|
Re: Valvesprings galling aluminum heads ???
[Re: Cab_Burge]
#862226
11/25/10 07:12 PM
11/25/10 07:12 PM
|
Joined: Oct 2007
Posts: 4,221
New York
polyspheric
master
|
master
Joined: Oct 2007
Posts: 4,221
New York
|
Don't run just spring shims on any aluminum head
X2 - the entire valve & collar assembly flaps around on the head at high speed like a sparrow in a birdbath, and it will split the shim. If you're lucky it will spit it out, if not it gets caught between coils.
Boffin Emeritus
|
|
|
Re: Valvesprings galling aluminum heads ???
[Re: Stanton]
#862232
11/26/10 05:34 AM
11/26/10 05:34 AM
|
Joined: Jan 2003
Posts: 5,875
communist bloc of new jersey
jamesc
master
|
master
Joined: Jan 2003
Posts: 5,875
communist bloc of new jersey
|
Quote:
So can I run just the spring in the cup or does there have to be a shim underneath to let things rotate?
no shim is required under the cup/locator. personally i wouldn't run springs against shims and certainly not on an aluminum head. imho if you need shims they go under the cup/locator
|
|
|
Re: Valvesprings galling aluminum heads ???
[Re: jamesc]
#862234
11/26/10 10:45 AM
11/26/10 10:45 AM
|
Joined: Oct 2007
Posts: 4,221
New York
polyspheric
master
|
master
Joined: Oct 2007
Posts: 4,221
New York
|
X2 - under the cup, same surface area as the cup (not smaller).
The spring ends should be ground off and polished so they don't try to eat the cup anyway.
Boffin Emeritus
|
|
|
Re: Valvesprings galling aluminum heads ???
[Re: Stanton]
#862236
11/26/10 09:44 PM
11/26/10 09:44 PM
|
Joined: Jan 2003
Posts: 14,575
So. Burlington, Vt.
fast68plymouth
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 14,575
So. Burlington, Vt.
|
most of the Indy heads i sell dont get cups or locators. like Al said, unless the springs are mis-matched to the cam/rocker combo, this wont really cause any problems.
tens(hundreds?) of thousands of SBC heads are in service all over the world with the pocket machined into the casting being used to locate the spring on the head.
if the customer wants cups or locators, i will modify the heads to use them, no problem.
i'll also use cups/locators on the more radical combinations that require a larger diameter spring than will fit inside the machined pocket of the Indy head.
attached is a pic of some 440-1's that were cut to accept a 1.740 OD cup/1.640 OD spring combo.
not the best pic of the spring pads, but you should be able to get the drift.....
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123
Dealer for Comp Cams/Indy Heads
|
|
|
|
|
I use a .015 harden spring shim to set on the head when using any cutter so I don't cut and lower the spring pocket at all 
I then use a harden spring spacer under the locator to set the spring pressures 
I use the 1.500 or 1.550 springs usually and so far I haven't had a problem installing them with those parts at 1.900 to 2.00 depending on the heads and valves 
. My net lift at the retainers with the lash is right at .700 to .720 so far so that may be why I am not having any problems 
