Dave at Wesco put some hopped up 330's together for "Dyno" here on oso about 10 years ago. 475HP, 5400RPM, Stock Crank/rods, no issues. Picked up 10+mph in his 31 sonic. I think at one point there was a dozen or so hopped up 330's making 450+hp running up and down the east coast of lake Michigan.

Yes I agree with you! That's why in my first post I agreed with everyone to leave his engines stock and run them for a few more years and save the money for better engines. My budget build 330 did not produce a significant gain in HP. But the OP and others wanted to see what you can do on a budget with a 330 so I posted my build.

i might have to hop up the 330s in my sea ray,now that would be one bad mo fo.instead of a top speed of 27 maybe il see 30.:boat:

I guess I miss the days when guys worked on their engines, rather than pulled them out and swapped them.

If 330HP out of a 454 is acceptable and all she wrote, nothing more can be done, I might as well start hanging around the prius forums.

Best of luck buying a set of 400+ hour used marine engines. Works so nicely when you drop 10-15k and get a pile of $hit delivered to your doorstep. So now your out that money, plus another bunch to rebuild them. But at least you'll have 20k into some 415HP monsters that might net ya a 8mph top speed gain.

I hear you! I don't know when guys stopped building their own boats or cars?? But guys like us that build our boats and engines ourselves are very far and few between now.

Apparently on oso, its okay to tear apart a HP500, put a better set of heads on, a better cam, and gain 75-100HP for 3k per engine. But if you want to gain 75-100HP from a 330HP 454, from a cam and head swap, you're wasting your time and money. If 400HP and 5000RPM blows apart a 4 bolt main, BBC cast crank and forged rods, I'd say you forgot to put oil in it. :coolcowboy:

Can we port those penis port heads and install some solid rollers?

i have an idea,lets buy all the 330s we can find,put afr265 oval port heads and some nice cams in them,il bet they will make 550hp at 5000 rpm.well put mercury marine out of business.we all know the cast cranks&small rods and cast pistons are good at 5000 rpm.:eekdrop:

Well said!!!
I only got a 2 bolt main running 400HP at 4800rpm for 3 seasons now!!

i heard there is a guy in texas that does MAGIC with the peanus port heads.

LOL!! I don't have peanut ports anymore but my 2 bolt with ARP studs is doing good at 400hp. I have beat the piss out off it for 3 seasons and still runs great at less than 5000rpm! I would not try and push it any farther.

My next engine will not be based off a 330. But I have been happy with my budget 330 build the last 3 seasons. And the best part about my build is I read posts and listened to all the guys that are posting right now in this thread.

wich of these 2 engines would be easier to sell?and wich one would you buy ?for me ill take the 600 hp500 for 6500 over the 400 hp 330 for 4000 any day of the week.but if the 330 is all that is in the budget id still wait until the 600 hp engine is in the budget but thats just me.

why do you want to build a different engine?

a lot of people underestimate the 2 bolt main block,with arp studs and a fresh line hone i would trust it to 500 hp all day long.

I'm on a budget as said in earlier posts and that's why I have the budget 330 build ( I'm a poor enlisted military man). I am saving money and would like to do a quality 502 or 540 build in a few years and would like to see at least 75mph in my boat.

for the record,this is the first mild and myself had different thoughts on engines.

no doubt in my mind you will achieve your goal and thank you for your service!

I agree. I also think people underestimate the limits of a cast BBC crank, in a 4 bolt main setup. How many 455 Buicks, Olds, Pontiacs, raced back in the day with cast cranks and 2 bolt mains, twisting out 500-600FT lbs at the strip every weekend? or the old Ford 427's racing back in the 60's spinning big rpm with a nodular?

Im not disagreeing that it is not near what a forged crank can handle, and wouldn't try to run 600-700HP with one. And definitely wouldn't run one with a roots blower hanging off the snout at that level. . But my original advice of bolting a pair of vortec L29 heads on, which can be had for pennies, would be a nice upgrade. Even if he stayed with a flat tappet setup, those heads, better intake and exhaust, he can see a nice increase in mph for not a ton of money.

Guys over on yellowbullet, chevelles.com, and some other sites, are running GM nodular bbc cranks, shifting at 6500+ making 600+hp with very few failures. They aren't as bad as people think. And I know Dave Wessledyke would not have used them in some of his customers builds at 475HP level if he felt they were timebombs.

Mike and Mild I have learned so much from reading your posts and you guys answering questions! My questions and other OSO members questions! I thank you both! I will be back on the Great Lakes soon! Either if get stationed on the lakes again or when I retire in 8 years. (I'm from MI originally). Hope to run on the big pond with you guys one day!

That's all i got to say I don't think I can be anymore help on this thread.

i know what you are saying but if 10 guys had the 475 hp 330, and 1 failed guess who would own the bad one,ME.

I don't think it's been brought up yet. How many hours are on the 330's in question?

I agree, I had a 468 years ago that was a shoe string budget build 2 bolt block, Gm cast crank, 3/8 rods. A used set of Merlin oval ports. Dynoed 514hp and 550+ ftlbs. Beat it mercilessly in a pulling truck which is one of those games where pride won't let your foot off the floor until the red flag waves or smoke roles out. Ran that motor hard for two seasons then it ended up in my buddies dually where it still lives.

420 hours on the boat, not sure if that is the same for the engines but both passed with great numbers for the leak down test and about 6 hours of run time without the slightest concern.

If I keep this boat I am going ahead with the upgrades to the 330s. The way I look at it is I can run around for another 2-3 years waiting to have the boat do what I want or I can do it now and roll it out in the spring time so I can enjoy it for the next two to three years.

I have just bought my first set of heads today for $185 I will pick them up tonight and have them in the shop tomorrow. If I can buy one more set of heads for a good price I will be easily on my way and under budget.

The way things have been going I will probably be able to buy a newer faster boat in 3-5 years If I want the same as many other OSO members have done.

What heads did you buy?

Cool! Now that you have a specific direction in mind it puts us all on the same page. I know some of my previous posts may have suggested otherwise but personally I would take much more pride in a pair of 400hp 454's I built myself than 500hp motors built by someone else. I have always had a greater respect for the guy that "built it himself" than the guy with the fat wallet and the big name on the valve covers.

420 hours isn't allot on a 330. I know of 330's that have gone 1200+ hours without ever being apart and a good leak down rate is a good sign that the short blocks are OK. You should be able to tell if the motors have ever been apart once you dig into them.

I'm going to assume you plan on doing all of the work without pulling the motors completely out of the boat. I'm not familiar with that engine compartment but make sure you have at least 22 inches from the timing cover to get the cams out.

I bought a set of L-29 heads. I already have two Mercruiser aluminum hi-performance intakes and on hp500 carb in my collection so I am hoping that these parts will work together, if not I will keep shopping until I get what I need.
I believe there is enough room to do the cam swap but I am pulling the engines out so that I have better access and the ability to clean and refresh everything in the bilge area. I far from a beginner at working on boats and pulling engines/drives but I am new at doing my own engine work so this will still be a fun learning experience.

Did Merc. ever have a oval port aluminum intake? I am pretty sure all Merc. motors with aluminum intakes where rectangle port. I know GM made a large oval port aluminum intake, but for some reason Merc. never used a large oval port setup.

Just my opinion, which you can add a buck too and by a cup of coffee,there are many many guys running some screaming 468's with cast stuff in them and oval port heads. You can make decent HP and alot of torque with Peanut port heads . Now I'm not talking about a 8 thousand RPM engine but they run Damn good.

My 32 fountain has a pair of bone stock blue water 454 merc inboard motors in it.Came out of a 39 sea ray.Boat with a a pair of stock 27 3 blade mirage props,1/2 tank fuel and 3 people in it will run on GPS 71.4 with the drives out WOT.I think if he just puts some decent used exhaust on it he will pick up some MPH then he could use the exhaust on a new build when the time is right.That is what we are going to do.Boat cruises all day at 48 MPH and around 33 3400 RPM It is a non step with 1.50.1 bravo's and easy on fuel. Just my 2 cents PS got the motors off craigslist for 3000.00 we ran cast cranks and 2 bolt motors with no problem for years in the ss flat bottom NP We were always on a budget.

To JBA there is something I always try to remember with a boat engine... Horsepower sells the boat.. TORQUE is what moves it. I tell you what I did with my engines which my not be what you want to do. 454 2 bolt block ARP studs and align-honed . Stock rods with ARP bolts resized them. Had it balanced, I have a cam grinder that worked with Mercury racing years ago to help them develop the engines so he knew exactly what I'm running, now my boat is a barge compared to you guys, 38 ft long with a 13 ft> beam and 15,000 lbs. So I went with a 060 overbore and a 210 tho. dome piston with 781 GM oval port cylinder heads. its about 9.25 cr. .Eldelbrock performer intake a HYD roller cam, Norris steel roller rockers and a marine HEI dist. I wanted **** loads of torque right off idle to about 4800 to 5000 rpms it will probable never see that many R'sI but wouldn't be afraid to spin it 6500. I was not worried about HP I wanted big torque numbers I realize the HP will come with the torque. Bottom line is decide what you want to do, have a boat that runs wfo all the time and have a hell of a time at the dock because it wont idle for crap or something you can do just about anything you want to just maybe not as fast as you could go if you had a different camshaft and cylinder heads. I admit my heads have a lot of bowl work and are port matched and SS valves but they are long way from a race head. You can get a good running boat just look around find out what you want to do and stick with your plan you have a foundation with what you have but for 1500 a engine will be tuff but I support you all the way. IT gets very expensive to change direction in the middle of a build. I was IHRA national record holder 1/4 and 1/8 mile in 85 and 86.. A/Gas ...468 bbc gm square port heads two 4500 on a tunnel ram 8.51 164 MPH would I put that engine in a boat ....HELL NO. I run a Top Alcohol Funnycar now and would I put that engine in a Boat.......Yeah just to be stupid, I have gotten older 53 and slowed down a lot but this is just my opinion that's all.

Very well worded! And I'm here for your example Jamie
My engine is original to the boat, I am second owner of my 1987' IMP Eleganze 255
Now here's my setup as follows
Original 2 bolt Main Block (stock was 330)
ARP everything.
Steel crank
Stock rods
Forged Pistons (wiseco/TRW) can't remember 10.5:1
Port match good Oval Port Heads reworked everywhere matched to Team G Intake
Solid Roller Lifter cam .693 .695 on a 104 LSA
Heads have comp cams stud girdles as well for valve train support
KrausMotorSports (me...lol) reworked 850 Holley idles great at 850-1000 and docking.
Also still running stock thunder bolt Mercruiser ignition. With 6cyl box
And huge 4.5" dry exhaust Stellings.
****now I am just freshening this setup for next season and I am looking @ around 2k for total rebuild in parts. Bearings seals, heads checked, line hone, crank cut and polished etc....
But I am only giving an example for Jamie. This is probably a MAXED setup of what the stock 330 could be? I have spun this to 6500 a few times and put me in the really low 70's. 23.5 pitch and 6500lb bucket of resin. I haven't dynoed but will this summer. My guess is maybe 500hp?? Maybe! Id love the power from my old 540ci but that's another story.

I would love to have a 632 or a Sonny Leonard 1008 CID screaming under my deck but Cubic inches=Cubic Dollars , there is no Replacement for Displacement , also something I wanted to add. You will hear alot about boat engines are hard on exhaust valves, I dont feel they are any worse than a race engine , most of the time when something has happened to a exhaust valve it was because the engine was lean, making sure your fuel curve is correct is a must !! A 7.4 330 HP is not a bad place to start, especially on a budget. ....Grasshopper Boat safe and remember to pull back throttle when boat leaves water.......GO BOOM.......nuf said..

Yes, keep in mind the Vortec heads are closed chamber around 110cc vs 119cc so you get a nice bump in CR......... I pretty much did exactly what Mild says here to my 2000 L29 motor. I did do afull rebuild with forged JE pistons and scat H-beam rods. Cast crank and a set of new Vortec heads with some mild porting and 2.19/1.88 valves. I picked up a new hyd roller cam for the 454 mag motor for about $150 brand new. Lift is .510/.540 and works fine with stock valvetrain. I was after a real flat torque curve and think I got it! Max rpm is only 4,400 but I did go up a prop size from 22P > 24P Bravo 3....... Top speed in my wellcraft cruiser was 47 now 51 MPH so I gained 4Mph turning the same rpm with a bigger prop. I did use a new stock style log exhaust and would recommended a 496 dry joint if you are changing........ I don't think I gained much from using th big valves and would not recommended it. I picked p a set on eBay that wre already done so Imfigured I would give it a try. Shop flowed them and said the gains were maybe 5% and no good above .550 lift.......... One mans trash is another's gold so I grabbed them for $750 complete! Perfect for my combo!
My engine is an MPI and I had to increase my fuel,pressure a bit to get my afr's in line. The only downside for me is the engine does run rich at idle and I have to clean or change the plugs a little more often than normal.
I never run full,throttle as i Don't see the need to beat this thing to death burning 29gph as well. I can cruise at 3,000rpm at 32mph burning 12gph, 3,700rpm Is 40mph burning 20gph so that is my fast cruise speed. Engine runs great 0N 87 octane. It's not a powerhouse but makes great torque right where it's needed! building an engine is all about using the right combo of parts for YOUR needs.... TBF