I'm doing the detailed design for a tool for locking the cam gears from rotating while changing the belts. I made a couple of prototypes together out of nylon & pieces of innertube for the 2nd round of JWise's timing cover. Even tho pretty crude & not quite a good fit, they worked like a charm. We were able to get the belts on/off very quickly by using them, marking the cam gears & belts, transferring marks between the old & new belts, & aligning the new belt marks with the marks on the cam gears. However, I stupidly forgot to measure the center-center spacing of the cams while we had things apart. Does anyone have the exact center-center spacing for the 2V & 4V cams? (I think they're the same, but need confirmation). Once I have this dimension I'll machine a set of masters & make molds. Initial production parts s/b available in Jan or Feb '05. Don't have price figured out. Which would you buy: a) A Single tool to do 1 bank at a time? b) A Pair of tools to do both banks at once & speed things up. (~2x the price of a single tool). How much would you be willing to pay?
If you can belive it..Ferrari says to use visegrips on the 360 to keep the cam pullies from moving. It even shows a picture in the manuel. As far as the plastic pullies on the 2 valve cars..the cams don't really move during a belt change. The 4 valve cars the front bank exahust cam likes to spring back, and also sometimes the intake aswell. But seeing as these are metal gears..using a pair of visegrips is fisable..just aslong as you don't go too tight..just light pressure is all you need to hold the cams in place. I have never used visegrips to hold any cams on any cars. I do the job with valve adjustment and replacing the cam seals...so the cam covers always come off so I have know need to lock the pullies with anything. This is the only correct way to do the job. Becuase you don't know if the last guy missed on the marks..and your only putting it back the same way agian..if not a little bit further out of time.
I think that is a great idea. Do you think it could be rugged enough to lock the cams to prevent rotation while torquing the cam pulley bolt? Unlike the newer 308's, the cams on the older cars (like mine) don't have a hex nut type surface behind the pulley that you can use to hold the camshaft while you torque the bolt. Short of using a pipe wrench in the camshaft, I don't know how to prevent the cam from jumping a tooth while torquing this bolt. Stacy
I have never replaced cam belts on a Ferrari before but I have reasearched it extensive enough to know the factory cam markings on the gears are only there for reference and a great way to leave the cam timing in error. I am with tbakowsky in doing it right and making sure you use degree wheel to set the timing than eyeballing the factory markings. Bad things can happen to the engine with cam timing off by only a few dgrees (2 or 3).
While I agree that the cam covers should be off when changing belts, I still think that a cam locking tool would be a useful item. When I change the belts on my car I use the cardboard under the cam cap trick to keep the cam from rotating when the belt is off. A tool like verrell is describing would make locking the cams easier.
I need the cam spacing dimensions if someone has them. Otherwise I'm going to have to spend half a day pulling a cam belt cover & measuring the spacing on my car. Also, I need to know whether people are more likely to want to buy 1 tool or a pair & what a reasonable price is. (BTW, SnapOn & Baum are getting around $300-$500 for a pair of cam locking tools. I believe I can come in well below this.) For several years I've been using 2 3" binder clips/cam gear, and 2 1" binder clips on the belt drive gear to keep an old belt on while breaking the cam gear bolts loose w/an impact wrench & later torqueing them down. Usually in conjunction with a business card under a par of caps/cam. I'd like for the tool to be able to let you do this, especially with metal cam gears. I tested the prototype tool on JWise's car. It did keep the gears from moving while I torqued the cam gear bolts down. I still had the old belt & binder clips in place for insurance, but there was a slight amount of slack in the belt so I could tell if the tool held. It did!! However, I've not made the final material selection for the tool. One of the materials most likely won't provide that much clamping force, it's a little too hard, but it's very easy to work with. Another material should provide sufficient flex to grip the teeth under reasonable pressure, but it is much harder to mold. At the risk of letting the thread be hijacked, I feel I must clear up some confusion about cam alignment. I agree that a degree wheel & dial indicator is a good way to precisely adjust the cams. However, once you've got the cams precisely lined up, it's darned difficult to keep them from moving while slipping the belts on(been there...). Especially the 4V engine front bank intake cam which is balanced on a couple of lobes & moves if you even blink fast near it. The front bank exhaust cam is almost as bad. I've spent a couple of hours fighting to get the belt onto A QV engine w/o losing alignment. This one place where the tool comes in, it lets you preserve your work in degreeing the cams. Get the settings spot on, then use a couple of the tools to lock the cam gears so they can't turn. Also, once you've changed belts & know you've got the cam timing right, it isn't necessary to redo the timing every time you change belts. The belts are manufactured to quite tight dimensions, so can be replaced w/o having to re-time the cams. This is routinely done on most other belt driven cam systems. I'm just trying to develop a tool to make it easier & more affordable for 308/328s. Unlike you, I have replaced several 308 cam belts, and some of them more than once as with JWise's project we just finished. So far, every engine where I've pulled the cam covers to replace the belts,seals,etc. had at least one cam with it's timing mark at the very edge of the cam cover mark. When I checked & reset the timing, every cam ended up with the marks centered. With the miss-timing, every one of them had been passing emissions & running quite well with that much miss-timing. While I do advocate getting the timing spot on. I must quibble with the above statement. It takes more than 2 or 3 degrees cam miss-timing to do anything other than slightly affect peak performance, MPG, & emissions Admittedly a small miss-alignment is undesirable, BUT NOT SERIOUS, especially for a daily driver/street car. Factory cam timing is always compromise between performance, MPG, emissions, etc. Just consider the extreme difference between the cam timing for the various 308 engine models, and the Euro vs US spec versions of those engines, not to mention the timing effects of some of the performance cam grinds. These differences are a lot more than a degree or so.
Sorry, didn't want to hijack the thread... but there is a reason why older Euro cam timing is different than US spec., only 3 degrees separate TR's Euro spec. vs. US spec. which is equipped with catalytic converter. I can attach the shop manual if you are interested... Image Unavailable, Please Login
Snap On do a cam lock tool.Used it earlier this year to do the belts on my 308QV.Got to say it worked a treat,can defo recommend it. Cost about £50.I bought 2 and locked all 4 cams at the same time. Steve
£50 ~$95 USD at current exchange rates.- Not a bad price. What is the Snap-On # for the tool? It's not the Snap-On version of the Baum Universal cam-lock tool, that goes(went) for more like $200, & Now I can't find it on the Snap-On web site. Also, please post a picture. Martin, Tnx for the pix. it looks like the tool is a flat bar with scribe marks to line up with the cam flange marks. Can you remember what the other side of the tool looks like? Any chance your scanned image is higher resolution than you posted? I can almost read the p/n on the tool, should be legible if you have a higher res image & can email it to: [email protected] Inquiringly,
Verell; sorry no better picture, but the p/n is AV 1198. It's also mentioned in the workshop manual Mondial 8 / qv called 'Tool for checking valve timing with engine in car'. I will do a quick sketch how the other side of the tool looks like and send it to you directly via e-mail. Best Regards Martin
Baum advertising follows: Multi-Lock II acts as a second pair of hands! Universal camshaft sprocket locking tool for twin and quad cam gas and diesel engines, holds camshafts in position during timing belt service. It is great for retaining timing when changing belts or adjusting belt tension. Retains cam timing on difficult to time four cam vehicles during simple belt changes. Eliminates expensive "One Model" timing brackets. Incorporates "Pitch adjustment" feature to easily handle varying sprocket diameter and tooth pitch. Unique design that provides maximum horizontal and lateral/off-set adjustment. Ratchet Lock Handles for strong lever action within limited space. Image Unavailable, Please Login
That's the tool I mentioned earlier. It's also sold by Snap-On, Gates, & several on-line sites for $155 each. It seems to be a reasonable tool, but a tad pricey. $300 for a pair of them is pretty steep. I'm hoping to do better. BTW, so far no one has come up with answers to my questions in the post that started this thread: 1) Does anyone have the exact center-center spacing for the 2V & 4V cams? (I think they're the same, but need confirmation). 2)Which would you prefer buy: a) A Single tool to do 1 bank at a time? b) A Pair of tools to do both banks at once & speed things up. (~2x the price of a single tool). 3) How much would you be willing to pay: a)$75/tool? b)$150/pair of tools c)$100/tool? d)$200/pair of tools
I wish I could answer your first question, but on the 2nd, I'd pay $50 for ONE tool (one side at a time). What I'd like to know is if I could use this tool to hold the cams to remove the timing belt sprocket off the cams. There is no flat edge on my cams so I have no way to hold the cams and remove the bolt holding on the sprocket (unless someone can offer a suggestion???). I know the later cars had a "nut" face machined on them so you could hold them in place, but mine do not. I'd like to check my cam timing, but if it's off, I have no way to adjust it if I can't hold the cams and remove the sprocket.
I'm trying to figure out if I have to get the price down to around $75 in order to get reasonable volume for the tool. Right now it's looking like it's going to be closer to $100/tool. It's going to have at least two custom molded plastic pieces. Possibly, it depends on which material I end up selecting, and it possibly may only be safe to use it this way with the metal cam gears. You don't need a tool that grabs your cam shafts in order to remove the cam gears (aka sprockets). See my 2nd post in this thread for a brief description of what I use to lock the cams & cam gears while removing/installing the cam gear bolts. BTW, Don't use anything thicker than a business or playing card to lock the cams tho, you're risking bending or breaking the cam caps. I've heard a lot of shops use folded over $ bills. There's a thread in the old fchat archives about this.
Hi Verell, Considering that I need to do my cam belts this winter, we could pull off the covers on mine and measure it and do the cam belts while we're at it. If you want the measurement soon, I would have to do it at your house because I haven't ordered my new lift yet. I'm planning on having a lift within a month though. To answer yor questions, in an ideal world, I would prefer to buy a pair of the clamps because then you can lock everything at once. If you were to replace one belt at a time, the belt on the other bank keeps the entire engine locked if the other bank's cam gears are locked and the belt is still connected to the drive gear. $100 a pair would be a very reasonable price. At $150 a pair, I think most people would only pony up for one. I have no idea why I think this, just a WAG. Birdman
How do you do precision timing then? And suppose, the precise timing was correct when the car left the factory, it will still be correct 25 years later? Even if the car had 5 timing belt changes, maybe even one of those timingbelts was mounted 1 tooth off, if you renew the belts now, and are sure you have the belt on the right teeth indicated by the cover pointer, then it will be good? Thanks.
If you guys are doing Birdmans belts- give me a call. I would love to work on someone else's car for a while!!! Here is a photo of the mock-up cam locking tool the Verell made for my project. It worked like a champ. I would think buying a pair would be the way to go also. Image Unavailable, Please Login
Can someone post a pic of this as I can't seem to picture this in my head. I've thought about using the belts to hold the sprockets and an impact wrench, but I can't get an impact on the exhaust cams because it won't fit(fuel tank on front and shock/spring on rear). Can I use a breaker bar in conjuction with the belts to get the bolts lose? It doesn't seem like it would hold! Now of course I have to ask how I'm supposed to move the cams themselves once I get the sprocket lose? I have nothing to hold them with and I doubt I can turn them with my hand. There is no flat edge to grab onto them with a wrench and rotate them into the correct position.
That's a lot of 'IFs'. The biggest assumption is that all prior belt changes were done w/o removing the cam gears from the cams, or that if removed, they were reinstalled exactly as they came off. The 1st time I change belts on an engine, I want to pull the cam covers & make sure the cams are properly timed. So far every engine I've opened has had at least 1 cam that was miss-timed by a few degrees. Implication being that somewhere along the way the cam gear's position on the cam flange had been accidently misadjusted. In the pull the cam cover case, the tool is used to keep the cam gears from rotating once the timing is properly adjusted. Thus making it easy to install the new belt because it keeps the gears from rotating. Where the tool really pays off is in subsequent belt changes after you know that the cams are properly timed. There's always at least one or 2 cams that want to move a few degrees on you, just enough so that slipping the belt on is a real PITA because the teeth on the cam gears are slightly off relative to each other.
Don't have a pic, but it's simple. Remove a pair of cam caps. degrease the cam caps & matching cam journal surface. Lay a ~25mm wide strip of paper on top of each of the cam journal surfaces. Reinstall the caps, thus clamping the paper onto the cam. The paper acts like a brake shoe to keep the cam from turning. There's room to get an impact wrench in there if you use a short impact socket. Can also use a long impact extension to get past the spring for the rear exhaust cam. Also can just undo the top of the spring & move it out of the way. See my previous post, with binder clips on all 3 cam gears, the tensioner still locked down, & paper under the cam caps, the combination will hold so you can use a breaker bar. Actually, I generally just leave the sprocket on until I've got the cam in position, then lock it down with paper under a cam cap until I've got the cam gear alignment where I want it. However, you can turn the cams with the cam gears off: Easiest is if the cam covers are off. You can use a pair of channel lock or vice grip pliers to clamp on the cam & turn it. With the cover on, it depends on your engine. A strap wrench around a cam gear mounting flange will work with any of the 2V & 4V engines. Alternatively make a tool with a pair of pins that go into the alignment holes in the cam gear mounting flange. On the 2V engines, & the forward bank of the 4V engines, there's room to grip the cam between the front of the seal & the cam gear mounting flange with alligator pliers (like channel locks, but don't have a thru bolt that makes them too wide). The 4V engine cams are set up so that somewhat special wrenches can be used. The rear bank cams mounting flanges have 2 flat sides you can turn with a large (44mm I believe) open end wrench. You'll probably have to make it out of thin (3mm/1/8") steel stock as I don't know of a source tho. The front bank cams have a partial hex pattern that a thin wrench can grab. With the cam gears on the cams, it's a bit easier. If the cam gear mounting bolts are torqued down, just put a wrench on them. Use a strap wrench around the cam gears, Alternatively you can use an old belt. Just wrap it around the gear mounting flange & squeeze it with vicegrips, or use it & a wooden handle to make a custom strap wrench. Or on the 4V engines, use thin wrenches as above.
I was under the assumption there is only 1 way to put the gears on the cam, because of the woodruff key.
