Help identifying Merc 454
 

1993 31 Scarab Thunder Im looking at serial number is OD511917 comes up as 454 with Bravo drive. Can anyone tell me which version it is? The guy says it has a QJet carb. Thanks

PPT website says 454 magnum bravo engine

https://www.perfprotech.com/mercury-...g/searchserial
i buy / bought a lot from these guys, good knowledge base and easy to use website with pictures / diagrams
story i got was mercury employee(s) started ppt after mercury closed stillwater

That's where I looked. I know it's a Magnum but aren't they all "Magnums" in that era, even the 330 hp versions ?

all magnums ? i don't think so,
tons of searching when i was looking for an engine leads me to believe
7.4 bravo is 330
454 mag is 365 and forged rotating assy

87 was the year they called 330's magnums. They were hooked to alphas cuz TRS was done and bravo wasn't out yet. They had the power to blow an alpha's brains out, so maybe by that definition they were magnums...

My 1993 454 mag in my Baja was 365hp. It had a Weber Carb, but I know Q Jets were used on them also depending serial#

TRS weren't done till '93.

it was available to buy. It was no longer installed in new boats. I have seen some confusion where some 330's come up as mags on some websites. Take a magnet to the intake manifold. If it sticks it is a 330.

Serial #
 

serial number comes back to 1991 454 Bravo. Magnum W/PS. It was manufactured 10/90. It was originally sold in a 1991 and put in a 28 Apache Brave. Don't see any other info on engine.

wow!

Pic of one engine and intake

https://photos.smugmug.com/photos/i-...X7QFxQS-XL.jpg

https://photos.smugmug.com/photos/i-...kszrCPm-XL.jpg

That is aluminum intake with winters snowflake on it. Correct OEM mag intake. So, it is a 454 mag intake. It could be a 330 with a replacement intake. Probably not. Probably 365 hp 454 mag, but not absolutely sure.

Thanks for the reply

The guy is a former cruiser guy who has only had it for 2 yrs....I know more about the boat than he does

I checked and it runs 25 mirages ...do you think 330s would pull 25s?

The odds of it being a 330 with rectangle alum intake are slim. To be sure, pull a valve cover and get head casting number, but these are mags. I had a 30 IMP with 330's in it and TRS drives. 72 mph with 25 merc props and 1000 hr 330's, so yes 330 could run those props. Really, 365 minus 330 is 35 hp. Not a lot. It is more the durability of the forged parts than the actual hp figure.

They were still installed on some new Cigarettes up until 1993.

I know, that is why I care so much. It is all the boat that will fit in my shop so I'll probably keep it for a long time so Id like to know what Im getting into. Thanks.

That pic also shows a Weber carb, not a quadrajet.

Ran the serial# at Mercruiserparts.com and it comes up as

• 454 MAG. BRAVO GM 454 V-8 1988-1992 - 0B721206 THRU 0D805068

Genuine Mercury & Mercruiser parts. CYLINDER BLOCK AND CAMSHAFT shows that the camshaft is # 431-9830

Going in my notes, I have the following on this Part #:

Hydraulic Flat Tappet Cam 454/502 Magnum Engines w/rectangular port heads
Merc Part#431-9830 / GM#14096209
004” 296*, 296*
.006” 286*, 286*
.050” 224*, 224*
.200” 130*, 130*
Valve lift with 1.7 .510”, .510”
LSA 115.5
ICL 114 ATDC
ECL 117 BTDC