I THINK I MAY NEED A BIGGER PROP!!!

[FreeBeeTony]

Just got back from a short fishing trip.<br /><br />Really went out for a test ride.........<br /><br />IT'S FIXED!!!!!!!!!!!!<br /><br />Let's see who can put their finger on it.<br /><br />All I will say is it wasn't fuel or ignition related.<br /><br />Boy am I happy........it was screaming at 4900 RPM's w/ 3 adults, ~60 gal's of fuel and some fishing gear. Probably could have been trimmed a little better also, was kinda choppy too!<br /><br />Temp was at 160*, oil pressure ~50lbs.<br /><br />This was w/ a 15" prop. Think I should go to the 17"?<br /><br />Even caught a short fluke!

 

[rbezdon]

Re: I THINK I MAY NEED A BIGGER PROP!!!

Hey Tony.<br /><br />Good News. I have been one of the guys distant from this site during the cold but I have been curious all winter if your repair fixed your problem. From the numbers a WOT it sure seems to be fine. Bet youre having more fun this year.<br /><br />For what its worth, I think the 17 would knock your WOT RPWs down pretty close to the 4600 level recommended for the Chev 350 but your going to loose some of the ability to get up on plane with the size boat you have and the load you were carrying. If that is a typical load, I migh just stay where your at. Just my opinion.

 

[Don S]

Re: I THINK I MAY NEED A BIGGER PROP!!!

I think it would be nice if you just told us what you found. After a year and over 1000 posts full of guesses as to what could be wrong,I would imagine no one is interested in guessing what was actually found as the problem.<br />Regarding the prop, I would take it out again on a smooth day and see what it is when trimmed out properly. If it's 5000 or more, yea, try a 17" prop.

 

[Bondo]

Re: I THINK I MAY NEED A BIGGER PROP!!!

Boy O Boy,.... Let there be Joy....... <br /><br />Do we get Any Hints,....... Other than "All I will say is it wasn't fuel or ignition related."<br /><br />Tony,..... I'm So Glad for you,........ This makes Me Happier than running My Own Boat........<br /><br />And,......... Ayuh,.... I'd atleast Try the 17" prop....

 

[FreeBeeTony]

Re: I THINK I MAY NEED A BIGGER PROP!!!

Don, you really need to try and lighten-up a little bit. <br /><br />Thanks Bondo.......can't tell you how happy I am.<br /><br />I knew it wasn't fuel or ignition related becasue of tests I had run (contrary to some people's belief). <br /><br />The original problem must have been related to either a bad head or head gasket. Remember what the #5 cylinder looked like when I removed the head.<br /><br />

[/IMG] <br /><br />Then in the fall I decided to replace the heads and intake with the Vortecs.<br /><br />I started it in the driveway and it ran great.<br /><br />When I put it in the water a couple of weeks ago it seemed to have the same problem, dropped dead at 3200 RPM's,s but it seemed as though I was loosing the #2 cylinder.<br /><br />Anyway.......when I installed the heads, I adjusted the valves according the the manual, 1 turn after zero lash. This appears to be TOO TIGHT.<br /><br />Last week I readjusted the valves while running and, set them to 1/4 turn after they became quiet. In order for me to get them to make noise (clatter) at normal operating temp at idle I had to loosen them between 1 and 2 turns.<br /><br />Well this morning while going across the bay I pushed it to ~3800. Then after a few drifts we shot down the state boat channel and, to my suprise it kept responding the more I pushed the throttle!!!<br /><br />On the way back to the dock I opened it up and it hit 4900!!!!<br /><br />Guess after the rebuild I tightened the valves too tight and it seemed to act just like it did last season.<br /><br />I readjusted the timing to 10* BTDC.....<br /><br />Still want to say thanks to everyone for their assistance here........

 

[Bondo]

Re: I THINK I MAY NEED A BIGGER PROP!!!

Ayuh,......... That's the Reason I Just Love spilling All that Oil in the bilge,....Adjusting the Valves...........<br /><br />I'll do a Static Adjustment to get it to Light,.......<br />Then I do a Final Adjustment,.... Running..........<br />

Thanks Bondo.......can't tell you how happy I am.

Probably just a Smiggin' Happier than I am reading this..............

 

[FreeBeeTony]

Re: I THINK I MAY NEED A BIGGER PROP!!!

10* OK for the timing?.....had it at 8*.....thought the Vortecs could withstand a little more.<br /><br />After I get the prop set I may want to fine tune the carb.......seemed a little shakey around mid throttle........<br /><br />But for right now it is fine!!!!<br /><br />Also, what is a good cruisin RPM........3800 OK?

 

[Bondo]

Re: I THINK I MAY NEED A BIGGER PROP!!!

10* Could be Hot,.... Or Could Be Not......<br />What's the Advance stamped into your Ign.Module,.??<br /><br />The Carb. might want Richer Springs for the transition into the high-speed range.......<br /><br />3800rpms Won't Hurt a Thing,.......32/3400roms is Probably where you'll find the Best Economy.......<br /><br />If I could only Explain just How Happy it made me feel to find this thread this morning,...... <br />Much More Rewarding(Wrong word, just the best I can think of) than when your Self-Engineered Closed Cooling worked............ <br /><br />Oh,....Btw,......<br />I've got My new Intake for My motor Right Here,....<br />I'm going to drill,+ tap it,... So I CAN install a Vacuum Gauge,......<br />A Vacuum Gauge would have Found this Issue,.. ALONG Time ago,...<br />It Really $uck$ that boat motors Never have a usable Vacuum Port..............<br />Well,........... Here goes my Bondo Re-Engineering,.......................................

 

[fleopis67]

Re: I THINK I MAY NEED A BIGGER PROP!!!

whew!

 

[FreeBeeTony]

Re: I THINK I MAY NEED A BIGGER PROP!!!

I had a vaccum gauge on it.........read 19-20, steady!<br /><br />What color spring should I try next?

 

[John_S]

Re: I THINK I MAY NEED A BIGGER PROP!!!

Great news!!! Just in time for the upcoming holiday weekend. <br /><br />Actually, I thought the vortecs took a little less total advance timing. On the pre-vortec heads, initial timing was 8 degrees for Thunderbolt4 ignitions, and 10 degrees for T5. Total advance was around 32 degrees. I'd leave it at 8, if it performed well.

 

[FreeBeeTony]

Re: I THINK I MAY NEED A BIGGER PROP!!!

I will go back to 8*.......<br /><br />Ignition module is 24S.........<br /><br />I thought the Vortecs were more tolerant of more advance.

 

[FreeBeeTony]

Re: I THINK I MAY NEED A BIGGER PROP!!!

Bondo.......just re-read your post about the vaccum gauge........were you talking about your engine?

 

[tie_one_on]

Re: I THINK I MAY NEED A BIGGER PROP!!!

I think lilmandavis said to back off the rocker nuts about mid way throught your last post.<br />lilmandavis ----- you da man!!!!!!!!

 

[FreeBeeTony]

Re: I THINK I MAY NEED A BIGGER PROP!!!

I believe you're right tie_one_on........

 

[tie_one_on]

Re: I THINK I MAY NEED A BIGGER PROP!!!

Glad you got it together Tony, now for a year of enjoyment. Good luck.

 

[FreeBeeTony]

Re: I THINK I MAY NEED A BIGGER PROP!!!

Thanks........<br /><br />This a great forum.........could not have done it w/o the help of everyone who responded to my pleas for assistance.<br /><br />I know it was frustrating for some..........but believe me, there was noone more frustrated than myself.<br /><br />But when I saw those RPM's increasing........it felt GREAT!

 

[Bondo]

Re: I THINK I MAY NEED A BIGGER PROP!!!

Ayuh,..... I'm talking about having 1 on My motor....A Vacuum Gauge.........<br />You'd Think that Tight Valves should show,..... Shouldn't it,.??<br /><br /><br />Have you got the Carb Tuning Kit,.??..<br /><br />I think I've got 5 sets of springs, from 3"v to 10"v......<br /><br />I just went a step Fatter with my Needles,...... Starting the Spring Tuning All over again........

 

[lilmandavis]

Re: I THINK I MAY NEED A BIGGER PROP!!!

hey thanks man!!! yeah i knew it was either a bad lap job or something to do with a valve. but you never know right?! i was gonna say that it might be wrong pushrods too!!! hats off

 

[FreeBeeTony]

Re: I THINK I MAY NEED A BIGGER PROP!!!

Changed the springs tonight to 1 higher.....need to do a test run though.<br /><br />Also changed to the 17" prop.<br /><br />Don't really want to start changing the needles.