454 Hp?

[sfitzgerald351]

So does anyone know what kind of horsepower my 1984 PCM 454 big block puts out? Insurance company wants to know and I haven't a clue. I told them 330HP since I think that's what Mercruiser used to rate their 454 Bravos at. Anyone know for sure? I've heard numbers as high as 425 HP, but I don't know how they measure it (crankshaft, prop shaft?).

[Footin]

I think it is 425hp.

[OhioProstar]

502s/496s are around 425...I don't think the older 454s were that high.

Stern drive 7.4liter engines are around 310.

Of course for insurance the lower the better since they may not make a difference between a go-fast boat with 400hps and a ski boat.

[OhioProstar]

There are 454 Mag options that could run 385.

[jsonova99]

502s/496s are around 425...I don't think the older 454s were that high.

Stern drive 7.4liter engines are around 310.

Of course for insurance the lower the better since they may not make a difference between a go-fast boat with 400hps and a ski boat.

They don't, atleast not the insurance companies that I got quotes from.

[ski_king]

Back in the early to mid 80's PCM had 2 454's available.

They had the 425 HP version and a 300 (or 325?) HP version.
The only one I ever saw in a MasterCraft was the 425 version with the powerslot that they called it the SuperSlot.

As far as your insurance company is concerned, I am sure you have the 300 HP version.

PCM may be able to tell you based on the serial number.

[Brn85ss]

My experience with the insurance tells me that what ever you tell them won't matter because they will get the specs. from their data bank if they are correct or not.My insurance will not carry anything with 350 hp or more period.

[ski_king]

I wasn't asked HP when I got my insurance, only top speed.
I was told by dealer ahead of time to be consertive with the answer.

[OhioProstar]

So there you have it....have you checked with Ski Safe. They may have a better understanding of inboard power vs. stern drive.

[Prostar19]

If it is a dual line carb it would be 425 hp
If you have the single line carb it will be 325 hp.
If you go with ski safe for insurance they still ask for hp but do understand that in a ski boat it is not for speed.

[sfitzgerald351]

What's a dual line carb vs. single line carb look like? I have separate feeds off the main fuel line for the primary and secondary barrels. Is that what you mean or something different? I also have the direct-drive transmission.

I agree with not telling the insurance company 425 hp. But I do want to know what the actual number is. I had trouble when I first got the boat getting it insured. My insurance agent couldn't get coverage since they didn't like even 330 hp in a 19' boat. I finally had to certify that the boat would only go 45 mph to make them happy. Ski-safe didn't care about the hp, just the top end.

[rodltg2]

tell them 285.

[sfitzgerald351]

Here's a photo of my carburator. You can see the fuel line going into the carb in two places (front and back ends). Is this dual-feed? If so does a single feed just have one fuel-bowl or does it route the fuel to two bowls internally? Or am I totally off base in my understanding?

[Jim@BAWS]

Scott yours is 335 HP Standard 454. Even though yours is a dual feed All 454 Marine where dual feed. The 425 HP Where considered HO motors.

The SUPERSLOT was a 440 Chysler with a POWERSLOT tranny. It had a HUGE prop and was used in a Barefoot version of the boat. Not alot where made. Yes I said Chyrsler (sp). Early 80's only 82/83. Used to own a ALL GRAY Metal flake one. great looking boat a REAL GAS HOG.

[SKI*MC]

well 454 goes by cubic inches, not by actual horses, i would say 375 if it was stock and not really built, but it really depends on what you are running in it.

[6ballsisall]

Scott yours is 335 HP Standard 454. Even though yours is a dual feed All 454 Marine where dual feed. The 425 HP Where considered HO motors.

The SUPERSLOT was a 440 Chysler with a POWERSLOT tranny. It had a HUGE prop and was used in a Barefoot version of the boat. Not alot where made. Yes I said Chyrsler (sp). Early 80's only 82/83. Used to own a ALL GRAY Metal flake one. great looking boat a REAL GAS HOG.


The mopar sounds cool!! Did it have dual quads?

[sfitzgerald351]

So Jim, if all the 454s were dual feed, how can you tell the 325/335 hp version versus the 425 hp version? The use of the powerslot trans? Something else?

Scott

[Jim@BAWS]

Scott, The feed system has nothing to do with it nor does the Powerslot.
Your motor, if it is stock is 335 HP. The High output 454 came out in 90/91. If your insurance company want HP rating tell them 335. Hope it is not STATE FARM i am sure it will be $700 PLUS. use a experienced Ins Company Ski Safe or Inamar. Probably $400 MAX. The powerslot IS NOT a hull design, It is a transmission. 1.5:1.0 1 and a half turns of the motor to on turn of the prop. Runs highr RPM's burns MORE fuel. Gets the RPMS up higher in the TORQUE Curve creating more power NOT HP.

Hope this helps.

[sfitzgerald351]

Thanks. Makes sense to me. The boat didn't pull like it had 425HP but lots of folks seem to get excited about that number when they saw the huge motor box on my boat.

[ski_king]

Scott yours is 335 HP Standard 454. Even though yours is a dual feed All 454 Marine where dual feed. The 425 HP Where considered HO motors.

The SUPERSLOT was a 440 Chysler with a POWERSLOT tranny. It had a HUGE prop and was used in a Barefoot version of the boat. Not alot where made. Yes I said Chyrsler (sp). Early 80's only 82/83. Used to own a ALL GRAY Metal flake one. great looking boat a REAL GAS HOG.
Jim, I didn't know they also offered the SUPERSLOT with the 440 Chrysler, but I do know they did offer it with the 454. I considered trading my 82 in on one in 83. I know the engine was a 454 GM. was told the HP was 425, but never quite believed it had that much. It had way more power than was needed. Top speed was a little over 50. Had a nice sound, but it was a gas hog and had twice the vibration my 82 351 has. The one I tested had a gray hull and maroon metalflake stripe.



Here is a copy of the 82 price list showing the option of the 454 GM Superslot (transmission).

[sfitzgerald351]

So I guess that goes back to my previous question. Were the 454s with the powerslot tranny rated at 425 while the direct drives were rated 335 or were they the same hp motors in front of both?

[mgurley]

A 335 hp motor is a 335 hp motor no matter what is behind it.

[sfitzgerald351]

A 335 hp motor is a 335 hp motor no matter what is behind it.

I understand that, but it seems that MC might have been putting the 425HP motor with the powerslot tranny and the 335 HP motor with the direct drive (different motors). Just trying to confirm the circumstances under which the motor is a 425hp vs. 335 since the information above conflicts a little bit.

[OhioProstar]

Honestly if it was an H.O., there would be stickers or stamping on the engine to that effect.

[sfitzgerald351]

All the stickers on the engine have faded so they really can't be read. I'd doubt I have the 425hp model, but I'll double check the serial number when I unwrap the boat later this spring.

[André]

Scott
If it sip a lot of gas,it's a 325 HP
If it sip gas like CRAZY ,then it's a 425 HP! LOL

[sfitzgerald351]

It's more like:

If it sips gas like CRAZY it's the 335hp.
If you need to own a small oil producing country to feed the motor it's the 425hp.

It's a gas hog for sure.

[jsonova99]

Who cares, 425Hp would be sweet!! :D

[Ski-A-Rees]

Not to get everyone started... but when my boat was beefed up with a super charger and a blower out the drivers side it was said to produce 500 HP. That boat set the world record 10 men around the boat ( Boat-O ) in southern region show ski tournament. Do you think those extra's produced the extra 170 Hp to get a 454 with around 330 Hp up to 500Hp? Mine only has the 1:1 Tranny!

[sfitzgerald351]

Do you still have the supercharger on your 454? Wow! I'd hate to see your gas bill, mine is bad enough.

[Doug Hodges]

Scott, I have an '85 Stars & Stripes with a PCM Ford 351 with 240HP. My PCM engine manual lists specs for their Chevrolet 454 and shows it at 330 HP @4400 RPM. Compression ratio is 8.8:1.

[sfitzgerald351]

Cool. Thanks!

So it seems the consensus is that the 454s were 330 hp until sometime later (90/91?) when a HO option came out boosting the HP to 425.