Logo

Need repower info please help 454 crusader to

tankmfd

New member
"88 25 seavee with 350 hp 454

"88 25 seavee with 350 hp 454 crusader the engine is shot...money says buy a long block and some new parts and through her back in. but where and what am i getting 4 my money. lot of lower hp blocks out there, was told go higher hp block and save gas 375-400 hp block? how hard would it be to go from 88 crusader to new 09 8.1 375hp crusader wiring and guages wise(have a digital flowscan as main guage) but dont they come with a 10 pin wiring harness and would need returnless efi setup. finally 12500$ is alot for a bobtail... help or comments appreciated thanks"
 
""the engine is shot"

""the engine is shot"
As in "not rebuildable"? Did it ingest seawater, or throw a rod, or, is it just worn?

Anyway; lots of options for you. What is most important? Lowest $, lowest labor, best fuel efficiency. What is the condition of the accessories? Save gas with a larger motor?? The fuel injection will save fuel, but the higher speed capability will tend to use up the savings. There are tuning tricks on the carb 454 that will save fuel as well."
 
"'88 makes all the bolts o

"'88 makes all the bolts ons 20+ yrs old. depending upon their condition, refreshing the whole thing may make sense....

Like Dave suggested, get your expectations prioritized and share them. Once those are understood the options usually sort themselves. The trade is usually time vs money."
 
"In my opinion: You have so ma

"In my opinion: You have so many options but I don't THINK you want to spend $12,500.00 for an 1988 boat that you can probably buy the long block and finish the job for under $5k. I might believe you are better off taking that extra $7500 ( and it is always more than that) and use it elsewhere.

I only say this as IF THIS were my decision on my boat...NO way...I'd replace the entire boat. There are a lot of engine changes from 1988 to 2009 in the Crusader line including the use of NEMA digital dash displays and other really cool stuff."
 
"Gonna race somebody? Probably

"Gonna race somebody? Probably not, so why spend BIG $$ for horsepower you don't need?

Here's the dirty little secret: For "normal" cruising, a low hp 454 big block makes nearly the same torque at 3,000 rpms as a newer, much high hp 496s. And that's what counts--mid range torque.

Jeff"
 
"The 8.1 will bolt up as a dir

"The 8.1 will bolt up as a direct replacement for the 7.4 if you want to spend he money. You will need to reroute the fuel line. Crusader has the adapter to allow you to plug into your old harness wiring.

If sticking with the 7.4, don't consider replacing the longblock without replacing the exhaust system at the same time. The 7.4 is still available new but only in Gen VI. This means there is no accommodation for the old mechanical fuel pump. Crusader has an electric pump kit available to remedy this.

A reman is the best choice in my opinion. Most carry a two year warranty even it it is very limited. Al is right, you should be able to buy the parts to do this yourself for under 5K.

Another slightly more risky option is to find a good used motor. I recently bought a really nice Formula 252 with a water ingested 7.4. I was able to find a good used 7.4 MPI FWC Horizon Mercruiser with 400 hrs. on it on Ebay for $2,500.00. I did a lot of work to it before I was comfortable putting it in, since it had been sitting two or three years, but it worked out really well.

The nice thing now is that I can part out my old motor and FI system and get my $2,500.00 back.

Anybody need a complete multiport EFI system for a 7.4?

Good luck
Rick"
 
"ok block seized, dropped valv

"ok block seized, dropped valve into block, most parts are in so/so shape, old rodchester quad rebuilt twice, manifold shot, mounts shot, alt.rebuilt(ok), starter rebuilt(crappy), trans has surface rust bad but ok, recirc.waterpump looks orig. shot, 4 years ago used to cruise at 28.5 mph at 2mpg, engine got tired 27mph at 1.5 to 1.75 before seize. talked to 2 guys both went to 496 375hp, both said was nite and day from 454 carb 350 hp. but 12500 for engine and 2500 for new zf trans to much $. probably gonna buy rebuilt block and other parts and build new engine but what block and heads(hp?) had aluminum hirise intake off ebay but cheap and rotted even with zincs. want 30+ cruise and 2+ mph. old engine wouldn't hit more than 3700 rpm. turning 17x19 wheel but engine was real tired and already had low comp in one cylinder. wondering the headache involved in wiring chand ge from carb 454 to 496 efi."
 
"nothing but time and money Gr

"nothing but time and money Greg.

You could buy a rebuilt long block and the EFI from Rick. The gear can be redone by many shops if you don't want the new one; I'd go local just in case. Probably better off buy new bolt ons. You'll wind up with something similar to mine - I've dubbed them MercruiSaders, a hybrid combination of the best from different OEMs.

Ebay is ok but I'd stick to the known brands, especially in aftermarket. there a bunch of really-cheap-s**t fromm china that doesn't deserve to be on the ocean floor."
 
You can get the 8.1L in a retu

You can get the 8.1L in a return or returnless fuel system. The adaptor cable they sell routes everything over just like it was.

Don't forget that the heat exchanger is on the rear of the engine so you need room for it. I had a hard time when I put mine in my 25' Carolina Classic. I could have used a spacer on the driveshaft and it would have made it easier.
 
"From experience I say go with

"From experience I say go with the new Crusader, no long block. Since times are slow can probably negotiate a good deal with the installer or wherever buying from.

I had a 454 RWC intake manifold go and motor ingest water. For $$$ reasons I bought a very good reputation long block with 2 year warranty - it was a headache and I regretted it until day sold boat. The problem is all the peripheral parts...wiring, water pumps, fuel pump, etc were also from 1986 and much of it needed to be replaced although initially said didn't. Plus the time to remove all the old parts and reinstall racked up pretty quick ans this extra time = $$$ with mechanics. Trust me you will not be happy when go though all this work, use seemingly "good" parts off old motor and then 2 months later your circulating pump goes.....oh and not under warranty as came from old motor.

Spend the extra $$ you will be much happier in long run, will have greater confidence in reliabilty of your boat and greater value if sell it."
 
Back
Top