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iokua
05-22-2006, 11:53 AM
Took my boat in this weekend for a before the season check up - I noticed a slight tick coming from the engine last season so I wanted to make sure it wasn't anything serious. Well my worst fear was confirmed - the previous owner had apparently replaced the starbord head with an automotive head and ONE of the lifters. This then wore down the lobe on the cam on that lifter/cylinder, so there is a flat spot, thus the "tick". The shop told me I had 2 options: 1. Rebuild (for $4000) or 2. Replace with reman. He said the engine "could go" at anytime - he personally wouldn't run it as is. So the options abound:

1. Complete rebuild of my engine
2. Install reman
3. Drop in junkyard engine for this season and spend time rebuilding my engine with a little more pep.
4. Replace just the cam and lifters.


The best option for me at this point (due to budget and time constraints) is to replace the cam and lifters.

Thoughts? Has anyone tacked this? The only two things I've never done on cars/boats is rebuild the engine and transmission. I need to learn at some point so this may be a good time to learn.

Also, anyone have any thoughts on keeping the mismatched heads?

Oh yeah, it's a 1985 S&S with 351W.......

stevo137
05-22-2006, 12:09 PM
Can't you get a new engine for less? :confused:

iokua
05-22-2006, 12:20 PM
Yes; according to the internet I can get an exchange for around $1700.00 + shipping. I haven't called around locally yet, but this is even a little high for my budget right now.

For $300-$400 I can get a cam kit. As little as I actually use my boat, this is the most cost effective option.

stevo137
05-22-2006, 12:22 PM
My hats off to you for being able to do it. I'm mechanically challenged and could not even think about it. Not to mention, impatient.

mplv
05-22-2006, 12:28 PM
i say drive it until it quits as is.

jmac197
05-22-2006, 12:59 PM
I have to agree with MPLV. What's the worst that could happen? The lifters sticks and you lose 1 cylinder. I don't believe it is one of the "interference" engines where the valves will come in contact with the piston should the valve hang open. You will still be able to get home.

Of course the guy wouldn't run it like it is...he also has all the resources available to fix it.

Does anyone know if there is any difference between the marine and standard version of the head and valve train? I can't imagine there would be. The cam maybe a tuned a bit to provide peak torque and HP at a different RPM, but the materials should still be the same.


Just My Opinion.....

86Craft
05-22-2006, 01:04 PM
If you use the boat very little why not run it as is? Just asking, because I'm not sure what kind of damage it will do over time. But, it sound like you have it handle if leaving it go is not a option.

iokua
05-22-2006, 01:48 PM
Thanks for the input, guys. I have a thing about making sure my toys are running in top shape. I have a Lake Shasta trip planned for July 4th and would hate for it to quite then. My buddy plans on taking his boat too, so we would at least have a backup.

The shop claims the #1 cylinder is getting gas and spark but isn't firing because the valve is at the wrong position for detonation. Don't know how true that statement is.

He did say I could run it and it could last all season; I just can't decide if I'm willing to take that chance.

tex
05-22-2006, 04:44 PM
Call DIM! They will give you an honest answer.

Thrall
05-23-2006, 07:03 PM
[QUOTE=iokua]Took my boat in this weekend for a before the season check up - I noticed a slight tick coming from the engine last season so I wanted to make sure it wasn't anything serious. Well my worst fear was confirmed - the previous owner had apparently replaced the starbord head with an automotive head and ONE of the lifters. This then wore down the lobe on the cam on that lifter/cylinder, so there is a flat spot, thus the "tick". The shop told me I had 2 options: 1. Rebuild (for $4000) or 2. Replace with reman. He said the engine "could go" at anytime - he personally wouldn't run it as is. So the options abound:

"The engine could go at any time". If the cam is just lobed, that's a bunch of crap! The tick is from the pushrod loosing contact w/lifter (or rocker arm). If the valves were adjusted correctly when the head was replaced, a lifter by itself wouldn't lobe the cam. Lack of lubrication or wear over time would, but not likely only one cam lobe. It won't cause the engine to blow up, it'll just run progressively worse over time as the valves open lesss ans less as the cam wears down.
Does the engine run bad, like it's misfiring on 1 cyl??
If it still runs good, that valve may just need adjusted. The mechanic would've had to take the valve cover off and put a dial indictor on the lifter/rocker arm to know that it wasn't lifting full ht. DId he do that??
Personally, if it doesn't run bad, I'd adjust the valve.
It's not too hard. In order to not make a mess, go get a junkyard valve cover and cut a rectangular hole in the top where you can get to the rocker arm studs. Put on the valve cover w/ gasket and start the engine. The partial cover will keep oil from going everywhere. Tighten the one thats ticking just until it quits ticking and you're done. I'd check them all.
There also may be a spec as to how far to tighten after it quits ticking.

The other possibility is that you may have dropped a lifter, assuming they're hydraulic lifters, although that usually results in a bent pushrod and engine no worky.
Does it run weak? The v

iokua
05-23-2006, 09:22 PM
It doesn't have any problems starting and seems to run fine. I ran it a few times last summer and it ran pretty good. the more I've thought about it, I think the next step is to get a dial indicator and check the rise/fall of the pushrod to see if the cam lobe is actually worn, since I don't think he did that. He did say he pulled the valve cover and that particular rod wouldn't spin as it should when the lifter comes into contact with the lobe.
On one hand, I could see how the wearing of a cam lobe could cause increased wear in the engine since the material has to go somewhere.....if a valve adjust doesn't work, maybe I just change the oil more frequently this season and work on the engine next Winter.

Thrall: Thanks for the valve cover idea....I may have to try that.

kwood
05-23-2006, 09:30 PM
drive it till it dies :)

SKI*MC
05-23-2006, 10:02 PM
We did that valve cover thing with our old Camaro. It worked fine to get things tuned. About how many hours a season do you put on the boat?

JimN
05-23-2006, 10:26 PM
With people not maintaining their cars and getting tens of thousands of miles out of them after the problems start, taking the valve cover off and tweaking the rocker arm a little won't really do much harm. If the cam isn't being lubricated properly, it'll fail anyway but a clicking rocker arm isn't a big deal. I would look at the valve springs, too. Make sure there aren't any borken ones.

Thrall
05-24-2006, 09:18 AM
iokua,
You said that it runs fine.
With that said, I'd bet, if you adjust the valve (s), you'll lose the ticking and forget it was ever a problem. How many hrs on the engine?
Do check for a broken valve spring though.

iokua
05-24-2006, 10:19 AM
Thanks a lot for the replies......

The boat has 800+ hrs on it; probably won't put much more than 30-50hrs a summer on it. The other toys in the garage would feel neglected.......

I'll be pulling the valve cover in the next week or two to check the springs and adjust the valve.

Hope everyone has a fun/safe weekend...........

rektek
05-25-2006, 12:38 AM
you can check the cam lift by cranking the engine and watching the movement of the rockers, a flat cam will cause less rocker arm movement, compare it to the neighboring cylinder, it will be obvious, the poor running condition is caused by poor or no valve opening.

so you have a flat cam ? now what ? where did the metal go that was once a cam lobe ? did it find it's way into every bearing inside the engine ? probably, personally I'd swap a cam and lifters and shorten your oil change interval for this year, removing a cam is not a big deal if there's proper access to the timing cover, you might have to r+r the engine to gain this access.

go with a quality roller cam and roller rockers,

ncgreg
05-30-2006, 09:51 PM
Ya got a lot of good advice here. Best thing to do:
1) Pull valve cover, put indicator on top of the valve spring keeper and measure stroke of both intake and exhaust of all cylinders, if bad cam you will spot it in a hurry which cylinder it is
2) Still, it could be simply a hung lifter. Pull off the intake manifold and put the indicator on the lifter body itself, and crank the engine. If you get full stroke off the lifter body, the lifter check valve is leaking. Replace the lifter , for $10 or something, and go skiing!
3) If bad stroke, then you need a new cam and lifter set, ie, $300 is my guess for a repacement Melling marine cam and liftr set. Definately somthing you can do and $4000 is crazy