JC316

iTrader: (1)

Ok, I have been planning a cam upgrade for a while, gathering funds for it. My corvette has made the decision for me, the lifters are rattling and I figure that I might as well do the cam swap while I'm in there. I get that there are better cams out there for the LT1, but I hate the lope of an aftermarket cam and I just want my LT1 up to the performance level of a stock LS1. The hot cam should do that nicely.

The issue here is funding. I just bought some lifters and some 1.6 roller rockers, but I need valve spring advice. I've searched till I have gone cross eyed looking for recommendations and it seems that no one can agree. Most people recommend a $200+ set of valve springs that are good for a cam much larger than the LT4, but again, not going any bigger, so I just need something good enough.

I've looked at the LS6 springs, but some people say that the LT1 valve is too heavy. I've looked at the Comp 986, but some people say that the LT1 head will need machining. Is there any spring that will work without machining, and is in the $100 range?

Jaxem

iTrader: (3)

Keep an eye out for Alex's Parts springs to come back in stock:

http://www.alexsparts.com/lt1-valve-...s-spring-base/

guppymech

iTrader: (7)

I've been very happy with PAC 1212X springs with my hot cam and 1.6 rockers. They drop right in with the stock hardware but they do cost more than $100.

JC316

iTrader: (1)

Yeah, that would be perfect, damn shame they aren't in stock right now. What about the PAC 1904's? They're close enough to $100 to not make me hate myself.

BALLSS

JC

the alex springs hit your $ budget. They do have good reports but I have no direct experience with them

Part of me says "you often get what you pay for" and IMHO Valve train is something you don't want to cheap out on.

The Alex springs are 1/2 the cost of springs I have used.

Crane 10308 for example are a plug & play drop in spring for LT1 AL heads.

Comp 918's for a bee hive type (Pac also may be a alternate)

both sets above will cost over $200 though

IMHO a valve train is worth the $125 difference, just my $.02

what I run now

Lunati 73925K5 kit (includes valve stem seals) $240 from Lloyd Elliott shipped

Jaxem

iTrader: (3)

I have a set of Alex's springs that are going on in a week or so, if you haven't decided on anything at that point, I'll post an update with some thoughts. I've only heard good things which is why I went with them. I've also heard they're just re branded springs from one of the major suppliers

JC316

iTrader: (1)

Oh I get that you don't want to drop a valve, but I don't see why I need a monster spring for a dinky hot cam that wont be spun over 6K. Thats why I ask about the pac 1904's, they're a dual valve spring from a popular brand and won't break the bank. With a 1.290 OD, I would think they would drop right in.

Thanks. I daily this vette, so I can't take TOO long, but I do have other cars to drive. Currently rocking a 69 lesabre convertible.

96capricemgr

iTrader: (1)

If not revving past 6000rpm then the HOT cam is a bad choice.

englundjd

I ran the alex springs valvespring kit in my camaro when I had a Comp Cams 304.. its a .210/.220 @.050 duration .500/.510 lift w/1.5 ratio rockers. Basicly its got .008 less duration and more lift then your hot cam. Beat it mercilessly for over 20k miles before I pulled the engine and changed the cam and springs for a much bigger LE cam... I was happy for the money, People have used them with cams as big as the Comp cams 503 and had decent results.

JC316

iTrader: (1)

Most people set the shift point at 6200RPM for the hot cam. This car is a daily, not going to be racing it every day, but I would like a little more punch.


Thanks for the recommendation, now if they would just come back in stock.

BALLSS

OP

The Alex springs on paper will support the lift specs of the Hot cam. They are obviously a budget spring and people report not having any problems with them.

Post back when you have done the swap and spun the motor to 6200-6400 rpm

JC316

iTrader: (1)

Ok, so here are the specs on the pac 1904 dual valve springs. Good for .650 lift. If I'm reading this right, it should be a drop in spring, capable of reusing the stock retainers and locks. That seem right to yall?

Outside Diameter of Outer Spring (in): 1.290 in.

Coil Bind Height (in): 1.010 in.

Spring Rate (lbs/in): 370 lbs./in.

Inside Diameter of Outer Spring (in): 0.950 in.

Inside Diameter of Inner Spring (in): 0.694 in.

Installed Height (in): 1.800 in.

Seat Pressure at Installed Height (lbs): 150 lbs.

Open Height (in): 1.125 in.

Open Pressure (lbs): 400 lbs.

guppymech

iTrader: (7)

You can't use stock LT1 single spring seats and retainers with dual springs. Dual springs use retainers with steps to locate the different diameter spring elements.

za355tx

iTrader: (108)

We have used the Howards 98215 springs and I know a guy on here making over 400rwhp on some LE2 heads with these springs. I sold them to him. I think they are even used with stock retainers and locks. They are $109 from Summit. They would be more than adequate for a hotcam with 1.6 rockers. They will support .575 lift if setup right.

IDriveChevy

iTrader: (5)

I just got my Alex's Parts springs in the mail friday and installed them with my 1.7 rockers. It was a great kit and everything went together nicely. Just need to go over the rockers one more time and adjust them

JC316

iTrader: (1)

Thank you! Looked into them and they check out. Will be ordering them first thing.

Puck

iTrader: (17)

I was going to suggest the crane 10308s until I saw how much the price skyrocketed on them, WOW.

rjmarazzi

iTrader: (1)

Good budget spring. You may want to take the dampers out of them. I think some guys have had the damper collapse and take out a valve seal.

rjmarazzi

iTrader: (1)

You may also need a .006 shim for the springs. I was talking to loyd last week and I am pretty sure he said with those springs to use a .006 shim. I'm not 100% sure though.

BALLSS

the Howard 98215, like many aftermarket springs, are spec for a 1.800" installed height. Stock AL heads are set up for 1.700-1.750 spring height. Typically you have the spring pockets machined down to allow for this taller installed spring height.

While the hot cam, even with 1:6 RR, will not see coil bind as a result of installing the Howard spring at a shorter height, the seat & open pressure will be more than what they show spec for if installed at 1.800"

Not sure if the damper spring on the Howard springs needs to come out so it won't hit the valve seal. some have the valve guide machined down for a .500 seal vs the stock .565 to clear dampers or double springs

For aluminum heads you need to run a spring locator. Also instead of blindly adding shims you should really use a valve spring height tool so you can install the spring at the desired height

Kits like the Crane 10308 and the Alex kit are drop in springs meant for 1.750" height but I would still use a measure tool anyway and add shims if needed under locator as each head casting, RR stud height can be slightly different

several springs will "work"...some will require "adjustments". don't take for granted they are like replacing a spark plug. pay attention to installed height specs and if installing them tighter to either get more open and seat pressure or because you are installing a higher than stock spring at a lower height to get it to fit in non machined heads, but confirm with the shorter height your specific cam lift does not then take it to or get uncomfortably close to coil bind. In the Ops case the Hot cam is not really a high lift cam