Forums
NautiqueParts.comNautiqueSkins.com - Correct Craft Upholstery and Part
  New Posts New Posts RSS Feed - 1981 Nautique on a diet...
  FAQ FAQ  Forum Search   Register Register  Login Login

1981 Nautique on a diet...

 Post Reply Post Reply   
Author
MourningWood View Drop Down
Gold Member
Gold Member


Joined: June-13-2014
Location: NorCal
Status: Offline
Points: 884
Post Options Post Options   Thanks (1) Thanks(1)   Quote MourningWood Quote  Post ReplyReply Direct Link To This Post Topic: 1981 Nautique on a diet...
    Posted: March-05-2018 at 1:23pm
Have begun futzing around with this '81 Nautique in a way that I've always wanted to do.....weight reduction.
Nothing fanatical, just see how it performs at around 1800 lbs.
First up-drivetrain. Beginning with standard 351w and 71c BW trans:

Edelbrock aluminum heads: Shave 42 ib.s total
Edelbrock aluminum intake: 31 lbs.
Aluminum front timing cover: 10 lbs.
Transmission swap to PCM 40i: 47 lbs.
Battery: 27 lbs.
Exhaust manifolds: 61 lbs..
Crank-driven rwp: 8 lbs.
Thermostat housing and hoses 7 ibs.
Starter 9 ibs.
Water circulation pump 11.5 lbs.
Alternator brackets 2 lbs.

So far: 255.5 lbs.

This winter: motor box/swim platform/seat bases/floorboards.....

.

1994 Ski Nautique "Riot"
1964 Dunphy X-55 "One 'N Dun"

'I measured twice, cut three times, and it's still too short!"
Back to Top
Hollywood View Drop Down
Moderator Group
Moderator Group
Avatar

Joined: February-04-2004
Location: Twin Lakes, WI
Status: Offline
Points: 13510
Post Options Post Options   Thanks (0) Thanks(0)   Quote Hollywood Quote  Post ReplyReply Direct Link To This Post Posted: March-05-2018 at 2:50pm
Hollow pylon, plastic windows (or none at all), and bare bones interior. I would be looking at basically everything with a jigsaw and holesaw in hand.
Back to Top
KENO View Drop Down
Grand Poobah
Grand Poobah


Joined: June-06-2004
Location: United States
Status: Offline
Points: 10606
Post Options Post Options   Thanks (0) Thanks(0)   Quote KENO Quote  Post ReplyReply Direct Link To This Post Posted: March-05-2018 at 4:12pm
Originally posted by MourningWood MourningWood wrote:


making a cooling system utilizing a crank-driven RWP and eliminating the engine-mounted circ. pump.



You could look at a 351 Indmar cooling system setup instead of "making your own".

The housing in the link is available these days and replaces an Indmar setup using a crank mounted pump.

No funny routing of hoses or anything

link
Back to Top
MourningWood View Drop Down
Gold Member
Gold Member


Joined: June-13-2014
Location: NorCal
Status: Offline
Points: 884
Post Options Post Options   Thanks (0) Thanks(0)   Quote MourningWood Quote  Post ReplyReply Direct Link To This Post Posted: March-15-2018 at 7:40pm
Thanks, yes, I had stumbled on the Barr item earlier.
Plan to use thermostat in the stock (automotive) location, and will make a housing that discharges to the exhaust.
Photos coming.
With the new Barr aluminum manifolds, the total weight cut to date is 238 lbs.
Will tackle hull (and attachments) soon.
1994 Ski Nautique "Riot"
1964 Dunphy X-55 "One 'N Dun"

'I measured twice, cut three times, and it's still too short!"
Back to Top
Gary S View Drop Down
Grand Poobah
Grand Poobah
Avatar

Joined: November-30-2006
Location: Illinois
Status: Offline
Points: 14096
Post Options Post Options   Thanks (0) Thanks(0)   Quote Gary S Quote  Post ReplyReply Direct Link To This Post Posted: March-15-2018 at 8:04pm
Why reinvent the wheel- just copy the Holman Moody method. Later on a circulating pump was added to better the cooling but this was the minimum

69 Mustang HM SS
95 Nautique Super Sport
Back to Top
MourningWood View Drop Down
Gold Member
Gold Member


Joined: June-13-2014
Location: NorCal
Status: Offline
Points: 884
Post Options Post Options   Thanks (0) Thanks(0)   Quote MourningWood Quote  Post ReplyReply Direct Link To This Post Posted: March-15-2018 at 8:25pm
....which exactly what I'm doing, based on an earlier, full-frontal shot of (I think) your motor, complete with red arrow illustrations.

Simplicity at its finest.

I can't find that type of t-housing, so I can make that.

And easier (for me) than to make the intake pipes, have taken an old aluminum engine water pump and gutted it, thereby turning it into a manifold, complete with a pressure bleed hose to the exhaust (ala Interceptor).

The pump housing also provides bosses for alternator bracketry.
1994 Ski Nautique "Riot"
1964 Dunphy X-55 "One 'N Dun"

'I measured twice, cut three times, and it's still too short!"
Back to Top
DW1 View Drop Down
Newbie
Newbie


Joined: March-22-2019
Location: Michigan
Status: Offline
Points: 21
Post Options Post Options   Thanks (0) Thanks(0)   Quote DW1 Quote  Post ReplyReply Direct Link To This Post Posted: March-29-2019 at 1:51am
@MourningWood: How difficult was the transmission swap? I have done similar weight reduction on my ski boat with excellent results. How satisfied are you with your project?
Back to Top
KENO View Drop Down
Grand Poobah
Grand Poobah


Joined: June-06-2004
Location: United States
Status: Offline
Points: 10606
Post Options Post Options   Thanks (0) Thanks(0)   Quote KENO Quote  Post ReplyReply Direct Link To This Post Posted: March-29-2019 at 9:28am
Not MourningWood but, here's an old thread where a PCM 40i 1 to 1 transmission was replaced with a B/W 10-17 which is probably the opposite of what you're thinking about, but has good info.

You can figure out differences in dampers, mount locations transmission length etc from reading his thread.

BTW   If you look at MourningWood's other threads he really swapped in a 40i and not a 40A like he mentions in the first post in this thread

link
Back to Top
DW1 View Drop Down
Newbie
Newbie


Joined: March-22-2019
Location: Michigan
Status: Offline
Points: 21
Post Options Post Options   Thanks (0) Thanks(0)   Quote DW1 Quote  Post ReplyReply Direct Link To This Post Posted: March-29-2019 at 9:55am
@Keno: Thanks, appreciate the link. I would be shopping for a 1:1 version of that box, I will have to learn the naming configs.
Back to Top
KENO View Drop Down
Grand Poobah
Grand Poobah


Joined: June-06-2004
Location: United States
Status: Offline
Points: 10606
Post Options Post Options   Thanks (0) Thanks(0)   Quote KENO Quote  Post ReplyReply Direct Link To This Post Posted: March-29-2019 at 10:32am
Dwight

A couple of things

Nobody really uses that goofy @ before the name here on CCF unless they're used to it from some "other site"

Somebody is bound to come along and want to know what kind of boat and engine you're dealing with (and which way it rotates) and probably demand some pictures too.

The i version of the PCM transmissions is the 1 to 1 ratio, there is a 40i which is older than the newer 80i.

The 40i can have it's pump oriented to work with either rotation engine just like a B/W but the 80i only works with normal rotation engines. The pump can't be reoriented.

And BTW, welcome to CCF

Strictly a guess, but I'll say it begins with M and ends with U and has a Chevy that turns in the normal direction
Back to Top
DW1 View Drop Down
Newbie
Newbie


Joined: March-22-2019
Location: Michigan
Status: Offline
Points: 21
Post Options Post Options   Thanks (0) Thanks(0)   Quote DW1 Quote  Post ReplyReply Direct Link To This Post Posted: March-29-2019 at 11:06am
Keno, thanks and yes that funky symbol works on those other sites. Nailed it, LHR Chevy powered 'vessel' and you might consider playing the lottery this week, your guess is spot on. Just to ensure I am in good standing here, my ride when I hit the course is a 200:-)

Thanks for the comment on the 80i & the various links, my early stages of learning the details on the PCM tranny's.
Back to Top
GottaSki View Drop Down
Grand Poobah
Grand Poobah


Joined: April-21-2005
Location: NE CT
Status: Offline
Points: 3327
Post Options Post Options   Thanks (0) Thanks(0)   Quote GottaSki Quote  Post ReplyReply Direct Link To This Post Posted: March-29-2019 at 11:57am
MourningWood tell us more about your battery ideas

I have a parallel effort going on, minus the transmission for now
"There is nothing, absolutely nothing, half so much worthwhile as messing around with boats...simply messing."

River Rat to Mole
Back to Top
jjtaub View Drop Down
Newbie
Newbie


Joined: June-24-2006
Location: CT/Western MA
Status: Offline
Points: 34
Post Options Post Options   Thanks (0) Thanks(0)   Quote jjtaub Quote  Post ReplyReply Direct Link To This Post Posted: March-29-2019 at 12:43pm
depending on budget and how much engine work your doing could you do a 347 stroker rather than the 351W, its something like another 50lbs
JJTaub
78 Ski Nautique-past
94 Ski Nautique
Back to Top
DW1 View Drop Down
Newbie
Newbie


Joined: March-22-2019
Location: Michigan
Status: Offline
Points: 21
Post Options Post Options   Thanks (0) Thanks(0)   Quote DW1 Quote  Post ReplyReply Direct Link To This Post Posted: October-02-2019 at 12:37am
I did not find a tranny for my weight savings program (yet), but did stumble on an aluminum (yep a GM) engine block then added an aluminum flywheel for a 100 lb reduction. Another noticeable wake improvement. So block, heads, intake, exhaust are now all aluminum so 280 lb off orginal Mercruiser,
Back to Top
MourningWood View Drop Down
Gold Member
Gold Member


Joined: June-13-2014
Location: NorCal
Status: Offline
Points: 884
Post Options Post Options   Thanks (0) Thanks(0)   Quote MourningWood Quote  Post ReplyReply Direct Link To This Post Posted: October-02-2019 at 3:16am
DW1-nice!

Sorry I forgot about this thread,

Have updated the first post to current.

I've moved everything listed over to a '82 SN 2001, and will continue shaving.

The PCM 40i install was very straight forward. The drive plate is different, otherwise straight bolt up. You may have to redial the aluminum cradle (if so equipped) because the mount holes will be slightly different. The mounts transferred over. Only other detail is the shift cable bracket is different height. Shaft coupling is the same too.


1994 Ski Nautique "Riot"
1964 Dunphy X-55 "One 'N Dun"

'I measured twice, cut three times, and it's still too short!"
Back to Top
GottaSki View Drop Down
Grand Poobah
Grand Poobah


Joined: April-21-2005
Location: NE CT
Status: Offline
Points: 3327
Post Options Post Options   Thanks (0) Thanks(0)   Quote GottaSki Quote  Post ReplyReply Direct Link To This Post Posted: October-02-2019 at 7:18am
Dwight please fill us in on the details, and solutions, as we have done the all-aluminum thought experiment, and could not talk ourselves out of it.
Mounts, induction, ignition, exhaust, cooling, all seem to have solutions available nowadays,
"There is nothing, absolutely nothing, half so much worthwhile as messing around with boats...simply messing."

River Rat to Mole
Back to Top
DW1 View Drop Down
Newbie
Newbie


Joined: March-22-2019
Location: Michigan
Status: Offline
Points: 21
Post Options Post Options   Thanks (0) Thanks(0)   Quote DW1 Quote  Post ReplyReply Direct Link To This Post Posted: October-02-2019 at 12:15pm
Gotta ski - it was a step wise process, started with a basic 94 Merc all iron engine, swapped heads to 'fast burn 385' and needed an aluminum edelbrock manifold to accept bolt pattern. Added Stainless Marine aluminum exhaust manifolds with 4" outlets so then I made my own exhaust tubes and SS 4" tips (that first hole is the hardest to drill, after that one a lot easier:-). Ditched the circ pump for a simple stainless tube and an automotive style tstat housing which shed ~30 lb over all that complex plumbing. Fast forward to now and once the engine was on a stand for a rear main replacement, I found an aftermarket aluminum block which then led to 383 crank, 030 Mahle pistons, aluminum flywheel and a pretty trick camshaft, so a $2 main seal suddenly got expensive, LOL.   Engine mounts all stayed the same, used same distributor so really the major fab work was exhaust and raw water inlet hoses with the circ pump delete. As I previously noted, looking for a lighter trans for another step. The rest of the boat has gotten a pretty good diet, made several carbon fiber parts and moved the fuel tank to move CG forward so total wt, reduction is 475 lb.

What have you done and how are your results?
Back to Top
GottaSki View Drop Down
Grand Poobah
Grand Poobah


Joined: April-21-2005
Location: NE CT
Status: Offline
Points: 3327
Post Options Post Options   Thanks (0) Thanks(0)   Quote GottaSki Quote  Post ReplyReply Direct Link To This Post Posted: October-02-2019 at 1:02pm
Dwight, wow. those are just amazing numbers
oh i see, old school aluminum chebby!
How did you stumble into an alum sbc block

Do you miss the heavy flywheel at all?

My particular case, 141# off the 351 so far
I didn't count the gear reduction starter i did years ago, and am still running the original cast iron circ pump, so thats an easy 20 combined if i were to go aluminum.

You can review the build here...
http://correctcraftfan.com/forum/forum_posts.asp?TID=46988&title=worn-valve-stem


before committing on the 351 'build', i ran this scenario, And still may do it on another boat someday
One can get an all-aluminum 5.3L LM4 LS for cheap from an old trailblazer EXT. Ive seen entire running truck examples on local craigslist for 600 bucks.. Give it new bearings ,
about 290hp factory rated, then add cam (the stock is like 194 intake duration) and proper valvesprings for an easy boost into the 320-330 range without even taking the heads off.
Aftermarket aluminum carb intake, and LS MSD spark box, alum LS ex manifolds are avail now from multiple sources.




"There is nothing, absolutely nothing, half so much worthwhile as messing around with boats...simply messing."

River Rat to Mole
Back to Top
DW1 View Drop Down
Newbie
Newbie


Joined: March-22-2019
Location: Michigan
Status: Offline
Points: 21
Post Options Post Options   Thanks (0) Thanks(0)   Quote DW1 Quote  Post ReplyReply Direct Link To This Post Posted: October-02-2019 at 1:42pm
Yes, old style SBC. It was challenging to find a block, ended up going with an aftermarket new one from Speedmaster. It has all the production attachments which others do not. Aluminum flywheel is fine, no issues and that was a concern as I built this thing up, going in to the unknown but idle quality and accel is great, I also have a pretty aggressive cam but it idles like a purring kitten and runs like a scalded cat so happy with results. I did debate the whole LS option, doing a fair amount of math it looks like a minimal SBC is lighter in the end mainly due to the whole accessory drive setup. I did the upper end years ago before the LS stuff was even on the market, so that helped the decision to stick with the old school SBC. An LS-7 would make one heck of a package:-)
Back to Top
MrMcD View Drop Down
Grand Poobah
Grand Poobah
Avatar

Joined: January-28-2014
Location: Folsom, CA
Status: Offline
Points: 3582
Post Options Post Options   Thanks (0) Thanks(0)   Quote MrMcD Quote  Post ReplyReply Direct Link To This Post Posted: October-02-2019 at 5:17pm
DW1 you did a lot of work reinventing the old Nautique.   How does it run on the water now?
Top Speed and at what RPM. I know a good 383 can be a real beast with over 450 ft pounds of torque. That has to be fun.
Mark
Back to Top
DW1 View Drop Down
Newbie
Newbie


Joined: March-22-2019
Location: Michigan
Status: Offline
Points: 21
Post Options Post Options   Thanks (0) Thanks(0)   Quote DW1 Quote  Post ReplyReply Direct Link To This Post Posted: October-02-2019 at 5:41pm
Mark, it has been a lot of tinkering which I enjoy. It runs great, although not broken in so top speed is not known yet, but given its around 500 hp and tips the scales at 2175 lb and previously at 100 hp less it would go in to the low to mid 50's, I expect it will do a bit more than that now. RPM is 3400 for 36 mph don't know what peak will be, it pulled 5,600 prior to the aluminum block and bigger cam (.560" lift) so who knows at present. It really squirts forward when the throttle is cracked open and the spool up is really quick a lot due to very low piston / rod / crank / flywheel inertia and overall light weight. So yes, it is a beast:-)

It's actually brand 'Bu' but I stumbled on the weight saving and transmission thread so I thought I would share my story. The real goal was to improve the wake via mass reduction so I was here poking around for a PCM 40I trans. It also tracks great in through the course, I was wondering how that would go. I do spent lots of sets behind a 200:-)
Back to Top
MrMcD View Drop Down
Grand Poobah
Grand Poobah
Avatar

Joined: January-28-2014
Location: Folsom, CA
Status: Offline
Points: 3582
Post Options Post Options   Thanks (0) Thanks(0)   Quote MrMcD Quote  Post ReplyReply Direct Link To This Post Posted: October-02-2019 at 9:50pm
DW1, I won't hold it against you for running the Malibu, I had one for 20 years. I actually have a set of 383 pIstons and AFR heads I planned to use on that boat but it ran so good factory stock that I never pulled it apart.   Sold it and back to Nautique and happy to be back. The Nautique brand just does some things better although the Malibu had a better wake than my 95. You should go north of 55 with that engine you have.
It seems to me that Malibu sold the Corvette model with a powerful 383 that ran 55 MPH.
Back to Top
DW1 View Drop Down
Newbie
Newbie


Joined: March-22-2019
Location: Michigan
Status: Offline
Points: 21
Post Options Post Options   Thanks (0) Thanks(0)   Quote DW1 Quote  Post ReplyReply Direct Link To This Post Posted: October-03-2019 at 3:42pm
MrMcD - thanks!   I am pretty confident it will go north of 55 and as you note the Corvette equipped with the 383 would hit 55. My boat is much lighter and the engine has a more aggressive cam that will open up the top end so it will be fun to find out :-)
Back to Top
DW1 View Drop Down
Newbie
Newbie


Joined: March-22-2019
Location: Michigan
Status: Offline
Points: 21
Post Options Post Options   Thanks (0) Thanks(0)   Quote DW1 Quote  Post ReplyReply Direct Link To This Post Posted: May-17-2020 at 4:47pm
I found a 40i trans on ebay for a very friendly price and took a flyer on it, now just need a few misc parts and then how to plug it in. It's missing the output flange so need to source that and depending on bellhousing bolt pattern may need that + a damper plate as it appears 15 v 26 splines on the current VD 71. Trans tipped the scale at 48 lbs (wet, no bellhousing or cooler) which compares I believe to the 95 lbs number for the VD. VD compete with bellhousing / cooler is 135 lbs. Should be a nice diet item.

So search is on for output flange, other req'd parts and good sources for PCM trans parts. May have to build that trans tester from forum member KENO, awesome, thx!
My rabbit hole is quite deep at this point so I may as well keep digging.
Back to Top
KENO View Drop Down
Grand Poobah
Grand Poobah


Joined: June-06-2004
Location: United States
Status: Offline
Points: 10606
Post Options Post Options   Thanks (0) Thanks(0)   Quote KENO Quote  Post ReplyReply Direct Link To This Post Posted: May-17-2020 at 10:44pm
Same bell housing bolt pattern so it'll bolt right up with a new damper plate for the different splines like you mentioned.

It seems ;like 135 pounds is pretty heavy on the B/W with the bell housing and cooler unless you're weighing it with the mounts included or you have a cast iron bell housing

I think I'd call Joe at FFI marine and see what he might have for a used output flange and a new damper plate

Here's his contact info from last year


Originally posted by FFImarine FFImarine wrote:

Hey guys! We have moved to a new location as of June 1st new address is
1669 w130th unit#403 hinckley oh 44233 are phone number is still the same.(330)273-8291. As always we will be here to answer any questions you guys might have day or night so please don’t hesitate to call. I’ve been working for this company for over 16 years and I’m proud to say that my hard work has payed off cause I Joe D’Amico am the new owner of fantastic finishes marine. Please spread the word for me guys and thank you for reading


And as far as the transmission tester, it kinda morphed into a transmission/raw water pump/ alternator spinner/tester too with a couple more easy to make brackets.

It keeps my simple mind easily amused   

Back to Top
DW1 View Drop Down
Newbie
Newbie


Joined: March-22-2019
Location: Michigan
Status: Offline
Points: 21
Post Options Post Options   Thanks (0) Thanks(0)   Quote DW1 Quote  Post ReplyReply Direct Link To This Post Posted: May-18-2020 at 11:06am
KENO thanks for the feedback, much appreciated. Correct the weight includes the trans mounts so knock off 14 from the 135 for trans / bellhousing / cooler. The bellhousing is aluminum, the mounts are cast iron, so I'll have to have my buddy scan the mounts to make some aluminum ones:-) Another option, tubular steel fabbed ones.
Back to Top
 Post Reply Post Reply
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Copyright 2024 | Bagley Productions, LLC