How to get to 80 mph with a single screw
03-03-2010, 06:05 PM
#31
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Location: Wayland, MI
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Be careful of just adding the smaller pulley without lowering the timing down to 30 or 32. I also sent my carb. out to Nickerson for a rebuild as the engine was very lean before the rebuild after adding the pulley. Last idea may be to go to big tube headers from CMI or Lightning.
03-04-2010, 02:57 PM
#32
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Be careful of just adding the smaller pulley without lowering the timing down to 30 or 32. I also sent my carb. out to Nickerson for a rebuild as the engine was very lean before the rebuild after adding the pulley. Last idea may be to go to big tube headers from CMI or Lightning.
03-04-2010, 11:31 PM
#34
Those are pretty good numbers in that boat. Unless you have a screwed up prop, I seriously doubt you will get 4 mph by cutting on the wheel. And yes, I have some pretty good experience with a dialed in single engine.
If you want you can blow a few grand on a prop and exhaust for that extra mph or so. Bottom line, you are running good numbers and it will take some more power to get 80.
Don't get me wrong, a labbed prop has its place but big singles like power.
I run WELL over 80 in a single screw and have been fooling with them for quite some time.
If you want you can blow a few grand on a prop and exhaust for that extra mph or so. Bottom line, you are running good numbers and it will take some more power to get 80.
Don't get me wrong, a labbed prop has its place but big singles like power.
I run WELL over 80 in a single screw and have been fooling with them for quite some time.
03-05-2010, 01:06 AM
#35
Charter Member # 55
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I switched from the stock Merc Gils to CMI's and gained ZERO on the top end. Actually, Merc switched to CMI's the last year or two that they made 525SC's.
03-05-2010, 01:13 AM
#36
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Be careful of just adding the smaller pulley without lowering the timing down to 30 or 32. I also sent my carb. out to Nickerson for a rebuild as the engine was very lean before the rebuild after adding the pulley. Last idea may be to go to big tube headers from CMI or Lightning.
Like all Merc stuff, the stock jetting is set up on the rich side with #98 jets on all around and 6.5 PV's on both sides.
13* at idle with a 22* module that made full advance at 4250rpms for a 35* total. Stock boost is 2:1 overdriven for 5.5#.
03-05-2010, 06:12 AM
#37
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what I do not understand, if you talk to the blower guys at weiand (who made the blower setup on a 525) or read the install manual, they recomend a max timing of 26-28 deg...whats up with this....I have always found backing the timing down under boost works best...Rob
03-05-2010, 11:45 AM
#38
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Blower engines like all the timing they can get and as long as its not having detonation issues, its fine. The 7.5:1 static comp ratio in the 525SC allows you run more timing and boost without having to worry about detonation.
