GS977

i'm installing new valve springs with my new cam and the old springs had a .015 smooth shimon both sides then a .060 shim on top, one side smooth and one side had the lines all the way around. then the springs were on top of that. .075 total.
to get the correct installed height with my new springs, all i need is a .015 shim.
can i put a .015 shim right on the head(lt4 heads) and the springs on top or does that .015 shim i took off have to go on first then what ever thickness shim you need go on top of that.

kize

If your install requires .015 shim for correct spring load/height put it on the valve seat side first then your springs. You should be good to go- as long as you do not exceed the compressed spring rates as recommened.

GS977

so i can put the shim right on the head. thats what i was wondering about. if the shims went directly on the head. so they put 2 shims on top of each other to get .075 when i pulled the old valvesprings out, they wore right thru the .060 shims and were sitting on the .015 shims.
if it weren't for the .015 shims they would have been digging into my lt4 heads
why did they do that. i orderded new comp cams hardened .015 shims for my new valvesprings. i hope it doesn't happen this time.
thanks!!!

STL94LT1

Shims can fit directly on the heads. But, the valve springs need a seat/locator. Don't put the springs on the shims.

GS977

whats a seat/locator. what does it look like and how thick are they. my old springs were right on top of the shims. you got a pic of them. i need to order them if i need them.

STL94LT1

The stock LTx valve seats/locators/shims are .035 thick, that's as thin as I've seen.

What springs are you going to be using? OD of the springs?

Your old springs were installed wrong. That's why they were eating through the shims.

Also you may need to get some .050 locks to get the correct installed heigth.

kize

A spring seat locator is used to keep the spring on the valve side from moving around on the head. It looks like a washer with a raised lip on the stem side. But I would research the application for your head type. Depending on the head - some configs require this - some do not.

GS977

without any shim on the head, from the head to the bottom of the retainers i have 1.890.......the springs call for installed height of 1.800
so if i use a .015 shim..thats 1.875....... i don't have enough clearance for .035 seat locators?
1.890 no shim at all, nothing
1.875 with .015 shim
-.595 cam lift
----------
1.280 max lift
1.100 coil bind
.18 clearance

these are the springs i have...
Part Number: 99846-16
Outer Diameter Top 1.255
Inner Diameter Top .870
Damper YES
Seat Pressure @ Installed Height 125 lbs. @ 1.800
Open Pressure and Height 383 lbs. @ 1.200
Coil Bind 1.100
Average Spring Rate 428 lbs./in.
Maximum Net Lift 0.640

GS977

this is a pic of what i found when i removed the springs that were on the motor when i bought it.
on the left is one of the few .060 shims that didn't wear all the way thru.
middle is one that did. on the right is one of the .015 shims that was under the .060 shims.

STL94LT1

I'd hate to see where the metal from the shims went.

If your installed heigth is 1.800 and without shims you have 1.890. That means you have .090 to shim. If you take the installed heigth (1.800) minus coil bind (1.100) plus a (.060) buffer, that still give you .640. Which is more than enough clearance, for your .595 lift cam.

STL94LT1

Look into Comp Cams 4705 valve spring seats, they may work with your springs. They are .060 thick.

GS977

.060 is enough for safty margin.
when i saw the shims i was i droped the pan and ran a magnet thru it good and there was no metal. then i pulled the intake, no metal then i ran the magnet thru the oil puddles in the top of the heads. i'll post some pics. i always changed the oil every 2000 miles mobil one. always had GOOD oil pressure. i guess i got lucky

GS977

here are some pics of the motor. when i pulled it apart it was very clean, no metal anywhere except in the top of the heads.
this is the metal that was in the heads, don't know why it looks red? no its not blood. it had oil on it.

LT4 heads and intake ports with 777 gaskets on them. ported

GS977

bottom end and oil pan.

STL94LT1

At a 1.80 installed height you'll have .105.

GS977

i was looking at the locators at summit. i understand it now.
another question, do i have to use a shim or could you just use the locator on the head and the spring on top of that.
i will find the right ones tomorrow night after work.
the ouside dia of my springs are 1.270
the inside dia is .0865
the seat on the heads where the spring sits is 1.450

and STL94LT1, thanks for the help!!!

STL94LT1

Looks like you are going to need locators and shims to get the correct installed height.