gasser repower questions

[thoward]

Not a Hatteras but I am thinking the folks here will have the answers. I have very little experience with gas inboards.

I bought a 1979 25' Blackfin Combi with twin PMC 305s(both locked up). I am looking to replace the entire unit as the accessories are suspect. I am leaning towards Crusader 5.7s.

Are the motor mounts on a PMC the same as a Crusader?
Is there a horsepower concern with regards to longevity with the 5.7? If so, what is the limit?
Is the exhaust outlet the same size?
This seems to be a pretty straight forward swap so, what am I missing?

 

[workingonadream]

what is pmc as for the blocks themselves, I believe they are the same size, just a different bore and stroke. your best bet is to call a crusader dealer. I had their 5.7s in my last boat and they were great engines, just make sure you do the exhaust risers every 4to5 yrs so you don't lock the valvetrain up. I put a set of crusader big blocks in a boat for my brother in law. we got the engines from marine engines in Hollister mass 1-800-runs-new we found them to very helpful. they can also set you up with whatever accessories you need. good luck

 

[thoward]

I do not know the history of Pleasure Craft Marine(PMC) but they are now part of Crusader. The risers are raw water cooled which is an issue for for my saltwater boat....

 

[workingonadream]

call the place in mass they will be able to help you. converting to a freshwater engine is not a huge deal. they will have everything in stock

 

[Texastailboard]

Do you want to stay with the gas option, a diesel Blackfin is an awesome set up

 

[jim rosenthal]

No kidding. A couple of 240 hp Yanmars would set you right up..... fast, easy on fuel, and last you decades....

 

[thoward]

From a fishing/diving perspective, there are lots of problems with layout of a 25 with twins. I cant justify a diesel conversion on a boat I am not going to love. I have lots of bilge detail and painting to complete so I am going to keep my eyes out for a couple low hour EFI takeouts. If I dont find a set, I guess I am going with old school carbed 5.7 300hp long blocks.

 

[Texastailboard]

That makes sense, but there are a lot of very economical diesel options out there, it will help with the resale value when that time comes.

 

[rwappleton]

My Opinion having owned both unless you are going to keep the boat a looooong time you will not recover the cost of the diesels unless you found a pair REALLY cheap even when you sell.

I would shop extensively for the 5.7 EFI units. The fuel savings and reduction in tune up type maintenance will pay for the difference and will help the value slightly.

The R/W risers will need extra attention but not a big deal. I opened mine up once a year for inspection and replaced them at 5 years.

 

[dsharp]

I would go with the Crusader's. The Crusaders are more expensive but it's the difference in a cast aluminum oil pan vs a painted steel pan and the list goes on and on. The engine stringers usually a standard width. If you want you could take the motor mounts off of the PMC and put them on the Crusader. They should be very close to the same. You can add fresh water cooling or buy kits from SenDure. If the gears are in good shape you could buy bobtails and use your old gears. If you can swing it buy brand new and enjoy using the boat