Forums
NautiqueParts.comNautiqueSkins.com - Correct Craft Upholstery and Part
  New Posts New Posts RSS Feed - When to rebuild?
  FAQ FAQ  Forum Search   Register Register  Login Login

When to rebuild?

 Post Reply Post Reply   
Author
ski-guy View Drop Down
Groupie
Groupie
Avatar

Joined: September-12-2011
Location: West Kelowna
Status: Offline
Points: 62
Post Options Post Options   Thanks (0) Thanks(0)   Quote ski-guy Quote  Post ReplyReply Direct Link To This Post Topic: When to rebuild?
    Posted: March-03-2019 at 1:43pm
Hi,
I was planning to pull my engine (1980 SN 351W reverse rotation) for a rebuild. It runs great but leaks oil (rear main) and burns oil - although I haven't actually put enough hours on it to say how much oil it might burn you can see it in the exhaust. AND, more disturbing it seems to get a scum line around the hull each time I have it out. So that kind of tells me I better address it - there is already enough crap goin in the lake without me adding to it,

The rebuild was kind of automatic - the next step sort of thing - but now that I see that reverse rotation parts might be an issue I hate to get it all torn down and be looking for parts when summer comes. And of course the question of marine versus regular for internal components I am still trying to get my head around. I had done a cold compression test before I took the engine out for the stringer work and it was pretty much 100 psi even in all cylinders. (I can't even remember if I pulled all the plugs at that time).

So my main question is whether it is worthwhile to do a bunch more checking of compression (or anything else) so I have a better idea of what it needs, or can the machine shop tell once it is torn down. I haven't taken an engine apart that far since about 1975! The machine shop I plan to use does marine engines for local marine shops but is more into hot rods and racing it seems.
1980 SN - don't worry dear, I may have $10+K into this project boat but I can easily sell it for $5k

2000/2001 Glen-L 'Squirt'

2006 Malibu LSV
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: March-03-2019 at 2:50pm
The Machine Shop I use is also into Hot Rods and Racing, he went that way because Automotive Engine Rebuilding pretty much dried up and blew away with the advent of Fuel Injected engines. In the old days any car with 100,000 miles needed a new engine and the machine shops were always busy. With computer controlled fuel injected engines the automotive engine now commonly last more than 250,000 miles and by the time the engine needs a rebuild the car is worn out and scrapped in most cases.. So don't hold this against your machine shop, I give him credit for seeing the change and adapting to survive. Many went out of business.
As far as your boat goes. a leak down test and a compression test would only take 2-3 hours and will tell you if your engine is in good shape and if it has compression leaks it will identify where your compression leaks are or if they exist.
Your oil smoke can certainly be from worn out piston rings but it could also be from valve stem seals and they can be replaced in the boat for a lot less work than a full overhaul. Leaking valve stem seals can cause you to burn a lot of oil.   Old valve stem seals sometimes fail and allow oil to leak right down into your cylinder.
If your compression test and leak down are good I would not overhaul the engine.
These same tests may show you are low on compression and it is due to leaking exhaust or intake valves.   A valve job can fix that for far less work than an overhaul.

Installing a new rear main seal in the boat is no fun but can be done.
My 78 Nautique 351W went about 900 hours and then needed a valve job, one valve burned.   I put new heads on that engine and it ran like brand new until we sold it with 1,500 hours on the meter. It still had great compression and ran really strong.

I would test yours first to see what is good and what is bad before making decisions.
When you pull the spark plugs read them, they will tell you what cylinders are burning oil and help search for your problem areas.
Mark
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-03-2019 at 4:22pm
Originally posted by MrMcD MrMcD wrote:


Installing a new rear main seal in the boat is no fun but can be done.


Since you have a 1980, if the engine is original, it has a 2 piece rear main seal.

Doing a later engine with a 1 piece rear main seal isn't too bad in the boat but doing a 2 piece means dropping the oil pan, loosening the main bearing caps enough for the crankshaft to drop down a little so you can get the top half of the seal out and roll a new one in while you're laying in the bilge hoping that whatever contraption you have holding the engine up doesn't fail and drop the engine on your face

If you do all the work to get the engine in a crazy position where you can actually do this, you might as well just pull it and save yourself some time and aggravation by doing it in good working conditions
Back to Top
ski-guy View Drop Down
Groupie
Groupie
Avatar

Joined: September-12-2011
Location: West Kelowna
Status: Offline
Points: 62
Post Options Post Options   Thanks (0) Thanks(0)   Quote ski-guy Quote  Post ReplyReply Direct Link To This Post Posted: March-03-2019 at 4:53pm
Just googled the two piece seal - that is a major undertaking compared to the one piece!

So I will do the compression and leak down testing as suggested by McD but looks like I will pull it out either way.

Thanks for the input
1980 SN - don't worry dear, I may have $10+K into this project boat but I can easily sell it for $5k

2000/2001 Glen-L 'Squirt'

2006 Malibu LSV
Back to Top
ski-guy View Drop Down
Groupie
Groupie
Avatar

Joined: September-12-2011
Location: West Kelowna
Status: Offline
Points: 62
Post Options Post Options   Thanks (0) Thanks(0)   Quote ski-guy Quote  Post ReplyReply Direct Link To This Post Posted: March-11-2019 at 3:21pm
A little update: Completed compression and leak down tests.

On warm engine, compression 112-128 (14% high to low).

All cylinders leak down significantly - most I could hear through the crankcase (could here it via the oil filler) - a couple through the exhaust.

Either way, have now stripped off most of the externals and will pull the engine today and take it to the machine shop
1980 SN - don't worry dear, I may have $10+K into this project boat but I can easily sell it for $5k

2000/2001 Glen-L 'Squirt'

2006 Malibu LSV
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: March-11-2019 at 3:52pm
Now you will know exactly what you have for next season.
Couple of notes for you on your rebuild.
Piston Choice, standard cast pistons are fine but for little more cost you can use hypereutectic pistons. They work very well and hold up longer in stock and mild performance engines, Sealed Power or Silvolite brands, Mahle also makes OEM quality but may not offer this piston.
Ring Choice: I would go with a Moly Top Ring set.   Like Hypereutectics Moly really improves the life of your ring set and they are soft on the cylinder wall so you have less wear over time.   About a $20 upgrade over stock cast rings. Sealed Power, Hastings or Mahle are top choices.
Gaskets, the Marine set will probably add $50 in cost but gives you a Stainless head gasket set which will avoid rust out for the life of the boat.   Many will say it is not necessary and for less than 10 years use it is not necessary in most areas but it is good to build it like the factory did for the same reasons. Fel-Pro offers the Marine sets.
Bearings I would stick with Federal-Mogul or Clevite.
Oil Pump Melling or Sealed Power
Timing Sprockets or set Cloyes or Sealed Power
Cam Bearings Dura Bond Sealed Power or Clevite
Back to Top
ski-guy View Drop Down
Groupie
Groupie
Avatar

Joined: September-12-2011
Location: West Kelowna
Status: Offline
Points: 62
Post Options Post Options   Thanks (0) Thanks(0)   Quote ski-guy Quote  Post ReplyReply Direct Link To This Post Posted: March-11-2019 at 10:23pm
Thanks for all that.

On all things I am marine only - even gaskets. Sometimes difficult to figure out if there is a marine version. - I see marine lifters at summit racing - didn't think there would be a difference.

Biggest concern right now seems to be the rear main two-piece seal which is NLA for RH engines. Going through the various posts seems making sure seal is smooth (no channeling thingys) and removing any RH directional (channeling thingys) in the crank are the best approach. (also now not sure where the oil was coming from cause not really visible now that the engine is out.)

Will know more once he takes it apart further.

Stripped down in boat


and then just plucked it out with their forklift at the shop
1980 SN - don't worry dear, I may have $10+K into this project boat but I can easily sell it for $5k

2000/2001 Glen-L 'Squirt'

2006 Malibu LSV
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-11-2019 at 10:56pm
Originally posted by ski-guy ski-guy wrote:

Thanks for all that.


Biggest concern right now seems to be the rear main two-piece seal which is NLA for RH engines. Going through the various posts seems making sure seal is smooth (no channeling thingys) and removing any RH directional (channeling thingys) in the crank are the best approach. (also now not sure where the oil was coming from cause not really visible now that the engine is out.)

Will know more once he takes it apart further.



You don't quite understand the 2 piece seal.

You don't want to get rid of the "channeling thingies" on the crankshaft, leave them alone.

Then buy a 2 piece rear main seal that doesn't have your "channeling thingies" and you'll be all set

The 2 piece rear main seal you get doesn't have the wick/helix in it and works just fine with the wick/helix lines on the crankshaft

Install it right and it won't leak unless for some reason you wick/helix lines on the crankshaft are screwed up

This link has info that may or may not confuse you

link
Back to Top
ski-guy View Drop Down
Groupie
Groupie
Avatar

Joined: September-12-2011
Location: West Kelowna
Status: Offline
Points: 62
Post Options Post Options   Thanks (0) Thanks(0)   Quote ski-guy Quote  Post ReplyReply Direct Link To This Post Posted: March-12-2019 at 3:43am
Keno - the link you provided I had reviewed and is where I saw the reference to removing the knurling on the crank.

From ArtCozier post in that link "'If you have to, you can have the knurling taken off the crankshaft and use either a rope seal or a non-directional one. "

So basically you are saying as long as the seal has no knurling should work fine whether there is knurling on the crank or not.
1980 SN - don't worry dear, I may have $10+K into this project boat but I can easily sell it for $5k

2000/2001 Glen-L 'Squirt'

2006 Malibu LSV
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: March-12-2019 at 4:11am
You would remove the helix on a crankshaft if you wanted to take a std rotation crank and convert it to a reverse rotation.   If you are planning to use your reverse rotation crank it is already set up correctly and you should be good to go. If worn they may turn the crankshaft mains and rods down to give you a new surface but you don't have to remove the helix if it is correct for a reverse rotation.
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-12-2019 at 8:28am
Originally posted by MrMcD MrMcD wrote:

You would remove the helix on a crankshaft if you wanted to take a std rotation crank and convert it to a reverse rotation.   If you are planning to use your reverse rotation crank it is already set up correctly and you should be good to go. If worn they may turn the crankshaft mains and rods down to give you a new surface but you don't have to remove the helix if it is correct for a reverse rotation.


Can't say it any better than Mark just did
Back to Top
ski-guy View Drop Down
Groupie
Groupie
Avatar

Joined: September-12-2011
Location: West Kelowna
Status: Offline
Points: 62
Post Options Post Options   Thanks (0) Thanks(0)   Quote ski-guy Quote  Post ReplyReply Direct Link To This Post Posted: March-19-2019 at 4:28pm
Any reason to change the damper plate while everything is apart? From reading on the forum it doesn't seem like there is really a need. Visually it appears fine.
1980 SN - don't worry dear, I may have $10+K into this project boat but I can easily sell it for $5k

2000/2001 Glen-L 'Squirt'

2006 Malibu LSV
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-19-2019 at 5:42pm
Originally posted by ski-guy ski-guy wrote:

Any reason to change the damper plate while everything is apart? From reading on the forum it doesn't seem like there is really a need. Visually it appears fine.


Maybe you should read how much easier it is to change the damper now while everything is apart and right in front of you than it is to change it when it's in the boat and you have to jack the engine up and pull the transmission to do it.

It's one of those "damned if you do, damned if you don't" type things.

It might last for years or it might last a couple of weeks after the boat's back together.

You can get one for 80 to 100 bucks depending on whether you want to trim it yourself or get a pretrimmed one.

Search CCF for ALTDA-106 or 106A if you decide that now is easier.

If the old one is original, it's going on 40 years old and when they crap out, the noise is impressive to say the least, then you get to paddle or get towed in.

It can look fine and the springs can self destruct with no real warning
Back to Top
8122pbrainard View Drop Down
Grand Poobah
Grand Poobah
Avatar

Joined: September-14-2006
Location: Three Lakes Wi.
Status: Offline
Points: 41040
Post Options Post Options   Thanks (0) Thanks(0)   Quote 8122pbrainard Quote  Post ReplyReply Direct Link To This Post Posted: March-19-2019 at 6:11pm
Originally posted by ski-guy ski-guy wrote:

Any reason to change the damper plate while everything is apart? . Visually it appears fine.

Chuck,
Visually it may look great but you have no way of determining the condition of the springs. A spring has a duty cycle that's determined on how far it's compressed and how many times it's compressed. Then there's the spline. What's it look like?

Just as Ken mentioned, for around $80, now's the time to get a new one and not wait until it's much harder to R&R in the boat. I've done it and it's doable but not the easiest.


54 Atom


77 Tique

64 X55 Dunphy

Keep it original, Pete
<
Back to Top
 Post Reply Post Reply
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Copyright 2024 | Bagley Productions, LLC