Engine Rebuilt Nightmare
#41
Registered
Just to give everyone here some more credible info:
Raylar has dyno tested on ours and other dynos probably more 496Mag and 496HO engines both stock and with our various upgrades, kits and engine packages than almost anybody on the planet.
A stock full y equipped 496Mag makes about 365-380HP at 4800 rpms at the crankshaft.
A stock fully equipped 496MAG HO makes 421-430 HP at 5000 rpms at the crankshaft.
This is on calibrated, SAE standard testing, with correction factors and specific fuel gravity calculation adjustments and these numbers are pretty much spot on - PERIOD!
Best Regards,
Ray @ Raylar
Raylar has dyno tested on ours and other dynos probably more 496Mag and 496HO engines both stock and with our various upgrades, kits and engine packages than almost anybody on the planet.
A stock full y equipped 496Mag makes about 365-380HP at 4800 rpms at the crankshaft.
A stock fully equipped 496MAG HO makes 421-430 HP at 5000 rpms at the crankshaft.
This is on calibrated, SAE standard testing, with correction factors and specific fuel gravity calculation adjustments and these numbers are pretty much spot on - PERIOD!
Best Regards,
Ray @ Raylar
#42
Registered
Join Date: Jan 2004
Location: San Diego, California
Posts: 2,777
Likes: 0
Received 6 Likes
on
6 Posts
Crankshaft versus propshaft horsepower?
I will post this one last time!
I know there is printed and website info from Mercury Marine and others that is confusing and sometimes just flat wrong.
My sources and tell me that since 2000, all Mercruiser (black)engines up to 2010 are dyno tested at the crankshaft on Mercruisers Stillwater dyno's.
The Mercury Racing (Blue) engines in Fond Du Lac are dyno tested on Mercruy Racing dyno's and are rated for approximate horsepower at the propshaft with their drive HP correction factors added.
This is why the HP525efi for example will test SAE on a new properly running engine fully equpped at about 540-550HP on most good dynos at the crankshaft and is rated at 525 HP at the propshaft.
Best Regards,
Ray @ Raylar
I know there is printed and website info from Mercury Marine and others that is confusing and sometimes just flat wrong.
My sources and tell me that since 2000, all Mercruiser (black)engines up to 2010 are dyno tested at the crankshaft on Mercruisers Stillwater dyno's.
The Mercury Racing (Blue) engines in Fond Du Lac are dyno tested on Mercruy Racing dyno's and are rated for approximate horsepower at the propshaft with their drive HP correction factors added.
This is why the HP525efi for example will test SAE on a new properly running engine fully equpped at about 540-550HP on most good dynos at the crankshaft and is rated at 525 HP at the propshaft.
Best Regards,
Ray @ Raylar
#43
According to the figures I've computed before, the TRS or III with a transmission will approach 10% driveline losses, while a Bravo is 5% or so.
#45
Registered
Thread Starter
iTrader: (1)
Join Date: Apr 2010
Location: SE FL
Posts: 1,459
Likes: 0
Received 0 Likes
on
0 Posts
I looked at the Livorsi site and did not notice an Air/Fuel gauge. I was wondering if their is a practical application for one on a boat?
I found this gauge on Auto Meter's site...
http://www.autometer.com/cat_gaugede...earch&gid=3607
I found this gauge on Auto Meter's site...
http://www.autometer.com/cat_gaugede...earch&gid=3607
#46
Registered
I will post this one last time!
I know there is printed and website info from Mercury Marine and others that is confusing and sometimes just flat wrong.
My sources and tell me that since 2000, all Mercruiser (black)engines up to 2010 are dyno tested at the crankshaft on Mercruisers Stillwater dyno's.
The Mercury Racing (Blue) engines in Fond Du Lac are dyno tested on Mercruy Racing dyno's and are rated for approximate horsepower at the propshaft with their drive HP correction factors added.
This is why the HP525efi for example will test SAE on a new properly running engine fully equpped at about 540-550HP on most good dynos at the crankshaft and is rated at 525 HP at the propshaft.
Best Regards,
Ray @ Raylar
I know there is printed and website info from Mercury Marine and others that is confusing and sometimes just flat wrong.
My sources and tell me that since 2000, all Mercruiser (black)engines up to 2010 are dyno tested at the crankshaft on Mercruisers Stillwater dyno's.
The Mercury Racing (Blue) engines in Fond Du Lac are dyno tested on Mercruy Racing dyno's and are rated for approximate horsepower at the propshaft with their drive HP correction factors added.
This is why the HP525efi for example will test SAE on a new properly running engine fully equpped at about 540-550HP on most good dynos at the crankshaft and is rated at 525 HP at the propshaft.
Best Regards,
Ray @ Raylar
#47
Platinum Member
Platinum Member
iTrader: (1)
I just did a repower myself....had a 496 and researched it quite a bit before selling it and going with brand new horses. I've heard good and very bad stories about trying to beef up the 496. It has cast internals and needs to be completely replaced to make any kind of difference with maintaining reliability. I've got the 25 OL(not the 26) and it's 150 lbs less...and my 496 mag(375 HP) pushed it to 63-65mph at 5000 rpm depending on temp. If you are turning a 26p B1 at 4900 rpm, you should be seeing 70 at least. I'm not a fan of the B1 as it creates azz lift instead of bow lift like the baja hulls require. The B1 is made for a heavier boat. My opinion is if you find the HP and start getting 75-80 mph out of this setup...the B1 will create some issues in handling vs going to a 3 blade Mirage. I'm
Artic, i'm curious about your comment on a 5 blade prop? You think the 5 blade will help in bow lift? Wouldn't it be hard to turn that thing to any rpm's with this setup? If you're getting 560 HP....IMO it should be turning a 25 Mirage. BBlades can offer a more professional than mine.
Artic, i'm curious about your comment on a 5 blade prop? You think the 5 blade will help in bow lift? Wouldn't it be hard to turn that thing to any rpm's with this setup? If you're getting 560 HP....IMO it should be turning a 25 Mirage. BBlades can offer a more professional than mine.
#48
Registered
Join Date: Sep 2005
Location: stoughton wi
Posts: 108
Likes: 0
Received 0 Likes
on
0 Posts
I am running a B 1 26 from B Blades. I have a box,cmi sport tubs,Whipple stage 2 up grade with the low t stat. I run 69 to 70 gps. I have seen 72 @ 5500 rpm. Only once on the st clair river.
#50
Charter Member
Charter Member
Join Date: Nov 2000
Location: Lake Charles, LA USA
Posts: 1,094
Likes: 0
Received 0 Likes
on
0 Posts
Interestingly enough your 26 B1 and the 23p (Mirage + ??) are at the same slip, 15.5%. What was your rpm at the 61 mph speed? 61 mph was before the motor mods right?, also was it before the box and the shorty? I assume the 61 mph was attained with the old prop?
My old Baja 272 did 65,66 with a 502EFI, 72 with procharger and 78 with procharger, gil exhausts, cam, ported heads and roller rockers.
My old Baja 272 did 65,66 with a 502EFI, 72 with procharger and 78 with procharger, gil exhausts, cam, ported heads and roller rockers.
__________________
Long time cult member.
Long time cult member.