what wrong with my 383 stroker ?or i am over prop
05-09-2017 | 04:24 PM
#22
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From: On A Dirt Floor
Hope no hard feelings. Typically if someone is from overseas they will mention this early in thread. So that we know / understand. Plus you said from Nebraska. Anyway, we do get some english speaking people from the states that do type this way out of laziness which makes it hard for someone to help / want to help.
05-09-2017 | 05:38 PM
#24
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From: On A Dirt Floor
i like to take for tune but i can not fine any tune shop in Lincoln ne,the big thing i worry my valve spring i was used it with new ls6 spring,i am not try to get this boat hit 70 mph but i would to know what i did wrong with engine ,last year i check compression every cylinder it got 170 to 180 .
05-10-2017 | 07:31 PM
#25
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From: NW Michigan
Did I miss what cam your running. I built a 383 for my 73 z with just the camel back double hump heads lightly worked at 10:1 com, dual plane intake and 292 comp magnum king of the drive in cam and that engine pulled hard up to 5,600. Adv cam 4 deg. 750 holley dp
05-10-2017 | 10:10 PM
#26
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1.5 roller rocker.
Aftermarket aluminum head 64cc 2.02 intake valve 200cc intake runner.
05-14-2017 | 06:40 AM
#27
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From: Lake Winnipesaukee, NH
It's the carb, but it could be other things too. I have an OE Weber 650 from a 97 350 Mercruiser Magnum on my 383. It is the same as an Edelbrock 650. Literally uses the same parts. I tuned and tuned it. No gains.
My boat is heavier, it's a 4000 lb "dry" boat with a 22 degree hull. Means the engine has to work harder to push it. But it rides well for it's size.
My 383 has very carefully thought out quench and compression. The quench distance is .040" and the compression is 9.85:1 static, 8.0:1 dynamic. It is extremely quick to accelerate, I do not have a strong enough drive to handle full-on wide open starts so I just ease it up to speed.
I am telling you this as background for the suggestion of a carburetor. My engine hits 4950 and stops accelerating with the Weber/Edelbrock. I have a 21 pitch stainless prop, it's a major brand, I forget which model at the moment.. I have done lots of carburetor jet changes and it always seems to stay the same or get worse.
My heads have smaller intake runners so it could be them holding me back. But you have slightly oversize which should allow extra rpms.
I just bought a 750 from Quickfuel, I am plumbing it this week. I will let you know soon if it gives me any top speed.
But a 650 isn't enough for a 383.
Wanna buy a full set of jets and carb tuning stuff for an Edelbrock?
My boat is heavier, it's a 4000 lb "dry" boat with a 22 degree hull. Means the engine has to work harder to push it. But it rides well for it's size.
My 383 has very carefully thought out quench and compression. The quench distance is .040" and the compression is 9.85:1 static, 8.0:1 dynamic. It is extremely quick to accelerate, I do not have a strong enough drive to handle full-on wide open starts so I just ease it up to speed.
I am telling you this as background for the suggestion of a carburetor. My engine hits 4950 and stops accelerating with the Weber/Edelbrock. I have a 21 pitch stainless prop, it's a major brand, I forget which model at the moment.. I have done lots of carburetor jet changes and it always seems to stay the same or get worse.
My heads have smaller intake runners so it could be them holding me back. But you have slightly oversize which should allow extra rpms.
I just bought a 750 from Quickfuel, I am plumbing it this week. I will let you know soon if it gives me any top speed.
But a 650 isn't enough for a 383.
Wanna buy a full set of jets and carb tuning stuff for an Edelbrock?
05-14-2017 | 10:24 AM
#28
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It's the carb, but it could be other things too. I have an OE Weber 650 from a 97 350 Mercruiser Magnum on my 383. It is the same as an Edelbrock 650. Literally uses the same parts. I tuned and tuned it. No gains.
My boat is heavier, it's a 4000 lb "dry" boat with a 22 degree hull. Means the engine has to work harder to push it. But it rides well for it's size.
My 383 has very carefully thought out quench and compression. The quench distance is .040" and the compression is 9.85:1 static, 8.0:1 dynamic. It is extremely quick to accelerate, I do not have a strong enough drive to handle full-on wide open starts so I just ease it up to speed.
I am telling you this as background for the suggestion of a carburetor. My engine hits 4950 and stops accelerating with the Weber/Edelbrock. I have a 21 pitch stainless prop, it's a major brand, I forget which model at the moment.. I have done lots of carburetor jet changes and it always seems to stay the same or get worse.
My heads have smaller intake runners so it could be them holding me back. But you have slightly oversize which should allow extra rpms.
I just bought a 750 from Quickfuel, I am plumbing it this week. I will let you know soon if it gives me any top speed.
But a 650 isn't enough for a 383.
Wanna buy a full set of jets and carb tuning stuff for an Edelbrock?
My boat is heavier, it's a 4000 lb "dry" boat with a 22 degree hull. Means the engine has to work harder to push it. But it rides well for it's size.
My 383 has very carefully thought out quench and compression. The quench distance is .040" and the compression is 9.85:1 static, 8.0:1 dynamic. It is extremely quick to accelerate, I do not have a strong enough drive to handle full-on wide open starts so I just ease it up to speed.
I am telling you this as background for the suggestion of a carburetor. My engine hits 4950 and stops accelerating with the Weber/Edelbrock. I have a 21 pitch stainless prop, it's a major brand, I forget which model at the moment.. I have done lots of carburetor jet changes and it always seems to stay the same or get worse.
My heads have smaller intake runners so it could be them holding me back. But you have slightly oversize which should allow extra rpms.
I just bought a 750 from Quickfuel, I am plumbing it this week. I will let you know soon if it gives me any top speed.
But a 650 isn't enough for a 383.
Wanna buy a full set of jets and carb tuning stuff for an Edelbrock?
Last edited by tk350; 05-14-2017 at 04:08 PM.
05-15-2017 | 08:31 PM
#29
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Joined: Sep 2009
Posts: 419
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From: Lake Winnipesaukee, NH
No, not a rebuild. Get a bigger carb. You should be able to spin a 23 all day in a 17 footer. I had a 23 on a cammed up 350 in a 19.5 footer and it made 4500 rpm. Light boat at 2700 lbs but still you have a 17 foot boat. A 383 should be scary fast in a 17 foot boat.
