V4 and starboard bank

[Indymike]

Seems most of the posts here relating to V4 mechanical problems or failures are the result of carbon build up or lean conditions on the starboard bank.<br /><br />I am going through a 73 115 V4 and it also is a result of carbon on the starboard bank. Broken ring in the #1 hole.<br /><br />Is this coincidence or what ? How do you guard against this other than normal maintenance.<br /><br />By the way, she's on her way back to being the picture of health.<br /><br />Mike

 

[Solittle]

Re: V4 and starboard bank

I hope one of our resident experts jump in on this as I too am curious. It has been covered before some time back but I don't remember by who or when.<br /><br />On prevention there are a couple of things. One is to decarb your motor every 100 or so hours or once a season. The other is to have your rig properly propped so that the engine does not lug - which results in carbon build-up.

 

[DJ]

Re: V4 and starboard bank

Make sure the coolant water deflectors are, in fact there, and in the right place.<br /><br />Make sure the thermostats are in place and working.<br /><br />Make sure that the unit is decarbed often.<br /><br />See decarb here.<br /><br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=36;t=000006

 

[Dhadley]

Re: V4 and starboard bank

Very common. Do a search on block venting or just venting. <br /><br />Yes, the starboard side does run hotter on a V4 crossflow. Coking and the shortly-there-after broken rings have a lot to do with rpms. Set one up at low to mid 5000 rpm and you will, sooner or later, most likely end up with broken rings. Set up the same motor at 5800-6000 and you'll probably never have that.

 

[Indymike]

Re: V4 and starboard bank

Set up will be done in spring. Its cold up here.<br /><br />Venting makes sense. Where do you install a fitting? Would this be a check valve of sort or just make the vent a pisser? Checked the part # mentioned in another post (337594). It is described as a tee fitting. Is one of these locations correct for a vent. The exhaust plate would seem too low to me.<br /><br /> <br />

<br />EDIT>>>><br /><br />Just found another post that I believe describes this. Is this location better ? <br /><br /><br />

<br /><br />Thanks,<br />Mike

 

[lawyertob]

Re: V4 and starboard bank

Mike,<br /><br />Good job on the pics, I was going to take exactly the same pics and draw exactly the same circles, but you beat me to it. <br /><br />I have been told that you can tap in on the square at the bottom of the exhaust cover, but as you stated it wouldn't be much use as a vent. However, from looking at the manual it would appear that this is a fairly idiot proof place to drill and tap, because it is really hard to mess anything up there.<br /><br />I am not sure why the middle location is never mentioned. It seems like a perfect location, except that the clearance from the flywheel is pretty tight.<br /><br />The bottom picture looks really close to where flips put his, be aware that you have to be careful when drilling here because the water jacket is not very thick there. <br /><br />Anyway, I await the answer. I already have my fittings and tap all ready to go. Only thing I need to figure out is what size drill to use before I use my 1/8 in pipe tap, and where to drill for sure. And thanks to you, I don't even have to post pics. <br /><br />Just my $0.02 worth,<br />Joe

 

[OBJ]

Re: V4 and starboard bank

The common aproach on later models was to put the fitting in the little square place and loop the pisser hose up and over the starboard head and down to the outlet fitting in the lower pan. Looping the hose over the head helped the venting process and helped make sure the block got full of water.

 

[Indymike]

Re: V4 and starboard bank

Thanks for the replies men. This is probably beating a dead horse but maybe the pics will help someone else too. Maybe a FAQ topic? <br /><br />Dhadley you mentioned in another post

Lets put it this way -- any motor we found with a burned reg/rec that has this mod done has never again burned a reg/rec. Even on ones that were repeat offenders before. Any motor we have done this to, even though there was not a burned reg/rec, has ever burned one. Short or long finned type reg/rec.<br /><br />In the worst case scenario it cant hurt anything. You do not lose any more water than currently comes out of the indicator hose anyway.<br /><br />To be perfectly honest, that wasnt the reason we did it to start with. It just so happened it cured the reg/rec problem.<br />

What was the reason?<br /><br />Does the venting affect the stat operation?<br /><br />Mike

 

[angus63]

Re: V4 and starboard bank

The proper tap drill for a 1/8 NPT is a "Q" drill (o.332" dia) in wrought aluminum. Being this is a cast block, I would up the size to an "R" drill (0.339" dia) to ease the tapping stress. The tapered thread will seal just as well with the 0.007" difference. <br />Good luck