Home |  Forums |  Search |  My Profile |  Chat  Photo Gallery |  Events Calendar |  Technical Documents  No messages |  New Posts |  Watched Topics |  Register   Jim Mock Cams and chain / engine rattle? Goto page 1, 2  Next          Forum Index -> 6 Cylinder Workshop Latest ratings Highest-ranked posts Highest-ranked topics Highest-ranked posters   markr154 Fordmods - Getting Side Ways Age:41 Posts: 1569 Joined: 13 Oct 2005 Location: Perth WA, Australia View User Gallery (13) Posted: Mon Aug 11, 2008 2:15 am    Post subject: Jim Mock Cams and chain / engine rattle? Can someone explain to me WHY JMM's camshafts seem to cause timing chain rattle and worn / broken chain guides and timing covers? I've got a full DEV 5 set-up ...and recently had 2 chain guides replaced because of bad wear / breakage resulting in chain rattle (timing cover was worn too) ...but now the rattle seems to have come back ...and I get an annoying ticking sound at idle that seems to be coming from the bottom of the car AND the engine between the Rocker cover and BBM? NOTE: Can't be the lifters ...had all of those replaced last week, also had belt tensioner pulley replaced. I want to boost my engine shortly, and just want this problem fixed. Back to top badcooky Fordmods Tyre Shredder Posts: 345 Joined: 27 Jan 2007 Location: Toowoomba QLD, Australia View User Gallery (0) Posted: Mon Aug 11, 2008 8:25 am    Post subject: How new is the cam chain Mark? Back to top GeZza200 Fordmods - Getting Side Ways Age:20 Posts: 1042 Joined: 19 Feb 2007 Location: Lilydale VIC, Australia View User Gallery (9) Posted: Mon Aug 11, 2008 10:22 am    Post subject: could it be wrong size shims? Back to top markr154 Fordmods - Getting Side Ways Age:41 Posts: 1569 Joined: 13 Oct 2005 Location: Perth WA, Australia View User Gallery (13) Posted: Mon Aug 11, 2008 11:11 am    Post subject: The cam chain is less than a year old, recently replaced. Apparently it was noted that there were 3 shims per lifter when lifters were done last week ...and all replaced same way they came out. Pain in the a** this is.. Back to top markr154 Fordmods - Getting Side Ways Age:41 Posts: 1569 Joined: 13 Oct 2005 Location: Perth WA, Australia View User Gallery (13) Posted: Mon Aug 11, 2008 11:42 am    Post subject: Just spoke to Jim Mock himself ...he reckons it's likely that the Hydraulic Tensioner needs to be either replaced or adjusted. He also said that not many people ever set up the Tensioner correctly ...even using a couple of washers if necessary. Are there any other performance cams I can use that will still work ok with my JMM head, but not have the rattle problem? Back to top markr154 Fordmods - Getting Side Ways Age:41 Posts: 1569 Joined: 13 Oct 2005 Location: Perth WA, Australia View User Gallery (13) Posted: Mon Aug 11, 2008 1:38 pm    Post subject: Booked in again at BPT next THURS. Terry was saying that when a sticky lifter is replaced, the 'cap' thingy associated with that lifter will have to be machined, and the shims removed. They're also gonna do a diagnostic scan & dyno power run for me, to check for any faults or power loss probs. I haven't got the foggiest about what he's REALLY saying, maybe someone here could enlighten me? Back to top racer Fordmods Stock as a Rock Age:38 Posts: 126 Joined: 16 Jul 2007 Location: sydney NSW, Australia View User Gallery (0) Posted: Tue Aug 12, 2008 8:34 pm    Post subject: Nice looking car. I have read that the dev 5 kit gives these problems but i don't know why. I've read it on another thread. I would be looking at another cam from another company like WADE CAMS, CAMTECH CAMS, CREASENT MOTORSPORT. I have spoken to brenden mock & soory to say they are very rude & full of s**t. GOOD LUCK WITH IT BUDDY. Back to top ebxr82nv Fordmods - Getting Side Ways Age:26 Posts: 458 Joined: 15 Mar 2007 Location: thornton NSW, Australia View User Gallery (1) Posted: Tue Aug 12, 2008 10:15 pm    Post subject: it's. Cause all of their cams are regrinds if you get it measured and have a new one made froma billet you won't have any more probs. If you do post the specs up Back to top XR6EB Fordmods Stock as a Rock Age:26 Posts: 117 Joined: 29 Oct 2005 Location: Western Sydney NSW, Australia View User Gallery (0) Posted: Wed Aug 13, 2008 5:33 pm    Post subject: I had the same problem with the DEV 5 cam. Broke the guides twice in under 11000KM. The cam is simply to big and causes back lash. This was confirmed by JMM, although not easily. It will continually cause damage, as it is stretching the chain cause it to rub against the guides. I left the cam in there after the first time it broke the guides [3000km], and learnt my lesson when the second time a pieces of the chain broke off and stopped my oil pump. That staops the dizzy, which left me strandard with my car for two days, 1 hour away from home. I will NEVER use JMM products again! Thats just my experience. It may not be the same for everyone else. Back to top markr154 Fordmods - Getting Side Ways Age:41 Posts: 1569 Joined: 13 Oct 2005 Location: Perth WA, Australia View User Gallery (13) Posted: Wed Aug 13, 2008 6:03 pm    Post subject: XR6EB wrote: I had the same problem with the DEV 5 cam. Broke the guides twice in under 11000KM. The cam is simply to big and causes back lash. This was confirmed by JMM, although not easily. It will continually cause damage, as it is stretching the chain cause it to rub against the guides. I left the cam in there after the first time it broke the guides [3000km], and learnt my lesson when the second time a pieces of the chain broke off and stopped my oil pump. That staops the dizzy, which left me strandard with my car for two days, 1 hour away from home. I will NEVER use JMM products again! Thats just my experience. It may not be the same for everyone else. Which cam did you wind up replacing it with? Back to top MRESP8 Fordmods Newbie Age:26 Posts: 9 Joined: 10 Feb 2005 Location: Melbourne VIC, Australia View User Gallery (0) Posted: Thu Aug 14, 2008 10:30 am    Post subject: There is a simple rule that I am not sure all engine builders follow, as I had the same prob on mine, but was fixed when rebuilt. The head was machined down so much for compression, that it needed spaces to lift it back up to correct specs. If the head is to low its always going to have chain/guide problems. Since that was fixed I have no problems with chains and guides, but down side is I lost a bit of compression. Back to top Waggin Site Admin Age:25 Posts: 6797 Joined: 18 Dec 2002 Location: Sydney NSW, Australia View User Gallery (3) Posted: Thu Aug 14, 2008 11:39 am    Post subject: I had this exact issue on my JMM Dev5a setup. JMM's response was the same - "replace your tensioner, or adjust it". Now, these tensioners can't be manually adjusted, right? In any case, alot of time was wasted replacing the chain, tensioner, guides, etc - and it was just impossible to get rid of the rattle. Unfortunatley the regrinds that they do to produce the reasonably large cams mean you lose alot of meat off the cam itself, add this to the issue of shaving the head a couple of mm and you find the distance between the cam and the crank has decreased more than the tensioner can ever make up for. It may be possible to put shims inside the tensioner and build it up to make up for it, but I ended up selling my engine before I got to that. Back to top balizticbobo Fordmods Tyre Shredder Age:22 Posts: 320 Joined: 15 Apr 2006 Location: Wangaratta VIC, Australia View User Gallery (0) Posted: Thu Aug 14, 2008 9:31 pm    Post subject: Using a reground cam won't move the cam closer to the crank... But skimming the head will. Please feel free to correct me if i'm wrong, but aren't most Dev5's out there complete engine rebuilds? Therefore, the block deck would most likely have also been skimmed, a s**t also skimmed off the head, and a timing chain that is now way too long. Which also means that the tensioner has run out of travel, and cannot take the slack out of the chain. Chain is now free to rattle about and slam into the guides and simply destroy everything in its path. How would you like being whipped thousands of times every minute by a hot oil soaked timing chain. How many kms would you be able to handle it for before you finally broke? The only way I can think of checking for this is to run the engine with the rocker cover off, also preferably over an unliked neighbours front lawn! And watch the timing chain to see if it's free to shake. If so, try a new tensioner, it may also be necessary to modify the tensioner with the addition of a spacer JB WELDED onto the end, or modify the guide itself. Remember the tensioner has the same operating characteristics as a hydraulic lifter. When it's run out of travel, it's going to make noise. Noise means increased wear = BAD! I have the Head, Cam and Vernier gear off a complete JMM DEV5 that spat the chain and guides, also cracking a piston and bending some valves. VL's are notorious to snapping off the cam belt tensioner when fitted with a decompression plate. Belt is too short = massive load on tensioner in fully released position. Back to top balizticbobo Fordmods Tyre Shredder Age:22 Posts: 320 Joined: 15 Apr 2006 Location: Wangaratta VIC, Australia View User Gallery (0) Posted: Thu Aug 14, 2008 9:37 pm    Post subject: Also dont f**k about getting anything else done with the lifters at this stage. And also try not to drive it unless you have to until you fix your timing chain problem to you could kill the whole motor just like the motor my head came off. Back to top ebxr82nv Fordmods - Getting Side Ways Age:26 Posts: 458 Joined: 15 Mar 2007 Location: thornton NSW, Australia View User Gallery (1) Posted: Thu Aug 14, 2008 9:50 pm    Post subject: I wonder how you would go taking a link out of the chain or would it make it to short Back to top arm79 Cruise Moderator Age:29 Posts: 3682 Joined: 05 Nov 2004 Location: Westside VIC, Australia View User Gallery (0) Posted: Fri Aug 15, 2008 10:15 am    Post subject: balizticbobo wrote: Using a reground cam won't move the cam closer to the crank... But skimming the head will. Please feel free to correct me if i'm wrong, but aren't most Dev5's out there complete engine rebuilds? Therefore, the block deck would most likely have also been skimmed, a s**t also skimmed off the head, and a timing chain that is now way too long. Which also means that the tensioner has run out of travel, and cannot take the slack out of the chain. Chain is now free to rattle about and slam into the guides and simply destroy everything in its path. How would you like being whipped thousands of times every minute by a hot oil soaked timing chain. How many kms would you be able to handle it for before you finally broke? The only way I can think of checking for this is to run the engine with the rocker cover off, also preferably over an unliked neighbours front lawn! And watch the timing chain to see if it's free to shake. If so, try a new tensioner, it may also be necessary to modify the tensioner with the addition of a spacer JB WELDED onto the end, or modify the guide itself. Remember the tensioner has the same operating characteristics as a hydraulic lifter. When it's run out of travel, it's going to make noise. Noise means increased wear = BAD! I have the Head, Cam and Vernier gear off a complete JMM DEV5 that spat the chain and guides, also cracking a piston and bending some valves. VL's are notorious to snapping off the cam belt tensioner when fitted with a decompression plate. Belt is too short = massive load on tensioner in fully released position. Now there's a smart man, got the answer in the first go. I have zero noise and problems with my Dev 5 cam, but only after I have set it up properly and taken into account its and my engines characteristics. Back to top markr154 Fordmods - Getting Side Ways Age:41 Posts: 1569 Joined: 13 Oct 2005 Location: Perth WA, Australia View User Gallery (13) Posted: Fri Aug 15, 2008 11:16 am    Post subject: So, what can I do to remedy my situation? Different cam? Different head? Back to top arm79 Cruise Moderator Age:29 Posts: 3682 Joined: 05 Nov 2004 Location: Westside VIC, Australia View User Gallery (0) Posted: Fri Aug 15, 2008 11:51 am    Post subject: Shorten the chain if its too long. I have added shims under the tensioner spring to keep a tighter tension on the chain. Plus it ensures it will push the tensioner out a little further to keep adjustment. Back to top dc_todd Fordmods - Getting Side Ways Age:30 Posts: 3035 Joined: 05 Nov 2004 Location: Gymea NSW, Australia View User Gallery (12) Posted: Fri Aug 15, 2008 11:58 am    Post subject: I would suggest different cam, especially if you are goinf forced, you don't need the lift the dev 5 has, I would suggest something from wade, and spend the extra money and get a billet cam, Not suggesting there is anything wrong with a regrind, I run one myself, BUT if I was gonna blow my motor I would be looking for a billet, wade can provide this for you. there a few guys running blown motors with wade cams, they have one that suits a blown motor in their range too. Next I would be looking at the head trying to find out how much was skimmed off the head to bump up the comp ratio. my understanding is that JMM skims the head, and pulls meat out of the ports, and cuts out the valve guides to what they deem a minimum amount remaining. I would suggest you get BPT to have a look at the head, they will not be able to see too much with it on the car though, I would say maybe drop the exhause manifold and have a look in, If you have a decent digital camera try and get a clean shot of the inside of the port and post it on here, someone will be able to make an educated decision as to how much has been taken out and if it remains suitable for turbo'ing. as long as the head has not had too much taken off it, it should still be suitable. The cam I would definatly change, as previously suggested, yes you are definatly suffering from backlash. change of cam will fix this 95% of the time. Back to top markr154 Fordmods - Getting Side Ways Age:41 Posts: 1569 Joined: 13 Oct 2005 Location: Perth WA, Australia View User Gallery (13) Posted: Fri Aug 15, 2008 12:24 pm    Post subject: This is a slight bummer, since I am trying to keep the 40-50 rwkw advantage that the JMM gear gives me ...and maintain that advantage when I boost too. I think I'm gonna leave her in BPT's capable hands, and see if they can sort something for me ...even if it takes a little modification or engineering to achieve it. Maybe they can shorten the chain, or shim the tensioner as Arm79 suggested? Can someone post the link / model no. of the Wade cam I should be looking at? Back to top Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First             Forum Index -> 6 Cylinder Workshop Goto page 1, 2  Next Page 1 of 2   (c)2002-2009 Matti Jones and Brad Evans [47 queries :: 0.07949 seconds ]