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Old 04-04-2014 | 01:39 PM
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Default 525 efi rebuilds

I'm nearing the end of my winter project rebuilding all three 525's at 400 trouble free hrs.

The blocks where bored .30 head surfaced .10
The new parts list was extensive
3 sets of everything Pistons,
valves,springs,rockers, lifters and port work
oil pumps, timing sets and a mountain of gaskets
also had the computers re-calibrated by Mark at Precision Marine

The motors showed signs of reversion so I have converted to dry exhaust. With the port work, dry exhaust and the new computer program I'm hoping for some power gains. My local speed shop doesn't want to mess with putting one on the dyno I wonder what kind of gains I'll see.
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Old 04-04-2014 | 01:49 PM
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what did you have to do to convert to dry exhaust?
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Old 04-04-2014 | 03:26 PM
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I would make them dyno because you rpbably need to check the ecu having made all these changes . Have the AFR checks done. It should be easy with dry exhaust.

Wannabe
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Old 04-04-2014 | 05:05 PM
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I agree with wannabe. Unless you are using a known good running engine and ecu set up, those engines should be dynoed to check the ecu mapping.
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Old 04-04-2014 | 08:55 PM
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Originally Posted by Cole-One
My local speed shop doesn't want to mess with putting one on the dyno I wonder what kind of gains I'll see.
Why do they have any say? Aren't you the customer?

Last edited by Rookie; 04-05-2014 at 10:54 AM.
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Old 04-04-2014 | 09:00 PM
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Dyno, then if a problem occurs you have recourse. Money well spent. Never know what happens once they fire
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Old 04-04-2014 | 09:02 PM
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Thats like the kid from mcdonalds refusing to sell you a big mac because you had poptarts for breakfast. Find a new place to eat.
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Old 04-04-2014 | 09:18 PM
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Mike,
Haul one down to:
http://www.sonnysracingengines.com/
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Old 04-04-2014 | 09:48 PM
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On the dyno is the best the time to find oil leaks. Highly likely there is at least one somewhere that will be hard to fix in the boat.
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Old 04-05-2014 | 12:51 PM
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Having the shop, that builds the engines not wanting to dyno all three of them is a RED FLAG. That in simple words is NO WARRANTY, testing all 3 engines is money in their pocket. Testing 3 engines should also be discounted, being they are the same and will only encompass set-up, break-in time, and final pulls. Any changes at that point if needed, unless you changed cams and rpms would be the same MAPPING, bore size of course is going to change. Any changes from that can be made in the boat, while gathering the proper data for those changes.
I would be worried more about proper machining and assembly over some oil leaks, if found on dyno can easily be addressed. Nothing leaves my doors without dyno testing, if they refuse to want to pay for testing, there's no need to even start the project. This is related to any performance type engine, it protects the shop and the customer. The same goes for a water test and sign-off for engine installation.
Not having them tested, then you or someone else installs them, is a open door for blame.
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