Whacha Think Replace or Machine?

74Wind wrote: See lot of similar threads, always puzzled..exactly what indicates actual imminent failure/justifies these many rebuild/valve job/etc discussions?

Jeff,
I think most of the time it's responding to another issue that caused the head to crack or warp or head gasket to let go.
Water in the oil, an engine that overheated or degrading performance are probably the most common factors.
I would say overheating as probably the biggest culprit. How many posts do you see about engines that get hot at idle but OK at speed or vise versa or just plain overheated????? Ditto for water in the oil. Every one of those posts has the potential a cracked or warped head or a blown head gasket is the cause/effect.
Then you have the fatigue created if/when that engine got hot. It might not manifest itself right away but could very well cause problems several hundred hours after the actual incident.

Pat yourself on the back for for doing your preventative maintenance like you're supposed to. That makes all the difference in the world. If everybody did that like they're supposed to, I believe 90% of those posts get eliminated as well as the resultant head replacement. You'll always have some that fail from stress and/or wear over the years but that really is not that often if you do your part.

The last one is the guys that just want to rebuild and/or pump up the performance of their engines. I think they are really in a minority for the most part but driven by perfection, performance and/or necessity due to the above mentioned issues.

I truly believe that most everyone here is of the same thinking you are. If it ain't broke don't fix it. Unfortunately, s**t happens. Whether self induced or a PO that had an issue that finally manifested itself. Maybe even just stress and/or wear has finally reared it's ugly head.

No matter the case. You're story is what most strive for and a testament to what can be achieved with the right perventative maintenamce, a lot of common sense and just a little bit of knowledge. Congrats!!!!!

+1 with the pros. That crack will get worse. If you watch an old pro check a set, he'll look there first for the reason you have.

I had a less that wonderful experience with CCH. They put used parts on mine and I ended up replacing the valve train. That may be their standard practice and not always a bad one...but they didn't tell me that.

And they knurled the guides.   

See lot of similar threads, always puzzled..exactly what indicates actual imminent failure/justifies these many rebuild/valve job/etc discussions? On this thread you're talking about a boat that is 20 years newer than either of mine. I've got a Thermo-Electron 351 in my 74 Southwind which consistently runs great (knock on wood). Not original owner & no indication there's ever been any serious work done (or needed).

Similarly, have Chrysler 360 in my Century (original owner on this one, my father bought new in 1975) and it has never had a valve job or any sort of rebuild, and also runs like a champ.

Change fluids regularly/etc and treat properly, but adhere to "if it ain't broke, don't fix it" philosophy, which has always served us well.

Art thou just uber-mechanical and forever in search of the perfect tweak, or are there some specific symptoms that we must all watch for?

John,

I did not try to sound too down, and did have an excellent experience with Clearwater heads customer service, price and delivery, and will work with them again. I did not go back after any claims, but will be more questioning on my next order. They run a competitive business, and sound like they would honor any special requests or double checks.

Let me know what you think!!

Todd

Try looking at Tri-State Cylinder Head. They carry GT-40p Heads.

Don't forget the approx $100 in gaskets....
I bought a set of GT40P heads from Clearwater and had Woody put them on my old '96. Boat ran great with them and now for its current owner in Austin, TX.

Could not agree more, Cracked between the valve seats I have tossed many a head due to that and will not install on my customers engines. I have purchased out of the junk yards a few sets of GT-40P heads and sent them to our local head re builder and have done well cost wise. provided it is a standard recondition and to open up the bolt holes usually runs less than $350,After junk yard cost have had around $400.00 total into them and I know what I Got!

Todd, appreciate the input. I would be beyond ticked if I got the heads and still had to have them machined.

I just rebuilt my 454 and I replaced all the valves and springs. I do not like to risk the valve train parts. Had a valve head break off in a 396 HP motor years ago...It did unbeliveable damage and cracked the block.

I agree with Kap... for th 150 peace of mind, you could have the better head.. keep in mind that if your ford friends are car guys, the P's are more difficult to work with on the spark plug side of things, and may taint their opinions.   the P's work good on boats because the exh manifold goes up and back, not down and back.

Pulled the heads and got a few pricing quotes. Looks like to do a basic valve job, hot tank, deck if needed will be right around $250 for the set(GT40s). Or I can get a freshly rebuilt set of GT40Ps from Clearwater for $560 shipped to my door. After talking to some of my Ford friends I was leaning towards getting mine machined and asking the guy to work on the bowls a tad too(2 different Ford engine builders said that is where the 'money' is at for gains on the non-p 40s), but after really taking a look at mine and finding 2 micro cracks I'm wondering if I'm going to pay ~$100 to have them magnafluxed only to find out I should of gone the P route from the beginning. So take a look at the pics and give me some opinions. The cracks do NOT go into the valve bowl areas, they seem to only be inbetween the intake/exhaust valves and a little down the slants before the seat edge. The other head is fine from what I can visually see. The last pics are just of the valve conditions, which is not what I would expect from a ~500hr boat. Granted I did have a few carboned/mucked up valve seats that were leaking.