Tail Chaser 661
Member
- Jan 23, 2009
- 742
- Boat Info
- Furuno Navnet radar/chartplotter, fish finder, bait tank, 85 Gal main fuel tank, 75gal aux tank.
- Engines
- Merc 8.1 Mag 375 HP / Bravo III,4 blade prop. 28mph at 3200rpm.
Repower from 5.7 to 8.1 engine
I'm concerned with clearance issues
My 1985 26' dancer has approx 5" clearance from the front of the 5.7 engine to the 100 gal gas tank.
The overall length of a 5.7 is 36.8"
The length of the 8.1 is 40.1"
Ive heard a 8.1 with the 100 gal tank will have like 2' clearance in front of the engine.
I don't know how long a waterpump last in a big block.
But it seems to me you would have to pull the engine for a waterpump replacement?
The other options are the 6.2 or the 383ci efi Merc.
The 383 has 390 ft lbs of tq from 2800 rpm to 3500. 5k redline.
The Volvo D4 260 hp@ 3500rpm is sweet. 453 ft lbs of tq.
Length is 36.7 That beast weighs 1455 lbs with a duo prop compared to 1271 lbs for the 8.1 with a bravo 3.
The Volvo cost an extra 15k also.
I think the 8.1 TQ is near 500 ft lbs?
So it looks like the big block gets the most bang for the buck.
But maybe not being able to get a wrench anywhere near the front of the engine may be a very stupid upgrade.
What do you guys think?
As you can see from the pic. There's plenty of room everywhere, except the front of the engine.
I'm concerned with clearance issues
My 1985 26' dancer has approx 5" clearance from the front of the 5.7 engine to the 100 gal gas tank.
The overall length of a 5.7 is 36.8"
The length of the 8.1 is 40.1"
Ive heard a 8.1 with the 100 gal tank will have like 2' clearance in front of the engine.
I don't know how long a waterpump last in a big block.
But it seems to me you would have to pull the engine for a waterpump replacement?
The other options are the 6.2 or the 383ci efi Merc.
The 383 has 390 ft lbs of tq from 2800 rpm to 3500. 5k redline.
The Volvo D4 260 hp@ 3500rpm is sweet. 453 ft lbs of tq.
Length is 36.7 That beast weighs 1455 lbs with a duo prop compared to 1271 lbs for the 8.1 with a bravo 3.
The Volvo cost an extra 15k also.
I think the 8.1 TQ is near 500 ft lbs?
So it looks like the big block gets the most bang for the buck.
But maybe not being able to get a wrench anywhere near the front of the engine may be a very stupid upgrade.
What do you guys think?
As you can see from the pic. There's plenty of room everywhere, except the front of the engine.
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