On Time

Yes I follow all these 525 threads with interest since mine have 325 hrs all flawless but there is so much talk of preventative valve train maintenance. Mine had 1.2 hrs at >5000 rpm when I bought it at 225 hrs and they prob have 2.5 now. There's at lot more valve compressions at high rpm per hour than at low rpm for those of us that mostly cruise 3500-4000.

Pwraddr

I thought when he had header issues both tops were done? Also thought he had Gen X on both sides?

Am I mistaken?

Pwraddr

Just checked my files ( I was interested in th boat but didn't want to repaint the sides due to the name )

The starboard side was refreshed due to header failure. Both sides got Gen Xs. When I was interested there was around 10 hours on refresh and headers.

Hope this helps.

bblythe

Yes I had those details .I do know sometime in the near furture I will exactlly where I stand with hours on these motors and what is in them.

H20 Toie

I have just over 400 hrs on my formula 400ss with 525's
just had valve job done on both. turns out the only thing that i needed to do was the valve springs, every thing else was in great shape, but you never know unless you take it apart and since it was apart it is just makes sense to do the whole thing.
oh and new headers

Griff

Knowing what I know about Overactive. I was interested and talked to Mark about it quite a bit. All you really need is a top end refresh on the one engine that was not replaced.
That should not be more than 5k from start to finish.

It wasn't a refresh. It was a complete new Merc longblock.

bblythe

I thought mark told me the port was replaced pwrrda thought it was the starboard

Pwraddr

Was just going off what Mark told me, don't shoot the messenger. Just re-read the email again from him and says refreshed, not replaced. Maybe he meant replaced, I don't know.

Don't get me wrong, I don't care either way, just trying to save the OP a couple bucks on one side.

Pwraddr

Again, the email from him say stbd.

Call and talk with him, seemed like a nice fella over email. Also, no receipt for such an expensive job to reference??

Young Performance

The rumor was that Crane got a bad batch of needle bearings. That may or may not be the case. However, I have seen the rockers fail, or start to fail, on 2003 engines and on 2009 engines, and everything in between. There is no way that anyone will make me believe that they used the same batch of bearings for 7 years. Personally, I think it has more to do with the very light seat pressure of the valve springs. I've seen them as low as 100-105 psi on an engine with less than 200 hours. It had only 1 hour above 4000 rpm, so it certainly wasn't abused. Most we see are in the 110 psi range, which still isn't enough. New, they are only about 125 psi, at best.

It baffles me why they use such a short spring with such a low seat pressure. Over the nose pressure is fine at around 400 psi. In order to raise the seat pressure and use any other spring, you have to change the retainers and locks. We have been using a 10* retainer and lock that raises the install height to just over 1.900. The stock PAC springs install at 1.820. There are no other springs out there, that I have found, that will handle that much lift, go in at 1.820, and have enough spring pressure. The only other option is to install longer valves. Obviously, the retainers and locks are much cheaper and should be changed anyway.
Eddie