Clutch47 Posted March 3 Share Posted March 3 Thought ya'll might get a kick out of something I saw yesterday. A Benz of some vintage that needed the attention of the youngest wrench turner in my friends business. The mock up block has a nice window in the front if you look. FNG said he shifted to 3rd at about 3300 and the balancer along with the front of the crank fell out onto the road. Crank broke at #2 and FODded the roadway... so the Mustang donated the mock up engine. They're figuring out how to do a legal exhaust now. Motor mounts are after that.. 🤣 Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted March 3 Share Posted March 3 Thought ya'll might get a kick out of something I saw yesterday. A Benz of some vintage that needed the attention of the youngest wrench turner in my friends business. The mock up block has a nice window in the front if you look. FNG said he shifted to 3rd at about 3300 and the balancer along with the front of the crank fell out onto the road. Crank broke at #2 and FODded the roadway... so the Mustang donated the mock up engine. They're figuring out how to do a legal exhaust now. Motor mounts are after that.. 🤣 Jeez. Some people's kids... 🙄 Link to comment Share on other sites More sharing options...
Gary Lewis Posted March 3 Author Share Posted March 3 Jeez. Some people's kids... 🙄 The balancers on some of the Benz V6's were known to walk off and cause quite a bit of excitement, but hadn't heard about breaking the crank. Ouch! Link to comment Share on other sites More sharing options...
Nothing Special Posted March 3 Share Posted March 3 The balancers on some of the Benz V6's were known to walk off and cause quite a bit of excitement, but hadn't heard about breaking the crank. Ouch! When I worked in an engine test lab at General Motors (and yes, I drove a Ford truck to work), once I was looking into a dyno cell through the window and saw the harmonic balancer coming off an engine that was at about 6500 rpm. I yelled at the tech to shut it down. He hit the e-stop button which turned the 600 hp DC dyno into a 600 hp electric motor trying to turn the engine backward. I couldn't believe how far that engine torqued over! No way I'd have thought the motor mounts would allow that much motion! But we were too late, the balancer did come off. For what seemed like about 5 minutes (but was probably closer to 5 seconds) we listened to it bang off everything it could find. The bangs started coming farther apart, and as we waited to see if we had heard the last bang I had an image in my head from a Roadrunner cartoon, where the balancer was sitting there, spinning, waiting for us to open the door so it could take a run at us as soon as we opened the door! Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted March 3 Share Posted March 3 When I worked in an engine test lab at General Motors (and yes, I drove a Ford truck to work), once I was looking into a dyno cell through the window and saw the harmonic balancer coming off an engine that was at about 6500 rpm. I yelled at the tech to shut it down. He hit the e-stop button which turned the 600 hp DC dyno into a 600 hp electric motor trying to turn the engine backward. I couldn't believe how far that engine torqued over! No way I'd have thought the motor mounts would allow that much motion! But we were too late, the balancer did come off. For what seemed like about 5 minutes (but was probably closer to 5 seconds) we listened to it bang off everything it could find. The bangs started coming farther apart, and as we waited to see if we had heard the last bang I had an image in my head from a Roadrunner cartoon, where the balancer was sitting there, spinning, waiting for us to open the door so it could take a run at us as soon as we opened the door! And that's the reason test cells are bulletproof.... 😱 Link to comment Share on other sites More sharing options...
Gary Lewis Posted March 3 Author Share Posted March 3 When I worked in an engine test lab at General Motors (and yes, I drove a Ford truck to work), once I was looking into a dyno cell through the window and saw the harmonic balancer coming off an engine that was at about 6500 rpm. I yelled at the tech to shut it down. He hit the e-stop button which turned the 600 hp DC dyno into a 600 hp electric motor trying to turn the engine backward. I couldn't believe how far that engine torqued over! No way I'd have thought the motor mounts would allow that much motion! But we were too late, the balancer did come off. For what seemed like about 5 minutes (but was probably closer to 5 seconds) we listened to it bang off everything it could find. The bangs started coming farther apart, and as we waited to see if we had heard the last bang I had an image in my head from a Roadrunner cartoon, where the balancer was sitting there, spinning, waiting for us to open the door so it could take a run at us as soon as we opened the door! Yikes! I can only imagine! Those balancers are heavy, and spinning at 6500 R's would make them very dangerous. Link to comment Share on other sites More sharing options...
Nothing Special Posted March 3 Share Posted March 3 And that's the reason test cells are bulletproof.... 😱 Yes! And the window I was looking through was double-paned bulletproof glass, set in the wall at a 45° angle, so anything flying into it would be deflected to the floor rather than giving a direct hit to the glass. The fire suppression system in the dyno rooms was pretty serious too! Link to comment Share on other sites More sharing options...
Clutch47 Posted March 4 Share Posted March 4 When I worked in an engine test lab at General Motors (and yes, I drove a Ford truck to work), once I was looking into a dyno cell through the window and saw the harmonic balancer coming off an engine that was at about 6500 rpm. I yelled at the tech to shut it down. He hit the e-stop button which turned the 600 hp DC dyno into a 600 hp electric motor trying to turn the engine backward. I couldn't believe how far that engine torqued over! No way I'd have thought the motor mounts would allow that much motion! But we were too late, the balancer did come off. For what seemed like about 5 minutes (but was probably closer to 5 seconds) we listened to it bang off everything it could find. The bangs started coming farther apart, and as we waited to see if we had heard the last bang I had an image in my head from a Roadrunner cartoon, where the balancer was sitting there, spinning, waiting for us to open the door so it could take a run at us as soon as we opened the door! Your description of the cartoon version of the story makes me laugh.. All I can see is the Tasmanian Devil cartoon. The little tornado stops and its actually a balancer...looking for its next victim.🤣 This young man's story about his crank doing a disc Defrag isn't the first time I've heard of the early HO engines letting the crank leave the party early before that main cap. I'd suspect it's because of all the contributing unbalanced and unaccounted for forces happening before that main cap. Fuel pump eccentric comes to mind along with timing set and oil pump/distributor all making different vibrations. Who knows.... 🤷♂️ Link to comment Share on other sites More sharing options...
mat in tn Posted March 4 Share Posted March 4 Your description of the cartoon version of the story makes me laugh.. All I can see is the Tasmanian Devil cartoon. The little tornado stops and its actually a balancer...looking for its next victim.🤣 This young man's story about his crank doing a disc Defrag isn't the first time I've heard of the early HO engines letting the crank leave the party early before that main cap. I'd suspect it's because of all the contributing unbalanced and unaccounted for forces happening before that main cap. Fuel pump eccentric comes to mind along with timing set and oil pump/distributor all making different vibrations. Who knows.... 🤷♂️ I bought my flareside a few years back with an engine knock. once the tow truck delivered it, we started looking into it. it turned out to be the outer ring had come loose and beat a hole in the timing cover. I fixed enough to be able to test drive through the subdivision a bit and prove the rest of the truck. once done I put in another used engine from stock and rebuilt the engine. last week we visited our son on base, and he was saying his foxbody had a knock. we looked it over and sure enough the outer ring was wobbling all over but was still along for the ride. I told him to shut it off and replace the damper before starting it again! I would NOT be surprised if he drove the 250 miles to fix it here. haha Link to comment Share on other sites More sharing options...
Gary Lewis Posted March 4 Author Share Posted March 4 I bought my flareside a few years back with an engine knock. once the tow truck delivered it, we started looking into it. it turned out to be the outer ring had come loose and beat a hole in the timing cover. I fixed enough to be able to test drive through the subdivision a bit and prove the rest of the truck. once done I put in another used engine from stock and rebuilt the engine. last week we visited our son on base, and he was saying his foxbody had a knock. we looked it over and sure enough the outer ring was wobbling all over but was still along for the ride. I told him to shut it off and replace the damper before starting it again! I would NOT be surprised if he drove the 250 miles to fix it here. haha Don't be surprised if you get a call from the side of the road. Link to comment Share on other sites More sharing options...
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