Friends, As most of you know I started a major about 1.5 years ago. I was also going to replace my long hoses, paint a bunch of stuff, belts water pump, etc etc. I had a cam lobe that was slightly damaged, the consensus was maybe debris plus maybe some lack of zinc. A good friend and expert on this list had the cam redone and It was suggested by many that I degree my cams. After 16 years of doing all my work myself I though this was something I could handle. I am moving part of the thread from FBB's degreeing thread in Tech as I dont want to extend that thread with my difficulties. I was a little embarrassed to post this to Fchat at first but thought I would just post it so that others can learn from my experiences, and hopefully some of the experts will help me and boy if I ever needed advice it is now. Here goes: I found TDC with a Hill tool and double checked the position with a piston stop, which both matched my flywheel perfectly. At TDC I was checking my #1 intake valve on the rear bank, as part of my degreeing procedure. It was only a few degrees off the WSM but thought hey, I am going to try to make this perfect. I started moving the pulley around. I made a cut piece of belt so that I could have a baseline on where the teeth needed to be to match the other pulley on the rear exhaust cam, which was perfectly aligned to the cap. I tried to use Steve M. hole chart but was not sure how to use it properly as I am a bit mathematically challenged. Anyway, I seemed I had a plan. I would move the rear intake cam to a new position near the cam cap mark but in relation to get it closer to the figures I needed for my degree wheel measurement of 34° BTDC, then tried to find hole that would match up on the pulley with my exhaust cam teeth. I would then change the pin and re-measure, double checking all the marks, the pulley and then release the tension on the belt. I would then double check all the marks at TDC before rotating the engine twice to TDC and tightening the tensioner pulley then rotate the engine to check the degree wheel for the proper intake opening. It seemed as I was getting farther way from my target goal so I started working back the other way. After several tries I made a new hole combination which placed the rear intake cam shaft mark very close the cap mark, and my rear exhaust marks were spot on. I put the belt on, re-checked the location of the cam marks in relation to the caps at TDC and I started to turn the engine and the engine seemed to stop around (if I remember correctly) 45° BBDC. I cant be sure of this as my wheel has a 45 mark in four places. It was getting late and I kind of freaked out thinking I may have hit a valve with a piston and backed the engine up a few degrees. I had the plugs out and it looked like cylinder 2 &3 were nearing the top of their range. anyway I was so worried that I took the belt off & both front cams out. I then turned the engine around a couple of times to rotate it back to TDC and noticed that it seemed to stop or hesitate about in the same place?? I am thinking maybe I never hit anything. By this time I am very frustrated so I went to bed. Sunday I put my intake cam pulley on where it was originally and put the cams back in, checked all marks at TDC, belt on, rotated twice, set tensioner and rotated the engine around a few times. Every once and a while I feel it sort of stops or hesitates. I think maybe this is a normal cam event or something in that spot, so I am not sure now if I even hit anything or whether I was just confused and feeling the normal movement of the engine and its related parts. I am turning it with a long torque wrench, from below and depending on where the ratchet is and where I give it a turn seems to feel this hesitation in several spots along the revolution each rotation. But when I give it a crank it seems to pass over that spot and keep rotating. I am thinking this is just the normal feel of the engine turning with cams impacting the buckets. Of course with all the cams out, the engine turned smoothly. Many of you know more about these engines than I do. I was first wondering how far off the marks you would have to be to hit a valve, remember all my marks were within 1/16 of an inch before I started the rotation in question. And if I did hit one, would that bend the valve? I was not turning the engine very hard or fast and as soon as it seemed to stop I backed it up. So I either hit that bump in the rotation which is fine or somehow I did have a small impact. I have ordered a leak down tester to check the two valve in question which are in Cylinder #2 & 3. I think after 16 years of doing some quite amazing work on my engine and car I have reached my limitations and hope that with all of your help I can just get my car back together and running... I am going out to check my valve clearances now. This may not be of much info on this event as I checked, measured and replaced all my shims with new ones knowing I might have to adjust the clearances on a few once the cams were back in the engines. Both suspect valves had slight enlarged gaps of about .001". This is also misleading as I think only one intake valve may have been close to open at the moment in question. Thanks for all your help, I look forward to seeing all your comments and suggestions especially from the experts... Sincerely Rob
Rob, As usual, you make very astute observations. Nicely done and nicely worded treatise. Yes, the start/stop or high/low effort you are feeling (even with plugs out) is normal as you rotate a fully assembled engine. And yes, you are feeling cams coming up on the lobes (and a bit of piston ring friction stop/start). Surprisingly, I've found these engines will run with a belt a tooth or two off and not do any damage (granted, they don't run well). Valves are actually very durable elements. They take a significant pounding in normal use. You would have to have the motor way out of mechanical timing to induce contact and you would have to put a huge amount of effort into your crank mechanism to damage a valve. Even with your massively developed drummer's arms.... Speaking of which, you all healed up now? Rick
I got an OTC leak down tool today, looks like it will do the job. Does anyone have any tips on using this plus I know #1 is at TDC at PM1-4. Since I have my degree wheel still on and set to TDC is there anyone that knows the degrees or close where i would find the other TDCers?
Rob, every 90 degrees, one of the cylinders comes up to TDC. The firing order is found in your WSM. Start with cyl 1, then 5, then etc...
Thanks Rick and Mitchell, I am very worried. Has anyone had any experience doing the leak down, procedure. Any tips would be helpful. I also checked all my valves and a few intake are ending up at .254mm but the next shim takes it down to near the minimum. I am thinking more clearance is better than too little, any thoughts?
More clearance is better then to little. I usually set the exhaust valves on the high side and try to set the intakes in the middle. My experience is the exhaust valves have a tendency to pound in more then the intakes . I learned the hard way with my V12 XJS and had to do a valve job on one head.
Assuming your valve covers are still off... with #1 at TDC, note the orientation of the cam lobes. As you rotate the crank 90º look for the next set of lobes in the same orientation. This will be your next cylinder to test. Also, if you have a cylinder reading low, listen for where you hear any excessive noise, this will give you a clue as to whether you have a problem with either valve or the ring pack. Listening for a valve issue is a no-brainer... if you hear air escaping the carbs, it's intake. If you hear it at the muffler, its exhaust. Ring pack is a bit harder to detect. In the past I've pulled the hose that goes from the intermediate plate at on the back of the motor up to the rear head and stuff a longer hose into it so you can listen to the crankcase. A buddy recently recommended just pulling the dipstick to listen to the motor... sounded like a good idea but after thinking about it, he either had no oil in the motor or the tube that goes down into the motor at the dipstick nut was missing when he did his... not sure. For most systems, a little loose is better than a little tight, especially since you are doing them cold. As things heat up they swell a bit and your clearances will reduce. Rick
If you have the camcovers off why not consider just taking the cams out? In that state the engine is totally "safe" & you can rotate it and reset things as you wish - and do your leakdown test with impunity. I would imagine that for the purposes of the LD test a small stick in the plug hole resting on the top of the piston would tell you more or less where TDC for that piston is before you screw the leakdown test thing into the plug port & blow air in it. If you havn't done it before, taking the cams out is not hard - just go slowly & loosen all the journals gradually & evenly. Before you take any of the nuts & washers off then block the 4 main recess holes (and the plug ports) with tape or rags etc so that if you do drop a nut or washer it can't go anywhere bad. Have a magnetic tool handy. The journals must go back exactly where they came from - but they are all numbered (at least they are on my 328). When you put the cams back in then again tighten them down slowly & evenly. One or two may want to jump around but just get the cam locks on them before you start tightening them down seriously & it will be OK. If you wind the engine back to around 15 deg BTDC on #1 you will find that no pistons are anywhere near the head anyway. Then when the cams are in you can slowly wind the crank back to TDC - PM¦1-4
Ian, Brian C highly recommended this but I have had my cams out 3 times now and am worried that I will end up having a stripped cam cap stud. This whole episode has been very trying for me and my decision to degree the cams is one I am regretting. My cams are back in and the pulleys and camshafts are aligned exactly as they left the factory. I have never seen rode in or heard a 308 that had a stronger engine with no faults such as fouling plugs, stalling, trouble starting etc. I am not sure anything I could have done to it would have made it run any better than it did and only hope I did no damage and can reassemble it as was and start driving again. Cam covers are off, and since i have a degree wheel on still all perfectly aligned I will shoot for the 90° marks. Thanks for all your guys help and suggestions. I was told i need to put a bar on the crank to keep the engine from moving and use 80lbs, does that sound right? I am still worried that the pressure may cause some problem I dodnt kno about but assume the combustion process creates quite a bit more than 80lbs..... Rob
Rob, from what I've read I'm hopeful that you are going to find that you don't have a problem at all & I appreciate what you say about not taking the cams out again. If you are worried that the engine may not be timed correctly then I'd just put 8 sticks down the plug holes & turn it over very slowly watching the sticks come up & looking at the cams at the same time. I would say you probably do need to block the crank to do your test succesfully but that should be easy enough - and 80lbs isn't going to cause any problems I think - combustion pressures are much higher than that. If in doubt Google! Good luck & keep us posted
Yes, find some way to block the crank. If the wheels are on the ground you can even put it in gear (3rd of 4th) and set the brake or chock it. Otherwise a large ratchet on the crank braced against the rear motor mount works too. I like to use 100lbs only because it makes the leakdown percentages much easier to calculate (no brainer) on the fly. But even 100lbs is significantly less than combustion pressures. Hell, it should be less than your compression test without combustion. Rick
Just one more tip Rob. Connect up your leakdown tester to a 100lbs air line, turn the guage to full 100lbs, and read what the leakdown is without connecting it to the engine. You will find that it already has 1 or 2% leak down. Use that as a base line and subtract that value off the ones you will get when you connect to the engine. My test guage has a 2% leakdown when connected to nothing. So when I get a reading of 6%, it really means 4%.
Thanks for all the help guys. I still am confused after you put the pressure in the cylinder I assume it will keep leaking do you measure it right off or wait a specific time. Also I have hear you should rock the engine a bit to get the best piston ring seal. Does either one of these make sense. Also I was told 80 psi was the normal leak down pressure your thought? What figures have any of you come up with on a normal engine mine has about 50K on the clock. Rob
You connect the guage to the engine. Turn the air pressure up to 100 psi on the first guage. I use 100 psi as do many people. The second guage will read something less than 100 psi. Say 95 psi. Your leak down is 5% (assuming the guage does not leak any by itsefl). The result is immediate. You do want to rock the cranshaft back and forth a little bit and find the best reading, a few degrees will do.
Rob, I wouldn't worry too much what the exact %age on the LD says. It will be screamingly obvious if you have a bent valve type problem because you will hear the air coming out the exhaust or back up the intake (and the LD reading will be obviously high) +/- a few percentage points is going to be a product of engine wear, not damage I think. rgds Iain
I've stopped doing this... but I understand the reasoning and its completely valid. Just be careful and use a long breaker bar (not ratchet). With 100lbs of pressure on the piston if you get too far off TDC the bar will jump out of your hand if you are not hanging on tight. I know this is an issue for you Rob, but if you are going to try rocking the crank I'd really suggest you make this a two man job. One on the gauges and one holding the crank. Not just for your safety but for the safety of parts within the arc of whatever wrench you have on the crank. Rick
Dear friends, Not sure what this means but here are my readings today. I set my tank pressure at 95 psi and set the leak down tool left pressure gauge to 80psi. Below are the results of the right gauge: #1 79 #2 79 #3 69 #4 79 #5 77 #6 77 #7 79.5 #8 75 I was worried about #3 cylinder, so I squirted a few drops of oil into the cylinder and got consistently lower numbers first 59psi them after putting some grease on the threads I got 61. Note: I used my stethoscope to listen to where the air was coming from and used cylinder #2 for comparison. Mainly because it was next to #3 and also as it had a very high number. I rotated the engine around on both cylinders with the leak down tester attached and noticed the most hissing coming from the breather hole on the intermediate part between the block and bell housing (the one with the "s" shaped hose). At first I thought #3 was bad rings but then listened to #2 and it sounded the same even though it had a high value? I also listened to the intakes as my carbs are off and you can even see the intake valves. At 80 psi I listened to a full rotation of the engine and both intakes sounded exactly the same. It would be silent, then as the valve open the sound would get louder then softer then stop. I could hear no air escaping from #3 intake. I also listened to the exhaust and could only hear air escaping when I rotated the engine and the exhaust valves opened. I am a loss to understand what this means. The other cylinders are so high the #3 stands out like a sore thumb. I cannot imagine why oil would make the value go lower. Also I could not hear air escaping from either #2 or #3 intakes, these are the valves I was concerned I damaged in my event mentioned above. I am looking for some expert advice here. The plug and carb throat looked fine on this hole. I also did this cold, all the instruction I read said do it with the engine warm. Also my engine has been sitting for 20 months now....... I am at a loss on what to do next. Thanks for any and all advice, the good news is I am getting a good feeling about where all the valve and pistons are in the cycle and what they are doing....... The bad news???? Rob Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Rob, if you'd bent a valve I think you'd get very little of a reading at all so looking at those numbers I just don't think you have hurt anything. As you say the engine hasn't been run for a while. You may well have slight leakage round the valves - if so it needs an "italian tune up" i.e. running down the freeway at 80mph in 3rd gear for a few miles to get the valves nice & hot & clean them! (Maybe apply some caution to this if your car is a 2V because you have sodium filled valves!) With regard to subsequent tests producing worse results - each subsequent test would blow the oil away from the rings & so even with adding a bit (which you could probably only do by dropping some on the piston crown ) you were breaking up the oil film round the rings. It may well be that if you went back & did the test again after giving the oil some time to find its way down to the rings the result would be much better. My interpretation of the reults overall is that #3 is maybe a little slack round the rings but not a disaster & I wouldn't put too much store by the results given that you did it cold & then engine hasn't been run for so long. What I think they do show is that your valves are fine & so I would say button it up & run it. Maybe then run the test on #3 again when its warm & see what you get. I bet it will be better.
Totally normal results for a 2v motor. You're ok. What has a compression test yielded? 150-160lbs ish?
Dear Friends, Here are my values for my valves clearances. I am not sure what I can do with the values so close. I think I can maybe switch the #5 exhaust to a 3.35 shim to increase the clearances to .355. I do not want it to be so close to the minimum. I used all new shims on the advice of a FNA mechanic friend. I am hoping that my loose cylinder is a stuck ring. That plug looks great and I could not hear any air escaping from the intake or exhaust although, the exhaust was a bit harder to hear. If anyone has any suggestions let me know. Thanks for all the positive comments. If anyone wants a high res copy of the chart I made (from a Steve M. original design), email me and I will send a pdf Rob Image Unavailable, Please Login
ferraripilot I wont be able to do a compression test until my engine etc is reassembled, but i will do that as soon as I can. Rob
My dear friends, The belts are on and the cam marks line up with the cam journals exactly where they did when I took them off at the start of my service and where they were ten years ago.... I am still very concerned, however over the numbers on #3. However my hope is still for successful conclusion. I even put fresh, fresh belts on since I was using a new set to attempt to degree the cams and the WSM says if you ever take a belt off for service replace it. I got some fresh new ones from Brian, at least this set is made in Italy! I set the belts per the WSM, then rotated the engine ten full revs (20 times) to TDC and all cams are still lined up exactly. The only thing I have not done before is set my carbs from baseline. Still grappling with what to use on the valve cover gaskets this time and what oil to use, although I am leaning towards the redline 10/40 or 15/50. I thank everyone who is still posting. I think some of my friends I have really depended on for advice in the past have stopped responding, which has hurt my feelings. But I want all of you to know that my heart is in this car and I have tried with all of my being to do what is right by it. I believe that these cars have a soul, they are not just a random selection of nut and bolts. The men that created these fantastic machines were descendants from artisans that created the greatest works of art man has ever known. I have always treated this car and the way I serviced it care and respect befitting this heritage. Though I do not posses the experience or knowledge that many on this list have, I have tried my best to seek out their counsel, knowledge and advice with humility and sincerity. Sometimes getting opposing views is disconcerting, but I have treated all that have given me advice with the utmost respect and admiration and will continue to do so while trying to digest the information received. Any that know or have met me knows my Love for everything Ferrari runs very deep, and is at the very center of my being. I was born on the same day Dino Ferrari died in 1956 and my first memories are my love for everything Italian and especially Ferrari... I have created a shrine at my house to the man and the machine which is a tribute to Enzo Ferrari whom I consider a hero. Please bear with me as this has been a very difficult time.... Sincerely, Rob Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Rob, I'm so sorry for yor woes. I wish I could help you buddy but I'm just a lonely pizza guy. So all i can offer is support. Hang in there. Someone, please help my West Coast pal out! He's a good guy with a good heart.
