LT4 Valve Springs
Thread Starter
Le Mans Master
Joined: Nov 2002
Posts: 7,179
Likes: 2
From: Charlotte, NC
LT4 Valve Springs
I have a set of lt4 heads I am looking to install along with an lt4 intake.. I may possibly be using a comp cams, extreeme energy 306 cam and I needed to know what kind of valve springs I should use and hopefully without having to machine the heads. I have heard the stock valve springs on the lt4 will not hold up to the cam being it has .510/.540 lift and I am using the lt4 1.6 ratio rockers... Any suggestions on valve springs/retainers would be appreciated.
-Rick
-Rick
Le Mans Master
Joined: Jul 1999
Posts: 8,683
Likes: 6
From: Phoenix AZ
Re: LT4 Valve Springs (VetteTech81)
The stock LT4 spring will certainly not hold the lift of the CC306 cam. You'll ned a nice set of dual springs. I have Isky #8005-A (if I remember correctly), and I'm running a cam close to the CC306 (.542/.563). Oh, and the CC306 lift numbers with the 1.6 rockers will be .533/.576, the .510/.540 are with 1.5 rockers.
[Modified by Zix, 10:05 PM 10/14/2003]
[Modified by Zix, 10:05 PM 10/14/2003]
Thread Starter
Le Mans Master
Joined: Nov 2002
Posts: 7,179
Likes: 2
From: Charlotte, NC
Re: LT4 Valve Springs (Zix)
Well what brand springs and where can I get them should I use with this cam? and will I need to machine the heads? I prefer not to because of the cost. Also is this cam over kill.. I want a lopy cam. I will be running :
LT4 heads (stock not ported)
LT4 intake
1.6 ratio rockers
shorty headers
3.75 gears
2600 stall
thats the basic jist of it..
I am trying to figure out if the comp cams gruru made a mistake on his recomendation when he told me to use the 306 cam. It should be arriving in the mail tomarrow and I'm wondering if I shouldn't send it back.. I do want a nice lopy idle, I want it to sound like it's got something majorly done to it.
-Rick
LT4 heads (stock not ported)
LT4 intake
1.6 ratio rockers
shorty headers
3.75 gears
2600 stall
thats the basic jist of it..
I am trying to figure out if the comp cams gruru made a mistake on his recomendation when he told me to use the 306 cam. It should be arriving in the mail tomarrow and I'm wondering if I shouldn't send it back.. I do want a nice lopy idle, I want it to sound like it's got something majorly done to it.
-Rick
Thread Starter
Le Mans Master
Joined: Nov 2002
Posts: 7,179
Likes: 2
From: Charlotte, NC
Re: LT4 Valve Springs (VetteTech81)
I see summit sells the Isky #8005-A springs.. but do I need to have the heads machined? I'd rather not.. so I'm trying to figure out my options.. how would the stock lt1 cam feel with the 1.6 ratio rockers and lt4 heads/intake? I kinda would rather install a cam but I just want to make shure I make a good choice on what I use I would also rather use what I already orderd but if it's going to not do the job I will return it..
-Rick
-Rick
Le Mans Master
Joined: Jul 1999
Posts: 8,683
Likes: 6
From: Phoenix AZ
Re: LT4 Valve Springs (VetteTech81)
I see summit sells the Isky #8005-A springs.. but do I need to have the heads machined? I'd rather not.. so I'm trying to figure out my options.. how would the stock lt1 cam feel with the 1.6 ratio rockers and lt4 heads/intake? I kinda would rather install a cam but I just want to make shure I make a good choice on what I use I would also rather use what I already orderd but if it's going to not do the job I will return it..
-Rick
-Rick
As for the cam, the CC306 is a big cam, not so much in lift numbers but in duration. If you need to pass emissions than I would re-think using it. But if emissions are not a concern then by all mean throw it in, I'm sure it will give you the idle you're looking for...more so if you plan to do headers down the road. I've never seen the CC306 used with stock heads. Don't bother with the LT1 cam, if you're concerned about the cam, then I would recommend the CC305 cam, it's a slight step down from the CC306 but is a solid performer.
Overall I would go with the CC306, especially if you plan on doing more work down the road (head porting, etc...)
