When to rebuild/re-fresh Blown 540s?
 

There seems to be so many opinions out there on build refresh intervals! I know the typical 500 blue motor seems to be the benchmark (at least from what I've seen with my buddies):
-Valve springs at 150 hrs
-Top end at 300
-Complete rebuild at 500



My motors are 540 tall decks with Vortech Race V4-J Blowers and intercoolers on them.
Some nice internals
-Callies cranks, carillo rods, JE Pistons
-Dart heads (not sure of model number)
-Brodix intake drilled for injectors
-Electromotive standalone engine management
-Closed cooling

These motors make a conservative 775HP. They have 277 and 266 hours on them. Valve springs done at 150 hours and timing belts done at 200 hours (JESEL belt drives). NEVER a dry start, have pre-lubers for the motors. Oil thermostats too and never go past 3000 rpms until I see oil temps at 190.

I would say at least 200 hrs at 3000-4000 rpms and probably less than 20 minutes at WOT. They were always babied (not sure if that's a good thing!) and I spend most of my time at cruising speeds.

Should I be worried about pulling them and re-doing anything? I did a compression test at 250 hours, everything was within spec.

Any opinions would be most appreciated!


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I'd do a leak down and see where you are. Would be a good indicator if you are ready for top end. As for the bottom end if you change the oil religiously every 25 hours or so and look at your filters I bet you'll be good for 350-400 before you need a full rebuild. And maybe then you might only need rings and bearing along with the top end.

Ok, so I'm now just under 300 hours on both motors....
I talked to previous engine builder and he said top end at 450 hrs. But I'm thinking maybe valve springs now since it's been 150 hours since last change.

I've got Crane CAM 139741 and pretty stiff springs (99895).

Should I be changing lifters too? Or just springs, retainers, locks?
Last time the springs were changed, there were apparently two broken ones (inners of course). Ive heard that when springs break, they wreak havoc on the lifters (roller).

Any insight would be much appreciated! And yes, I will be doing a leak down test too.

Seems to me you are on a pretty good scheduled. Without a crystal ball, one never knows when parts will fail. You can install new stuff and it can break.

Lifters, springs, inspect rockers. No need to change retainers unless you're changing spring design

Thanks for the input!

Jamie - so you're saying replace the lifters too? I don't actually know which ones I have . Am running that cam mentioned above, those springs and crane gold 1.7 rockers.

I would definately have the intercoolers checked out too - maybe even replaced.

Those springs arent crazy stiff, pretty mild springs actually. Crane 741 cam is fairly mild as well and easy on parts. The setup seems to be working nicely for you. For the cost of those springs, I think I'd replace them for peace of mind. Approaching 300 hours, I'd probably consider a valve job as well. A leakdown test would be a good idea.

when you get it apart send me a pic of the lifters, see if I can identify them, should be able to get some while the heads are at the machine shop getting springs and valve job. Always a good idea to inspect the valves. I've seen a lot of inconel valves put at the weld on the stem. At 300 hours it's better to do them than have one come apart. I don't reuse any past 300 even on 500's 525's etc

So you're saying I so do a valve job now (ie full top end)?
I was planning to just do springs which I can do without pulling the heads. I could do lifters too , only need to pull the intake for that.
I'm planning to do a leakdown test too. It should tell me more.