there is nothing "uptight" with me. If you misunderstood my original post that's an "out" for you. "Not watching what Ferrari is doing" referrs to the fact that each 308 and later iteration is a dual distribution system. I'm not going to spoonfeed anyone niceness. I am just trying to get facts out in limited time. Maybe there are a few others who are sensitive about what they are doing and that is hitting close to home as they read something between lines that just isn't there. I give the free information because I hate to see people flounder and destroy these cars especially when I have the answers. I don't have all the answers I'm an enthusiest like you. If you all want me to shut up I'll do that. Every post I make has positive mechanical intent. I have nothing to loose. Afterall no one is paying me right? | ||
| Paul Newman (Newman)
Member Username: Newman Post Number: 420 Registered: 12-2001 |
Magoo and mitchell, if someone directs a comment which can be taken as offensive what would you do? Mitchell defended himself and I made a few comments because I didnt agree with fatbilly. No harm done and we quite offen get off topic on our posts. If I disagree with someone, I usually tell them. I think fatbilly came off wrong when trying to "help" mitchell by insulting his intelligence. He could have found a better way to express himself. | ||
| magoo (Magoo)
Advanced Member Username: Magoo Post Number: 3107 Registered: 2-2001 |
Mitch, I couldn't agree with you more. The price being sometimes you pay. Regards, | ||
| Edward Gault (Irfgt)
Intermediate Member Username: Irfgt Post Number: 1871 Registered: 2-2001 |
I go to my home in Florida every 6 weeks or so, for a week or so, where there is no Computer or broken cars. My new Vette made the round trip of 1600 miles with no problems and with an unbelieveable overall 26 MPG. Not bad for a 350 HP car. | ||
| Paul Newman (Newman)
Member Username: Newman Post Number: 412 Registered: 12-2001 |
A corvette also has a catalyst monitor and a misfire monitor to save the cats. Similar to a ferrari slow down light (alittle more primitive on the ferrari though). | ||
| David Jones (Dave)
Member Username: Dave Post Number: 298 Registered: 4-2001 |
Hey Ed, where have you been hiding out? | ||
| Edward Gault (Irfgt)
Intermediate Member Username: Irfgt Post Number: 1870 Registered: 2-2001 |
A Corvette only has one cup holder. | ||
| David Jones (Dave)
Member Username: Dave Post Number: 290 Registered: 4-2001 |
I'm sorry Billy Bob, But two distributors and two distribution systems are Not used on ALL Ferraris..... | ||
| Paul Newman (Newman)
Member Username: Newman Post Number: 407 Registered: 12-2001 |
You appear to be uptight fatbilly and I think you should learn to relax when dispensing your infinate wisdom about ferraris. Are you certian the slow down lights are there only because of the 2-4 cylinder thing? A simple misfire of 1 cylinder will damage the cats when you dump pails of fuel down the cylinder like in a ferrari. perhaps you should rethink your theory. | ||
| Mitchell Minh Le (Yelcab1)
Member Username: Yelcab1 Post Number: 347 Registered: 11-2001 |
Magoo, The first amendment to the Constitution, freedom of speech, has its price. | ||
| magoo (Magoo)
Advanced Member Username: Magoo Post Number: 3104 Registered: 2-2001 |
Well Mitch, Is this what the F.C. is all about???? | ||
| billy bob (Fatbillybob)
New member Username: Fatbillybob Post Number: 27 Registered: 8-2002 |
Paul, You either misunderstood my post or do not follow what Ferrari does. The problem and dumb desing has nothing to do with a 180 flat crank. The stupidity is using two distributors and two distribution systems. This style of system is used on ALL Ferraris. This is the reason for 1-4 slowdown lights and exhaust ECUs and dual O2 sensors. There is no other make of car that does this. This is no reason for this. Even in the 70's when Ferrari did this on carb 308's there was the crane system that worked better than OEM but did not last as long due to the non-OEM heavy dutiness. Today with modern motronics can handle everything and there is no need for 2 motornics which is what Feeraris run. Think about doubling the weight and wires and complexity with no gain in HP Torque etc... Remember the reason for going to the 355 body was to get ride of pininfarina's lack of function with the 348 side strakes and go to function like no slates and aero under tray. This is what Ferrari should be doing. If you want a Vette with cupholders you buy Vette's. If you want a racecar with a radio you buy Ferraris. If you really love your car you would take all the crap off and race it! | ||
| Paul Newman (Newman)
Member Username: Newman Post Number: 404 Registered: 12-2001 |
Billybob, I would like to comment on your crank response. The flat or 180 design is fantastic and makes the car rev as well as sound the way it does. I dont think its a stupid design. I also dont know if the firing order could be better arranged when using this crank setup. Perhaps its a comprimise but you get a crank that is naturally balanced by the opposing pistons. The engine is smoother and the two 4 cylinder thing is a US afterthought with the twin distributors. I set my single distributor setup like any other engine regardless of the number of cylinders. | ||
| billy bob (Fatbillybob)
New member Username: Fatbillybob Post Number: 26 Registered: 8-2002 |
Mitchell, I'm not trying to put you down. Perhaps 150 is close enough to 200 but your original post was "...the spec was north of 100 lbs-ft. The nut just kept on turning and turning and did not stop, even less than half of the specified torque. I stopped and just bent the tabs down.". So I'll stand by my response. With Ferraris you need to use common sence and reverse engineer what they do while remembering basic engineering of what others do as a referrence point. You can look at fastener size and load function to determine if a torque spec is justified. Also you have to realize things like a dirty oily fastener will have lower torque than a dry one. Metal type and thread cut will ad to the determination. There is a whole science here. Even the transfer gears are bevel cut and there is load along the shafts. There are large torques going through gears thus I have not seen a spec in a ferrari motor that is not justified. As to your funny point about the oil. Ferrari's are like idiot savtes. Their actual motor is amazing and the rest of the execution is crap. Who would time a motor as 2 4cylinder motors on one crank? They still do this today necessitating the need for exhaust ECU's 1-4 slow down lights etc. as a kluge to fix a stupid problem. It is stupid and non-functional and adds weight. So I agree with you and I disagree at the same time. Unless you really feel you understand these cars, which your posts do not seem to reflect, it would be wise to keep to factory specs. I once remember a Ferrari mechanic who had a TR3. He sealed the car so it would not leak. He kept wearing out suspension bushings. The english car mechanic said he needed the oil leaks to lube the suspension. Sometimes there is a reason for everything. | ||
| Mitchell Minh Le (Yelcab1)
Member Username: Yelcab1 Post Number: 342 Registered: 11-2001 |
Well Billybob On my car, 75GT4, the bearing is a one piece straight bearing on the tranny input shaft. The load direction is radially side to side, and not axially front to back. The retainer ring and the ring nuts have the job of positioning the bearing within the race. That job is not deserving of the 200 NM torque spec that the ferrari factory engineerss determined it to be. So, I stopped at 150 NM and call that good enough. The ring nut is not backing out with tabs in place and the bearing is not going anywhere. In this case, I determined that the the engineers were not always right; and if everything the factory engineers did was so right then ... why the hell can't they figure out how to keep the engine oil inside the motor, and not on the garage floor? | ||
| billy bob (Fatbillybob)
New member Username: Fatbillybob Post Number: 23 Registered: 8-2002 |
I have no clue what you did here but...I would not do this: "So, I would take it easy on the ring-nut torque and use a new snap ring, and maybe a new ring nut too. If it keeps on turning and does not want to stop, something is wrong." You see if the spec is 100+ and you get only 50 you have to determine what is wrong. I have not done this repair in a while but it sounds like the ring that fits the groove was not installed right. This causes the gear to run toward the gearbox. The ringnuts should not be reused. If you have to reuse them make sure to swap it from another area so that you stake the ringnut in a different place. Also a nice tip is to spend lots of time taking things apart and take notes. Then the assembly will be less problematic. | ||
| Mitchell Minh Le (Yelcab1)
Member Username: Yelcab1 Post Number: 341 Registered: 11-2001 |
One word of caution. On my car, when I went to torque the big ring nut at the end of the tranny input shaft, the spec was north of 100 lbs-ft. The nut just kept on turning and turning and did not stop, even less than half of the specified torque. I stopped and just bent the tabs down. I had to remove the bell housing againg this week, and found that the cut-out ring (the furthest in on the input shaft) was giving and being pushed almost off the groove it is supposed to sit in. This would be a disaster if it slides all the way off. So, I would take it easy on the ring-nut torque and use a new snap ring, and maybe a new ring nut too. If it keeps on turning and does not want to stop, something is wrong. | ||
| Tom Treue (Treue)
New member Username: Treue Post Number: 26 Registered: 4-2002 |
www.baumtools.com might be helpful. | ||
| Verell Boaen (Verell)
Member Username: Verell Post Number: 286 Registered: 5-2001 |
It's still there, It's the hot link in Gene's post. It's got one too many dubyas. (No White House jokes plz). Try: http://www.expensivecar.com/clutch.htm | ||
| Donny Bridges (Wildcatfans)
Junior Member Username: Wildcatfans Post Number: 80 Registered: 9-2001 |
I saved that procedure as a Word document before the site vanished. If you want it let me know and I'll email it to you. | ||
| david handa (Davehanda)
Junior Member Username: Davehanda Post Number: 172 Registered: 5-2001 |
Not any more.... :-) | ||
| Gene Agatep (Gagatep)
New member Username: Gagatep Post Number: 3 Registered: 8-2002 |
there's a good instruction with pictures and tool requirements on 308 clutch replacement at http://wwww.expensivecar.com/clutch.htm | ||
| Paul Newman (Newman)
Member Username: Newman Post Number: 333 Registered: 12-2001 |
The lower gear just slides off after the ring nut is removed. I replaced my rear main without a special tool. You just have to be carefull when reinstalling it. They arent very tight. A socket similar in size to the pilot will work as an installer and a slide hammer will work nicely to remove the old one. You need 3 new o rings for the transfer ports in the bellhousing that carry gear oil to and from the drop down gears. A snap ring plier will also be needed to remove a support bearing on the gearbox input shaft. It also just slides off. | ||
| Sal Ant (Ny308gtb)
New member Username: Ny308gtb Post Number: 1 Registered: 8-2002 |
I am about to change the clutch on my '77 308 US Version. Can anyone direct me to a gear puller on the web that will work for the lower gear. I am also looking for a slide hammer pilot bearing puller? Are there tools for replacing the rear main seal and pilot bearing? I know about the ring nut, and slide bearings, is there anything else that is really hard to remove, put back. Thanks Sal |