The "Blown Formula" Sonic Project !!
12-17-2008, 10:40 PM
#201
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Location: Marietta, Ga.
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Blown Formula, I have probably brushed elbows with you in the past. I used to be a volunteer at SGCH Fire Dept. until I left in Nov. 98. Still have family in Checotah/ Shady Grove.
I am very familiar with the area. Spent many days on the lake and used to spend weekends on the (north) side of the island. We always put in at Porum Landing. It is an awesome lake!! Small world!!
I would like to get back out there sometime with the boat!!
Good luck with your boat! Look forward to seeing updates!!
D
I am very familiar with the area. Spent many days on the lake and used to spend weekends on the (north) side of the island. We always put in at Porum Landing. It is an awesome lake!! Small world!!
I would like to get back out there sometime with the boat!!
Good luck with your boat! Look forward to seeing updates!!
D
12-17-2008, 11:27 PM
#202
blown formula and DKerns you guys both firefighters? I am a Columbus Ohio firefighter. It is a great job isn't it. Blown Formula you have a sweet boat. What are you thoughts on the older Sonics structure wise?
01-23-2009, 11:08 AM
#204
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Structurewise a Sonic is very strong & HEAVY!! At least the '88 models were comparitively so to a lot of boats.... but maybe thats why they take rough water so smoothly & the ride is so good (better than my 312 Formula was!!).
We have found there was a compression ring failure of the second (only the second) ring. Most appear to have not seated around 25- 50% of the bore diameter. The bores were rechecked and found perfectly round & thecross hatch honing was still evident..... the engines never overheated so seeing as how the 1st rings sealed, the seconds did not & there was no other failure.... one has to assume bad ring sets. I am going back in with nodular iron 2nd rings rather than the original cast iron ones. I am also going to add beehive valve springs this time for more valve stability considering the roller lifters, somewhat radical cam profile. Gotta keep those aluminum heads in good shape!!
Engines are due out the 1st of March (I hope!!). I am running them on the dyno again also..... maybe this will be the last time!~!~
We have found there was a compression ring failure of the second (only the second) ring. Most appear to have not seated around 25- 50% of the bore diameter. The bores were rechecked and found perfectly round & thecross hatch honing was still evident..... the engines never overheated so seeing as how the 1st rings sealed, the seconds did not & there was no other failure.... one has to assume bad ring sets. I am going back in with nodular iron 2nd rings rather than the original cast iron ones. I am also going to add beehive valve springs this time for more valve stability considering the roller lifters, somewhat radical cam profile. Gotta keep those aluminum heads in good shape!!
Engines are due out the 1st of March (I hope!!). I am running them on the dyno again also..... maybe this will be the last time!~!~
01-23-2009, 11:12 AM
#205
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Thread Starter
Oh, I also found a small water leak that has bee eluding me....
the port transom donut gasket was leaking, so I removed both assemblies & am replacing the gaskets. I am also replacing the drive input shaft o-ring and seal as it was leaking lube also.
What's the saying.... a boat is a hole in the water in into which copious amounts of money disappear!!
the port transom donut gasket was leaking, so I removed both assemblies & am replacing the gaskets. I am also replacing the drive input shaft o-ring and seal as it was leaking lube also.
What's the saying.... a boat is a hole in the water in into which copious amounts of money disappear!!
05-09-2009, 08:47 PM
#207
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Ok, here we go....
we found several things wrong with the engines.... God must love my previous engine builder cause he must have been asleep when building these engines!! Here is a list....
top compression rings were collapsed, not sealing
cracked rod at the wrist pin end (naked eye visible)
cracked piston skirt (probably from the 1st build when the valves were hitting the pistons)
oil pickups were 2" too short to reach bottom of the pan,
push rods were too short ( wrong valve geometry),
broken roller lifter,
replaced valve springs with "beehive springs"
rehoned cylinders, valve job again, re-align bored the crank & cam, resized the rods again & balanced, of course all new bearings & plasma rings, drilled the piston oil ring grooves for oil control, titanium retainers, MLS head gaskets, replaced the Merc distributors with MSD billets, all MSD ignition, rejetted the carbs.
Dyno- #1 engine- avg@ 5250= 528.8hp 528.3 torque
4500= 420.4hp 490.6 torque
6000= 591.8hp 546.9 torque
Dyno #2- engine- avg@ 5250= 527.5 527.7 torque
4500= 428.9 500.6 torque
6000= 579.9 547.3 torque
They sounded great on the dyno. I have been waiting for the correct air bleeds to install & marinizing the engines. Just installed #1 yesterday and hopefully will get to #2 this week, if the rain stops..... I also had a blown Bravo input shaft seal which I replaced ( the gimbal was full of oil on removal).
I have high hopes this time!!
Wish me luck!!
George
we found several things wrong with the engines.... God must love my previous engine builder cause he must have been asleep when building these engines!! Here is a list....
top compression rings were collapsed, not sealing
cracked rod at the wrist pin end (naked eye visible)
cracked piston skirt (probably from the 1st build when the valves were hitting the pistons)
oil pickups were 2" too short to reach bottom of the pan,
push rods were too short ( wrong valve geometry),
broken roller lifter,
replaced valve springs with "beehive springs"
rehoned cylinders, valve job again, re-align bored the crank & cam, resized the rods again & balanced, of course all new bearings & plasma rings, drilled the piston oil ring grooves for oil control, titanium retainers, MLS head gaskets, replaced the Merc distributors with MSD billets, all MSD ignition, rejetted the carbs.
Dyno- #1 engine- avg@ 5250= 528.8hp 528.3 torque
4500= 420.4hp 490.6 torque
6000= 591.8hp 546.9 torque
Dyno #2- engine- avg@ 5250= 527.5 527.7 torque
4500= 428.9 500.6 torque
6000= 579.9 547.3 torque
They sounded great on the dyno. I have been waiting for the correct air bleeds to install & marinizing the engines. Just installed #1 yesterday and hopefully will get to #2 this week, if the rain stops..... I also had a blown Bravo input shaft seal which I replaced ( the gimbal was full of oil on removal).
I have high hopes this time!!
Wish me luck!!
George
Charter Member
05-10-2009, 03:25 PM
#210
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Thread Starter
Right, no Christmas card this year (or ever!!). I hope you are correct on the speed. Last summer even with the problems & one engine only turning 4500, I was running 75. I hope to be able to move up to 28" props or more from the 26" I was using. Patients is the key... I keep telling the wife that!!
