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View Full Version : 454 Built for Blower W/O Blower



RLJ676
01-23-2009, 09:05 PM
I'm planning on buying a boat this spring. I am intersted in 28 Panteras and AT's, or maybe a nice Cig Bullet. As this will be my first boat I've owned, and obviously first perfomance boat, I can't get reasonable insurance then on as much power as I'd like to get

I have found a Bullet I like, but it has blown 454's. It has the 250 blowers, and was built to run blown. I'd estimate the HP at 600 or so. They are set up with twin 4 barrels.

So, my basic question is could I run them without the blowers for a while, or put on a bigger pulley to get the HP below 500?

I'm just trying to get a feel for what the options would be other than lie about the power, which I wouldn't want to do of course.

MOBILEMERCMAN
01-23-2009, 09:26 PM
If it is your first boat I would suggest picking one with out blowers. Pick you that will go about seventy with stock power.

If you lie for your insurance it will be useless at claim time.

HaxbySpeed
01-23-2009, 09:32 PM
Lie about the power... :26:
Depending on what it's got for heads, you can do a cam swap and still make some decent power with 8.5:1 compression. I built a blown 454 for a buddy who ran out of money and didn't end up buying the blower. It still made 510hp and 530trq. Depending on deck height, gasket thickness, etc, you might be able to find a bit more comp as well.

RLJ676
01-24-2009, 02:22 PM
Lie about the power... :26:
Depending on what it's got for heads, you can do a cam swap and still make some decent power with 8.5:1 compression. I built a blown 454 for a buddy who ran out of money and didn't end up buying the blower. It still made 510hp and 530trq. Depending on deck height, gasket thickness, etc, you might be able to find a bit more comp as well.

Thanks. I'm not too concerned with making the most power for the first season. I would like to be able to just leave the blowers off for a summer or two then use them once I've gained experience enough for insurance to still be reasonable.

I'm just wondering if with the lower compression setup for blowers would they run reliably without them?

HaxbySpeed
01-24-2009, 02:38 PM
There's no problem running without them.

YoungPerformance
01-24-2009, 03:16 PM
There is certainly no problem running without the blowers. Nor will you do any damage. It just will not make as much power as it would if it had a little more compression. It all depends on what the comp. ratio is as to how much power it will make.
Eddie

HaxbySpeed
01-24-2009, 03:44 PM
There is certainly no problem running without the blowers. Nor will you do any damage. It just will not make as much power as it would if it had a little more compression. It all depends on what the comp. ratio is as to how much power it will make.
Eddie

Ya, what would you know about blower motors.. :03::03: :rofl:

RLJ676
01-24-2009, 07:00 PM
There is certainly no problem running without the blowers. Nor will you do any damage. It just will not make as much power as it would if it had a little more compression. It all depends on what the comp. ratio is as to how much power it will make.
Eddie


Thanks guys, that is what I was hoping to hear. :26:

I know I can get reasonable insurance with 425 a side (which won't push a bullet too fast :ack2:), and think that'd be a safe estimate for these without blowers, so I wouldn't be "lying" to insurance.

I just figure with them "built" for blowers, they will make less power without them, but be "overbuilt" for running that way and be able to use lower octane, right?

HaxbySpeed
01-24-2009, 07:51 PM
I just figure with them "built" for blowers, they will make less power without them, but be "overbuilt" for running that way and be able to use lower octane, right?

Right. :)

RLJ676
01-24-2009, 08:19 PM
Right. :)

Thanks.:sifone:

Now if I can just figure out financing an "old" boat, reasonable storage, etc....

But I'm glad to know that the engines won't be a dealbreaker on this one, assuming the compression test and leakdown would be good.

YoungPerformance
01-25-2009, 12:16 AM
Ya, what would you know about blower motors.. :03::03: :rofl:

I read some stuff about them in Family Handyman Magazine.:26:

Griff
01-26-2009, 02:11 AM
Thanks guys, that is what I was hoping to hear. :26:

I know I can get reasonable insurance with 425 a side (which won't push a bullet too fast :ack2:), and think that'd be a safe estimate for these without blowers, so I wouldn't be "lying" to insurance.

I just figure with them "built" for blowers, they will make less power without them, but be "overbuilt" for running that way and be able to use lower octane, right?

You are gonna need new intakes, carbs, and props. With new parts it'll probably run about 3k + labor to do both engines. I think CP Perf had some deals on an Intake/carb combo.

Birdog
01-26-2009, 09:51 AM
I owned a "blown" Bullet...Leave them on. You will love it !1

RLJ676
01-29-2009, 08:10 PM
You are gonna need new intakes, carbs, and props. With new parts it'll probably run about 3k + labor to do both engines. I think CP Perf had some deals on an Intake/carb combo.


The carbs wouldn't work still? I had figured an intake maybe, and props to run the best without them.

Hmmm, for 3K to take off what I really want anyways.... that would hurt.

RLJ676
01-29-2009, 08:11 PM
I owned a "blown" Bullet...Leave them on. You will love it !1

I would, but my insurance wouldn't.

Hell, it appears moot anyways though as I can't find insurance for a 20+ year old boat.:(

Griff
01-29-2009, 09:56 PM
The carbs wouldn't work still? I had figured an intake maybe, and props to run the best without them.

Hmmm, for 3K to take off what I really want anyways.... that would hurt.


The carbs are gonna be too big without the blowers and they are probably already tuned for the blower application. They are probably 950-1050cfm carbs.

The Hardin Marine intake/carb kits are $700 each plus shipping. If you can find a used set of props, you might get by just over 2k.

http://www.cpperformance.com/SearchResult.aspx?CategoryID=235&Manufacturer=47

duunoit
02-04-2009, 11:30 AM
Is that the one in Old Saybrook, CT? I was ready to go up there and look at it. It seemed like a very good price until I found out it didn't have a trailer...

(sitting on one in the ad pictures, nothing said about it not going with the boat)

Hollowpoint
02-04-2009, 12:18 PM
If the engines were built for the blowers and is not running more than 5-6lbs boost, I can almost garentee the carbs are not 1050's. They will be 750 to 850's probably. Although they will need to be rejetted, they can probably be reused for a N/A application.

But as others have already said, if the engines were done right, that is about the ideal engine combo for that boat with bravos. I wouldn't change them. I'd find another way with insurance. I hate to say it, but I only carry liability on mine for the same reason.

I have the EXACT same setup with the B&M 250 blowers running about 5lbs and am guessing I have just under 600hp (probably 575). The boat should run mid to upper 70's with that setup turning 27 or 28 pitch props.

RLJ676
02-07-2009, 05:17 PM
Is that the one in Old Saybrook, CT? I was ready to go up there and look at it. It seemed like a very good price until I found out it didn't have a trailer...

(sitting on one in the ad pictures, nothing said about it not going with the boat)


This one is in OK.

RLJ676
02-07-2009, 05:17 PM
If the engines were built for the blowers and is not running more than 5-6lbs boost, I can almost garentee the carbs are not 1050's. They will be 750 to 850's probably. Although they will need to be rejetted, they can probably be reused for a N/A application.

But as others have already said, if the engines were done right, that is about the ideal engine combo for that boat with bravos. I wouldn't change them. I'd find another way with insurance. I hate to say it, but I only carry liability on mine for the same reason.

I have the EXACT same setup with the B&M 250 blowers running about 5lbs and am guessing I have just under 600hp (probably 575). The boat should run mid to upper 70's with that setup turning 27 or 28 pitch props.

I believe I'll need coverage for a loan. Assuming I could get the loan on a 20 year old boat. I haven't even gotten that far due to the insurance issue.

eichhoma
02-11-2009, 12:36 PM
454's with 250 blowers are basically 525SC's.... 525 horsepower, unless there is some other mods that up the HP that much. JMO....

Griff
02-11-2009, 09:37 PM
If the engines were built for the blowers and is not running more than 5-6lbs boost, I can almost garentee the carbs are not 1050's. They will be 750 to 850's probably. Although they will need to be rejetted, they can probably be reused for a N/A application.


Just reread and saw they were set up with dual carbs. Like you said probably 750's or so. They could probably be tuned for running without the SC's.




454's with 250 blowers are basically 525SC's.... 525 horsepower, unless there is some other mods that up the HP that much. JMO....

250's instead of the 525SC/177s will give a gain of 20 hp or so. Also a compression increase, roller cam, mild head work will be good for another 50-60hp. Done right, you can get about 600-625hp out of 250's on top of 454's.

RLJ676
02-15-2009, 05:26 PM
Thanks everyone for the help.

I'm thinking at this point if it were too cost too much more for intakes and tuning to run without the SC's, I'd just keep on and pay more insurance.:26:

Hollowpoint
02-16-2009, 12:52 PM
Trust me. You will LOVE the blower whine and the sound of blower motors. Just take care of them and run good fuel.

TomZ
03-02-2009, 11:28 PM
I owned a "blown" Bullet...Leave them on. You will love it !1

More like you'll need them! Bullets are heavy boats for their size (I'm pretty much first mate for Hollowpoint's Bullet) and will need all the power you can get to cross the 70 MPH mark.

More than likely you'll be in the 525 to 550 HP range with the 250s on the 454s.

RLJ676
03-08-2009, 07:17 PM
More like you'll need them! Bullets are heavy boats for their size (I'm pretty much first mate for Hollowpoint's Bullet) and will need all the power you can get to cross the 70 MPH mark.

More than likely you'll be in the 525 to 550 HP range with the 250s on the 454s.

I think I've found insurance that'll work with the blowers......so I wouldn't consider taking them off in this case.:26:

I think these are built fairly strong, as the boat runs 75+.

I will post build sheets here for opinions as soon as I get them.