Small Block rebuild
 

OK....I need to go 80+mph; should I:
a. Rebuild my 99'350MagMPI's into 383's NA?
b. Rebuild same into 383's w/superchargers?
c. Sell current power & purchase 383's complete(less exhaust)?

I wish $$money$$ was no object, but the whole reason I want to keep the boat is I love the fuel eff. of the twin small blocks. Also, the 28AT is big enough for ocean, it destroys the rough stuff and small enough to trailer anywhere w/o much stress on truck or wife.

If I decide to rebuild:
a. who to use?
b.Who to AVOID?
c. Who makes the best rotating assembly for small blocks?

Thanks in advance!
Spil

Chris,
I pm'd you my opinion. Leave the engines alone and install the sc.
In order to make over 400 hp with a 383 ci, you will not reuse the vast majority of your parts. You could certainly make over 400 hp with a 383 ci, thats not the problem. The problem is, you will need to replace the crank, rods, pistons,cam, valves,gaskets, oil pump, oil pan,timing set,rings, bearings, springs, retainers, keepers, rockers, injectors, possibly the heads, etc..plus all of the machine work.
You would do much better to start over from scratch and sell what you have. You will only reuse maybe a thousand or two dollars worth of parts. They are worth more than that if you sell them. I don't ever recommend messing with stock Merc engines except for installing an sc. They bring good money in stock trim. If you modify the engine and try to sell it, you will have trouble selling it. If you install the sc and want to sell, you can always remove it and return it to stock.
The sc will give you the most bang for the buck. I have done several and they are dynamite.(both the Procharger and Whipple) I like the Whpple a little better, but the Procharger system is very good to. The Procharger is cheaper, but the Whipple looks nicer. Either system will get you 450+ hp.
Let me know if I can help you. Thanks, Eddie.

More HP is going to burn more fuel...period.

I bored and stroked a set of 500's and agree with the above statement. For just a little more money I could have started over from scratch and sold the stock motors. Keeping the fuel injection looks cool (to me), but I could have made more power ditching all that stuff.

OK. How much are my engines worth? I know; they're worth what someone is willing to pay. So where do I start? Is $4,000 each, $7,500 pair about right?
They have 400hrs.....

I only have one question:eek:

How much HP is it going to take to get that boat into the 80MPH range you are looking for:grinser010:?

Sell your engines and get a pair of Raylar's LSM 550's!:evilb:

Oh, wait... you said money IS an object...:p

I just would like to get a report on how those things run. That would be one hell of a combination in your boat.:cool:

Seriously, I would opt to build engines from scratch and pull your stock engines untouched. You can sell them or keep them as back-up, and if you decide to sell your boat, put them back in and keep your high performance powerplants. You can take your time and build (or have built) from scratch naturally aspirated big inch small blocks that would easily get you over the 80mph mark. Why settle for 383ci? Done right, 400ci+ torque monsters would be the way to go.

$RaylarLSM550$
 

No Doubt, That would be AWESOME! However, not realistic...I would guess the 550's would put my wot speed close to 100.
My current motors are stock(300hp @ prop) except for exhaust and I can see 72mph in ideal, fresh water....salt might get 73.5-74mph. So with 400 hp per side I'm @ 82+/- 1.5mph, all things considered...every 20hp = 1mph, (except for the most important fact-it's a boat & you just never know!)
With 425-450 per side, upper 80's seem realistic; but we will find out when we get there.

Now, After a few quotes for 383's, natural asp. I am back to sc's and top end freshen up.....wtf!@#$%%$!?
BTW, What are a pair of 350magMPI's w/400hrs worth???....

With 400 hours... not much.
Just slam some blowers on there and have fun!

Put these in! 820hp and the best of everything. 80mph will be no problem.
http://www.offshoreonlyclassifieds.c...o26350-en.html