'82 38 KAAMA Scarab Questions
07-12-2017, 10:35 PM
#1
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'82 38 KAAMA Scarab Questions
So I'm now part of the Scarab family. Last weekend I bought a 38 Kaama with a notched transom, and I'm about to start a very comprehensive restoration. I have a few questions regarding this boat. First off lets start with the performance aspect. This is one of the few boats that I have a difficult time finding any info regarding power and speed. The boat came with a pair of 420's, BW Green Tag Transmissions and TRS drives. I'm considering replacing the TRS drives with #4's or #5's, but before I do that I would like to get some info from those of you with TRS's.
What are the speeds you are getting with your current power? Please list if its on the boats pressure speedo or GPS. I have some 675 hp engines that will be going in temporarily. At some point I will either build a pair of tall deck blower motors or stroke and supercharge my current engines. This is why I am considering SSM drives. When it's all said and done I would like to make this a 100+ MPH Scarab. I know the hull is capable of those speed with the right set up. Until then I would like to know what these are capable of with TRS drives. Plus I know I'm not the only one looking for this information. So for this, please post Drives, Engines, and Speed.
Next, Fuel capacity. My boat has saddle tanks and I have no side storage. It seems that the KV boats also have saddle tanks yet they have side storage. Is there a difference between the two boats? Also Wellcraft list the KV with 204 gallon fuel capacity, but the '83 Wellcraft brochure I have states 139 gallon. What size is the belly tank and what size is the saddle tank?
Last has anyone ever weighed their boat? It seems that manufactures weight stats can be a bit optimistic.
As I dig into this I know there will be may more questions, but for now, I'll start here. Thanks in advance!
What are the speeds you are getting with your current power? Please list if its on the boats pressure speedo or GPS. I have some 675 hp engines that will be going in temporarily. At some point I will either build a pair of tall deck blower motors or stroke and supercharge my current engines. This is why I am considering SSM drives. When it's all said and done I would like to make this a 100+ MPH Scarab. I know the hull is capable of those speed with the right set up. Until then I would like to know what these are capable of with TRS drives. Plus I know I'm not the only one looking for this information. So for this, please post Drives, Engines, and Speed.
Next, Fuel capacity. My boat has saddle tanks and I have no side storage. It seems that the KV boats also have saddle tanks yet they have side storage. Is there a difference between the two boats? Also Wellcraft list the KV with 204 gallon fuel capacity, but the '83 Wellcraft brochure I have states 139 gallon. What size is the belly tank and what size is the saddle tank?
Last has anyone ever weighed their boat? It seems that manufactures weight stats can be a bit optimistic.
As I dig into this I know there will be may more questions, but for now, I'll start here. Thanks in advance!
Last edited by endeavour32; 07-12-2017 at 11:56 PM.
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07-13-2017, 02:33 PM
#3
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Welcome to the 38 scarab straight bottom club. Mines an '81 model undergoing a full restoration. From what I understand the boats can go 100mph with 1000hp. It's been done with Arneson surface drives. Crazy Canucks boat's previous owner did it. Look in resto thread for more info. These boats carry a lot of gas. I had my center tank rebuilt and don't have the original tank anymore to look at the tag but I think it was 150 gallon capacity. It looks just like the one that came out of my scarab 30, and it was 150 gallons. The saddle tanks are 68 gallons apiece, for a whopping total of 286 gallons, and about 1800 lbs. Enough gas to go from Miami to Freeport Bahamas and back without worrying about running out. (if you get 1 mpg cruising, my 30' gets 1.3)
07-13-2017, 04:02 PM
#4
Here's the path to resto thread hblair mentioned. Back in the day I owned a '80 Scarab Kaama flat deck that originally came with the Merc 475 turbo package so I know enough about this boat and as a matter of fact my old scarab is now owned by phughes69 on this forum and in the resto thread. Hblair is right on with the tank sizes, 150 center and 68 for each saddle tank.
I'm hesitant about providing some stats as I've some bad experiences on this forum when I posted a reply of my experiences/opinion only to be, let's just say, 'put in my place'. I started with the stock 475 package the 1st year, then added intercoolers, wastegates, etc. as I upped the boost from stock. Good luck with your project, I think the Scarab Kaama flat decks are timeless to me.
http://www.offshoreonly.com/forums/s...-38-resto.html
I'm hesitant about providing some stats as I've some bad experiences on this forum when I posted a reply of my experiences/opinion only to be, let's just say, 'put in my place'. I started with the stock 475 package the 1st year, then added intercoolers, wastegates, etc. as I upped the boost from stock. Good luck with your project, I think the Scarab Kaama flat decks are timeless to me.
http://www.offshoreonly.com/forums/s...-38-resto.html
07-14-2017, 09:36 AM
#5
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I have a 1982 38 Kaama with a notched transom running green tags and trs'. I have a set of 440hp engines, with a gutted down bellow while only carrying a half load of fuel in all three tanks; the boat ran a best of 60.8mph gps. I turn my props out and I'm running three balde mirages; the slip is very high, normally greater than 16%. I plan on turning them in and using A pair of bravo ones, so I will have to update you later on how the boat likes them. The boat is a big heavy girl, never actually weighed it but I would assume we are talking greater than five tons with equipment. The boat is definitely an epoxy bucket so the ride quality is top notch. I haven't been land locked yet, although I do most of my boating in lake St. Clair. I have been following the back from the dead thread attentively, since I also plan on a full resto/mod sometime in the future.
Regards,
CM
Regards,
CM
07-14-2017, 02:14 PM
#6
CM
My Scarab ran with the outdrives (speedmaster #2's) turning outward and I tried swapping to spin inward and lost mph, seems the added lift in the rear only brought the nose further down to the point it felt like it was plowing at higher speeds. Don't know about the stepped transom type but my Kaama had quite the hook in the hull which drove the nose down the faster you tried to go. I put a straight edge on the chine and couldn't believe how much hook was there, that being said it sure did ride nice in sloppy water. I also boated on Lake St. Clair.
My Scarab ran with the outdrives (speedmaster #2's) turning outward and I tried swapping to spin inward and lost mph, seems the added lift in the rear only brought the nose further down to the point it felt like it was plowing at higher speeds. Don't know about the stepped transom type but my Kaama had quite the hook in the hull which drove the nose down the faster you tried to go. I put a straight edge on the chine and couldn't believe how much hook was there, that being said it sure did ride nice in sloppy water. I also boated on Lake St. Clair.
07-14-2017, 04:32 PM
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Great Info here guys! 82 Flatdeck, what pitch props are you running and at what rpms, also what is your prop shaft depth? If I can get enough information, I'm going to compile a spreadsheet and post it on here.
The pervious owner of my boat said the boat was good for 63-64 mph (gps), now he was pretty sure it was a kevlar hull. Seeing that your boat is almost identical to mine, I think he was correct. I'm sure 700 lbs is good for a couple mph. My boat was spinning 23 non-plus Mirages. As to your high prop slip, my formula was very similar until i both raised the shaft depth and added a sportmaster lower. I was running -2's on a 7" standoff box. I went from 15% to 9%. With this setup I really didn't gain a lot considering I also added an extra 400 hp. This year I swapped to a -3 and picked up 8 mph. Now I also added Dominator carbs and KE headers, but I think the extra inch really helped. I think with our notched transoms, unless you have a higher prop shaft height, it may actually slow you down. I'm not sure if the notched boats and the straight boats have the same X. This is where I hope this post sheds some light on that. I've read every 38 flat deck post here, and there is very little real info, for any conclusions, as to how to maximize these hulls. About the only thing I can say, is it seems it takes 600 hp to hit 80 mph with TRS drives.
Out of curiosity, what is the color of the resin used in your boat? I see with Hblair's boat, the inside glass looks like a standard fiberglass boat. Mine is orange, it looks nothing like Hblairs. With some of the other 38 restoration pages, they too look like Hblair's. Ive not seen any that are orange. Its not painted, it is 100% the color of the resin.
The pervious owner of my boat said the boat was good for 63-64 mph (gps), now he was pretty sure it was a kevlar hull. Seeing that your boat is almost identical to mine, I think he was correct. I'm sure 700 lbs is good for a couple mph. My boat was spinning 23 non-plus Mirages. As to your high prop slip, my formula was very similar until i both raised the shaft depth and added a sportmaster lower. I was running -2's on a 7" standoff box. I went from 15% to 9%. With this setup I really didn't gain a lot considering I also added an extra 400 hp. This year I swapped to a -3 and picked up 8 mph. Now I also added Dominator carbs and KE headers, but I think the extra inch really helped. I think with our notched transoms, unless you have a higher prop shaft height, it may actually slow you down. I'm not sure if the notched boats and the straight boats have the same X. This is where I hope this post sheds some light on that. I've read every 38 flat deck post here, and there is very little real info, for any conclusions, as to how to maximize these hulls. About the only thing I can say, is it seems it takes 600 hp to hit 80 mph with TRS drives.
Out of curiosity, what is the color of the resin used in your boat? I see with Hblair's boat, the inside glass looks like a standard fiberglass boat. Mine is orange, it looks nothing like Hblairs. With some of the other 38 restoration pages, they too look like Hblair's. Ive not seen any that are orange. Its not painted, it is 100% the color of the resin.
