86 scarab panther drive height
 

[ATTACH=CONFIG]542653[/ATTACH][ATTACH=CONFIG]542650[/ATTACH][ATTACH=CONFIG]542651[/ATTACH][ATTACH=CONFIG]542652[/ATTACH]So 4 -5 years ago i started a project that i never would have thought it would take this long to finish it.
I removed the trs engines, drives and transom assemblies to convert to a bravo boat and to increase the horsepower. When i got everything out the floor was delaminated and the transom was wet, i took it to have the transom and stringer replaced and to have the drive height set up with 3 up imco extension boxes installed.
The drive height. Boxes and prop shafts were supposed to be sat at 3 1/4 below the bottom of the hull. Some how they did not end up there and now i cannot get on plane with the prop shafts level or even a touch higher than the bottom of the boat. With props spinning in.

3 things i can do that i can think of anyone have any other good suggestion?
Try a 5-6 blade prop and take a chance of twisting the prop shafts
try a 3 inch spacer on each drive which will make the vertical shafts even weaker
remove the engines, boxes and drives and have the transon filled in again and lower everything to where it should be.

you need to have the prop shafts at least 3 inches below the bottom I would take the boxes off and mount the gimbals to the transom and try that. the cheapest route just have to lower motor mounts.

yea that is where they were supposed to be. 3 1/4 below the hull. I do not know wtf they were thinking when it was set up

do you think 5 or 6 blades would get me on plane? I was thinking of trying 3 inch spacers but those things are expensive to try

does it bog or props blow out. try and borrow some props. this is cheapest and quickest. even if you have to go to the extreme at least you'll know if still blows or grabs the water

It blows the props out and cannot lift the transom. I had them spinning in. I am going to try to spin them out . however I do not think it will make a difference

so I finally got on plane with a 1" spacers. I do have to work the throttles and I have not trimmed the boat to much as I was worried about the props blowing out. however the boat runs and sounds good. I want to take it back out with a set of 28 pitch props and run it again with a little less humidity and a little more trim..
I spun the 30 pitch bravo ones to 5300 and 75mph w.o.t. with out much trim. those calculations I have 25% slippage which is very high. I also did not have a lot of water pressure on one engine so I am going to address this before I take it back out.

has anyone used cutting edge prop or are they familiar with them?

Augy does great work I have been working with him for more than 20 years. I would try a 5 blade Maxmus style with no diffuser ring gets you on plane quick I works good with high X dimension. We did a 29 Python with 800hp staggered bravo's and it runs 109 with 32 Maxmus props

Wow that is moving!
I am hoping to get close to low 90's based on theoretical speed and what the boat actually weighs.
I'm not sure if i should try another 1/2 or 1" spacer or leave it where it is and start messing with props. Thoughts?
The maximus i was thinking about however i came across his website thought about trying him

He builds a prop that is similar to the maxmus . I would try this first then I would start trying more spacer. You should be able to get your slip down to about 10% spinning out works the best with a side by side setup. The Python is setup with the drives at about 2.5 inches below the bottom. But that boat is staggered so you might need to be a little deeper. I still think that you need to be at 3 inches below

I re-rigged my 1989 Panther, no boxes, prop shafts approx 4.5" below bottom of boat. I'm running a pair of 461" BBC with B&M Mega Blowers, 28" Bravos. I think I nailed the drive height for overall. The boat gets on plane pretty good as long as I don't push throttle to hard. The faster I go the more solid the boat feels. It runs solid mid 90's https://mail.google.com/mail/u/0/?ui...&sz=w1342-h547

what horsepower are you making approximately?

Mid 90's is crazy fast in one of these boats!

87 mph is the best i have seen. I want to get into the 90's but i don't either have enough horsepower or the x dimension is still to high

approx 700, the boat is very solid, no chine walk, very stable at 90+

I agree with Team Archer, remove the boxes, mount transom assemblies to the transom with drive height prop shafts at approx 4" below bottom of the boat. It worked out great on my boat!

what props are you running at what rpm?

Right now i am running 502's with a guestimate of 550 hp with the cams that were in them and maybe... 9-1 compression ratio? These were blower motors at one time.
So if i have see 87mph my fear would be to go down to far and loose speed even though i don't run every where at wide open it is fun to see hopped up. Jet skiers faces and other boats when they want to run and they can't keep up :)

28 Bravos, best I've seen 95 @5900RPM

With a gps speedo ? Are you getting 9 % slip, does that sound about right?

GPS speedo approx 9% slip.