well I did it. I made a vortec 5.7 run reverse rotation! I didnt want to post until I have completed it. So this is what I did!
I removed the old 305 with the 2 piece main seal. I bought 2 marine 4 bolt 350 vortec crate motors used for $500.. they got submerged. one of the blocks was completely useable. breaking the motor down found the mains and the rod bearing with very little wear. ( I was told by the seller that both motors were rebuilt). I dont blind trust deals on craigslist, so I wanted to see the state of the journals). As reported on here in other threads, YOU DO NOT have to change the direction of the pistons. Its complete bullshit, I just honed the cylinders and called it good. Ok now with the bare block assembled without cam or the roller lifters, the fun begins. First remove the injection and timing sensor and sprocket off the 5.7. and slide on the cam drive gear, fits right on too with a lil heat.. then I slid the old 305 cam back in. Being that its reverse running, the grind it totally different to allow for the goofy firing order. the cranks and oil passages are the same. I did camphor the holes to allow for better oiling. because I cant use any of the roller cam stuff, it was scrapped and the original lifters were stuck back in the new block. Fitment was perfect! ok continuing.... the original heads from the 305 and intake were used because of the deck angle of the vortec heads would mean new intake and carb to match it . now... at this point some different parts are needed, Reverse rotation oil seals, water pump and some 1" steel spacers. I ordered a new marine oil pan and gasket, plus a high-volume oil pump. I swapped out the old 50 amp alternator to a new GM 110amp one and just fitted the explosion screen off of the old alt. Scrapped the old thunderbolt ignition ( burnt through 4 coils in 6 years,) with a slick HEI one from volvo marine. The flywheel was the only part I had to have custom made. Because Im switching to a 1 piece rear main seal the flywheel pattern is different. So I took a flywheel from a 1996 chevy k2500 had the ring gear removed, and new ring gear grove cut into the flywheel on the pressure plate side and the gear put on that. They did a sweet job and only cost me 125$. With the new oil seals in place the final assembly came together. here is where those spacers come in handy. The larger harmonic balancer requires clearance of the alternator bracket. this was as simple as fitting them behind the bracket. At this point the belt alignment was spot on for the rear belt groove. The raw water pump required a trip to the local wrecking yard in search of a shorter pulley and I found one in 5 minutes!
attached the bell housing, transmission, and starter. I did have to change the starter however to a PMGR type. the original starter would now move the motor, it was "tight". The Gear reduction starter turned the motor easily. with the plugs out I cranked the motor about 4 mins to pre oil the block. Motor insertion day!! I had a friend that has a service truck with a boom and stuck it in a 10 mins! ok big day.. i slipped teh boat in the local dock and started the motor. I had pre "timed" the motor to TDC a safe bet to get her to light. It started up with a pile o gas down the carb (new starts need it), and she fired right up. a quick ear adjustment of the timing ( yes I can do that, and other old timers can too), and we were off!. first breakin at 1500 rpm, next 45 mins, retuned to dock. oil changed, filter changed, fresh ooil in and back out. Still on break in we took it out for a 3 hour tour break in at 1500 rpm. judge for yourself. And each and everyone of you who wrote, milined , discouraged and doubted, I give you this..
I removed the old 305 with the 2 piece main seal. I bought 2 marine 4 bolt 350 vortec crate motors used for $500.. they got submerged. one of the blocks was completely useable. breaking the motor down found the mains and the rod bearing with very little wear. ( I was told by the seller that both motors were rebuilt). I dont blind trust deals on craigslist, so I wanted to see the state of the journals). As reported on here in other threads, YOU DO NOT have to change the direction of the pistons. Its complete bullshit, I just honed the cylinders and called it good. Ok now with the bare block assembled without cam or the roller lifters, the fun begins. First remove the injection and timing sensor and sprocket off the 5.7. and slide on the cam drive gear, fits right on too with a lil heat.. then I slid the old 305 cam back in. Being that its reverse running, the grind it totally different to allow for the goofy firing order. the cranks and oil passages are the same. I did camphor the holes to allow for better oiling. because I cant use any of the roller cam stuff, it was scrapped and the original lifters were stuck back in the new block. Fitment was perfect! ok continuing.... the original heads from the 305 and intake were used because of the deck angle of the vortec heads would mean new intake and carb to match it . now... at this point some different parts are needed, Reverse rotation oil seals, water pump and some 1" steel spacers. I ordered a new marine oil pan and gasket, plus a high-volume oil pump. I swapped out the old 50 amp alternator to a new GM 110amp one and just fitted the explosion screen off of the old alt. Scrapped the old thunderbolt ignition ( burnt through 4 coils in 6 years,) with a slick HEI one from volvo marine. The flywheel was the only part I had to have custom made. Because Im switching to a 1 piece rear main seal the flywheel pattern is different. So I took a flywheel from a 1996 chevy k2500 had the ring gear removed, and new ring gear grove cut into the flywheel on the pressure plate side and the gear put on that. They did a sweet job and only cost me 125$. With the new oil seals in place the final assembly came together. here is where those spacers come in handy. The larger harmonic balancer requires clearance of the alternator bracket. this was as simple as fitting them behind the bracket. At this point the belt alignment was spot on for the rear belt groove. The raw water pump required a trip to the local wrecking yard in search of a shorter pulley and I found one in 5 minutes!
attached the bell housing, transmission, and starter. I did have to change the starter however to a PMGR type. the original starter would now move the motor, it was "tight". The Gear reduction starter turned the motor easily. with the plugs out I cranked the motor about 4 mins to pre oil the block. Motor insertion day!! I had a friend that has a service truck with a boom and stuck it in a 10 mins! ok big day.. i slipped teh boat in the local dock and started the motor. I had pre "timed" the motor to TDC a safe bet to get her to light. It started up with a pile o gas down the carb (new starts need it), and she fired right up. a quick ear adjustment of the timing ( yes I can do that, and other old timers can too), and we were off!. first breakin at 1500 rpm, next 45 mins, retuned to dock. oil changed, filter changed, fresh ooil in and back out. Still on break in we took it out for a 3 hour tour break in at 1500 rpm. judge for yourself. And each and everyone of you who wrote, milined , discouraged and doubted, I give you this..