4.3 to 5.0 swap in 2001 Crownline 180

[Erichlg]

I am considering buying a 2001 crownline 180 that has a 4.3L Mercruiser with a cracked block. I have a complete 2000 Bayliner 2050 with a low hour 5.0L Mercruiser. My intent is to get the Crownline and drop my 5.0 in and change the outdrive (to keep gearing correct). The best I can tell is that it is a direct swap EXCEPT for the engine mounts and the size of the engine bay. The 5.0 mounts are ~4" forward of the 4.3 mounts. I think the engine bay is either barely big enough or about an inch too small. Does anyone have experience with this situation?

 

[Scott Danforth]

I would simply drop in a new 4.3 and be boating in a short time.

 

[Scott06]

I did same swap for same reason in a 2004 Sea Ray 200 sport. First check if crownline offered a V8 in that boat- at 18 ft I doubt it.
You are correct it's 4" longer so you need that room in front of pulleys and stringer that engine side mounts sit on. In my situation the boat was offered with a V8 so engine compartment space and stringers were already there, just drilled holes farther forward on stringers.

https://samerwebapp01apncus01.blob....427a-a573-076ea700b2e6/50lalpha__996-2001.pdf

that is link to mercruiser engine installation drawings measure closely as it would be a PITA to modify the cowling to fit.

FWIW I didn't have to swap the drive just went from 19" to 21" pitch.

 

[Erichlg]

Scott D. I’m really leaning that direction. Just repairing the Crownline and selling the Bayliner whole or parting it out.

Scott06. I can’t find anything from that era. But, I think you are correct about it not being an option. There is 2 3/4” clearance between the front of the V6 and the cowling. I am concerned about modifying that and the results. Thanks for the specs. That’s awesome.

I apprecite the comments!

 

[Mad Props]

Agreed with Scott D. 4.3 engines are readily available at just about every auto salvage... You can pick one up for 500 bucks and swap over the marine components like I did with my Stingray. Plus, I think the vortec 4.3 which you should have in the crownline, is almost the same horsepower as the 5.0.

 

[Scott Danforth]

if you need to know what fits what on a 4.3 https://forums.iboats.com/forum/eng...history-of-the-4-3-liter-with-casting-numbers

however any post 2000 4.3 from an S-10 or Sierra would work as a donor block and heads.

 

[hvymtl939]

Following...my dad is looking to do the same on his Monterrey, but 4.3>5.7

 

[Erichlg]

Agreed with Scott D. 4.3 engines are readily available at just about every auto salvage... You can pick one up for 500 bucks and swap over the marine components like I did with my Stingray. Plus, I think the vortec 4.3 which you should have in the crownline, is almost the same horsepower as the 5.0.

The internals (long block) are the same?
im not concerned about horsepower. I already have the 5.0 is the only reason I’m looking at this. If I had a 4.3 I would have shoved my money in his hand already!

 

[Erichlg]

if you need to know what fits what on a 4.3 https://forums.iboats.com/forum/eng...history-of-the-4-3-liter-with-casting-numbers

however any post 2000 4.3 from an S-10 or Sierra would work as a donor block and heads.

Thanks!

 

[Buckischloo]

I agree with Scott and Mad. If you want the Crownline, don’t make it harder on yourself than it needs to be. Do it right and sell the Bayliner and 5.0 motor and buy a 4.3 block to fix the Crownline. Shoehorning the 5.0 in the Crownline (not built for it) and building a new cowling (which may never look or work right) is more time, headache and frustration in the long run. I can understand wanting to use what you already have, but you will come out ahead fixing the 4.3.
Otherwise, keep looking for a new 5.0 fitted hull for your 5.0 motor.

 

[Erichlg]

Thanks for your time everyone. Someone else relieved me of this situation.

 

[Sea18Horse]

Bummer! But probably for the best. Now you're free to stumble onto a V8 boat with a blown engine.

Cheers.......................Todd