355 Vortec Tuning. Watch the videos.
03-15-2014, 09:24 PM
#1
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355 Vortec Tuning. Watch the videos.
I built a 355. Flat top pistons, vortec heads, comp 262 xtreme marine flat cam, RPM air gap intake, GLM manifolds. I put on a Sea Demon 750 double pumper and new ignition. I am not quite happy with my tuning.
The first video is 12 degrees at idle, 32 all in. The carb had the idle set at 800 with the mixture screws about 1 1/4 out.
the next one is same timing but I played with the idle eaz and mix screws more. It Idled at 1000-1100. I felt it was too high but ran the best.
The last video ran at 750-800 but didnt sound as healty.
This is the first motor I have ever worked on that was carbed and not computer controlled. What do you guys think?
The first video is 12 degrees at idle, 32 all in. The carb had the idle set at 800 with the mixture screws about 1 1/4 out.
the next one is same timing but I played with the idle eaz and mix screws more. It Idled at 1000-1100. I felt it was too high but ran the best.
The last video ran at 750-800 but didnt sound as healty.
This is the first motor I have ever worked on that was carbed and not computer controlled. What do you guys think?
03-15-2014, 11:18 PM
#4
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wait until it warms up like mentioned..the AF screws you have out 1 1/4 turns,,put those at 1/2 turn and no more then one full turn...but first screw one of them all the way in,,if it still runs then you will have to reset the front throttle blades to stock spec..always leave the front one alone and raise and lower the idle with the rear one..
03-16-2014, 12:35 AM
#5
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Just adding some other info on top of to make sure your using a current gas blend. The RVP (Reid Vapor Pressure) of gas is totally different than it is in the winter months compared to summer months. My point is use current gas from the pumps since your weather is 36 degrees out trying to tune your motor. Some states change their gas blends & RVP 7 times a year because of climate change.
We have boaters quit using their boats after July in which is 110 degrees and then bring them in when its starts to freeze at 32 degrees for winterizations. A lot of times their engine will not start because the summer gas blend will not even light off or if it does start the engine runs like timing is way off or misfiring constantly.
Anyways maybe a pointer for someone trying to tune their motor in the winter months on what gas was left over in the tank from summer. Hawaii is the only state who does not change their gas blends or RVP because they have almost the same constant temps all year round. RVP or Reid Vapor pressure google it if you want to learn more about what the hell I'm talking about..
We have boaters quit using their boats after July in which is 110 degrees and then bring them in when its starts to freeze at 32 degrees for winterizations. A lot of times their engine will not start because the summer gas blend will not even light off or if it does start the engine runs like timing is way off or misfiring constantly.
Anyways maybe a pointer for someone trying to tune their motor in the winter months on what gas was left over in the tank from summer. Hawaii is the only state who does not change their gas blends or RVP because they have almost the same constant temps all year round. RVP or Reid Vapor pressure google it if you want to learn more about what the hell I'm talking about..
Last edited by BUP; 03-16-2014 at 12:42 AM.
03-16-2014, 01:12 AM
#6
Just adding some other info on top of to make sure your using a current gas blend. The RVP (Reid Vapor Pressure) of gas is totally different than it is in the winter months compared to summer months. My point is use current gas from the pumps since your weather is 36 degrees out trying to tune your motor. Some states change their gas blends & RVP 7 times a year because of climate change.
We have boaters quit using their boats after July in which is 110 degrees and then bring them in when its starts to freeze at 32 degrees for winterizations. A lot of times their engine will not start because the summer gas blend will not even light off or if it does start the engine runs like timing is way off or misfiring constantly.
Anyways maybe a pointer for someone trying to tune their motor in the winter months on what gas was left over in the tank from summer. Hawaii is the only state who does not change their gas blends or RVP because they have almost the same constant temps all year round. RVP or Reid Vapor pressure google it if you want to learn more about what the hell I'm talking about..
We have boaters quit using their boats after July in which is 110 degrees and then bring them in when its starts to freeze at 32 degrees for winterizations. A lot of times their engine will not start because the summer gas blend will not even light off or if it does start the engine runs like timing is way off or misfiring constantly.
Anyways maybe a pointer for someone trying to tune their motor in the winter months on what gas was left over in the tank from summer. Hawaii is the only state who does not change their gas blends or RVP because they have almost the same constant temps all year round. RVP or Reid Vapor pressure google it if you want to learn more about what the hell I'm talking about..
03-16-2014, 08:22 AM
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I had no idea they had different blends of gas. I knew diesel has winter blends but thought that all gas was the same. My fuel is from mid October. I think I will just wait till it warms up a bit.
03-16-2014, 10:21 AM
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the proper way to adjust the air/fuel ratio at idle speed is to open all adjusting screws one and one half turns, then put a vacume gage to read intake vacume,then start engine and let it run until it is warmed up and the choke is open,now you adjust the screws evenly to achieve the most vacume.you might need to adjust the idle screw that controles the closed position of the throttle blades.this information is just as it is written in the holley tech section.i forgot to mention this is done with the car in gear so in the boat the drive needs to be in gear in the water.
Last edited by mike tkach; 03-16-2014 at 12:10 PM. Reason: adding more info.
