Large Wake

[smclear]

Re: Large Wake

mmmm I love Century's.

Green isn't my favorite color, but that is a great boat.

I think the wake is typical for the hull shape and drive system. In my experience it often requires to go into and out of gear as you make your way down the channel.

Don't change your set up. It is correct for the boat.

I to despise the color. The boat was custom ordered by the Marsh family. They own Marsh Supermarkets and the boat was ordered that color as it matched their company logo. From what I've been able learn, it is the only 18' resorter ever made in that color. That being said, I still want to paint it.

 

[MikDee]

Re: Large Wake

I still say trim tabs of some type in a "flaps down" position will slow you down, & kill that wake at idle. Automatic spring loaded Smarttabs that are highly praised here, & very reasonable, might even do the trick, and make your good hole shot on that skiboat even better, or there's always Bennet adjustable tabs. The alternative ideas are too pricey, & a lot of work, and do you really want to change your tranny, or overrev your engine with the wrong prop? My motto is K.I.S.S (keep it simple stupid)

 

[smclear]

Re: Large Wake

Get the prop that will get you to 5,400 rpm at WOT. That is the optimal thing for your motor and that will also get you to slow to a "no wake" speed. Im not sure what kind of prop you got on there now but you need to do it right!

The boat came from the factory with that prop. I doubt that Century would have put the wrong prop on. Every mechanic I have spoken with, some of which I have known for 40+ years and trust entirely, have said that the proper RPM for a 440 marine engine is around 4,400. What is your reasoning for suggesting that 5,400 RPM is correct for a big block marine engine? I'm not neccassarily saying your wrong, but that is counter to what quite a few knowledeable people have told me. I could understand if the engine was a small block.

 

[smclear]

Re: Large Wake

I still say trim tabs of some type in a "flaps down" position will slow you down, & kill that wake at idle. Automatic spring loaded Smarttabs that are highly praised here, & very reasonable, might even do the trick, and make your good hole shot on that skiboat even better, or there's always Bennet adjustable tabs. The alternative ideas are too pricey, & a lot of work, and do you really want to change your tranny, or overrev your engine with the wrong prop? My motto is K.I.S.S (keep it simple stupid)

To be honest, I hadn't considered Trim Tabs. I'll have to look into that fix. As I said, I DON'T want to change the prop. I love the torque it creates as I can easily pull four skiers. (don't see that too much anymore) As for changing the transmission, I'd rather not as it would be quite costly. If that was my only choice, then I would glady do it though. I just know I have to do something. I am a bit fanatical about following the "rules of the road" and am quite sensitive to how my actions affect others. I just wish there were more folks who held that belief.

 

[45Auto]

Re: Large Wake

Posted by fixb52s:

BTW: here is a photo of my idle wake.
There is really not much you can do with it other than say "sorry, but it IS at idle".

No excuse at all for an idle wake like that. An incompetent mechanic setting the idle speed and an inconsiderate owner is the only explanation.

You come through the no wake zones around here pulling a wake like that and you'll have a ticket in about 10 seconds. Tell him that's as slow as it will go and he'll tell you to get it towed. Drive away from the cop doing it again and the boat will be impounded.

You do realize that you're responsible for your wake???? I can't believe anyone is inconsiderate enough to operate a boat like that.

 

[MikDee]

Re: Large Wake

I think you should get your tach checked for accuracy, I find it hard to believe at idle you have that big a wake

Ditto 45Auto, supposedly that's a 750rpm idle , it looks more like 1500rpm, that tach must be off by 750rpm.

 

[fixb52s]

Re: Large Wake

**edit** Content removed because the better part of me cooled off.​

 

[lkbum]

Re: Large Wake

Yea yea yea. I think back, and the photo I included might have been more than idle speed wake, (took this during my initial sea trials) but I still have quite a wake at idle. I am going out today and will look at getting a true idle photo to quiet the bitching.​

As far as "incompetent mechanic", I think I know how to set the idle. Compared to trimming a P&W J-57, it is a walk in the park. I am not as stupid as implied before and know the tach on the boat is wrong. Yes, I know it is, and that is why I use my Snap On engine analyzer whenever setting dwell and idle. I don't think I can get any more accurate than that. You think you can do better? Come on out and set it yourself.​

Man, settle down.... When I saw that photo that YOU stated was at idle, it was clear that it was not at idleor your idle was WAY OFF. Now after being called on it, your be-memory seems to think maybe it wasn't at idle???? Come on.... It doesn't matter if you work on J-57's or T-56's, or what tools you use. If that was your wake at idle you've got a serious problem....​

 

[MikDee]

Re: Large Wake

Hey Mate, Chill, We got it now, that's the wrong picture. It happens, and is understandable, but it was a scary pic. especially to a boater By the way, Nice boat! it's the "Cats Meow"! Plus you must be pretty handy, & mechanical, by the looks of it.

 

[fixb52s]

Re: Large Wake

Sorry folks. Rough night with the Lightning losing in overtime and the Rays blowing a 7-0 lead to Boston.

Like I said though, I am going out this morning to reverify. I think that photo does not represent the idle speed wake. I also took the hydro foil off to see it that will improve things.​

 

[salty87]

Re: Large Wake

To be honest, I hadn't considered Trim Tabs. I'll have to look into that fix. As I said, I DON'T want to change the prop. I love the torque it creates as I can easily pull four skiers. (don't see that too much anymore) As for changing the transmission, I'd rather not as it would be quite costly. If that was my only choice, then I would glady do it though. I just know I have to do something. I am a bit fanatical about following the "rules of the road" and am quite sensitive to how my actions affect others. I just wish there were more folks who held that belief.

simplest fix of all is to lower your idle setting a bit.

 

[fixb52s]

Re: Large Wake

your be-memory seems to think maybe it wasn't at idle???? Come on....

Years of JP-4/8 fumes does that to the memory.... ​

 

[lkbum]

Re: Large Wake

fixb52s,
Your response's have shown you're a better man than most. Sorry, my reply was on the harsh side also. Funny, with TB up 7 runs late, I turned off the TV and went to bed. Al I can say is wow. Much like the Falcons on sunday coming back with 14 seconds on the clock. I've spent some time with various grades of JP also, mostly on large transports.. Closest I ever came to a B-52 was at the AF museum in Dayton. Impressive machine though.

 

[45Auto]

Re: Large Wake

Hey FixB52s, sorry if I offended you with my post about your wake. Unfortunately all the info we have to go on here is what you post. If that pic isn't at idle speed as you stated then all my comments were irrelevent! But if it is, as Ikbum stated, "you have a serious problem!".

 

[45Auto]

Re: Large Wake

Was it ever stated in this thread what engine is in the boat? Is it a GM or a Chrysler? I see Jaxnjil referenced a MIE 340 (GM 454) but then Smclear later says a "440 marine engine". Is it a Chrysler M-440?

Either way, the idle is way too high. Mercruiser specifies 650-700 RPM in gear for the 1974 big block inboards. Chrysler just says 700 RPM.

 

[RotaryRacer]

Re: Large Wake

Century used Chrysler Marine engines almost exclusively in the mid '70s in their straight drive boats. I would assume that the 440 is a Chrysler.

 

[smclear]

Re: Large Wake

Just reread all my posts. I can't believe I left out the fact that is indeed a Chrysler Marine 440. Doh!!!! Anyway, I will adjust RPM down to 700 and see what that does. Unfortunately, I'll have to wait until spring to do so as I just put it bed for the winter last weekend.

 

[fixb52s]

Re: Large Wake

Guys, we are cool. Sometimes, my NY Italian temper gets the best of me. ​

I am glad this subject came up though. I took the hydrofoil off and took it out to the bay. BIG difference. The wake is gone, and my low speed handling is much better. It does point the nose sky high before getting on the plane, and my speed dropped about 4 mph, but I think tabs will help that out.​

Sorry if this went a little off topic, but I got something fixed here, and isn't that what it is all about?​

PS: Photo of the wake at 750 RPM.

 

[Gary H NC]

Re: Large Wake

Now that looks like a normal at idle wake...

Smart Tabs will fix you right up.They also take care of that side to side wondering at idle and low speed..if your boat does that as most stern drives do.

 

[45Auto]

Re: Large Wake

Now that looks like an idle wake - good job!