Setup For Weiand 177 On 454
08-07-2012, 08:22 AM
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Setup For Weiand 177 On 454
I've got a weiand 177 on a 454 mag in an 88 Formula 242ls. Motor is fresh and just broken in 4 bolt main forged internals 7.75:1 compression inconnel vales in steel heads with blower and carb off an old 525sc. Carb is a 1050 dominator. Boat only runs 62 mph gps with a 25p mirage plus prop at 30 degrees timing and 4800 rpm and 5lbs of boost. . It seems to run very rich the exhaust is getting the swim platform dirty everytime I take it out. I ran it before with a 23p mirage plus and it would turn too high 5500 at ~7lbs of boost but ran ~65 mph. I want to keep a safe tune most importantly but what can I do to increase speed and how fast should it run? More boost more timing? Thanks
08-08-2012, 04:14 PM
#2
my 454sc
88 scarab 30ft. twin 454, mercruiser weiand 177, 6lb. boost,
9.0 to 1 or 9.5 to 1 compression? 850 holley, 29p prop.
27degrees timing, 62mph gps at 3800rpm, rev limiter set at 4700rpm.
Runs a little rich at idle not bad.
dyno 2500rpm 603tq 305hp
dyno 4500rpm 540tq 460hp
hp still climbing at 4500rpm (cam lift .573?)
That makes me feel bad for the bravo1s.
Rev limiter for reentry.
9.0 to 1 or 9.5 to 1 compression? 850 holley, 29p prop.
27degrees timing, 62mph gps at 3800rpm, rev limiter set at 4700rpm.
Runs a little rich at idle not bad.
dyno 2500rpm 603tq 305hp
dyno 4500rpm 540tq 460hp
hp still climbing at 4500rpm (cam lift .573?)
That makes me feel bad for the bravo1s.
Rev limiter for reentry.
08-08-2012, 06:56 PM
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I ran 8.75:1 @ as far as 35
32 is safe.
merc is known for over carbing this set up, so idle speed is real fat = fuel on platform
Wouldn't go crazy with the boost. These mini blowers work hard & make a lot of heat already.
What is your estimated power high 400s?
32 is safe.
merc is known for over carbing this set up, so idle speed is real fat = fuel on platform
Wouldn't go crazy with the boost. These mini blowers work hard & make a lot of heat already.
What is your estimated power high 400s?
Last edited by scarab63; 08-08-2012 at 06:59 PM.
08-09-2012, 01:26 AM
#6
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Stock 525SC timing is 35* which comes in gradually up to about 4500rpms.
Stock CR is 7.5:1
Stock boost is 5.5#. Running 7# of boost is no problem with a 525SC. I did almost 8# for years.
Stock carb jets are 98's all around.
You should prop it to spin 5200 rpms.
With the right cam, you can make 550hp reliable hp.
Stock CR is 7.5:1
Stock boost is 5.5#. Running 7# of boost is no problem with a 525SC. I did almost 8# for years.
Stock carb jets are 98's all around.
You should prop it to spin 5200 rpms.
With the right cam, you can make 550hp reliable hp.
08-09-2012, 09:28 AM
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Cam is the #90767 b&m blower cam but there was no rpm listed on the cam card. I have no way to check a/f mixture. 98 jets in carb. So should I be safe with 7lbs of boost and 32 degrees timing? I have a 3" pulley I can try instead of the 3.5 I'm currently running. The loweer pulley is 7"
08-09-2012, 11:31 AM
#8
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What are the actual cam specs???
Stock 525SC cam is 228/236, .530/.551, 114 lob sep.
I should be plenty safe with 7# and 34* of timing on 92-93 octane fuel.
Stock 525SC cam is 228/236, .530/.551, 114 lob sep.
I should be plenty safe with 7# and 34* of timing on 92-93 octane fuel.
