BlueAndWhite

wat am i looking for? mine has the same fittings with the number 3X stamped ( could be 31 33 37, the second number is unreadable) nothing else.

flashgordon

Hello,,,looking for two tapped holes,,,one big one ,,one smaller one....i think all 4 bolts have the two tapped holes,,i dont think two bolt main have boths hole.....
Maybe someone else can verify????
Did you search for casting number???
I did search my casting numbers ,,comes right up telling me 4 bolt main

BlueAndWhite

Yes, i my casting number is posted a few comments above, witch comes out as 2 or 4 bolt main thats why i was asking about the oil fittings. My block has the same fittings as on the above picture.

Edit : Afther googling about this, a 4 bolt main will have a 3/8 small hole taped into oil galley(most foward) and a 1/2 biger hole(center)taped into oil, the 2 bolt will have a 5/16 small hole(most foward) not taped trough and a 3/8 taped into oil( center). Both will have a 1/2 threaded hole not taped in the rear.

Cant see from the pics ive taken but i will go verify my block next time i have access to it.

phragle

This would do it (know nothing of the seller or condition of the motor, but it would fit the bill)

525SC Engine

flashgordon

i dont think gen 5 are set up , casting wise for a mech fuel pump.
i put gen 5 502 is my 33 scarab,,,had to add electric fuel pumps.
if u have mech fuel pump, i think u have a mark 4 motor
maybe someone else can comment on...
keep posting..what u find

SB

Correct. No mech fuel pump bosses Gen V.

Rookie

Boost

Xcomunic8d

Here’s a build on a 454 and I’d look at skipwhiteperformance for the rotating assembly etc. make sure you really consider that compression ratio. I’d also look at a high rise intake manifold. Spacer too may net you some hp. Consider carefully the trade offs of low end vs high end. It’s almost impossible to get one without sacrificing the other.

in old days we’d swap out the intake, port the heads, maybe add a spacer, swap or tune the carb, swap a cam and fiddle with timing and distributors. If you were rich you could stroke it out.

now I’d go:
stroker kit from skip white (lots of options scat and eagle are good)
ported aluminum heads- pick your brand lots good ones out there
machine shop- block cleaned, decked, overbored (probably), balance the chambers, hone, line hone, heads get the works and a good valve job, crank polished and balanced (ask about bob weight), have your clearances mic’d, etc. just tell him what you’re doing and ask what he recommends on your budget. Give respect but make sure he knows what you’re after. Good guys eyes will light up.
timing chain and cam upgrade
Roller lifters
roller rockers are great on cars. I’ve heard horror stories on boats but I’m sure it can be done.

when choosing your cam make sure your exhaust manifolds won’t have reversion. My LS swap headers only allowed 226 on cam. Problem is these huge cams have both valves open at BDC and you get a vacuum that sucks water back into combustion chamber.,,BOOM. Fluids don’t like to be compressed. Cars make tremendous power. Boats have engine failure. This can be avoided on some marine manifolds that are fully sleeved or designed for it. Just see what the max cam specs are…

this should give you a starting point on
YouTube search horsepower s3,e13. I can’t post links yet. Sorry.

of course you can go bigger like the 502 or more. But if you have a working 454 seems like a direction is laid out for you.

Fasterboatman

I used Skip White to great success. 572, with a marine cam, 9.2:1 compression, runs like a beast on pump gas. 12k per motor 2 years ago. Best decision Ive ever made having a drop in crate motor from Skip. Since I was swapping out Merc 496s, nothing, and I mean nothing swapped except the drives. I did a pulley to prop replacement. If you can, be sure that your peripherals will bolt up, then you can put all your old bits onto your new engine and save some cash. I also went with the Edelbrock Proflow-4 injection and that too has been great. 4000rpm 544hp/715tq and 4800rpm 634hp/694tq. Built for big torque at lower RPMs. With a lighter boat, your could jump the compression and put in a bigger cam and push that to much higher. Skip white will work with you. They have options if you ask. You can go with 454 all the way up to 632.

Start here if you go that route: https://www.skipwhiteperformance.com...ce-desc&page=1

But I would bet you cant get it done in your timeframe with the supply chain issues we have today.

Good luck!
-j

Shotgunn

I learned an expensive lesson, by holding my newly built, but broken in 509 full throttle for almost 15 miles. I felt that the engine had good enough parts and was built meticulously to the task. Wrong. I still am not sure why the failure occurred. Doesn't matter now. That was july 3rd(of course) and I was getting back out on the water ASAP. Ended up getting a 1053 forged steel crank in a .060 over Gen 5 454, good rods and decent pistons. I had very little available pistons to choose from, and had to go with 9.6-1 hypereutectics. My edelbrock heads(ported, marine) were unscathed, Conservative marine roller grind, and a bunch of goodies salvaged from the carnage. I do 91 octane non ethanol and have no problems, with a mild advance curve in the Daytona Sensors box. Guarantee the build( though never dynoed) is 500hp I never run at full throttle for very long and always keep the rpm under 5000. I know it is at the 500 mark as it pushes a Baja 272 past 70mph. I was back on the water on Aug. 15th. There is the recipe for easy and available 500hp.