Holmberg379

Hello, installing btr 660 dual spring kit. I have an installed height of 1.720. springs are spec'd for 1.780. I have an open pressure of 418lbs, the machine shop says the spring pockets need to be machined .060 I'm pretty sure that information may be incorrect. The cam is a btr stg 2 turbo cam, heads are plain Jane 862 castings. Any suggestions appreciated thank you

.boB

iTrader: (1)

Proper installed height is a simple math formula:

Coil bind height + Valve lift + 0.050"

If that number is greater than 1.720", then you need to cut the pockets or use longer valves.

Holmberg379

Do you know how deep the spring pockets can be cut on 862s .060 seems to be alot to remove, I looked into +.050 locks I was told I would have enough clearance between retainer and rocker then. as they sit at 1.720 the spring pressure is 180lb closed 418 open nor close to bind should I just run them with the higher spring pressure? This machine shop hasn't done lsx heads before is there something he could be missing. It's a well recommended machine shop. Any information is appreciated

KCS

iTrader: (20)

I've installed dozens of BTR spring kits and never got an installed height that short. BTR springs are drop in springs. They shouldn't need the spring pockets cut. You don't want to do that anyways as there isn't much material under the spring pocket, especially on ported heads.

Darth_V8r

iTrader: (4)

Agreed. However, strongly advise getting the largest OD pushrods you can get if the math works out ok.