Starting to Learn on 95 G30 5.7 for Towing

[donf]

I tore the intake/timing cover off last night. The block is fully roller compatible. So the my 14097395 cam will work. I have also been able to pick up a GMPP vortec intake and an Edelbrock 3704 for less than the cost of a cheap tbi plate. I am waiting to have my heads checked for cracks to see what manifold I use. Torque from 2000 to 4500 is what I am looking to improve. I really do not care about anything above that for this application.

[Fast355]

I tore the intake/timing cover off last night. The block is fully roller compatible. So the my 14097395 cam will work. I have also been able to pick up a GMPP vortec intake and an Edelbrock 3704 for less than the cost of a cheap tbi plate. I am waiting to have my heads checked for cracks to see what manifold I use. Torque from 2000 to 4500 is what I am looking to improve. I really do not care about anything above that for this application.

Under 4,500 rpm, I would stick with the swirl ports. If you wanted to make power to about 5,000-5,200 run the Vortecs.
Get some GM 0.028" compressed head gaskets rather than the Felpro .038 or 0.43 that are typical of the rebuilder gasket sets.
I am guessing your engine has the dished pistons with long bath tub shaped valve pockets that are 18cc total dish.
If you mill about .010 or .020" off the heads and run the .028" composite gasket with the 18cc dished pistons you should be able to get close to 9:1.
With the Ramjet cam that should work very well on 87 octane in the lower rpm ranges.
Also no matter what else you do, the old GM pellet box cat needs to hit the scrap bin.
Replace it with a modern cat that actually flows decently, the one on my 305 was not clogged and swapping the smog exhaust for anOEM 80s 1-ton van dual exhaust without cats with the OEM tubular manifolds was like unhooking a trailer from behind the van.

[donf]

Thanks for the heads up. The converter has been changed to a recent 3" but it has a few goobers stuck to the bed. It may get left off for now, to be replaced in the future. No bathtub pistons, the standard ones that all light duty vans have. No ridge and very little carbon build up. My van is 800 lbs short of the heavy duty GVW. I found it has a replacement passenger side exhaust manifold made in China. The front port has the entire top half blocked off with some excess iron.

[Fast355]

Thanks for the heads up. The converter has been changed to a recent 3" but it has a few goobers stuck to the bed. It may get left off for now, to be replaced in the future. No bathtub pistons, the standard ones that all light duty vans have. No ridge and very little carbon build up. My van is 800 lbs short of the heavy duty GVW. I found it has a replacement passenger side exhaust manifold made in China. The front port has the entire top half blocked off with some excess iron.

I just read back all 5 pages. I forgot you mentioned that the cat had been replaced. That exhaust manifold sounds like a junky dorman replacement. I am not a fan of having those cast iron heat sinks dumping heat into my cylinder heads but they are simple and usually reliable. You might be able to port out the casted shut part without hurting the integrity of the manifold. With the standard pistons you should be in the 9.3 to 9.5 range when you use the thin gasket.

[donf]

Out with the flat tappet, in with the roller.

[donf]

So new vortec heads will be here in a week via slow UPS from Jegs. They have some house brand castings that are made in the USA. I don't know a lot about them but they should be good enough for this mild engine.

[donf]

I have looked a lot on here the last few days and this place has a lot of information, but no where that I looked was a simple list of what to change for a starting bin when vortec heads and a mild roller cam are added. Here is what I think needed changed, this is not a tune, just a basic changes to fire the engine and prep for wide band logging.

1. Scalar: Change Engine Constants - Injector Flow Rate from 61 to 74 to compensate for 18 psi spring
2. Scalar: Temperature for EGR On changed from 74.8 C (0x99) to 149.8 C (0xFD)
3. Scalar: Initial Spark Advance changed from 0.0 deg (0x00) to 9.8 deg (0x1C).
4. Table: Change both open and closed throttle Main Spark Table vs. MAP vs. RPM to base 1998 truck vortec timing table. zero out all negative numbers, smooth slightly.
5. Table: Desired EGR vs. RPM vs. Vacuum changed to 0.
6. Table: EGR Fuel Reduction vs. RPM vs. Vacuum changed to 0.
7. Flag: Code 32 EGR Failure changed from Set to Not Set.
8. Flag: Linear EGR/EVRV EGR changed from Not Set to Set.
9. Flag: Backpressure EGR changed from Set to Not Set

The idea is to let the computer know that the injectors now flow more fuel. Get the initial timing to 10 from 0 and load the most conservative vortec timing table. The Egr changes were made according to the instructions for the WBO2 zip and I increased the temp for EGR On to make sure it was off as I have it blocked. Any other suggestions? This is not a tune or even a complete list of what has been changed on my Bin, just some basics to build on and get the engine fired when switching to higher flow heads and a small cam on a TBI. There are a few thread where people lose 10 degrees of timing when messing with the scalars for timing so I just changed the one and will check to make sure its working as intended by setting the timing tables to all one number and reflashing as a quick test with a timing light.