VP 5.7 GXI-j Setting Distributor T

BRICH1260

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I am in the process of re-powering my engine. I have purchased a new VP GXI,320 hp long block and have some questions about distributor timing. I have installed the distributor and feel that I have it aligned properly with the engine in the #1 TDC position.

I have read conflicting information on setting of timing. Everything from it’s not adjustable, the ecm controls it, to 10 degrees BTDC, Can someone shed some light on what procedures I will need to do to make the engine run properly. Thanks.
 

alldodge

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Once your at TDC on number one, its drop in and go. If there are runability issues later, then there are other things that can be done.

This is Merc but its the same for VP

Click image for larger version  Name:	HVS Distributor Timing.jpg Views:	8 Size:	63.0 KB ID:	10686943
 

aimlow

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Once your at TDC on number one, its drop in and go. If there are runability issues later, then there are other things that can be done.

This is Merc but its the same for VP


Those distributors are crap. Used only on GM CSFI vortec engines in real life. Timing is NOT adjustable. Gap the plugs to 0.038" to reduce voltage requirements.
 

BRICH1260

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My distributor rotor is oriented in the location as the diagram above and the oil pump tang is engaged. But I notice that the distributor base rotates a few degrees either way until it strikes the intake manifold. This rotation has the effect of slightly changing the contact point between the rotor and the distributor cap contact. This adjustment is what I am uncertain of. Where in this allowable rotation do I stop and tighten down the distributor hold down bolt. Do I need a Rinda type scanner to make this final adjustment?
 

alldodge

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Bring the number 1 cylinder to TDC, then align as in pic above, tighten bolt and your done.

Issue that may be of concern is how close you are to TDC when installing the distributor. Could use a piston stop bolt if needed
 

Wave34

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If you have an old distributor cap, make a hole with a hole saw or other tool just near of the #1 cyl.
Then you can adjust the distributor to have the rotor tip centered to the contact of #1. (engine at TDC on cyl 1)
 

BRICH1260

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If you have an old distributor cap, make a hole with a hole saw or other tool just near of the #1 cyl.
Then you can adjust the distributor to have the rotor tip centered to the contact of #1. (engine at TDC on cyl 1)

I may try this method to get close as I do have an old cap I can sacrifice. The new engine appears to have been shipped in the #1 TDC location based on valve positions and new indicator marks on the harmonic balancer.
 

alldodge

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I wouldn't do that because that shows where the distributor is pointing at, not where the crankshaft and piston is. You will gain nothing by doing it this way.

You have 2 ways to find out TDC without limited disassembly.

1) If the harmonic balancer has a groove and tab on the timing chain cover, then remove port valve cover and watch for both valves to close and then get the groove to the tab.

2)If no tab and groove, you need a piston stop bolt or remove timing cover so the cam and crank gear can be seen for alignment.

If the motor was running before and the crankshaft was not moved with the distributor out, then just reinstall.
 

aimlow

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I may try this method to get close as I do have an old cap I can sacrifice. The new engine appears to have been shipped in the #1 TDC location based on valve positions and new indicator marks on the harmonic balancer.

Y'know, that's not a bad idea, but here's the catch. The timing doesn't stay at Zero with the engine running..it may advance 30 degrees or more. At 30 degrees advance the pointer is way off the terminal. Sometimes setting the distributor so the rotor and terminal line up at 15 degrees advanced splits the difference.

Ascertain the line on the damper is indeed TDC. Use a piston locator on # 1 cylinder., but remember, every 8 cylinder firing sequence, TDC comes up twice! Once on firing TDC, once on "crossover" TDC.
 

BRICH1260

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The one thing that I seem to be learning with setting cam retard is that it is probably not something I am going to be able to get perfect without a trip to the dealer so that they can put the engine on the computer scan tool. Was kinda hoping to avoid that.
 

alldodge

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The dealers scan tool will not help the dealer either installing the distributor correctly.

I'll put it this way, if you get it close to TDC and install the distributor you will be either on target within a degree, or you will be off one tooth. The distributor has very little room to move, so if its not close your not going to be able to align it. If it doesn't start and backfires then your off one tooth.

That said you need to get it close, so pull the valve cover and number one plug
 

Lubak572

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I thought you needed the Volvo Penta timing shunt.

Volvo Penta part #885163 or a homemade jumper on those distributors
 

aimlow

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The one thing that I seem to be learning with setting cam retard is that it is probably not something I am going to be able to get perfect without a trip to the dealer so that they can put the engine on the computer scan tool. Was kinda hoping to avoid that.

That's why your method is ideal. The cam retard used a pickup in the distributor with round shield with 180 degree cutout. Whether or not the cutout was thru the sensor told the brain which phase the engine was on.
 

BRICH1260

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Thinking about purchasing a Rinda scan tool to read the cam retard , as an option to taking the boat to the dealership and paying their fee and save the hassle. I`m guessing that they would charge a couple hundred dollars at least. I could save that money toward the scan tool and do it myself and have the tool then for future use.. As you may know, they are kind of salty, about $600.

Does anyone know of a similar device that would read the cam retard, hook into my VP system and be less expensive?
 

aimlow

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Thinking about purchasing a Rinda scan tool to read the cam retard , as an option to taking the boat to the dealership and paying their fee and save the hassle. I`m guessing that they would charge a couple hundred dollars at least. I could save that money toward the scan tool and do it myself and have the tool then for future use.. As you may know, they are kind of salty, about $600.

Does anyone know of a similar device that would read the cam retard, hook into my VP system and be less expensive?

Don't do it..your method is perfect.
 

muc

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Using the scan tool to set cam retard is the "gold standard" but not necessary. Both MerCruiser and Volvo have published service bulletins on how to fine tune the HVS if just the straight drop in gives you troubles.
 

aimlow

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Using the scan tool to set cam retard is the "gold standard" but not necessary. Both MerCruiser and Volvo have published service bulletins on how to fine tune the HVS if just the straight drop in gives you troubles.

Thanks. Both Marinizers just get their info from GM. Sequential operation was more important for street operation than marine applications. The cutaway cap is a great idea. Alter the plug gap to the new spec, match the rotor to the cap, "retard" the distributor base slightly, make sure the plug wire resistance is manageable, those units should work fine.

My only other advice..don't replace cap or rotor unless they have failed. Replacement may be worse than what you have. Corrosion on the tips of the rotor/terminals does not constitute a problem.
 

BRICH1260

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Using the scan tool to set cam retard is the "gold standard" but not necessary. Both MerCruiser and Volvo have published service bulletins on how to fine tune the HVS if just the straight drop in gives you troubles.

AMTECH, Anyway of knowing how to get a copy or location of those service bulletins?
 

muc

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AMTECH, Anyway of knowing how to get a copy or location of those service bulletins?

While I sometimes see them posted online, the only way I know of is thru a dealer.
 
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