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Rookie 03-30-2019 07:38 PM

What about just throwing 6-71's or 8-71's on? Probably best bang for the buck.

Griff 04-01-2019 12:31 AM


Originally Posted by Jim Diesel (Post 4679339)
Maybe check with The Blower Shop!


How much horsepower could you make out of the 525SC before changing to a bigger SC, could 700 hp be capable out of the 177 with the right heads, valvetrain, and pistons? I have also wondered if anyone has ever converted over to an EFI setup? Reason I ask is I have a pair of 525SC in my boat, I keep getting the bug to have a pair of 700-725 HP engines. I like the idea of keeping the 177 setup and improving it, but I also keep looking at switching to a Whipple EFI setup with good heads and a strong rotating assembly.

A 177 will never make 700hp.......well not unless you put it on top of a 550hp NA engine. It can only pump so much air so the boost it creates will add a max of about 150hp.

Precision 04-01-2019 09:13 AM


Originally Posted by Griff (Post 4679158)
I also went with a Crane 731 when I did the top end on my old 525SC. I ran about 7.5# of boost with no chiller.

Finding smaller pulleys to fit the Merc 177 splined shafts is nearly impossible anymore.

I have a few. NIB.

tmmii 04-01-2019 09:15 AM


Originally Posted by Precision (Post 4679779)
I have a few. NIB.

i just started looking so no idea how hard they are to find. How much for 2?

hogie roll 04-01-2019 12:08 PM


Originally Posted by Jim Diesel (Post 4679339)
Maybe check with The Blower Shop!


How much horsepower could you make out of the 525SC before changing to a bigger SC, could 700 hp be capable out of the 177 with the right heads, valvetrain, and pistons? I have also wondered if anyone has ever converted over to an EFI setup? Reason I ask is I have a pair of 525SC in my boat, I keep getting the bug to have a pair of 700-725 HP engines. I like the idea of keeping the 177 setup and improving it, but I also keep looking at switching to a Whipple EFI setup with good heads and a strong rotating assembly.

Of course, if the engine can make a lot of HP with out it.

MILD THUNDER 04-01-2019 12:13 PM

Have them do a steady state pull at 5400rpm. Im sure the power will fall off after a few seconds there.

I think 650hp is about where the 177 starts failing at power production. The blower only has so much capability to move more air than that. You need air to make power. They do make some great low end torque. Sort of like a 2.3L whipple, they make great low end, but they are somewhat limited to hp capability. Youre not gonna want a 2.3L for a 1000hp engine.

Usually lower static compression, and more boost, will make more power than higher static compression, and low boost. Filling the cylinder with more air and fuel will be better than filling it with more metal and less air/fuel.

dykstra 04-02-2019 08:03 AM

Another vote for the 731 cam here. I have one in my 525SC and love it!

tmmii 04-03-2019 07:53 PM

Wow the new shaft kits are $280 per blower from tbs. really not a bad price with what all it came with and the pulley selection it opens up.

phragle 04-03-2019 10:03 PM


Originally Posted by Griff (Post 4679740)
A 177 will never make 700hp........

Sure it will..but only for a very short time, as an added bonus, the resulting scrap metal is recyclable too,,,,


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