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525SC Weiand 177 On A 454 MAG in Formula 242LS

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Old 03-29-2011, 09:13 AM
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Your compression ratio is good where it's at now. The 177 blower needs to be crutched up some with compression to work well on a bbc. I run 9.5:1 compression with alum heads. Don't mess with the heads. Just make sure you run conservative timing (30* max), a/f ratios (under 12 WOT) and keep the engine coolant cool, like 140-150f.

You should upgrade your fuel pump to 110-120gpm and take a look at your line sizes and total fuel system. Restrictions should be eliminated where possible. You should also add a fuel pressure gage so you can see what's happening at WOT. That will be the ulitmate determiner of if you need a better fuel pump/system.
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Old 03-29-2011, 01:30 PM
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The fuel pump will be fine for the power you are going to make. Unless you want to start spending a ton more money, I wouldn't worry about getting different heads. You could get some mild porting done on you stock heads and have the combustion chambers enlarged to about 120cc. That bring the CR down to about 8.5.
Griff, didn't Hawk Racing throw a 177 on a Merc 420Hp 454 to make their 525 Hawk motor? With that in mind, I just don't see why the stock compression ratio will hurt?
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Old 03-29-2011, 02:04 PM
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Griff, didn't Hawk Racing throw a 177 on a Merc 420Hp 454 to make their 525 Hawk motor? With that in mind, I just don't see why the stock compression ratio will hurt?
It won't hurt it will help. The 177 is a might small for a bbc. The higher comp ratio allows one to run the blower slower. I spin mine 11,700rpm which is as fast as I would want to go with them.
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Old 03-29-2011, 03:15 PM
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Griff, didn't Hawk Racing throw a 177 on a Merc 420Hp 454 to make their 525 Hawk motor? With that in mind, I just don't see why the stock compression ratio will hurt?
Yes, thats what Hawk did. I think the Hawk 525sc's were set up at about 4.5-5# of boost. The CR isn't the real issue.
He just needs to make sure that he doesn't run too much boost for the CR that he has.
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Old 03-29-2011, 03:17 PM
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Yes, thats what Hawk did. I think the Hawk 525sc's were set up at about 4.5-5# of boost. The CR isn't the real issue.
He just needs to make sure that he doesn't run too much boost for the CR that he has.
Thanks for the clarification Griff!

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Old 03-29-2011, 10:25 PM
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How big of a chance am I taking not changing the valves? I was reading the B & M blower guide and it made me nervous. As long as I run a fuel pressure gauge, a boost gauge and watch the water temp I should be fine assuming I keep the boost below 5#? Thanks.
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Old 03-30-2011, 08:18 AM
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Yes you will be fine, plus 93 octane, no more than 30* total timing and under 12 a/f at wot. It'll run like a raped ape.
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Old 03-30-2011, 01:07 PM
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How loud is a 177 at idle and wot? Will I be able to hear it with hatch down? I know the "whine" has to do a lot with the cog belt on bigger blowers and also the way the gears are cut? Thanks
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Old 03-30-2011, 03:43 PM
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Not much whine at idle. A little if you burb the throttles. Pretty pronounced at wot. At about 5000rpm engine speed the blower really starts whining.
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Old 03-31-2011, 12:29 PM
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How loud is a 177 at idle and wot? Will I be able to hear it with hatch down? I know the "whine" has to do a lot with the cog belt on bigger blowers and also the way the gears are cut? Thanks
At WOT the whine takes some getting used to. The whine of my twin 177s could be heard over the exhaust and stereo system at WOT.

If you have room for a chiller I would highly recommend it. These little blowers make a ton of heat, and power loss after WOT runs is very noticable. Once it cools back down the power is back, so if you race someone wait about 30 mins before you race them again
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