Cross

iTrader: (10)

Ok so as some know I bought a Rebuilt LT1 that was supposedly an LT4... No it was an LT1 Bottom end, LT4 Heads Ported, LT4 Intake Manifold and LT4 Hot Cam (The Kit they used to sell basically).

The rings he used sucked because they looked old when we pulled it apart for burning oil with less then 1500 miles on it.

I decided screw it I want to do this right so I called a local friend/builder who knew what was going on and told him it was time. We talked and decided on a 355 Build.
I told him my goals, a 100 to 150 Shot Max Wet after I am able to add an LSx ECU when that is done but for now a nice fun NA motor.

He ordered and did all the machining. I told him i trust him and I would go with what he recommended, he is blue printing the motor and giving me all the boxes, write ups on everything etc.

So far he went with Pistons that were 10.8:1
Thinner Head Gaskets
Taken .030 over
The rings cam with the new Pistons he ordered
Stud kit for everything of course
And we went with a Comp XE Cam but now I can not find the damn specs.
Its under the GM 847 I believe it is but bigger then my current LT4 Hotcam (If you want to buy it I am selling it say 125?)

Anyway the Machine Shop said two things that raised alarm with me.

Now supposedly the prior builder did a few modifications to the heads besides porting. However I will not know tomorrow for myself until I meet with the builder again.

But they told me that I did not need different Valve Springs and to my knowledge the heads have the stock LT4 Valve Train but I do seem to remember the prior owner of the motor saying he made a few changes but I have no idea what as I did not write them down lol.

Second they told me the stock injectors would be fine... I was going to buy some 30lbs injectors but he said no...
Now the tune for the motor originally was by MadTuner for an LT4 with porting and bolt ons which of course I am keeping.

Now with the cam change and we bumped the compression slightly. (Before the thinner gasket its actually right around what I think the LT4 was stock) For the Compression yes the Tune I had done would be fine but the cam requires a tune change.

But not needing larger injectors... I will be going directly to the dyno after the 500 mile break in and I am def going to keep it under 3k until the 500 then 4k on the way to the dyno shop.

What do you guys think? Plus I have no idea how good this tuner at the shop is... I can only hope they would not screw up the current tune to much since most of the work has been done..... I hope.

blackz93

iTrader: (2)

I doubt the LT4 springs are gonna suffice.

Cross

iTrader: (10)

I felt the same way and asked that direct question. They said the springs on it were fine (As I was ready to just buy some new Springs or Springs and different Rocker Arms just to be safe) but maybe he did upgrade them.

I tried to ask but being ADD he mentioned something else and I took off in that direction. I will ask again tomorrow.

bombebomb

I think I would buy better springs to stay safe.

Many people are going to tell you different ways to break the engine in, and I will assure you they will range from take it easy, to run the pis out of it, to run it how you will drive it.

Me personally, I would drive it how you are going drive it. As long as you believe the tune is safe. My engine was WOT roughly after an hour of idling (was tuning checking stuff, it adds up time lol). Also making sure nothing sounds bad while in the garage/where ever your doing this. Everyone will tell you different.

Given your engine appears to be a little more mild then mine, so just a heads up on how many people will tell you different ways to break an engine in.

moehorsepower

iTrader: (3)

LT4 springs are are nothing special, not even really enough for the LT4 cam, @ around $40.00 for a set, that alone will tell you the quality of the spring. Definitely go with better springs, and I would go with the 30lb as you said, as far as breaking in the motor, I can tell you we have broke in motors with zero miles on the Dyno,, years later....those cars are still going strong....but do as you feel necessary....

great421

iTrader: (1)

FYI - My LT4 retainers (from my Hotcam kit) failed and I dropped a valve into the #1 cylinder; then I found a couple threads (here) that stated they were the weak point. So, if you've got everything apart anyway, get some good retainers.

NightTrain66

iTrader: (7)

if you already have bigger injectors and better valve springs (NOT the LT4 springs), then MAYBE you do not need new ones but if you still have stock injectoirs and the LT4 valve springs, you WILL need new springs and retainers.

I would ask for the seat and open pressure on the springs at there current set up ht.

You want AT LEAST 130 seat and 320 open pressure (preferably 145 seat and 350-380 lbs open) for an XE cam. If it 230+ duration on intake, I would want 145 seat and 380 open.

Lloyd

xx_ED_xx

iTrader: (17)

Damn I used to live in Tucson. Who is doing the machine work?
Yeah if you arent positive on the springs. The machine shop should of checked them for installed height and spring rate. And if they thought they were adequate. I am sure that is why they said that. And yes the stock injectors can be fine. Regardless of what you do when you get done you will need to tune it anyhow. That is if you want to do it right

Cross

iTrader: (10)

They assured me they checked the Springs but I too thought I had read about the springs being the weak point. Now since the heads have less then 1500 miles on them due to the rings on the last block going then I would assume thats why they think they are fine but if I am in there why can't we make sure they are better so I don't have to worry about dropping a valve.

Now not going crazy I saw the Partiot Kit and for what I am running its a great price but I think its over kill.

So whats a good kit to go with over these LT4 Springs and Retainers but not as up there as the Patriot kit? I just don't think I need that much in a kit considering I have a mild build as has been pointed out. (This is just supposed to be a fun Toy with some Juice at times for a kick in the pants when trying to keep up with a few of the turbo guys)

xx_ED_xx

iTrader: (17)

lt4 springs are good for a 1.6 rocker arm on a lt1 cam about it. And a stock small block

xx_ED_xx

iTrader: (17)

and if loyd elliot tells ya what you need i would listen to him I am pretty sure he knows his ****.

Cross

iTrader: (10)

I just noticed that was him posting o.O!! Hey want to go have a beer at Hooters Lloyd? lol

I will be talking to Chris shortly he is coming over, I will have all your info shortly ED and I am asking for the info on the springs I am requesting they be changed but I would like a few opinions on what to go with. If someone has a set they did not need any longer I will be happy to get them.

blackz93

iTrader: (2)

If you decide you need a set of 30# injectors, I have a brand new set of SVOs for sale.

$235 shipped

Cross

iTrader: (10)

Exactly what I was thinking about going with. But for now I want to get it on the Dyno. However I want it there with better springs so let me see what people have to offer in advice or if someone offers what they have for sale.

If you still have them come the end of Jan I will probably be ready to buy a set.

xx_ED_xx

iTrader: (17)

Man I miss Arizona. You never did tell me what machine shop damn it

blackz93

iTrader: (2)

Find out those cam specs!