You're thinking of "L.S.A." or "lobe seperation angle" Actually you are describing the cam "advance/retard" itself and is probably better defined as piston TDC vs the exact center between exhaust closing and intake opening. My two heroes of cam timing are Smokey Yunick and David Vizard. JM
Any time you want to try to put me straight we can step out back. Until then keep your pie hole shut. Any mechanic doing a belt change on a 355 without removing the engine is what is known in the trade as a Butcher, or in the USA a cowboy. It is not the correct way to do it, but if you and your boys down the gym want to have a crack at it then off you go. As for what I base my statement on about covers is personal experiance, i.e been there, done that, and seen the "T" shirt.
LOL!! Keep my pie hole shut ey Step out back Down the gym ey If only you knew LOL!!....Anyways I forgive you dude becourse you no not what you do Any ways so in a nut shell you base the so called bent covers on.......nowt ..as we say in the UK LOL!!!
Yes got it. Lobe center = angle between centerline of intake lobe and between exhaust lobe. lobe centerline = angle between lobe center and crank TDC which is what is tweeked to advance/retard cam timing. err.. no. Lobe centre is the point of max openng of the valve, measured as crank degrees referred to TDC/BDC depending on terminology. On a symmetrical cam profile (which almost all road cars are), the max open point is halfway between opening and closing. clarifications Yes got it. Lobe center = angle between centerline of intake lobe and between exhaust lobe. You're thinking of "L.S.A." or "lobe seperation angle" lobe centerline = angle between lobe center and crank TDC which is what is tweeked to advance/retard cam timing. Actually you are describing the cam "advance/retard" itself and is probably better defined as piston TDC vs the exact center between exhaust closing and intake opening. My two heroes of cam timing are Smokey Yunick and David Vizard. Err...I think we are really all talking about the same thing....I found the referrence I was correct as I remembered it.... "Racing Engine Preparation" by Wilson. I like Vizard and Smokey too.
I guess 20 years with Ferraris in nowt. Especially as I was trained in the UK by Ferrari, would give me a little insite into the goings on, still have all my Family there, but those of us with a little bit of smarts above the bi-ceps got out. That as we say is that. Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
You realy do have a problem dont ya dude. And whats with the bi-ceps comments. Are you basing your comments about me on a bloody picture?? Being that you know the UK so well then you will know of the Royal Marines comandos then wont ya, i was in 40 comando for 9 years with two tours of Irland under my belt so YOUR family an live safe in our country,and thats were i got my bloody bi-ceps from. Also i have been in the close protection industry in which its alot more than just being a large lump stood on some doors for a couple o years. Look up the subject and you will see num nuts.I have been in this field for the best part of 15 years bud doing K.N.R work for the banks/Insurance companys. And thats only a part of my story. So you see num nuts its alot more than just being all bi-ceps. So my sad little friend, before you launch an attack on me about my by-ceps do ya home work ey And when you were attacking me by saying that you would "take be around the back", i did not respond to you in an angry way becourse you were just being a loud mouth. Anyways what the hell would YOU do to me ****....change me oil on me ferrari. LOL!!! clown. Post a picture up of ya self so we can have a laugh at the sado who wants to take me around the back Hey and remember you were attacking me first nob. And i ask again what do you base your bent cover comments on??? Also what did i ever say to piss ya of in such a manner that ya start attacking some one becourse of the way they look?? You sad little man. MB: Hey this thread has gone stupid i know and i am very sorry.But just read what the guy was saying to me in an unprovoked attack, threatning me Not good and i wont stand for it. Hope he comes home to the UK soon for a holiday
Chaa, Listen mate, I only "attacked" you because of your response to my orignial post, I felt you attacked my integrity as a professional. I had no idea you served queen and country and am thankfull for your service, but i would never attack your experiance and knowlage in your field and would only ask the same respect in return. Again I base my knowlage of the bent/missing shields on a car I saw when last in the UK, (about 4 months ago), and reports I get from people I still have contact with in the indusrty over there. All I was getting at is there is more than one way to skin a cat, and to see if anyone would comment on timing a cam with the engine still in. Anyway enough of the personal BS and lets stick to what we are good at. PM sent.
Having read your exchange with chaa, I fail too see anything even resembling an attack against you. Therefore your comments were both rude and ignorant. I think whatever "integrity" and respectability you had has just been flushed down the toilet. But then ...you hide under the mask of anonymity so maybe that does'nt bother you. Rather than PM'ing him, perhaps you should make a public apology.... as public as your attack was. As for Chaa's comment that appeared to create such umbrage.... Now I'm not a Marine or a Ferrari Technician and I also don't have very large biceps so feel free to "attack" me. I do however have some knowledge of the UK Ferarri scene and I can tell you now that some Main Dealers and well respected specialists can and will do an engine in cambelt change without causing damage. I'm not saying if it's a good or bad procedure, but that it is done and can be done. I'm also not disputing that you've seen butchered cars, but then that's just down to the person who does the work. a bad mechanic will butcher anything. Apologies to all for this slight hijack, but I just got a little annoyed with this chaps attitude.
I beleive my last post was an apology for a miss understanding and have cleared up as much with chaa, and my original post was actually an enquiry into how the belt change is done with the engine in as much as anything else. I know it can be done, have seen the results(good and bad) but have just never wanted to attempt it. I guess I'm just to cautious in that area, but i would love to see someone do it or like i said post a work procedure. Its also funny to me that 2 english guys cannot "feel" sarcasim when its posted, because thats all it was. Looking at Chaa's profile I dont have any doubts about his ability to turn me inside out at will. TTFN
Bump the thread, I need some help please. I´m currently degreeing my cams on the F355. I´m using the lobe centerline method because I find i the easiest, at least to begin with. Ok, so according to the math and enginefixer´s notes: Intake max opening = 103* ATDC Exhaust max opening= 110* ABDC OK, the intake is perfect. Now, I have some doubts with the exhaust. It may be the dumbest doubt ever but here it goes... Ok, so I turn the crank CW and reach BDC. Keep turning until max lift. Now, what are the degrees I should be reading? the big numbers or the little ones? it reads 110* on the big ones dead on. But I´m thinking: If its 110* AFTER BDC shouldn´t I read the little numbers that start at 0 from BDC??? Or is it exhaust max opening =110* BTDC istead of ABDC???
Can't agree with that exhaust math. The 355 cam timing Fig 47 in post #89 says max exhaust open occurs at 70 deg ABDC (or 110 deg BTDC), not 110 deg ABDC - you are A-OK.
I was reading while setting up my cams and can anyone tell me what this diagram means. I have been ready too much and I think I on overload. Ha ha Image Unavailable, Please Login Thanks
I think you are misreading that Mitchell (and it is a super-confusing graphical representation). The cam timing specs are given in much clearer form on page B14 in Tab. 9. The difficulty is that the 355 has self-adjusting hydraulic lifters that are always in contact with the cam lobe, so rather than trying to detect when an opening or a closing event occurs (which is super-vague because the slope is zero), their method is to measure the bucket deflection of both the intake and exhaust when at the TDC (overlap) position -- i.e., Set the dial indicator to "0" when the intake bucket is on the base circle of the intake cam lobe and the dial indicator is touching one of the outer intake buckets (not the center intake bucket), then rotate the crankshaft in the direction of normal operation until the intake bucket starts to move downward, keep rotating until you reach TDC -- if things are perfect, the deflection of the intake bucket will be 2.41 mm and this corresponds to the intake valve opening at 16 deg BTDC. If the deflection of the intake bucket is something else when at this TDC position, Tab. 9/A on page B15 will give you an estimate of where you are for that deflection. Likewise for the exhaust, the dial indicator is set to "0" when the exhaust bucket is on the base circle of the exhaust cam lobe and the dial indicator is touching one of the exhaust buckets, then rotate the crankshaft in the direction of normal operation until the exhaust bucket starts to move, keep rotating until the exhaust bucket goes thru its maximum deflection, keep rotating until you reach TDC -- if things are perfect, the deflection of the exhaust bucket will still be 2.29 mm and this corresponds to the exhaust valve closing at 16 deg ATDC. If the deflection of the exhaust bucket is something else when at this TDC position, Tab. 9/A on page B15 will give you an estimate of where you are for that deflection.
I never did like those circle diagrams. I always have to linearize it to make sense for myself. Image Unavailable, Please Login
This is a great thread. Perhaps a mod could clean up the "off-topic" posts and leave the factual content?
Appreciate the effort, but how about keeping it consistent with the "wheel" and correct. Image Unavailable, Please Login