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/cgi-bin/YaBB.pl General Category >> Rubber Side Down! >> Did I Choose The Wrong Camshaft? /cgi-bin/YaBB.pl?num=1608942203 Message started by d3adrock on 12/25/20 at 16:23:23 |
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Title: Did I Choose The Wrong Camshaft? Post by d3adrock on 12/25/20 at 16:23:23 I decided to put in a stage 3 camshaft in my bike to go with the 10.5 compression piston. Unfortunately my engine is having trouble. It seems the valve guides were wrecked after the piston hit the valves. So it's in the shop. This has made me reconsider whether I made a good choice in installing the stage 3 cam. All I care about is low rpm torque. But the duration is increased from 224 in the stock cam, to 238 in the stage 3. wouldn't that greatly raise the rpm at which I feel torque? If so should I go back to a stock cam? Or maybe webcams standard with a duration of 226 is better for me? Help me ratiolanlize my choice, or understand whats going on. Thanks! For reference I'm including the specs sheets for stock vs stage 3 cams dragbikemike included in his excellent comparison of camshafts. I hope he doens't mind. |
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Title: Re: Did I Choose The Wrong Camshaft? Post by d3adrock on 12/25/20 at 16:43:16 Graph |
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Title: Re: Did I Choose The Wrong Camshaft? Post by d3adrock on 12/25/20 at 16:45:09 Graph |
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Title: Re: Did I Choose The Wrong Camshaft? Post by d3adrock on 12/25/20 at 16:45:52 chart |
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Title: Re: Did I Choose The Wrong Camshaft? Post by Armen on 12/25/20 at 19:58:29 Are you sure the cam thing was correct? |
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Title: Re: Did I Choose The Wrong Camshaft? Post by d3adrock on 12/25/20 at 21:06:16 What do you mean? |
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Title: Re: Did I Choose The Wrong Camshaft? Post by DragBikeMike on 12/25/20 at 23:01:20 I believe Armen means "Are you sure the cam timing was correct?". I'm sorry to hear about your disaster. A collision between the valves and piston is usually the result of installing a cam with too much TDC lift or by installing the cam with the timing incorrect. The stage 3 cam has very low TDC lift, intake .053" and exhaust .074". In contrast, the Web 340b cam has significantly more TDC lift, intake .143" and exhaust .092". I've been running the 340b with a Wiseco pop-top. No problems with valve interference. That Web stage 3 cam should not present any problems. However, if you only care about low rpm torque you should have stuck with the stock cam, or the stock factory DR650 cam. You need to tell us more about your installation. The Web cam comes with an installation check sheet. It tells you to check all the critical clearances and provides specs for those clearances. You should have checked valve-to-piston clearance, valve-to-valve clearance, spring retainer to guide seal clearance, spring coil bind, rocker arm to spring retainer clearance, rocker arm to head cover clearance. Did you check all those clearances? Tell us how you checked cam timing. Which valves hit, intake or exhaust? Tell us about your cam chain tensioner. Are you running the stock tensioner or did you remove the pawl? What was the tensioner extension? If you have pictures those would help too. How did the failure occur. Did it fail at initial startup or were you riding it when it failed? Was it making noise before it failed (clack, clack, clack...)? I wish you had not taken your bike to a shop. I'm sure they will do a fine job but you won't really learn what went wrong. Personal observation is the best way to learn. Oh! One last thing. What Wiseco piston are we talking about here? Did you install the Wiseco pop-top (1221M09400) or the Wiseco flat-top (12984M09400)? If you installed the flat-top I suspect you are the first to do so. That flat-top will require extra careful attention to detail since the compression height is .125" taller than the pop-top. Valve-to-piston clearance on the flat-top is an unknown at this point. The flat-top does have generous valve reliefs but to my knowledge no one has actually set one up in a real-life application yet. |
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Title: Re: Did I Choose The Wrong Camshaft? Post by d3adrock on 12/26/20 at 19:51:56 I actually had the shop install the cam along with the piston in the first place. I don't have a garage to do allot of work in and I wanted it done professionally the first time around. (I think it was a pop top. It's the 95mm one that lancer sells) According to them they did all the timing correctly and checked the clearances you mentioned. They said it had ample clearance between piston and valves. It's hard to say how much to trust their word. It doesn't look they hit the piston strongly since there are very weak marks (pic below). The guides are what seems to have taken the biggest beating. (pics below) It was working pretty well for a while, on about the fifth or sixth ride after having it back from the shop (after another problem with the chain gear shattering, it started slowing down and dying, and then it wouldn't start. When the shop checked it they said they found oil in the carb and when they checked further they said the found oil leaking in from the valves. Initially they thought it was a bad gasket but they say now that it's the guides/valves letting oil in. They suggested that maybe I had let the engine over-rev (which I can't remember ever doing but it's possible) which had caused the valves to float and thus hit the piston. You said that I chose the wrong cam if all I care about is low rpm torque. That might have been a sliight exaggeration, I care mostly 80% about low rpm torque, and about 18% about mid range torque. and maybe 2% about high rpm torque. I'm a bit dense with all these numbers ect and I will be the first to admit I didn't really understand what I was doing when I had these parts installed. My thought process was mostly Stock=Bad, Mods=Good. If you would help me understand the differences in the cams and what the numbers mean. I would greatly appreciate it. I have a little understanding of the properties of cams now, in that higher lift lets in/out more air/fuel. And that longer duration is bad for low end torque but good for high compression and high rpm torque. When I bought the parts I didn't even know that there was more than one cam option aside from the stage 3, let alone several, let alone that I might actually like the stock profile more. When I rode it for the brief while it was operational the midrange and high end felt very powerfull but the low end felt "smoother" than stock. It didnt feel like it pulled quite as hard right off the line. That could be the jetting which I'm still getting dialed in, but it could also be the cam. what do you think? |
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Title: Re: Did I Choose The Wrong Camshaft? Post by d3adrock on 12/26/20 at 19:52:21 seats |
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Title: Re: Did I Choose The Wrong Camshaft? Post by d3adrock on 12/26/20 at 19:52:38 guides |
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Title: Re: Did I Choose The Wrong Camshaft? Post by DragBikeMike on 12/27/20 at 00:57:03 " I'm sure they will do a fine job" I retract that statement. You might wanna get your bike out of that shop. I have never seen valve guides snap off like that. Something clearly wasn't right. If you had a gross timing problem you probably would have heard a lot of ugly noise right from the start. If it was only slightly out of time it may not have resulted in a collision until you revved it up to a high rpm. Either way, the shop would be responsible for the timing error. I routinely take my engine up past seven thousand rpm. When I was running stock valve springs I used to take it up past 7K all the time. How far up the rpm spectrum do you think you took it. If it was timed correctly you should have been able to safely take it to 7500. Since it was all fresh I suspect you were breaking it in so it shouldn't have seen more than about 4500 rpm. If you don't have a tach and you need to get a feel for what 7500 rpm sounds like, LMK and I will post a vid. You said it had a problem with the chain gear shattering. This is a known problem and it is associated with over-torqueing the primary drive gear nut (LH threads). How did that problem manifest? What compelled you to return it to the shop when the chain gear shattered? Noise, failure to start, running bad etc.? When that gear was replaced it's conceivable that the cam timing was thrown off. Tell us more about your problem with that gear. Where did you get the cam. Are you sure it's the Stage 3 that Lancer sells? Are there any markings on the cam? The snapped-off guides imply that the cam lift exceeded valve travel. The valves hitting the piston can be the result of incorrect cam timing, but the spring retainers hitting the guides can only be the result of the cam lift exceeding valve travel. Max lift on the Stage 3 cam is .393" intake and .376" exhaust. Stock valve travel is .430". That only leaves .037" on the intakes. I believe the Web spec is minimum .060". Can't say for sure that the spring retainers hit the guides but given the failure it's certainly something to consider. I guess it's possible that the valves stuck in the guides and then the piston clobbered the valves and snapped the guides. Were those guide remnants difficult to get off the valve stems? I assume the valves are bent. If so, where are they bent? I can see from your photos that the intake valves hit the piston and the intake valve guides are snapped off. Is there any damage to the exhaust valves or guides? BTW, thanks for the photos. Very informative. |
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Title: Re: Did I Choose The Wrong Camshaft? Post by d3adrock on 12/27/20 at 01:18:53 Thank you for your help, I really appreciate it. Unfortunately, the shop has been the ones to do the work from the beginning. When I initially took it in to get all the parts installed they told me that on the first test run of the parts installed along the first block or so they heard the shattering and took it back. They then replaced the gear, chain, guides, and tensioner (at my expense might I add, I know I know, I'm an idiot.) After they replaced all the parts, they said it was finished and told me to pick it up. A few rides later and this happens. I don't think I took it anywhere near 7000rpm but without a tach it's hard to say. If it helps I can say I've barely taken it full throttle. The longest I've been at WOT is probably 7-8 seconds. I don't know if that's long enough to put it into the 7000's. From what the shop has told me the valves are not bent (although they say they're replacing them anyways. I don't think the exhaust has struck, but ill double check anyways when they re-open. Are there any more pictures that you think would help clear up this dreadfull mystery. For reference my bike has been in the hands of this shop for nearly a year now getting these mods done. The cam is almost definitely a stage three since I bought it directly from lancer along with the piston, and at least according to him he doesn't sell anything else. Ill double check with the shop what the exact toleranes where again. I recall them telling me that there was more than enough, but I can't remeber the exact numbers so ill double check. Also could you elaborate on the different cams and their results. If I wanted to go back to stock or some other cam, now would be the best time to pick one up I imagine. What effects should I expect with this cam vs the DR650 or stock? What do you reccomend? Thanks again! |
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Title: Re: Did I Choose The Wrong Camshaft? Post by Dave on 12/27/20 at 03:52:33 The Wiseco 95mm and Stage 3 cam are normally a "bolt in" upgrade and there is no interference between the valves and piston. My engine has the 95mm Wiseco and the Stage 3 cam.......and it has been running that combination for several years without any problems - it is as reliable as a stock engine and only requires periodic routine maintenance. It makes good power and runs great, and it is a very good cam/piston combination for a daily driver as it runs very smoothly. (I probably don't ride it enough to get 160,000 miles on it like Youzguyz did in my lifetime). I am not aware of anyone installing any size (95,96,97) Wiseco and any Stage 1, Stage 2 or Stage 3 cams that has had an interference issue and needed to do anything extra to provide valve/piston clearance......they are "bolt in"parts. You would need to check with Lancer and get exact numbers - but I suspect he has sold a hundred or more of these combinations over the years.....and you are the first one on this forum that has reported this problem. I suspect your mechanics are doing something wrong, and likely they got the timing too far advanced and that is why the intake valves hit the piston......the valves had not yet closed when the piston was coming to the top of the stroke. |
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Title: Re: Did I Choose The Wrong Camshaft? Post by d3adrock on 12/27/20 at 11:02:47 I suspect you are right. So far every time something has gone wrong the shop offers up nothing more than a shrug and it ends up taking months on end to fix. What was your experience with the stage 3 cam? Did you feel a loss of power or an increase in smoothness in the very low rpm torque. I can't tell if it was because I was still getting used to it but when I first bought the savage, the power down low felt, for lack of a better word choppy. Like it came on really fast and strong. It actually made low speed driving and shifting down from second slightly scary and exilerating. When I got it back after the cam/piston I don't know if it's because it was set up poorly, or the carb not adjusted well, or I had just gotten better at driving it and new how to shift it, but when I started driving again it didn't have that same scarry impulse of power from the get go, it was suddenly smoother and easier to shift between 1sts and 2nd and back. Do you think the new cam explains this behaviour, or am I imagining it ect? I don't know what's going on. |
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Title: Re: Did I Choose The Wrong Camshaft? Post by Dave on 12/27/20 at 12:09:29 When I modified my engine I initially had the Wiseco 95mm and a Stage 1 cam......the engine had a noticeable power increase everywhere. My bike is a Cafe' bike and it lost a few pounds in the conversion - the bike can easily get to 80mph, 90 takes a little longer.....on 2 occasions I have been over 100 and it doesn't want to go any faster. I believe the exhaust system may be a bit too restrictive to let me go any faster. I now have the Stage 3 cam and a lightened flywheel - and although I really couldn't feel the change the 0-60 mph times have dropped by 1/2 second. Your engine should make more power with the Wiseco and Stage 3 should be noticeable......and for my engine the changes really didn't require any drastic jetting changes. |
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Title: Re: Did I Choose The Wrong Camshaft? Post by d3adrock on 12/27/20 at 13:25:07 At what rpm aproximately did you feel the most power increase? I've got a delkevic shorty muffler (with baffle) which sounds amazing but makes my ears ring. I've also got the vm36 with ufo so that accounts for some differing jetting. |
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Title: Re: Did I Choose The Wrong Camshaft? Post by Dave on 12/27/20 at 14:58:22 05520005130E020A610 wrote:
It makes more power everywhere......the power pulses are stronger and it pulls harder, and goes faster. |
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Title: Re: Did I Choose The Wrong Camshaft? Post by LANCER on 12/27/20 at 16:07:15 I have sold hundreds of cams and pistons over the past 15 years without any interference issues. That includes my own Savage which has had 0.025” taken off the cylinder and 0.015” from the head, for 0.040” total, a 97mm Wiseco and used with all the cam profiles I’ve had, the Stage 1, 2 & 3. Like DBM my engine has been to 7500 several times and 8000 once with no damage. It starts and runs just fine. Your particular case is the first I’ve heard of. |
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Title: Re: Did I Choose The Wrong Camshaft? Post by d3adrock on 12/27/20 at 23:09:48 I don't doubt you. I'm sorry if I made it seemed as if I blamed your for the malfunction. I'm just trying to figure out what went wrong and what I should do, and also if I made a wrong choice in terms of camshafts. As I said before, if all I cared about was torque down low, was choosing a cam with longer duration a mistake? I don't entirely understand how to make sense of the graphs and tables. Perhaps somone here can clear it up? |
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Title: Re: Did I Choose The Wrong Camshaft? Post by DragBikeMike on 12/28/20 at 01:05:46 You did not choose the wrong cam. The Stage III cam is pretty mild. When combined with the high-compression piston you will not lose much, if any, low-end torque. Explaining all the ins & outs of camshaft design and selection is way too much to go over here in this post. Just rest assured that your camshaft selection was reasonable & proper. "Unfortunately, the shop has been the ones to do the work from the beginning. When I initially took it in to get all the parts installed they told me that on the first test run of the parts installed along the first block or so they heard the shattering and took it back. They then replaced the gear, chain, guides, and tensioner" This nugget of gold may hold the answer to what happened to your engine. These cam chain drive sprockets don't just fail out of the blue. As I mentioned earlier, the cam drive sprockets are known to fail in the manner you described. These sprocket failures can be attributed to over-torqueing the primary drive gear nut. In your case, there's a lot of "IFs" involved. IF the shop over-torqued the nut, it may have resulted in the sprocket failure. IF the sprocket failure resulted in the sprocket separating and falling apart, the drive chain would have jumped time. IF the chain jumped time, or fell off altogether, it could have altered cam timing enough to cause the piston to run into the intake valves. All of those IFs would explain why the piston hit the valves. IF the valves were extended just the right amount when the piston made contact...and...IF the rocker arms were at just the right angle there may have been sufficient side loads to result in the guide fractures. They fractured right at the weakest point (circlip grooves). Right now, the burning question should be what caused this failure? Your failure is not attributed to your cam selection. Your failure is not attributed to wear & tear. I think your failure is the result of an assembly error. Sometimes you just have to lick your wounds and move on. Pick up the pieces. Make the most of the situation and see what you can learn. As long as the shop has your engine in their possession you aren't going to learn anything about your engine, why it failed, how to properly assemble it, etc., etc. Based on what you have said so far, it seems highly unlikely that the shop will share anything with you that might reveal any errors on their part. Get it out of there. Bring it home where you can see it, feel it, smell it, take pictures of it. BTW, do you have any pictures of that cam chain drive sprocket? Pictures of the left-hand nut that secures the primary drive gear would also be insightful. |
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Title: Re: Did I Choose The Wrong Camshaft? Post by LANCER on 12/28/20 at 06:34:49 722577726479757D160 wrote:
I did not feel that you were blaming me, so that is a non issue rest assured. As DBM just said the Stage 3 cam is a mild grind. |
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Title: Re: Did I Choose The Wrong Camshaft? Post by d3adrock on 12/28/20 at 10:08:14 0C010E0305125257600 wrote:
I did not feel that you were blaming me, so that is a non issue rest assured. As DBM just said the Stage 3 cam is a mild grind. [/quote] Here's the only picture I have of the sprocket failure and the subsequent engine disassembly they say they did. I would hope that since they claim they disassembled the engine after the sprocket failure that they would have seen if the valves or guides were astray. Besides wouldn't it have demonstrated the problem immediately afterwards? I really don't know. As an tangential question, do you think it's fair to request that the shop pay for the costs associated with these repairs? I can't directly prove that it was their fault for the failure, however since they were put in charge of the whole process I feel they should take responsibility for the cost of replacement parts/repair? What do you think? I already paid for all the repair costs associated with the sprocket failure on top of the cost of the modifications for which I had already paid them. Am I being reasonable? |
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Title: Re: Did I Choose The Wrong Camshaft? Post by d3adrock on 12/28/20 at 10:31:11 post sprocket failure |
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Title: Re: Did I Choose The Wrong Camshaft? Post by badwolf on 12/28/20 at 13:25:06 Does anyone else think that broken gear looks just like the one a couple months ago from the guy whose counter balancer went out of sync? I thought we pointed at someone not knowing the nut was left hand thread and over torqued it trying to get it off the wrong way crushing the gear. Those gears don't ''JUST BREAK'' Might be the same cause this time with a different result. |
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Title: Re: Did I Choose The Wrong Camshaft? Post by verslagen1 on 12/28/20 at 16:34:57 If they screwed up, aren't they responsible for fixing it? |
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Title: Re: Did I Choose The Wrong Camshaft? Post by oldNslow on 12/28/20 at 17:23:25 Torque spec for that nut is 65-80 ft.# That's not all that tight. I can do that easily with an 8'' or 10 " ratchet handle and socket and I'm not real strong. If the shop used a 1/2 in. drive air wrench to take the nut off, and put it back on with the same tool, it's very likely they broke the sprocket when reinstalling the primary drive gear and nut. I think even one of the newer 20V or more battery powered impact wrenches are probably strong enough to do it. |
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Title: Re: Did I Choose The Wrong Camshaft? Post by DragBikeMike on 12/28/20 at 22:31:02 "As an tangential question, do you think it's fair to request that the shop pay for the costs associated with these repairs? I can't directly prove that it was their fault for the failure, however since they were put in charge of the whole process I feel they should take responsibility for the cost of replacement parts/repair? What do you think? I already paid for all the repair costs associated with the sprocket failure on top of the cost of the modifications for which I had already paid them. Am I being reasonable?" IF your engine was in good running condition when you took it in to the shop, and IF the shop disturbed your primary drive sprocket nut prior to the sprocket failure, you are being completely reasonable. You know the answer to the first IF, it's the second IF that's a mystery. How was your engine running before you took it to the shop? Mileage? What's the history? Has it been apart before? Are you the original owner? Tell us more about the shop. Where is it? Is it a Suzuki dealership or an independent shop? Does your city or state have a Repair Industry Board that issues licenses for repair shops? Do they have a Department of Commerce and Consummer Affairs? I personally do not like conflict. That's probably why I rarely hire people to do work. It's not worth the aggravation and stress when the work isn't done correctly. A lot depends on your disposition and willingness to fight. As it stands now, the shop has your money and they have your engine. You don't have any leverage. If there's a licensing agency at least you can file a complaint. If they are an Authorized Suzuki Dealer you can file a complaint with Suzuki but I'm thinkin Suzuki will stay out of it because you had the shop modify the engine with non-OEM parts. If it were mine, I would get my engine out of that shop. At least I would have the engine. A top-notch repair facility would have told you right from the first failure that they were gonna make things right. BTW, thanks for the pics of the failed sprocket and engine parts. The sprocket did not split in a manner that would have resulted in the chain jumping time. I guess it's possible that the fragments might have gone through the drive and caused all sorts of havoc but there's just no way to know. |
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Title: Re: Did I Choose The Wrong Camshaft? Post by DragBikeMike on 12/28/20 at 22:43:48 I also wanted to share this with you. This is a picture of a primary drive gear nut. It has obviously been grossly over-tightened. My guess on this screw up is that someone was working on the engine and they were not aware that the nut has left-hand threads. They tried to remove the nut and just kept reefing on it until the corners folded over. I suspect the drive sprocket on this engine was toast by the time they figured out the nut is left-hand. You can actually see the "L" stamped on the face of the nut indicating its left-hand. |
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Title: Re: Did I Choose The Wrong Camshaft? Post by d3adrock on 12/29/20 at 00:27:28 I am not the original owner, however the bike was in good running condition when I brought it in, aside from the carb being way to lean. It only had about 5000 miles on it. It's never been apart before but it had been gone through by the dealership mechanic I bought it from. The shop is in chicago and is called Acme cycle. It's an indy shop. I didn't have a suzuki shop nearby, and even if I did, I don't think they'd do the work I wanted. In my stupidity, I figured I'd be better off having a professional shop do the work instead of me since they would have experience plus the benefit of a garage instead of just a muddy back yard. As things stand, I've already paid for the sprocket issue. Now it's a question of whether I pay for the work of the valve issue, unless I wanna go demanding a refund for the previous work. I also don't like conflict and would like to avoid it if possible. Unfortunately you are right that they have my bike and my money. In a messed up sort of way it's kind of good that they messed up my egine as much as they did because without it I would never have been driven to learn as much about motorcycle mechanics as I have. I've even given a lecture presentation at my local college about the mechanics of curberators! Thank you so much for your help! As a young guy just getting into bikes it means allot. |
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Title: Re: Did I Choose The Wrong Camshaft? Post by DragBikeMike on 12/30/20 at 01:40:01 Good luck with the project. Maybe your next lecture presentation will be on proper engine assembly. Keep us in the loop. Your valve guide failure is unique. Figuring out what happened will help us all. |
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