My new Beta 25 is in the boat, bolted down, and engine aligned. Hooking up the plumbing now and there are some clear differences from the old plumbing for the M25-XP that it replaced. In searching prior threads, nobody seems to cover these. Among them:
1. M25-XP utilized 5/8" raw water supply; Beta 25 utilizes 3/4". This was solved for the time being by purchasing a new Vetus knock-off strainer with "progressive" barbs (1/2", 5/8", and 3/4"). I was able to keep the 5/8" intake from the thru-hull under the head sink but cut the "outflow" on the strainer to the 3/4" barb and ran new 3/4" hose to the raw water pump.
2. On the back end, the M25-XP had a 5/8" hose going to the anti-siphon loop, and then 5/8" to the injection nipple in the 1 5/8" exhaust riser. The Beta 25 has a 1" barb off the heat exchanger. To accommodate the existing Catalina 34 wet exhaust infrastructure, this needs to be reduced down to 5/8" before the anti-siphon loop. Again, nobody seems to have mentioned this.
3. The exhaust flange on the M25-XP is 1 5/8" (OD), and on the Beta 25 is 2". This required a reducer, and then a welder to cut and reduce the length of the 1 5/8" pipe coming off of the Engine exhaust flange (to accommodate the length of the reducer).
So there are some clear plumbing differences which need to be sorted. The one I dislike the most is the reduction of the water supply from the the heat exchanger to the injection nipple on the exhaust riser (1"> 5/8"). Although I haven't actually fired everything up yet (I was sent the wrong alternator--I am set up for external regulation to my Firefly battery bank and was sent a 120 amp alternator with internal regulator) I'm thinking a wet exhaust overhaul might be in the future.
Hoping to post later with photos and modifications needed.
Patches
1. M25-XP utilized 5/8" raw water supply; Beta 25 utilizes 3/4". This was solved for the time being by purchasing a new Vetus knock-off strainer with "progressive" barbs (1/2", 5/8", and 3/4"). I was able to keep the 5/8" intake from the thru-hull under the head sink but cut the "outflow" on the strainer to the 3/4" barb and ran new 3/4" hose to the raw water pump.
2. On the back end, the M25-XP had a 5/8" hose going to the anti-siphon loop, and then 5/8" to the injection nipple in the 1 5/8" exhaust riser. The Beta 25 has a 1" barb off the heat exchanger. To accommodate the existing Catalina 34 wet exhaust infrastructure, this needs to be reduced down to 5/8" before the anti-siphon loop. Again, nobody seems to have mentioned this.
3. The exhaust flange on the M25-XP is 1 5/8" (OD), and on the Beta 25 is 2". This required a reducer, and then a welder to cut and reduce the length of the 1 5/8" pipe coming off of the Engine exhaust flange (to accommodate the length of the reducer).
So there are some clear plumbing differences which need to be sorted. The one I dislike the most is the reduction of the water supply from the the heat exchanger to the injection nipple on the exhaust riser (1"> 5/8"). Although I haven't actually fired everything up yet (I was sent the wrong alternator--I am set up for external regulation to my Firefly battery bank and was sent a 120 amp alternator with internal regulator) I'm thinking a wet exhaust overhaul might be in the future.
Hoping to post later with photos and modifications needed.
Patches