94 Bandit, LS swap?
#11
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From: Mechanicsville Maryland
This is the info I was hoping to find out. Things I don't know to consider like the great set in the drive, how it's effected by the different platforms. A greatest change wasn't in the cards for this, just taking advantage of what I already had wanting to re-power an old 310 HP 454. I think this hull will go fast and it's not heavy at all. If I remember correctly, it's 3470 dry weight.
#12
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From: Ohio
This is the info I was hoping to find out. Things I don't know to consider like the great set in the drive, how it's effected by the different platforms. A greatest change wasn't in the cards for this, just taking advantage of what I already had wanting to re-power an old 310 HP 454. I think this hull will go fast and it's not heavy at all. If I remember correctly, it's 3470 dry weight.
Also that hull wants bow lift. The light weight engine package won’t be helping.
#15
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From: BC
LS engines don't 'need' a 2:1 reduction. It's all about the package of what you're trying to achieve. Large diameter props required for big reductions have a larger drag...that cancels out any benefits at speed.
Typically, porpoising is from a stalled out bow lift scenario. Lots of prop options to help reduce bow lift, or lift the stern.
In this case, having less weight astern may smooth out the porpoising.
#16
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From: Mechanicsville Maryland
TRS drives also have a 1.5 reduction built in.
LS engines don't 'need' a 2:1 reduction. It's all about the package of what you're trying to achieve. Large diameter props required for big reductions have a larger drag...that cancels out any benefits at speed.
Typically, porpoising is from a stalled out bow lift scenario. Lots of prop options to help reduce bow lift, or lift the stern.
In this case, having less weight astern may smooth out the porpoising.
LS engines don't 'need' a 2:1 reduction. It's all about the package of what you're trying to achieve. Large diameter props required for big reductions have a larger drag...that cancels out any benefits at speed.
Typically, porpoising is from a stalled out bow lift scenario. Lots of prop options to help reduce bow lift, or lift the stern.
In this case, having less weight astern may smooth out the porpoising.
Interesting, I can see how that would help. I will say this hull loved the Rev 4 I had. As for the LS I wouldn't be scared of RPM, but my understanding is the outdrive can only take so many RPMs.
Last edited by Danimal182; 10-01-2024 at 06:01 AM.
#17
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From: BC
Assuming you mean the drive...drives do have rpm limits, but 5500-6000rpm isn't too hard on them if setup well.
Drives are rated in torque. Get the rpm up...for a given tq, your safe HP is now higher. Broaden out the max rpm/speed, you also have the issue of increasing your cruise rpm. But the drive is working less and loaded less with a lower pitch prop..and a bit more cruise rpm.
Trim tabs can solve the porpoise issue. Trim will also help, but if you move the trim out of optimal to account for the hull, the prop becomes less efficient.
#18
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From: Mechanicsville Maryland
Just looking to confirm what 'office' means? I suspect Voice to text or auto-correct is messing up.
Assuming you mean the drive...drives do have rpm limits, but 5500-6000rpm isn't too hard on them if setup well.
Drives are rated in torque. Get the rpm up...for a given tq, your safe HP is now higher. Broaden out the max rpm/speed, you also have the issue of increasing your cruise rpm. But the drive is working less and loaded less with a lower pitch prop..and a bit more cruise rpm.
Trim tabs can solve the porpoise issue. Trim will also help, but if you move the trim out of optimal to account for the hull, the prop becomes less efficient.
Assuming you mean the drive...drives do have rpm limits, but 5500-6000rpm isn't too hard on them if setup well.
Drives are rated in torque. Get the rpm up...for a given tq, your safe HP is now higher. Broaden out the max rpm/speed, you also have the issue of increasing your cruise rpm. But the drive is working less and loaded less with a lower pitch prop..and a bit more cruise rpm.
Trim tabs can solve the porpoise issue. Trim will also help, but if you move the trim out of optimal to account for the hull, the prop becomes less efficient.
Yes I meant outdrive, I didn't proof read before hitting send. I was always told 5200 rpm for my drive. Now that being said it opens me up to more prop options.



