Consider buying a 502 for my 242SS
 

Hi All

I am planing to uppgrade my 1988 242 SS

I looking to buy 502 (8,4L) mercruiser MPI 1999

Complitely rebuild and upgraded in 2008, gone 35 hours
since. Somewhere between 500 - 550 HP claimed by
current owner.

Question1:
Will there be space for this engine?? Of course with out the
headers ( see picture)
I think it is allready thight with my 454 standard 330 hp, Do the 502 have the same outside messures??

Question2.
What kind of top speed on a 242 SS with 500 hp ++??

Question3
What kind of price can I get for the existing headers, supose to be in mint condition?? See picture

Regards
Rune

Thier will be enough space for the engine, Im not sure about fitment with these headers though. For reference My 242 ls with performance bravo one and 509 c.i. is currently at 68 mph on gps with a 23p standard mirage (non plus) at 5200 rpms. The motor on the dyno made 470 hp and 550 ft lbs of torque. The motor originally made 525 but the builder ended up putting in a smaller cam on rebuild. I should see 70-72 when I get the proping figured out/ tweaked, and maybe a -2 shorty.

would you be interestred in trading your headers for a set of fully polished emi thunder exhaust?

Hi
Thanks for the reply

The engine room in a 242SS and a 242 LS is different , see attach pic. Thats why I am concerned about the space.

A guy I know in Sweden has upgraded his 242LS to a 496 HO Bravo1 1:65 prop bravo1 28 pich. Top end so far 64,8 mph GPS, not to bad. Are the 470 hp messured at the prop? If so I am sure with the correct prop you should see 70mph ++ :-)

Regarding the headers, first I did not buy the engine yet and second I am living in Norway (North Europe). I think we will have a transport/frieight price issue he he

I know their is a difference between ls and ss models, still you should have no problem with it fitting, and the hp numbers were at the crank I run a 1.50 ratio drive. Just thought I'd ask about the headers.

Engines are the same external dimentions. FYI those headers won't work with your boat. Those are for a boat with an SSM drivetrain. The HP that that engine is putting out will get you close to or at 70 MPH!

If I buy the engine the headers will be for sale :-)

Could a Bravo1 1.50 handle 500+ hp??

The engine in my 242 is putting out a little over 515hp... The bravo should be fine as long as you don't go WOT when getting on plane.. But I guess it also depends on how healthy your B1 is.. My B1 is only 2 years old, but I only go 60% throttle and the boat still jumps out of the water.. Once I'm on plane and trimmed I will increase the throttle if I want to go faster..

You'll love having a 502 in your boat.. I cruise right around 42 and am at 3900rpms, the engine feels like it's not even breaking a sweat!!

https://lh3.googleusercontent.com/-t..._242SS_010.jpg

Hi your boat look awsome for the age :-)

I am planing on doing an upgrade on my SS too

What is the speed at around 3-3200 rpm?

Have you tested the top speed yet?

What kind of proppeler do you use?

Thanks! I wish I could take the credit, but I just bought the boat 3 weeks ago.. The previous owner had it for 10 years. He is a commercial airline pilot so he only works 2-3 days a week.. I'm convinced he spent the rest of the week cleaning, maintaining and upgrading the boat... But anyway, back to you questions..

I have only taken the boat out on the water once... I haven't used it enough yet to figure out where the different sweet spots are. As for the prop, I think it's a 21 4 blade, ss of course. I might change mess around with different props next year...

Sorry I can't be more help!

You should be faster with that kind of power...

I had a 242LS with a 390HP 502 and 40-42MPH GPS was around 3600RPM with a 22 pitch 4blade

Really?? That's really good to know.. How high do you trim your outdrive? I'm wondering it I'm not bringing the outdrive up far enough..

Is that was a 3-blade or a 4-blade??

I will be taking the boat out 1 more time before winterizing it, and hopefully I'll be able to play with it some more..

edit: just saw you said it was a 4 blade.. What was your top speed??

61-62MPH GPS with that 22Bravo1 prop. You should be at 65+ easy with 515HP

I would assume 70+ or what??


A guy I know in Sweden has upgraded his 242LS to a 496 HO Bravo1 1:65 prop bravo1 28 pich. Top end so far 64,8 mph GPS, not to bad. This is veryfied GPS numbers 420 hp at the prop. Allmost 100 hp more, should at least make 5 mph more???

I am going to inspect the mentioned engine wednesday or thursday

A 28 pitch prop seems like too much, I would imagine his hole shot isn't fantastic..

That's awesome!! Make sure you take some pics!!

But note , his bravo1 is not 1.50 but 1,65 thats a diiferent story when it comes to proppeller and pitch

:-)

I will for sure take some photos

Oh, good point!

The Merc 502 in my 223SS fits just fine although there was some modification needed. Height is the biggest concern as I needed to cut out and reinforce the underside of the engine hatch. Wholley worth it though. My boat cruises nicely at 2600-2800 RPMs just loafing along then kablam I'm doing 65 in matter of seconds.

242 Ss 502
 

I have a 242 SS 502. No problem with fit with Merc manifolds.
Cruises comfortably in low to mid 30's at 3200 to 3400 rpm with Mirage + 23
Eric

Well finaly decided to buy this engine :-)

It is suppose to be aprox 560 hp with the the Stelling
Big Tubes on, but I have to take them off :-(
No Space for thos in the 242SS

What exhaust system should I buy?? Yes I am going to keep the Silent Thunder Plattform.

242 SS cruising speed
 

My 242 SS cruising speed with a 502 Merc Bravo and a Mirage+
23 does 30 to 35 MPH at 3000 to 3200 depending on revs, weight, etc

Eric

Stainless Marine should fit ok and still give you a long dry run with tails that reach near the transom. With that power level I would be certain that engine needs performance exhaust with a longer dry run to avoid reversion.

I have stainless marine that I plan on putting in my 242SS. The tails are not ready yet but I think they will be around 20" or better which will give a very good long dry run for a performance cam.