Alpha 1 gen 2 / bravo 3 swap

[HT32BSX115]

Re: Alpha 1 gen 2 / bravo 3 swap

Reasons : 1) I spoke to the propulsion engineer from Regal (30 years on the job) about putting 5.7L in.............................. he said the boat would porpus due to the extra weight in the stern 2) the water would sit dangerously close to the intake due to the extra weight in the stern sitting lower in the water.

I would seriously dispute this "Propulsion Engineer"s expertise making a statement like this for a difference of only a couple hundred pounds!

That would make the boat nearly uncontrollable if a couple of passengers simply walked to the back of the boat while underway!

Methinks his "calculations" are seriously in error.........

I would absolutely put a set of 5.7L engines in that boat and I wouldn't look back! If you're worried about extra weight, put a set of aluminum manifolds and risers+extensions on it and install closed cooling!

1. Porpoising can be sorted out with trim tabs (not the useless bits of plastic rubbish on the drive, but proper metal tabs secured to the transom). Or add an extra fuel or water tank up front.
2. Low water line level is solved with exhaust elbow extension kits. They come in 1.5", 3", 6" and 9"... Take your choice. (They are designed for exactly this situation)

Chris.....

Absolutely! AND properly adjusting the drive trim!

And if the boat is that heavy, then the 1.62:1 drives will be PERFECT with 5.7 engines....

YES!

 

[racer17]

Re: Alpha 1 gen 2 / bravo 3 swap

This is good stuff guys.... I Automaticly believed the Regal engineer based on his position and years on the job. Pretty bad when the guy designing Regal boats is in question...??? Maybe he was saving face for an epic mistake he made designing the 2760???

I would like to pose this question to you well seasoned gentlemen... any idea why my props cavitate at WOT while trying to get on plane? You can hear (and my mechanically inclined friends have agreed) the props loosing traction in the water when the boat is at its crutial point of trying to shove it huge *** on plane. I've looked at the obvious and made sure the drives are going all the way in. They both have the same amount of ram remaining so I'm assuming they are at Max (I would say 2" by memory?) .

Cheers, MIKE

 

[achris]

Re: Alpha 1 gen 2 / bravo 3 swap

Check the installed height of the engines/drives. To do that, trim the drives in until the anti-cav plate is parallel with the hull (this is NOT the fully trimmed in position). The anti-cav plate should be level with the hull. If the installed height is too high, the props will suck air (ventilate) under high power. If you have the installation manual (should have been handed to you when you purchased the boat) it should show the correct height. The problem if they are installed to high is that changing a stern-drive height is a serious pain in the ***. It involves fully removing the engines, drives and transom plates, glassing the holes and cutting new ones.

Chris..

 

[muc]

Re: Alpha 1 gen 2 / bravo 3 swap

Hi Mike,
Read StevNimrod’s post again. He does a very good job of explaining “if you need a faster boat, buy a faster boat” because after more than 30 years working in the boat business that is usually the best idea.
But maybe you don’t need a faster boat, bigger engines or twin prop drives. Maybe you just need to change a few things?
First you need to figure out if you’re experiencing “blow out”, “cavitation” or “ventilation” on takeoff --- that must be corrected first.
Here are 6 fairly inexpensive things you might try.
1) Weigh the boat. It’s possible that there is some trapped water somewhere in the hull. Or that because Regal mounted all the batteries, water tank, holding tank and water heater on one side of the boat the selling dealer glassed some lead into the other side of the boat so it wouldn’t list while tied up to the dock. Don’t laugh; this happens more often than it should because it’s cheaper to add weight (lead) to balance the boat than it is to fix it right.
2) Can you move some of your weight closer to the bow of the boat? Try your hole shot with 2 or 3 buddies in the back of the boat and then try it again after they move into the cabin. It can make a big difference.
3) The high 5 propeller would be a good place to start. They do have a good hole shot.
4) If one of your drives is counter rotating. You can switch the drives from side to side. Conventional wisdom is that having the props “spin out” provides stern lift. But different hulls can have the opposite reaction and sometimes having the props “spin in” will provide stern lift.
5) There is a spacer in each of your trim rams that can be removed to allow the drive to be trimmed in further. NOTE THAT THIS CAN CAUSE THE BOAT TO STEER MUCH DIFFERANTLY AND NEEDS TO BE LAKE TESTED BY SOMEBODY WHO IS QUALIFIED AND KNOWS WHAT “BOW STEER” MEANS.
6) Put “whale tails” on the drives. While I’m not a fan of them --- in RARE occasions they do work.

It sounds like you might have more than one problem going on. And in the end you do need a different boat. But I will tell you about a new boat we sold this year. Customer wasn’t happy with the hole shot and wanted to return the boat. So we installed “smart tabs”, a high 5 prop and removed the spacers in the trim rams. Cut down time to plane by 7 seconds and he kept the boat.

 

[thumpar]

Re: Alpha 1 gen 2 / bravo 3 swap

I have read where a bad exhaust bellows has caused "cavitation". The trim spacer on the Alpha is not like the Bravo. They are inside the cylinders so would take some work to get removed.

 

[racer17]

Re: Alpha 1 gen 2 / bravo 3 swap

Hi Mike,
Read StevNimrod’s post again. He does a very good job of explaining “if you need a faster boat, buy a faster boat” because after more than 30 years working in the boat business that is usually the best idea.
But maybe you don’t need a faster boat, bigger engines or twin prop drives. Maybe you just need to change a few things?
First you need to figure out if you’re experiencing “blow out”, “cavitation” or “ventilation” on takeoff --- that must be corrected first.
Here are 6 fairly inexpensive things you might try.
1) Weigh the boat. It’s possible that there is some trapped water somewhere in the hull. Or that because Regal mounted all the batteries, water tank, holding tank and water heater on one side of the boat the selling dealer glassed some lead into the other side of the boat so it wouldn’t list while tied up to the dock. Don’t laugh; this happens more often than it should because it’s cheaper to add weight (lead) to balance the boat than it is to fix it right.
2) Can you move some of your weight closer to the bow of the boat? Try your hole shot with 2 or 3 buddies in the back of the boat and then try it again after they move into the cabin. It can make a big difference.
3) The high 5 propeller would be a good place to start. They do have a good hole shot.
4) If one of your drives is counter rotating. You can switch the drives from side to side. Conventional wisdom is that having the props “spin out” provides stern lift. But different hulls can have the opposite reaction and sometimes having the props “spin in” will provide stern lift.
5) There is a spacer in each of your trim rams that can be removed to allow the drive to be trimmed in further. NOTE THAT THIS CAN CAUSE THE BOAT TO STEER MUCH DIFFERANTLY AND NEEDS TO BE LAKE TESTED BY SOMEBODY WHO IS QUALIFIED AND KNOWS WHAT “BOW STEER” MEANS.
6) Put “whale tails” on the drives. While I’m not a fan of them --- in RARE occasions they do work.

It sounds like you might have more than one problem going on. And in the end you do need a different boat. But I will tell you about a new boat we sold this year. Customer wasn’t happy with the hole shot and wanted to return the boat. So we installed “smart tabs”, a high 5 prop and removed the spacers in the trim rams. Cut down time to plane by 7 seconds and he kept the boat.

Thank you for the info.You don't know how much I appreciate everyone's help. Just to be clear, I'm not interested in top speed just a boat that will plane with a few friends, fuel, water, and weekend supplies. My friend had a late 80's 34ft sunrunner with volvo 5.7's and duo drives. That puppy would come out of the water in the length of itself and plane for a joke @ 3200rpm. I want that ! Or at lease close... I am curious to try your recommendations before I spend any money on 5.7's .

Thanks a million and like I mentioned many times before... keep the ideas coming I'm open to any and all information.

Best Regards, MIKE~

 

[racer17]

Re: Alpha 1 gen 2 / bravo 3 swap

I have read where a bad exhaust bellows has caused "cavitation". The trim spacer on the Alpha is not like the Bravo. They are inside the cylinders so would take some work to get removed.

Thanks for that tidbit... I would have been scratching my head while looking for a spacer. This is a great idea. I always said if I could get the drive to trim in more it would help.

Also, can you elaborate on the bad bellows theory please?

Cheers, MIKE~ :canada:

 

[Walt T]

Re: Alpha 1 gen 2 / bravo 3 swap

Hang on, I personally drove one of these Regal 27s on Lake Powell, and also a Sea Ray 2005 280 Sundancer both with twin 4.3 and Alphas. I should note the 2005 was EFI, I dont recall what the '97 Regal was I assume it was carbureted. Both got on plane and cruised at a reasonable speed. I wouldn't call them pigs, but wouldn't call them speedy either. They were... Adequate. I believe there may be another issue such as water intrusion, foam is soaked, something like that. He rebuilt the 4.3s for cryin out loud! Tried props too! OR perhaps he just doesn't like.... adequate. My girlfriend says adequate is 'fine.' The guys are right though, 5.7s are good in a boat like that. I caution you though it's not as dramatic an improvement you may think if you stay with the Alphas. Many many of these boats were built and I really haven't heard many complaints about the 4.3s. Something else is wrong and 5.7s may not fix it like the gentleman said in a previous post. The engines do sit way low in the bilge and the static line is pretty close, but if they wanted to install 5.7s they can easily design it to take them or install higher risers. I bet that boat has a generator and batteries back there too so adding a couple hundred pounds has already been done.

 

[HT32BSX115]

Re: Alpha 1 gen 2 / bravo 3 swap

My friend had a late 80's 34ft sunrunner with volvo 5.7's and duo drives. That puppy would come out of the water in the length of itself and plane for a joke @ 3200rpm.

The duo-Prop drives are largely responsible for the quick to plane performance.

My Brother bought my current 1987 21ft Four Winns Liberator new with the OMC 460 + King Cobra drive.

From day one, it was a very fast boat (60+ mph) but was also always VERY sluggish out of the hole. (and he had Bennett Sport Tabs installed)

When i got it in 2005, I removed the (340 crankshaft HP) OMC 460 + Cobra and replaced it with a 1997 (330 crankshaft hp) 454 + Bravo III drive.

With literally the 'same' HP, The difference in top speed was minimal. (probably about 3 MPH SLOWER with the Bravo III)

But the hole shot was incredible! It went from being a literal dog out of the hole to being a ROCKET!

It's pretty obvious why most larger boats are equipped with either Volvo's Duoprop or Mercruisers Bravo III


Cheers,


Rick