Valve adjustment procedure questionI have a CH I bought the truck a few years back. Bought it with k miles, and now it has about k. Runs very well. Power is good. Pulls 32lbs of boost. Engine is labeled HP, but previous owner says he had it turned into a HP?? Is that possible? I drove a stock yearand it felt like a slug compared to mine. That truck empty felt like mine loaded. Anyhow, I noticed my jake doesnt seem to be strong at all. I have not had the engine touched since i bought it. Someone told me i should have the valves adjusted. Is this the cause of a weak jake?? The Jake might need a tune up kit. I'm not sure what is involved or how much it is but after a while they wear. It wouldn't hurt to have the valves done. Did mine at k and made a big difference in power and mileage. Should help the Jake too. In any case, if you do decide to run the overhead yourself, be sure to adjust the brake loosely at. Otherwise you could end up with a broken guide pin and possibly replacing a head. Is this something I should just let the Mack dealer do?? Have them adjust valves and rebuild jake? About how many hours labor would it cost? Im only a few miles from the dealer but dealer prices scare me sometimes, but so does the idea of screwig up my motor trying to save a few bucks! I had mine done a year ago They replaced the solenoids, adjusted the valves and had to replace a worn out set screw thingermajigger The biggest deal was finding the time, as the truck has to sit almost over-night to allow the motor to cool to 'room' temperature. I think they call it stealth because you don't even know it's on.
Valve adjustment procedure question
Charts show that the new AMI revs higher and produces more maximum horsepower but less torque than the older EM Veteran Maxidyne drivers will have to adjust. Except that I had. I was in the seat of a new Mack Granite mixer, a lot like the one I drove and wrote about when it was introduced at the same place, during the same show, more than a year before. That was inyou may recall if you're as old as I, and you like their folksy music. By then Mack's original Maxidyne had been out several years. That engine lugged down to 1, or 1, rpm, which meant a 5- or 6-speed transmission was adequate while 9- or speed gearboxes were needed with engines that had much narrower operating ranges, which was most of 'em. That 2,rpm Maxidyne went away aboutwhen Mack switched to a lower-speed version. Its rev range was 1, to 1, rpm, yet it pulled exactly as well as the higher-revving engine. I know because a colleague and I spent a day comparing two rigs that were identical except for their hp engines and different axle ratios. We cruised on level stretches, climbed long highway grades, and even drag raced on Mack's track in Allentown, Pa. The only performance difference was fuel economy: The then-new low-speed Maxidyne delivered about 0. Lower rpm's save fuel. New I-EGR engines. So why would Mack go back to the higher, thirstier rev limit? To let the new Maxidyne's internal exhaust-gas recirculation system work, explained Steve Ginter, the vocational marketing manager at Mack's headquarters in Allentown. EGR cleanses diesel exhaust of enough nitrogen oxides to meet the latest EPA emissions limits, which went into effect last Oct. I-EGR uses valve overlap to let a bit of exhaust bleed back into combustion chambers. Exhaust gas displaces oxygen, which lowers combustion temperatures, which in turn cuts NOx. Camshaft lobes are ground just-so to achieve the proper valve action, and it took a lot of theorizing and testing to get the grind right, engineers say. I-EGR doesn't need special plumbing, extra valving or the jacketwater aftercooler used in the on-highway system. The downside is that I-EGR uses a bit more fuel. But that's not a major priority with operators of construction and trash trucks, who probably won't notice any penalty in everyday operations, Mack engineers say. Veteran Maxidyne drivers will notice the new engine's weaker low-end "grunt," though. A small-fleet owner I met at a previous demonstration of the engines said his drivers noticed this, and griped about it. But less low-end torque means fewer broken U-joints and that'll save repair money, said another fleet owner at the same demo, last November in Allentown. He counted this as a real advantage. The new AMI engine makes its torque at higher rpm's, and makes less of it—1, pounds-feet at 1, rpm, compared to the older EM's 1, pounds-feet at 1, rpm. You feel this while accelerating and upshifting, and while slowing and downshifting. Because horsepower with the new engine is also higher on the tachometer, you need to keep revs above 1, or 1, Once revving, the AMI produces more maximum horsepower— from about 1, rpm almost to 2, when it drops abruptly to horsepower at 2, the advertised rating. The EM makes horsepower at about 1, rpm, and drops off quickly before and after that point. So if drivers keep revs up, they'll be happy with the new engine. Neither was available before. Transmission changes. The new Maxidynes' power and torque characteristics effectively shorten the operating range, so drivers need one extra transmission gear to get the job done, Ginter said. He and other professional Bulldoggers would prefer that you buy the recently introduced ES for easy shift T series triple-countershaft gearboxes, and these were in the two Granite mixer chassis I drove at the speedway near Las Vegas. This has three low-low ratios for creeping and six on-pavement ratios vs. All ratios are in the same wide H-pattern, with the LL ratios gotten by flipping a thumb switch. If you shift fast, there are just enough steps to keep the engine between 1, where serious horsepower begins and 2, rpm.
Discussion in ' Mack Forum ' started by brianApr 18, Log in or Sign up. Find Trucking Jobs. Valve adjustment procedure question Discussion in ' Mack Forum ' started by brianApr 18, Apr 18, 1. Does anyone have the procedure and specifications for setting valve lash on a E in a CX Vision? I have done this on Cats and Cummins but never a Mack. Yes, let employers and TruckersReport text me with new opportunities, job alerts and other career information to the number I provided. There is no charge for this service, but standard message and data rates may apply. Apr 18, 2. I do not have my book here tonight but intakes 16, exhaust I believe the E7's have timing marks on the flywheel but it takes two and I was often alone and use companion cylinder method. Write done the firing order. Then under that write down 6 2 4 1 5 3. Rock the valves on 1 exhaust closing and intake opening and adjust the valves on 6, draw a line through 6. Then rock 5 and adjust 2, etc. You can start anywhere as long as you keep up with it. If no one else answers and you want by the book let me know but it will be tomorrow. BoxCarKiddApr 18, Apr 18, 3. Apr 19, 4. No problem only 7 and a half pages. The first 4 tell you there is a pointer in the center of the hole, at the bottom of the flywheel housing, after you remove the cover. Tool JA is used in the flywheel housing hole at the right rear of the oil pan to rotate the engine. If you cannot read them there are instructions on here to remark them if you have a typical flywheel. If you have a non-typical flywheel it should be replaced. Then use the marks and adjust the valves the same as I explained in the companion cylinder method. BoxCarKiddApr 19, Apr 25, 5. Pedigreed BulldogApr 25, Apr 25, 6. Show Ignored Content. Draft saved Draft deleted. Your username or email address: Do you already have an account? No, create an account now. Yes, my password is: Forgot your password?
Asked by OldRedMack. Any ideas on whats going on? The truck has plenty of power, just all after rpm. I had an s built for it, then read that posting a couple days ago and swapped the manifold. And it helped a good bit, but you can still tell when it opens up. I thought I read somewhere that the torque curve was programmable on that engine, but when I call the local Mack dealer here in Atlanta they sound like idiots and acted like they have never even heard of the updates for that engine. So I have no idea if it has had the 12b update or not. If your still not happy Don't bother to call mack in Atlanta, they no nothing other than Mack starts with the letter M, I don't even by parts from them, we have them shipped in from KY. Boost sensor not picking low pressure reading?? Good luck. That engine should pull strong way below AMI data sheet. No I have not done injectors yet. I'll pull it up in the morning and see what the software levels are at. The ole dirty was as small as you would ever want to go in a AI engine. They actually had the same torque output as a The uses a turbo but injectors. The A for Allisons uses a injectors and turbo. Ok, y'all are awesome. I've learned more from this place than I have the last 3years of talking to every mechanic I can find to try and figure this truck out. Or request the HP upgrade to the ? The injectors are probably getting close to needing replaced so Id go with ones and the download. I take that back. The AI has And the has ft pounds of torque. Get a good boost pressure guage and see that your in the psi spec. I ended up with a program they called "the smoke file". They said it was made for the bottom end pull, and the truck has more power. But now I feel a lag in the pedal and don't know if I should get a new throttle positioning sensor or just go ahead and get the injectors. Mack tech, did the 5" exhaust come in yet? Did they give you part numbers? Dont waste your money on the throttle pedal. The rest is then in the engine module EECU. I know the pedal was calibrated, but they didn't tell me if they went to the 12b or not. I have to go back because my engine oil temp sensor got turned off and I'll make sure it is moved to the 12b then. Looking back I forgot to mention that it has the mack t ten speed, not sure if that makes a difference. After a full day of working the truck, it is way better than before. By tuffenufOctober 27, in Engine and Transmission. Just got 2 know, why this Mack does not have the power it should? No boost gauge on truck seems I drive around with fuel pedal mashed towards floor, and doesn't seem able to get up and go? Hate the need to constantly stay near redline. Pyro never aboveno boost leaks, clean filters, maybe grossed out 73K is too much for the pup. Mack has real problem with emmisions restrictions choked engine. I have a turbo and injector combo that wakes engine up. Thanks for the infoI did talk to service manager and got to get there for appointment. Boost gauge will be installed to monitor things. You can post now and register later. If you have an account, sign in now to post with your account. Paste as plain text instead. Only 75 emoji are allowed. Display as a link instead. Clear editor. Upload or insert images from URL. Engine and Transmission Search In. Recommended Posts. Posted October 27, Share this post Link to post Share on other sites. Posted October 29, I should call and ask about solutions, Thank You. Posted October 30, Posted November 2, Join the conversation You can post now and register later. Reply to this topic Insert image from URL. Go To Topic Listing. Sign In Sign Up.