Back from the Dead; '81 Scarab 38 Resto
#1391
Registered
Correct
But in Hblair's situation it appears the cylinders on the Arnesons have more of a mechanical advantage by the cylinder acting further away from the steering pivot than the Bravo ITS.
Be nice to know the differing lengths between the 2.
Also it's sort of moot as he showed boats that have similar setups already in use and proven.
So he should be fine.
But even though he doesn't have a push pull setup (actually he does), just not on each drive as an ITS has.
At the end of the day though it comes back to this example.
They're going to steer.
But in Hblair's situation it appears the cylinders on the Arnesons have more of a mechanical advantage by the cylinder acting further away from the steering pivot than the Bravo ITS.
Be nice to know the differing lengths between the 2.
Also it's sort of moot as he showed boats that have similar setups already in use and proven.
So he should be fine.
But even though he doesn't have a push pull setup (actually he does), just not on each drive as an ITS has.
At the end of the day though it comes back to this example.
But have you ever seen the extreme mechanical disadvantage some dump bed scissor mechanisms have in order to obtain lots of travel out of a short stroke cylinder?
It's boggling and proves the force of hydraulics.
It's boggling and proves the force of hydraulics.
#1392
Platinum Member
Platinum Member
no doubt its going to work I just thought there would be more angle to the rams, killer project HB
#1393
Registered
Actually I need to correct myself, once I brought up the distance between pivot and where the cylinder acts it got me to thinking.
The ITS steering cylinders are at a great angle, they are 90 degrees it appears. Because it’s acting on the gimbal ring itself. So the mechanical advantage is the distance between the cylinder at the gimbal and the swivel shaft.
Not the drive itself as in many external steerings systems on a Bravo.
The ITS steering cylinders are at a great angle, they are 90 degrees it appears. Because it’s acting on the gimbal ring itself. So the mechanical advantage is the distance between the cylinder at the gimbal and the swivel shaft.
Not the drive itself as in many external steerings systems on a Bravo.
#1394
VIP Member
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Thread Starter
Thanks guys, very interesting conversation. I should have paid more attention in school.
We got the u joints lubed and drives back on. The smart thing to do here is remove the props from the drives then use a cherry picker or fork lift to remove and install the drives from the boxes, so, of course, we left the props on and assigned welding gloves to the guy on the sharp end and did it the dumb way. For reference it takes two strong guys and an old man to do it this way. The old man installed the nuts while the young guys did the work. 😂
Here they are, turning “in” now..
We got the u joints lubed and drives back on. The smart thing to do here is remove the props from the drives then use a cherry picker or fork lift to remove and install the drives from the boxes, so, of course, we left the props on and assigned welding gloves to the guy on the sharp end and did it the dumb way. For reference it takes two strong guys and an old man to do it this way. The old man installed the nuts while the young guys did the work. 😂
Here they are, turning “in” now..
Last edited by hblair; 01-03-2023 at 08:04 PM.
The following 11 users liked this post by hblair:
1983ScarabIII (01-03-2023), AllDodge (01-20-2023), cheech (01-04-2023), HEMTT (01-19-2023), jeff32 (01-04-2023), ksalmine (01-03-2023), larslindroth (01-22-2023), NautiSouth (02-07-2023), outonsafari (02-25-2023), rak rua (02-03-2023), resurrected (01-04-2023)
#1396
Registered
Stunning sir, as someone who did it back in the 1990's, it is quite an undertaking!!!!!! I started with a Cobalt 300 Condurre with twin 400 Cyclones and TR drives. It ended with blown BBC's, B&M 420 Megablowers, 2 tuned 750 Holleys per engine, Stainless Marine exhausts and ASD6's with Rolla props. We would get, as best we could tell, 93 mph @ 4400RPM. Because of the relatively short hull, I got some longitudinal instability above that speed. I know from experience a 38' Scarab has more longitudinal stability at speed, we teased that it had the stability of a great log in the water.
I only wish someone else was clearly crazy and as talented as you sir, my boat has been sitting since 1991 . . .
I only wish someone else was clearly crazy and as talented as you sir, my boat has been sitting since 1991 . . .
The following 2 users liked this post by HEMTT:
larslindroth (01-22-2023), resurrected (01-20-2023)
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#1398
VIP Member
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Thread Starter
Stunning sir, as someone who did it back in the 1990's, it is quite an undertaking!!!!!! I started with a Cobalt 300 Condurre with twin 400 Cyclones and TR drives. It ended with blown BBC's, B&M 420 Megablowers, 2 tuned 750 Holleys per engine, Stainless Marine exhausts and ASD6's with Rolla props. We would get, as best we could tell, 93 mph @ 4400RPM. Because of the relatively short hull, I got some longitudinal instability above that speed. I know from experience a 38' Scarab has more longitudinal stability at speed, we teased that it had the stability of a great log in the water.
I only wish someone else was clearly crazy and as talented as you sir, my boat has been sitting since 1991 . . .
I only wish someone else was clearly crazy and as talented as you sir, my boat has been sitting since 1991 . . .
#1399
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Thread Starter
We’ve got some done lately. Shon has been plugging away at the wiring, he’s got the trim pump and fire extinguisher wiring all cleaned up as well as the instrument panel getting closer.
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#1400
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Thread Starter
I dodged a scare a few weeks ago when I noticed a huge puddle of fluid in the bilge. I wasn’t sure if it was from when we ran the motors and could be trans fluid or if it was trans fluid coming from what was left in the trim pumps. Turns out it was coming from where the hoses connect to the k plane tubes at the transom where yours truly didn’t tighten then. Luckily Shon is a bilge monkey and shimmied right back to the transom on both sides and tightened them up.
Also got a set of 4 large fenders with covers from wholesale marine. I’ve been trying to find what I wanted for a while and they had them..
Also got a set of 4 large fenders with covers from wholesale marine. I’ve been trying to find what I wanted for a while and they had them..
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larslindroth (02-17-2023)