68FishNate
Member
I've scrolled past threads that have talked about this issue, and just need a further head examination.
Recently, I bought and rebuilt a 340. First time building a roller motor. It has been an art of patience and learning along the way. Cast crank and pistons reused, freshened and turned, block and heads checked with new bigger springs to match cam, new rings and hardware.
Fast forward to, I got it in the car and running, driving so I thought. I had the throttle linkage getting caught on the carb and turned that around. Problem solved. Now I have full throttle instead of sticking throttle. Last Tuesday, figured that out and decided im gonna finally go down the highway and see how it feels. Went a mile or 2, turned back around and got back on the highway and backfired drivers side muffler and now I have a hole. Don't waste time with patch kits, learned that. Got 2 new mufflers 2_1/2 inch. My inlet is 2_1/2", but my exit is 2". I had a cat shop fab 2 reducers to make up for the length of mufflers and got those installed, sealed, and bolted Saturday. Still had an exhaust leak and now after running, I was vibrating and shaking motor, shifter, car. I didn't and still dont think I'm off that far on timing, but I can't seem to see the line on passenger side timing marks to say differently. Tonight, I took it up to the shop that made the reducers and welded the exit side with the exit pipe. No more exhaust leaks. However, still have vibrations and loss of power. Stopped at oreillys, and checked plugs, wires, disconnected, reconnected, replaced 3 plugs, 2 had some oil on them.
Sorry about the long story. I had a 318 prior and thought that I could use the harmonic balancer that was less than 6 months old and put it on the 340, no issues. It was shiny I thought, still good. Everything else has been replaced in the 340 outside of pulley brackets and this balancer. I remembered I still have the balancer that was on the motor when I bought it, before I disassembled and put it in the machine shop. My question is, is this harmonic balancer a "meant for 340 externally balanced" balancer that I need to immediately put on my 340? Over thinking and over doing here, I think.
Recently, I bought and rebuilt a 340. First time building a roller motor. It has been an art of patience and learning along the way. Cast crank and pistons reused, freshened and turned, block and heads checked with new bigger springs to match cam, new rings and hardware.
Fast forward to, I got it in the car and running, driving so I thought. I had the throttle linkage getting caught on the carb and turned that around. Problem solved. Now I have full throttle instead of sticking throttle. Last Tuesday, figured that out and decided im gonna finally go down the highway and see how it feels. Went a mile or 2, turned back around and got back on the highway and backfired drivers side muffler and now I have a hole. Don't waste time with patch kits, learned that. Got 2 new mufflers 2_1/2 inch. My inlet is 2_1/2", but my exit is 2". I had a cat shop fab 2 reducers to make up for the length of mufflers and got those installed, sealed, and bolted Saturday. Still had an exhaust leak and now after running, I was vibrating and shaking motor, shifter, car. I didn't and still dont think I'm off that far on timing, but I can't seem to see the line on passenger side timing marks to say differently. Tonight, I took it up to the shop that made the reducers and welded the exit side with the exit pipe. No more exhaust leaks. However, still have vibrations and loss of power. Stopped at oreillys, and checked plugs, wires, disconnected, reconnected, replaced 3 plugs, 2 had some oil on them.
Sorry about the long story. I had a 318 prior and thought that I could use the harmonic balancer that was less than 6 months old and put it on the 340, no issues. It was shiny I thought, still good. Everything else has been replaced in the 340 outside of pulley brackets and this balancer. I remembered I still have the balancer that was on the motor when I bought it, before I disassembled and put it in the machine shop. My question is, is this harmonic balancer a "meant for 340 externally balanced" balancer that I need to immediately put on my 340? Over thinking and over doing here, I think.
