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Old 05-08-2006, 12:42 PM
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Default HP500 rebuild...what next?

Here's where we're at: Rebuilding both Gen 6, HP500 motors with a new set of Dart Iron Eagle 308cc heads (Inconel Valves) Crane Cam 168731 (copper). Already has a new Dart Intake on both. The only 2 areas needing attention is Carbs (so far just stock Holly 800, jets supposedly replaced from size 70 to size 80 but this doesn't make sense) and Exhaust so far just stock GILS with a weird NRS exhaust tube.

The question is...what's next?
I have not replaced the original ignition and figured a new MSD (6M-2, MSD8560 & Soft Touch Rev Control 8768) was next for this. Won't this be necessary in order to get everything synced up correctly and to increase the rev limiter?
The Holly 800 I'd like to just keep but didn't know what problems I'm going to face or if a 900-950+ was necessary.
And as for the GIL, I know my choices is GIL or CMI and would prefer CMI, but I'd like to just get on the water this year and look at a winter project for exhaust. I'd like to have silent choice but do not want reversion. I'm not counting ponies just want the most out of a reliable set up. OSO has been great source of information... keep it coming.
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Old 05-08-2006, 12:56 PM
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Default Re: HP500 rebuild...what next?

I sent my carbs to laz. I think the 800 is plenty.

I switched to the crane HI-6M ignition. You can play with the rev limiter and its a better spark.
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Old 05-08-2006, 01:09 PM
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Default Re: HP500 rebuild...what next?

Crane ignition is the way to go.
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Old 05-08-2006, 01:23 PM
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Default Re: HP500 rebuild...what next?

Originally Posted by cstraub
Crane ignition is the way to go.
Summit's Estimated ship date is 5/29. Anyone have a lead on 2?
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Old 05-08-2006, 03:51 PM
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Default Re: HP500 rebuild...what next?

I kept my Tbolt and switched to the V6 module and MSD rev limiter. No sweat, runs to 5800 and I still have the V8 module in the boat if something fails. Just need to change timing.
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Old 05-08-2006, 11:36 PM
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Default Re: HP500 rebuild...what next?

The 800 should be plenty of carb. As for jet sizing, stock jets are not 70's and jetting is staggered. Here are the stock jet sizes.

Pimaries--port-81, starb-75
Secondaries--port-89, starb-93
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Old 05-09-2006, 08:02 AM
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Default Re: HP500 rebuild...what next?

Go to the Crane 741 cam. The 731 is smaller than some of the HP cams. The new HP 525 cam has the same lobes as a 741 except it is ground with a 114 lsa instead of a 112 lsa.
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Old 05-09-2006, 08:08 AM
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Default Re: HP500 rebuild...what next?

Originally Posted by PatriYacht
Go to the Crane 741 cam. The 731 is smaller than some of the HP cams. The new HP 525 cam has the same lobes as a 741 except it is ground with a 114 lsa instead of a 112 lsa.
I almost begged for the 741. Crane told me the 741 is not for Gen 6. That only the 731 would work. I questioned it 3+ times and still received the same answer. Is crane wrong?
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Old 05-09-2006, 09:45 AM
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Default Re: HP500 rebuild...what next?

They changed the part no. I'm not sure what it is now. Do a search or maybe someone can chime in. Or use the new 525 cam. Again the part no has been listed here before, have to try a search.
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Old 05-09-2006, 10:14 AM
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Default Re: HP500 rebuild...what next?

The part no. for a mark 4, Gen 5 741 is now 139021. Have to use a cam button in a Gen 6 instead of the retainer plate. Maybe Crane can make one to fit a Gen 6.
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