Has anyone measured the pressure on a set of new GM vortec head valve springs? I measured some and they were so low it is hard to believe.

Looking for installed height, installed pressure, and pressure at say .450 valve lift.

Originally posted by Doug F.:
Has anyone measured the pressure on a set of new GM vortec head valve springs? I measured some and they were so low it is hard to believe.

Looking for installed height, installed pressure, and pressure at say .450 valve lift. =
Hi Doug,
No but you can damn near take them apart by hand :D

I will measure one for you tomorrow & get you the rate & all as I have a set sitting on the bench & a set of untouched vortec's along side of them.

Tell Harold Hi ;)

Doug,
According to my AERA software they are 76-84 lbs @ 1.700 installed hgt and 187-203 @1.270 open. Probably would give you right about 200 # @ .450 lift.
I also have a set of springs sitting on the bench, if Mike does not have time to check them I will put one on the spring checker in the AM and also see where it coil binds at.

Hi Doug,
The installed height on this head was 1.710. & the retainer hit the seal at .465 lift
The spring is 81 @ 1.700, 204 @ 1.250
Measured rate is 274 & coil bind is 1.135 according to my handy dandy computerized spring checker ;)

On a related note...
Aren't Vortec motors roller cammed? If so why the wimpy springs? Wouldn't spring pressure be a nonissue with a roller? And do Vortec heads have the 7th exhaust manifold bolt hole? Thanks.

Regards,
Gary Anderson

Gary,
The stock camshafts have very little lift. .411 intake and .425 exhaust. Alos stock Vortec engines are in trucks and probably rarely see 3000 rpm, if that. There is no reason for any type of higher spring pressures.

Is it possible to install longer valves and springs and still have the correct geometry if longer pushrods are used? I know most usually have the spring seats and guides cut, just wondering if there is an alternative. I would think is should be easy to get another .100 inch of clearance if the right parts are used, retainers, locks, springs, and valves?

Originally posted by baddbob71:
Is it possible to install longer valves and springs and still have the correct geometry if longer pushrods are used? I know most usually have the spring seats and guides cut, just wondering if there is an alternative. I would think is should be easy to get another .100 inch of clearance if the right parts are used, retainers, locks, springs, and valves? =
Yes but with most 1.250 type springs with a damper you will need to machine the guide boss OD down at the bottom on most of the vortec heads

Originally posted by BillK:
Gary,
The stock camshafts have very little lift. .411 intake and .425 exhaust. Alos stock Vortec engines are in trucks and probably rarely see 3000 rpm, if that. There is no reason for any type of higher spring pressures. Bill,
The factory ECM shifts the truck at over 5500 in passing gear mode...
They rev the **** out of them compared to the old K motors.
I am surprised it is so low though..
Those heavy roller lifters...

Those heavy roller lifters...That was my thought... wimpy cam or not, you are throwing around more weight than an old flat tappet engine.

I have a set of vortecs I am going to be running. What sort of cost am I looking to get these things ready for some good springs etc? And a .480 - .520ish cam.

I'm putting them on a .010 high nickel block .060. all arp bolts on the inside. Stock rods, and cast crank. 10 - 1 pistons. What kind of carb and intake do I want? I'll be running a MSD pro billet HEI. All backed up by a manual valve body th400. Any help at all would be awesome. Oh... also a 355 posi 12 bolt out back.

You can get upgraded Vortec head packages from Scoggin-Dickey (http://www.sdpc2000.com/cart.asp?action=catalog_start&catid=2172) . They aren't much more expensive than the stockers and are available to handle something like .600" lift.

I already have a set of vortecs here tho.

YenkoChevelle69 -
I'm putting them on a .010 high nickel block .060. all arp bolts on the inside. Stock rods, and cast crank. 10 - 1 pistons. What kind of carb and intake do I want? I'll be running a MSD pro billet HEI. All backed up by a manual valve body th400. Any help at all would be awesome. Oh... also a 355 posi 12 bolt out back.

not all 010 blocks are high nickel, look for 020 cast into the area behind the timing chain, that is the mark for nickle content. This is one of the most common blocks around with both two and four bolt versions available, many people think they are all high nickel.

mine does have the 020

Try some good old $125/set, Z-28 springs, (-142's), and grind the bottoms of the retainers down, but do it slowly so you don't heat them and burn your fingers!!

BUT, imho, I would just run a lift limited cam b/c there's a heck of a bunch of them out there that the roundy-round guys use due to class restriction stuff..

pdq67

Sorry, I can't type at all tonight!! Shoulda been $25/set!!!

pdq67

well, I just want a big cam... 292 at 480 is pretty small, no?

Go for the 292 cam if all you want is "cackle"!!!

Otherwise, think about a good old Crane 274H06 for "cackle" AND it will be down in the advertised intake duration range so that it will still make great low to mid rpm grunt, imho...

The 106 LCA will "cackle" quite well to you...

pdq67

I want to put this car into the 11's. That is my goal.
What do I need?

Also, since I don't know... I'll ask.... what part of the cam to I want to be bigger? The Lift or the duration?

Crane makes a guide cutting tool thats fairly inexpensive. It's nicer to use in a head a machine but it included instructions on use with a 1/2 drill. It will cut the guide height down and size the guide for positive seals at the same time. I think I paid somewhere around $50 for the one I have.