525 EFI valve spring change
 

So I hit 325 hrs and it's the end of the season. Motors running perfect. According to most it's time to change the valve springs. What a shock! $75 a pc for valve cover gaskets, $1150 for spring and keeper kits per head! Does everyone out there suck it up and pay the almighty Merc or is there a better alternative?

What engines?

Dont know the replacement part # off hand, but yes, there is a better alternative!!! Someone will chime in im sure with the proper spring part #.

525 EFIs

An Isky 8005A is a direct replacement, and an Isky 8205 is a nice upgrade. The 8205's retail for about $200 for a set of 16, the 8005A's are less than that... not sure what they're quoting you on for $1150 per head??? Also... valve gover gaskets are re-usable on the stock covers.

Personally, I feel that the whole valve spring replacement thing on a 500EFI at "X" hours is alot of internet lore, which has been carried over from the early carbureted HP500's which did have issues with valve spring breakage. Myself, I've never seen a 500EFI with a single broken spring... not one... and I've rebuilt many of them. Some with as many as 550 hours which had never been opened up previously. To be honest, the entire upper end usually needs attention above the 400 hour mark. In my experience, you're more likely to have head gasket issues, exhaust valve seat issues, and roller lifter issues when you get beyond that time frame, rather than valve spring related isuues. Just my opinion, based on my experiences.

You mention 500 EFI...any change in your opinion for 525's?
I too am suspect of Internet lore and research stuff to the bitter end. As such, any way I can find a cross reference to the Isky replacement you suggest? What makes the 8205 superior to the 8205A? Thanks for your responses.

My bad... I mis-read and thought we were discussing 500EFI engines. I see now that you're talking about 525's. While I have less actual experience with the 525's... I have worked on a few, but never a full rebuild... I know of many with 400+ hours and, again, never any valve spring issues.

I'm not positive exactly which spring the 525 uses, but I'd be inclined to believe, based on cam specs, that the springs are similar in specs to the 500EFI.

the 525 uses a PAC spring,i can give you the part number in the morning,i have it in the shop.

Greatly appreciated

According to Merc... the 525EFI doesn't need to be freshened till north of 450-500 hours... its the 500EFI that needs it north of 300 hours.

However, the P/N is PAC-TVS1631 for the 525EFI. You can also use Crane 99896 spring set @ 132# @ 1.906 seat and 414# open.