Shibby1485

An it is 4" stroke

Shibby1485

why would the rocker studs hit the valve cover? i took the engine apart and the valve covers have the o-ring in the groove, plus there were two layers of cork gasket under them... if i only use the o-ring, the valve cover wont go down, hits the rocker retaining nuts.

Budman II

iTrader: (1)

Some of the poly locks on certain roller rockers are too tall to fit under stock type valve covers. My Scorpion Race Series rockers would not clear, but the set of Scorpion Marine Endurance rockers that I bought will clear with no problems, because the poly locks are shorter.

MILD THUNDER

iTrader: (3)

The Oring and cork gasket works good together. I ran some thick, i wanna say Mr. Gasket cork ones, that were like .300 thick before. I actually liked them better than the thin cork ones. Just make sure the bolts are long enough that hold the valve cover on.

airjunky

iTrader: (2)

That's why some of those rockers have the rear corner ground a bit , those have to be in the right spot and the cover will bolt down normally with just the o ring

Budman II

iTrader: (1)

The new Scorpions that I have have both corners of each rocker radiused. Kind of nice.

I recall reading that the O-rings will only work with the later model heads (like came on the Gen V / VI) which have a slightly wider surface for them to seal against.

MT, I was under the impression that you had to mill the late model valve covers that used the o-ring flat to work with the cork gaskets. If not, then I'm glad to hear it - one less thing I will have to do. Did you glue the cork gaskets to the head with RTV or something?

Shibby1485

let me clarify.... the head is stripped... no springs, no rockers, no valves... the valve covers hit the rocker studs, not the rockers.


the motor was together with TWO cork gaskets stacked, plus the o-ring in the valve cover. it never leaked a single drop, and there was no RTV or permatex or anything.... i was just wondering if there was a way of NOT stacking valve cover gaskets as i reassemble.

Young Performance

Those valve covers were made to go with later model GM heads used on Gen V and VI that used a non adjustable valve train. They weren't designed to work on an engine with roller rockers are poly locks. You will have to use the gaskets to get them to clear. There are also a few companies that make spacers to raise the covers a bit. The other option is to replace them. These are pretty nice covers for the money.

Satin http://www.cpperformance.com/p-15793...-machined.aspx

Polished http://www.cpperformance.com/p-13496...-machined.aspx

If you have a 4.560 bore with a 4" stroke, then you have 524 ci.
Do yourself a favor and ditch that flat tappet cam and get a hyd roller and hyd roller lifters. You will be glad you did. Not only will it make some power, but you won't have to worry about running an additive because of the lack of zinc and the possibility of wiping a lobe off the cam. i would certainly yank the pan off and at least have a look. You could have rust on the crank, rods, etc. from all of the water. You will also find out exactly what parts are in it.

Does the engine have an oil thermostat. If not, get one. You can certainly run the engine without water temp, but usually, you will make condensation without any oil temp. Not to mention, it's really hard on the valve train by not having any oil temp. Ideally, you want the oil to get at or neat the boiling point of water to steam out any possible condensation. It won't make any oil temp idling, but once up and running, the oil will bypass the cooler until it gets to around 190*-200*. Once there, the thermostat will direct the oil to the cooler.

Hope this helps.
Eddie

airjunky

iTrader: (2)

Someone must have slipped.a late set of valve covers in there on ya . Or something si way not right . The blue merc valve covers for the bowtie motors are unique , cast aluminum for gen 4 head . Still didn't clear the crane gold rollers they put on the blue motors without a little rocker clearance on the ones by where the covers bolt down flip em and post a pic

BUP

iTrader: (9)

Just wanted to add about the HP500 bulldog 8.9 L 540 CID. I really liked that motor from Merc.

The internals for it was Manley heavy duty push rods, Crane hydraulic cam and Crane hydraulic lifters, Wiseco forged alum pistons, Speed pro rings, Lunati forged steel crank and Manley forged steel connecting rods. GM HP cast iron head with a 3 angle valve seats, the valves were 2.25 in diameter S.S. for the intake and 1.88 in diameter Inconel exhaust, dart alum single plane intake manifold. I have more on this motor in my notes but that's all I remember as we seen a few back in the day but not many at all.. . Have not seen one in years