Inboard head-scratcher

[CFO94]

I brought this problem to this forum several months ago and got some good suggestions, but no solutions. <br />To breifly summarize the whole story (which is a VERY long one), I keep spinning rod bearings in my 351 Ford IB.<br />This is a reverse rotation 351 Ford in a Ski-Nautique. The original engine ran great but had a lot of crankcase pressure which blew oil out. Rather tan rebuild, we opted to buy a factory rebuilt engne. It ran great for a few hours an stated knocking. We sent it back and got another one. It did the same thing. Sent it back again and got another which did the same also. At this point gave up with that company and got money back. Took the original engine to a very reputable local rebuilder. He rebuilt the engine that had been in the boat for 27 years. New heads, but pretty much everything else original. It ran great for a few hours and sarted knocking. Took it back and he did it again. He ran it in his shop and it started knocking within an hour. He did it again and we reinstalled it. It ran a few hours and started knocking again. This guy's been building engines for 30 years and is baffeled. I'm pretty knowegable with old V-8's too but this is crazy. <br />Keep in mind that this is an abbrieviated story. We've explored and tried a LOT of other ideas.<br />Any one with any similar (right) problems, or ideas would be more than greatly appreciated.

 

[petryshyn]

Re: Inboard head-scratcher

>Is this the original crank?<br />>Do the replacement bearings have a machined oil passage for the full internal radius?<br />>Is it always the same bearing?<br />>how much oil pressure?<br />>are the bearings blue?

 

[CFO94]

Re: Inboard head-scratcher

I was hoping I'd hear from you. Don't you remember me??? Still haven't gotten this thing right. I'd really like to talk to you on the phone. Call me at 305-302-4976, please. You won't believe what I've been through with this engine (engines).

 

[CFO94]

Re: Inboard head-scratcher

To answer your questions. The first time we tried a completely new (different) engine. Thought the problems were re-builder related. Then had the ORIGINAL engine, which had been running in this boat for 27 years, rebuilt by a very reputible guy in Hollywood. Actually, the problems were different. In one case it was rod bearings, in the other it was mains. Don't see how one could possibly relate to the other, they were completely different engines. The only component common to all engines was the oil cooler, which we eliminated prior to the last failure.<br />No it's not always the same bearing, and the oil pressure had ALWAYS been above 40 psi. <br />I'm telling you, this is a real mystery. If you can figure it out you get the prize.

 

[snapperbait]

Re: Inboard head-scratcher

Have you given thougth to go with a standard rotation engine?? I put standard roration engines in two different nautiques(1960 & 1979) with excelent results... The only changes you will have to make are to turn the pump on the trans.(B.W. 71-C) to work with a left engine, and a left prop..

 

[f_inscreenname]

Re: Inboard head-scratcher

I have been through many nightmares with motors in the past but not one like that thank god. Were any of these motors balanced (Crank,rods,pistons that kind of stuff)?<br /> Are they internal or external balanced. If external did you change the flywheel or harm balancer? Had a unbalanced flywheel problem with Chrysler small block once. If I was you I would give up on blaming the motors. There are to many and from different places (your rebuild,store bought) that have the same problem. I would start where the motor bolts up to what ever drives your prop (you didn't say). It may have been moved during removal or replacement of the motors and be out of alignment. Or it could have been out to begin with. Then there is where the motor mounts bolt up to the motor. Are they in the same place (the port mount put back on the port side every time)? Were they adjusted during the first motor install to accommodate for any differences in the blocks and not put back? From a old block to the newer blocks you always end adjusting them some. Then there is the bearings in tranny thing (sorry I/O guy,BW velvet drive?) If the drive shaft that comes in contact with your motor is flopping around you will burn up some stuff quick. Is the thing that joins the two (coupler of some sort) centered on the flywheel?<br />Just a few long shot guesses. Sorry if I wasted your time.

 

[petryshyn]

Re: Inboard head-scratcher

Is too late in the evening to call tonight. I'll call tommorro.....

 

[CFO94]

Re: Inboard head-scratcher

I think we might be getting somewhere now. Thanks for all the responses. Schematic, I saw you called but too late to call you back. Will try to call tmorrow. Snapperbait, We are going to try a standard rotation now. I have my doubts though, can't understand why all this has happened to a motor that was in the boat for 27 years. Inscreenname, You reaffirmed my thoughts and fears. We re-built the hull prior the engine. From the stringers up, which means the mounts might not be exactly the same as they were. We are able to align the engine/driveshaft without problem though. And it is a BW Velvet drive trans.<br />Keep the ideas coming. At this point I'm not trying to place blame...It'll probably end up being my fault, I just want to get a full w/ski season out of it.

 

[snapperbait]

Re: Inboard head-scratcher

I must agree with screenname about the balance problem... I just looked at some ford 302/351 harmonic balancers and flywheels and they are externaly balanced which means the flywheel and the balancer must be in sinc.. If the flywheel is not bolted on in the correct position the balance of the recriprocating assembly is out of whack the bearings will go bye bye... If your engine builder has 30 years of experience he should know this... I would ask him "nicely" about it..

 

[CFO94]

Re: Inboard head-scratcher

Snapperbait, have you ever heard of a place in Hollywood called Expert Engine?

 

[snapperbait]

Re: Inboard head-scratcher

CFO94: Nope. Doesn't ring a bell...

 

[CFO94]

Re: Inboard head-scratcher

I (tactfully) tried to mention some of the things we've talked about to my re-builder. He didn't seem real pleased that I was questioning his knowlege and ability. One thing he stated was that Ford didn't make a 4-bolt main 351 W. Anybody know different, for sure???

 

[f_inscreenname]

Re: Inboard head-scratcher

I don't think there was any 4 bolts from the factory but there is a lot of custom stuff out there. The easiest way to find out is look at the mains caps and count the bolts.

 

[snapperbait]

Re: Inboard head-scratcher

Only 2 bolt main on SB Windsor engines... As for your builder, he should welcome your questions...My 2cents worth..

 

[petryshyn]

Re: Inboard head-scratcher

if your rebuilder doesn't welcome suggestions, it must mean he has all the answers!

 

[DJ]

Re: Inboard head-scratcher

All,<br /><br />Pay special attention to crankshaft thrust bearings.<br /><br />I believe something is loading this crank forward or backward.

 

[CFO94]

Re: Inboard head-scratcher

Prepped the engine today for removal tomorrow. My plan is to buy a "junk yard" engine, standard rotation, and use as much original parts as possible. After talking to Schematic, I realized there could be a problem with the intake manifold. The intake manifold and carb are the only parts left that are common to all the engines we've had problems with. My re-builder says we didn't have that problem. I'm going to insist that we not use the brand new I/manifold, that has been common to all the problem engnes (don't think the carb could matter), but use the one that comes with the engine.<br /><br />Keep the thoughts coming... I'll let you know how it works out.

 

[CFO94]

Re: Inboard head-scratcher

Up-date since my last post...Still running good and keeping fingers crossed. Had to replace the condensor again. Probably didn't mention the first time since minor problem considering. Any thoughts on what would cause premature condensor failure?

 

[f_inscreenname]

Re: Inboard head-scratcher

Glad to see things worked out for you. I know how it feels to have the same problem over and over again and you just cant seem to get it right no matter what you do how much money you spend. Lucky you live in FL so you can enjoy it. The last time I had a problem like that it took till Oct to figure it out. Up here boating season is about over by then. <br /> As for your condenser problem. I had the same thing happen to me with the last 351W I had. I ended up changing it three times till I got one to work for two years before I sold the boat. I know there is a reason for this but I cant think of it right now (after boating season I work on my house, been painting for the last few hours). When I come up with it I will let you know if someone else doesn't first.

 

[CFO94]

Re: Inboard head-scratcher

Seems (so far) to be another isolated problem. The boat is still running good, however still hasn't had a lot of use. still keeping fingers crossed.