292 fastech repower options
 

Hello. What options are available these days as an upgrade from stock 2004 6.2 MX mercruiser engines. Any one running a custom rebuild, Ilmor, Mast, Marine power LS engines with more horsepower? If so, how much gain is there?

I'd be surprised if there is room. in my 292, those 350s sure are in there tight.

Simpson,

These should fit
:thankyouthankyou:

Thanks. Brad.
(937)545-8991

Big blocks will not fit in a 292 fastech.

Simpson,

Read that description again…..

Thanks. Brad.
(937)545-8991

Haha I had to look twice! Then I saw the exhaust port configuration.

Resurrected,

How they managed to squeeze 454ci out of a SBC is beyond me, but they apparently did.

Thanks. Brad.
(937)545-8991

Aftermarket block that can handle the added 4”stroke and 4.25” bore.

You can do in LS world too. 4.185” bore x 4.125” stroke in a LSX block.

SB,

Actually, it specs a 4.25 bore, so it's a 4" stroke. I'm guessing they'd have to be Siamesed cylinders.....?

The key, here, is that it would appear to be feasible squeeze a couple of "BigBlocks" where there isn't room for a couple of BigBlocks. I don't know how well these would hold up to the duty cycle in a marine application, but I'm sure that could be addressed at assembly/build with proper valve train specs, right?

Thanks. Brad.
(937)545-8991

Sorry. I wasn’t done typing. All good. :thumbs

Get 2 of these: https://www.boatblurb.com/post/is-th...ing-to-boating

IMO, those 454 GEN 1 small blocks are nice dragstrip or street car mills. Anywhere you can work on them easy. LOL
4.250" bore on stock 4.400" bore space blocks leaves a whole .150" between cylinders.

Those have to be head gasket nightmare's.

Depends on what you're after and your budget.
I had to go look for this as I remembered it awhile ago.

Well done but probably pricey redone 292.
​​​​​​​

160 HP each.
Yeah 2 of those are going to upgrade his power. :bong:

Sorry, 10 then!

67 pound motor makes 670 HP.

you'd only need 1, but 2 would make it more fun.

Sure, with 10,000 pounds of batteries on board to supply energy to that.

For an hour if he's lucky.

My guess is the OP is looking for REAL solutions and advice on upgrading his boat.

So far he's got:

• A time bomb small block. (with power levels that a good engine builder could achieve with less in³ and be reliable)
• 160HP turbines that'd take probably more money than the boat is worth to rig in his boat.
• Motor above with the aforementioned limitations.

What's next a nuclear reactor???

Please. sure you COULD put a nuke on it. but the radiation shielding would weigh more than the boat.

I got it. Rip out the engines. Strap on an outboard bracket with positive flotation, and not 1, but TWO 600HP Mercury's.

Problem. Solved.

Or superchargers.

But, at the end of the day, the 292 is only so big (I know, I have one) and the engine bay already sits 1/2 sunk at idle. So the 'best' upgrade path? New boat.

My 292 had 350 mags. Currently have the engines out of the boat. Thinking of pulling the trigger on forged stroker kits to make them 383's. Already have 2 sets of AFR heads ready to go with imco powerflow echaust with 12 inch stainless tails. Trying to decide on a cam i want to run since i really dont want to spend $7,000 on dry exhaust. Considering a new intake/throttlebody setup for more power. I figure they should make 425+ HP being 383's with bigger heads, cams, intake and TB combo. 400 horse a side with the right props will push a 292 into the high 70's, maybe even 80 in perfect conditions. Blue Scorpion 292's will run 78-80 in perfect conditions. All depends on how fast you wanna go and how deep your pockets are. The blueprint 454's are nice, but with those big azz cams, you will NEED dry exhaust. Boost power marine makes a nice 383 long block that makes 435hp too.

Or a Mr.Fusion and a Flux Capacitor!

383's with blowers, depending on goals and budget.

My vote is also 383 with a small supercharger. Very reliable. A TBS 192 on top would make really good power. You could probably just go with 350s and that combination so long as all is forged down below.

And get this battery **** out of here…

AMEN

But the batteries for YOUR Lucid drive suggestion wouldn't?

Depends on what HE wants to do. I linked an extremely nice example already of one.

Otherwise the only thing that comes to mind with your suggestions is this:

I like those 6.2 motors and think rebuilding that motor and setup for whipple's like the 292 in the link in the article provided in post #13 is best idea for serious power. Those 6.2 motors are hard to find used, probably get good money for them if you wanted to start all over.

you guys are funny I bet you said the same thing about these new fanged horseless carriages.

https://tenor.com/view/old-man-yells...s-gif-17741451

If the boat is worth $50k and you do $30k in modifications, you don't end up with a $80k boat. I bet you could find a better boat for the cost difference.

I fully expect boats, houses, cars to drop in price in 2023. A lot of pandemic boats going to be sold from people who bought in 2020ish.

What about a pair of SC Ilmor 6.2's?

Interesting, do you know of anyone who has this engine in use?

I foresee prices will drop like a BRICK

Probably not as a retrofit, they are done by Ilmor for MasterCraft wake sport boats.
I'd say outright they'd be pricey.
And it'd be total custom to retrofit in an original Mercruiser Gen 1 boat.

Likewise there are LS conversions out there. Probably more in the wild that we never hear about.
There has been a few on here pop up from time to time.
One guy with a Checkmate that did complete his and another with an Eliminator that had his running, but he tore it down for paint and seems to have stalled.
Maybe a few more that we hear about but then never hear it being finished.

As I asked before you have a goal in mind or a budget?
Your 6.2's can be tweaked pretty well by someone who knows what they are doing if you're after more power.

Tweeked 6.2s would be alright. Who and what engine builder does them? Is anyone running them?

Seeing you're in Canada I'm not aware of anyone local to you. I'd guess there is but you'd have to ask local boat enthusiast I guess. There is a few on here that are on OSO from your neck.
If you neglected to read that article I linked or missed in there, Harris Performance in Alabama did those small blocks. https://harrisperformanceonline.com/

Running them? Probably, just don't hear much about them.
Unfortunately, performance boat wise we are in a big block dominated field.
An engine is an engine though. Seems some marine builders will do anything and some stick with the big blocks only.

It's a whole can of worms though, depending on how much "tweaking" you want, also may include new heads, induction, headers ($$$$$), on and on.
It will need tuned, therefor it'd be best to stick with an experienced marine builder who also tunes.

Whipple sells a prepackaged supercharger kit for the 6.2's with a tuned ecm.
Procharger also I believe. Don't think has ecm.

No way I'd install either on a stock short block though myself.

Search on the forums for 6.2 and read away, there has been some informative threads.

Seems to be lots of information on other threads or various web sites. It really comes down to your goals and budget. I quick look on the web and 6.2's should get you around 70.

Pricey but they will sell them set up for a bravo drives.

https://marineenginedepot.com/new-62...-airpac-620-hp

https://www.akfrontierfab.com/invent...ska---15786601

Little cheaper not sure why Marine power dropped thiers.

https://www.akfrontierfab.com/invent...ska---15789851

Those are cool Wildman. Did you see any pricing at the AKfrontier site?

Those linked above will work as they are turnkey with ECM.
Those are LS (LSA) and LT (LT4) based.

Simpson8

Just a heads up also after rethinking about your first post and those linked above.
Your 2004 Mercruiser 6.2's are not LS based if you or anyone else are mistakenly thinking so.
A lot of people do based on the "6.2" moniker.
They are Gen 1 "Vortec" essentially. 4.00" bore x 3.75" stroke.

I have not seen pricing from KEM on those motors. I would assume close to marine power, from the research I have done I believe these motors are built by GM and marine power or KEM puts the heat ex changers etc on them to for marine use.
This shows the power curve, but lots of info missing.

https://www.kemequipment.com/manuals...er%20Curve.pdf