Valve Spring recommendation needed 502 Mag MPI
 

Having my heads redone, will be replacing the valve springs, but unsure about what I should get. Stock hydraulic roller cams, as far as I can tell. Anyone have an aftermarket part number that will work with stock cam?

Comp 911 spring is the recommendation from Comp.

Those cams are really small with only .483 lift. They are very easy on the valvetrain. When i had my heads redone, the springs tested just about new with 400 hours. I might get some flack for suggesting, but if they check out, I don't see a need to replace them.

Yeah, I get that I could probably get by - but not knowing how many hours are on the old springs, I'd feel better with new.

Turns out the Comp 911 is the direct replacement for Gen VI / hydraulic roller so I ordered 2 sets of the 911 springs, plus 10 degree locks and retainers at the recommendation of my machinist.

Sticking with the 911. Seems to be correct. We'll see.

They should be good. Easy on the lifters.

One thing to do with your heads is to have your valve seats replaced. The 088s are famous for dropping them.

I discussed new seats with machinist - he said that these seats are cast-in and could not physically drop. He sounds very confident in that assessment. I dunno?

The 10 deg retainers might cause an issue. I have found that Comps retainers usually give you an additional .100 installed hgt. Then you have to mess with shims under the valves etc etc etc. I would just reuse the stock retainers and put some new locks on them.

I also thought the 088 heads have seats in them but I have a set I am getting ready to work on and it does not look like they do ? Cant say I have ever seen one drop like Tom mentioned but I have seen them eaten up pretty bad and had to replace them.

Good info, Bill, thanks.

If the stock retainers can be reused with the Comp 911 springs then I'd be inclined to reuse them. Do you have familiarity with the 911 springs, or have another recommendation in this application?

intake seats are cast in,,exhaust seats are replaceable.only time I've seen an exhaust drop out is after severe reversion.they pit so bad that they crack and fall out.some biotchs are in there good from the factory.

I have used the 911 springs quite a few times on car engines but I am pretty sure that most Mercruiser engines have a double spring ? The 088's at the shop are off a 454 MPI and they have dual springs on them. Are your springs a single spring or dual ? Ill have to check in the morning to be sure but I think the most common spring I have been using is the Comp 924. .