350 vortec 5.7 lower intake leaking vacuum?? Help please

[squaredeal91]

Here's some pics. And that's my battery freaking out. It won't work now??

 

[squaredeal91]

Mod approval again?? Lol

 

[bucket]

Mod approval again?? Lol

Yep, just random selections I guess. It will never make sense to me.

As for your lifter adjustment, you weren't far off before. GM calls for a lot of lifter preload. I've always run 1/2 turn on everything Chevy, it works well. I know guys that often run 1/4 turn preload and it seems to work for them.

 

[squaredeal91]

Same here. Gm says 1 full turn. Chilton says 3/4. On flat tappet I have always gone 1/2 turn like your saying. I've always thought that less is better for higher rpm. Not that I'm racing but I like to now and then. Not often shift at 6 grand so I can hear her scream Dixie a little. That's why i love my wheeler. Quads open wide

 

[SquareRoot]

WOW. I never knew factory Vortecs were such a POS and PITA until seeing this thread. I just took a Goodwrench motor, threw Vortec heads on it and and Edelbrock PF4 and never had any of these issues.

 

[squaredeal91]

WOW. I never knew factory Vortecs were such a POS and PITA until seeing this thread. I just took a Goodwrench motor, threw Vortec heads on it and and Edelbrock PF4 and never had any of these issues.

I like the vortec 350 because I love small blocks but at some point in my frustration I was yelling I want a carburetor! Lol

 

[SquareRoot]

Or maybe I'm confused. Did Vortecs have tbi or did they come later after gm dropped tbi for the much better port injection?

 

[squaredeal91]

@SquareRoot Tbi then vortec. Vortec from 96-02. But vortec is much different than tuned port. I really like tuned port engines too

 

[SquareRoot]

So obviously your engine is a transplant. From what? Just curious as it seems you have both factory tbi and Vortec heads. Correct? If so, I find that odd since tbi sucks with aftermarket Vortec manifolds. Does the OEM manifold have a heat or coolant crossover?

 

[squaredeal91]

So obviously your engine is a transplant. From what?

No. Maybe i got confused and answered wrong. This is the original engine setup for this vehicle. This engine is in my wife's 99 suburban. This isn't my square

 

[SquareRoot]

No. Maybe i got confused and answered wrong. This is the original engine setup for this vehicle. This engine is in my wife's 99 suburban. This isn't my square

Gotcha. I'll research the 99 engine. I'm in the learning mode tonight. Lol

 

[SquareRoot]

Well. Now I get it. Central Sequential Fuel Injection (CSFI) with it's poppet valves controlled by fuel pressure versus MPFI and it's electronic injectors. I was not aware of the short lived CSFI system. This is what happens when one gives up drinking. I no longer drink beer and know things. Lol

 

[RanchWelder]

Running a stock TBI on an EDL-7116 with a flat cam, SquareRoot.
It starts on a single turn every time.
The stock TBI is no where near the flow capabilities of my heads, intake and headers.
It's cheap on fuel for a grocery get'r and OBD stoopid for higher elevations.
The Map works well. over carbs here at 5K ft.

The Edelbrock 7116 square intake, with a riser and the Chaos TBI plate works great.
You can run a Holley carb, TBI, Sniper or a Toilet on it.
You can tap it for external injectors, (which is what I want to do, rather than the Sniper), but the Holley Stand Alone computer injection system is $$$$$.
The Sniper with the 7116 is the solution to the Vortec engines, in my 4 years of research.

You must be registered for see images attach

7116 allows you to plumb coolant under the intake manifold for cold weather. It outflows almost anything in its class.
The casting has a 3/8" wide x 4" reinforcement bridge underneath the rear deck to prevent warping, which cheaper look alike manifolds do not offer.
James Harris advised me to buy this Vortec Manifold. I am very glad I did. THIS MANIFOLD WILL NOT WORK FOR EMISSIONS.

Had issues with the V-6 injection spider Nut Set on my 1996 Vortec S-10 three times.
I know all about the injector spider nut set.

The GM Recommended pre-load on the roller cam is likely due to the spider and roller keepers in play.
GM springs are under tuned explicitly for the added turn. If you change the spring rate and use a custom cam, everything changes.
There is OEM rocker pre-load and there is everything else...

OEM springs can and will wear out. Over tightening again and again on the same loose rocker is a sign of reduced spring tension.
Individual Springs can go bad.

If you go link bar lifters and floating the spider under higher-ish rpm is not a concern, you can probably go with a lighter pre-load, with certain springs.
The Comp Cams Flat cam card called for 1/4 turn on the cam in my 94 Mexico Chevy casting Jasper engine. There is no such thing as a standard pre-load.
Nm of every spring is different.

Had to install poly locks for the exact reason mentioned in my post, in my 94' Jasper Crate engine.
The threads in my machine shop Vortec heads were loose. The darn nuts would re-adjust themselves 1/4 turn just starting the engine.
Some would continue to loosen so bad, the truck would not start.
The lock nuts kept loosening up, even with new lock nuts from Comp.
How many do-it-your-selfer's re-evaluate the lock nuts three times a year, map and document lock nut float?
We just set them once, and drive for years, right? Wrong.

Even the Poly Locks had to be re-adjusted and double checked with my flat cam.
It's probably time I dig out the Allen keys and do it again soon.

Have 2 sets of roller lifters now and a 96 roller cam laying around.
The 96 block and the heads are sitting in my storage. It is the LH block with the crank sensor.

Haven't started to build it yet because the 4L80E is on the to do list.
The rebuild parts and 5.7L converter are getting close to $1800.00, sitting in my Summit and AZ carts.

The roller cam re-grind form is on my desk. Would love to roller the 94' engine this spring, however the burned 700R4 needs an overhaul.
Build a few 4L80E's here in the middle of no-where, and grind several electric guitar bodies to fund the swap.
That's the plan anyways.

The cam manufacturer will specify a certain set of springs, when you go aftermarket camshaft.
This Nm requirement sets the spring rate so the Rockwell hardness of this specific camshaft meets the expected spring rate and preload spec.
If you ignore the cam manufacturer's recommended spring selection and you alter the pre-load, you either float the valves or dig your lifters into the cam surface, ruining the camshaft. There is no need for 65 Rcockwell hardness on the cam, if the springs suggested allow for 42 Rockwell hardness.

The spring rate, Nm, pressure on the pre-load and pushrod length are critical, as is the cam timing. Or you will burn a cam lobe.

You guys are all correct. You remember what you use for adjustment from rebuilding stock engines or what you cam card said to load.
The problem is, when NOT to use what you think you know... Stoopid Human tricks cause the engine building industry to flourish!

So long as you are using the 1999 valve train and OEM GM springs, I would stick with what The General suggests in the Dealership Manual for rocker arm adjustment

 

[squaredeal91]

Pretty much at a standstill till the spider comes in. While I'm waiting I'll check and regap the remaining plugs and check all header bolts. I found a loose one. Otherwise I've just got a couple things to do while I wait. I am wondering about my egr valve because its really old and electronic. How can I test it?

 

[bucket]

I'm not sure how to test the EGR on them. In the oodles and oodles of vortec 350's I've messed with, I've never had to replace an EGR valve. Not that I can remember anyway.

When you get your updated spider injector, make absolutely sure that you route the injectors to the correct cylinders before you push them in place. Once they are snapped in place, there's no way to safely remove them without damage. The main body should have the injector tubes labeled by cyl number to make it easy.