Vertus Engine mounts

Indian Falls · June 13, 2011, 10:27:16 AM

Hi Ron, Thanks, I'll pursue that further. I've got no soot, no smoke and the engine starts right up with only 5 secs. of glow plug, and I don't have a glow plug relay. If I pull one injector and it's squeaky clean.... maybe I should just put it back in?

Mike, what condition were your old mounts in? Could you see that the metal in the bottom center of your old mounts had been hitting the mounting surface? What is your low idle? If you pull the stairs at that idle speed roughly how much shake is taking place?

I've got one spot on the stringer behind the starter where either the factory chiseled the corner away for clearance or the engine is hitting it in certain situations. I'll have to put some putty on that spot and see if my engine is banging that stringer 30 times/second and making the majority of the noise. Since it looks like it's shaking to and fro +/-.25" it may be able to hit it now that the mounts are much less movement limited.

Thanks guys!

Kyle Ewing · June 13, 2011, 07:13:28 PM

Here's another mount related question: How smooth are things when making sharp turns under power? By sharp, I mean coming hard about, as if tacking. I think I had some noise/vibration with the old mounts but its much more noticeable with the new mounts.

On my shake-down motor tonight I still have some vibration above 2500 RPMs so I'm not quite there, but getting close. It's smoother than with the old mounts not kitten smooth like I want it to be.

Update: I found this thread indicating the noise is prop cavitation: http://c34.org/bbs/index.php/topic,360.0.html. It doesn't sound like anything to worry about.

Mike and Joanne Stimmler · June 13, 2011, 08:51:29 PM

Dan & Dar,
My Stbd forward mount had completely separated and the rest were questionable.
My low idle is 800 rpm's and although it runs rougher at that speed, it is still smoother than it used to be and is acceptable as far as I am concerned. It smooths out even more above 1000 rpm's and stays that way all the way to full throttle.

Hpoe that helps,
Mike

Indian Falls · June 14, 2011, 01:59:12 PM

Mike, what's the maintenance history on your injectors? I wish I could get back down to 800rpm.... we'll see soon enough - I'll be on this problem like a monkey on a cupcake this weekend.

Ron Hill · June 14, 2011, 02:06:31 PM

Dan : Nobody wants to get their diesel down to 800rpm - it's a tooth shaking rpm.
Diesels don't like a low idle, infact I beeped mine up to 1100 !!

Mike and Joanne Stimmler · June 14, 2011, 03:40:30 PM

Dan,
I have no history on the injectors.
I've owned the boat for five years and I've never replaced or repaired them.Don't know if the PO did anything or not.
As Ron said,800 rpm's is going to be shaky, no matter what and although my engine will idle at 800 rpm's, I usually keep it at 1000 just to keep my fillings in place.

Mike

Indian Falls · June 14, 2011, 05:34:21 PM

Thanks fellas, Its Likely an indication my tach may be reading low. We'll find out soon.

Ron Hill · July 04, 2011, 04:52:20 PM

Once again Guys : This engine mount topic has morfed off into a completely differant topic. That's why people need to start a new thread!!

_______________________________________________________________________________

Engine RPM : You need to check the engine instrument tach against the actual engine RPM.
Only then will you know what the real RPM is!!

Laser tach's are about $35 on the internet!! A few thoughts

Indian Falls · July 05, 2011, 07:11:57 PM

Sorry Ron!! I do believe my input so far is due to changing engine mounts. It does seem that the thread has leaned toward injector issues but all related to solving a problem following mount installation.

I was very dissatisfied as I am not enjoying the purported benefits of smooth and quiet. I went from nice and manageable at I think 950 rpm and just noisy at 2500 rpm -to- very noisy and extreme vibration at exactly the same idle rpm I was used to. I'm paying far too much attention to shifting speeds. It never used to matter whether you were in gear or not at idle speed, now if at idle speed of 1200rpm, upon shifting you must up the rpm to 1200 again to compensate for load and stop the horrific noise from below. I found similar complaints to mine in other forums as well. To get rid of all the noise at low rpm under all conditions I have to be at 1500 rpm and this makes shifting and docking a pain.

However 2400 rpm at 5.5 - 6 knots is definitely smoother than the old mounts.

(Kyle) I do get some odd noise and vibration from hard turns but I believe this to be more from throwing a spinning prop sideways into water during the turn than from my new Vetus K75's.

Sorry for not having yet met the requests to run injector cleaner, clean or replace the injectors, check the tach for accuracy, or change the hump hose. (Short of time lately, and I don't quite see how harder mounts were masking a dirty injector problem... seems to me I'd have had what I have now only worse)
At this point in time I really wish I hadn't changed the mounts at all.

Thanks to all for your comments and input. This forum is invaluable.

DaveM, please post your end result after all this!

DaveM · July 06, 2011, 05:52:14 AM

Well Dan

After all the great discussion and iput, including my regret that you are having such great difficulty, I will be installing K50s fwd and K 75s aft. Will post my results when I have data.

Thanks to All
DaveM

Ron Hill · July 06, 2011, 02:37:48 PM

Dan : Not too sure what to say, except I'm most certain your vibration is not caused by the new Vetus mounts !! Your vibration is too severe - is the problem.

You need to pull the injectors and have them checked is my advice.

The engine should run smoothly at 1000rpm (actual) in neutral.

All the mounts do is to keep the "normal" slight engine vibration from being transmitted to the beams on the engine bed and subsequently throughout the hull.
You may not know it, but I seen the old Atomic 4 engine bolted directly to the engine bed - NO mounts. However, it was a smoother running gasoline engine !!

Indian Falls · July 23, 2012, 01:32:02 PM

UPDATE

It so happens that a fellow C34 owner in our club has an 87 C34 that he just re-powered with the last M25xp Catalina had sitting around in a crate. He mounted it on Vetus K75/K50's. I had him look at my engine and he confirmed that his new M25 moves and shakes around as much as mine. I decided to recheck the the flange alignment and it was off a few thou. During this check I was able to determine the shaft is bent a small amount as the shims tell me the flange on the prop shaft wobbles a few thousandths. So this fall when she's hauled we'll get the prop shaft straightened, replace the cutlass bearing and align the transmission output to the holes in the strut and shaft log. The idea is that after all this is done the, horrible slapping banging vibration noise will be gone,, not the vibration itself. I've also reduced my RPM to 900 at idle and this has done away with the excessive prop walk, thrust, hard shifting encountered with docking when the idle rpm is at 1200. It purrs like a kitten at this idle speed, runs like a top at 2200 rpm 6.5 kts on the GPS. So I figure that digging into the injectors at this time is not warranted. I will however be setting the valve lash, I'm sure that's never been done either. Thanks!