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Nice, looks like propping for 5200 should be close and 25 mirage + for a starting point
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Originally Posted by Formula_272_SR1
(Post 4294632)
Guys,
I wanted to thank everyone for all the great information shared with me and the many PM's, phone conversations and other threads I have read.....As such, I owed you all a little follow-up. I spent the last year or so thinking about all my various options. I even debated just selling the boat and buying something else entirely. Honestly, I just couldn't come to terms spending a ton of $$ satisfying the missing performance. In the end, I love my 272 and fits exactly what I need. I find its an exceptionally good rough water boat. While it makes ZERO financial sense, I'm moving forward with the project and hope to create something "special" for my enjoyment while also getting the old bird ready for her 30th birthday. I still have a lot of planning, shopping and work.....however, here is a teaser from my dyno sheets. I have two new 383's sitting in my garage now. The only run time is the dyno. [ATTACH=CONFIG]540146[/ATTACH] "What should i expect ?" you may be asking yourself. Expect this: You clear the no wake zone of the marina...slowly throttling up. As the bow rises you suddenly move the sticks to get on plane. You then realize that the bow is already dropping to level and you nail the throttles. Without warning there is a loud whine that comes from the stern as the twin SBC's wind up and you are amazed at the tremendous acceleration that you are feeling...in fact it's so strong that your survival senses kick in as you try to process all that is happening in an un expected short period of time...you look down at the speedometer and the needle is quickly moving past 60 towards 70. You reach for the sticks and pull some fuel away from the two compact power houses behind you before things get out of control. A big grin appears on your face as you exclaim "HOLY $HIT".... Keep in mind that you are almost doubling the total amount of horsepower and torque while adding NO ADDITIONAL WEIGHT to your boat. Remember Newton's First Law of Motion?... I am "On the Hunt" for the right pair of Bravo I's and Transom assemblies for your boat...stay tuned. As I mentioned in the PM I sent...seriously consider setting aside the $$$ for new style low friction throttle and shift cables along with a Zero Effort controller. |
John,
As always, thanks for all the incredible help you have provided myself and others. While thinking about this conversion, I spent lots of time thinking about what's important and not falling into the trap of more is always better lol. As you noticed, I was looking for torque. Horsepower was really a secondary consideration. Durability and longevity were really the very first consideration for this upgrade. I want to be able to cruise comfortably in the high 30's or low 40's and still hit 70 when the right arm feels the need. No radical parts, just good selections including cast iron vortec heads. Based on all my research, 850hp and 900 ft lbs of torque should get the job done. Lots more parts chasing for me. Since the season is so short here in the NE, I might use the next couple of months chasing all the remaining parts required for this upgrade and just use the tired 260's this season. Then instead of winterizing, I'll pull the old engines and get the new ones properly dressed for spring 16. After all , why rush now. Rather take my time and do it right. |
Originally Posted by Formula_272_SR1
(Post 4294783)
John,
As always, thanks for all the incredible help you have provided myself and others. While thinking about this conversion, I spent lots of time thinking about what's important and not falling into the trap of more is always better lol. As you noticed, I was looking for torque. Horsepower was really a secondary consideration. Durability and longevity were really the very first consideration for this upgrade. I want to be able to cruise comfortably in the high 30's or low 40's and still hit 70 when the right arm feels the need. No radical parts, just good selections including cast iron vortec heads. Based on all my research, 850hp and 900 ft lbs of torque should get the job done. Lots more parts chasing for me. Since the season is so short here in the NE, I might use the next couple of months chasing all the remaining parts required for this upgrade and just use the tired 260's this season. Then instead of winterizing, I'll pull the old engines and get the new ones properly dressed for spring 16. Afterglow, why rush now. Rather take my time and do it right. |
What are the specs on these motors?
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Originally Posted by areyouliving
(Post 4295469)
What are the specs on these motors?
hypereutectic pistons, Moly rings, Scat cranks, Arp bolts, vortec heads with upraded springs,.500ish lift on 112, 9.5 to 1 compression |
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