Chevy & GMC Vans

Ok, now for an update ....... So, we got the engine back together Saturday & I drove it home to collapse & succumb to the cold that I was battling. Since I was feeling sick, I was concentrating on getting the job done - not taking pictures However, I know that Sanja took some pics.........

Spent a good portion of the morning cleaning the components & performing modifications as required to make it all fit together properly. Because of the different bolt patterns of the intake manifolds, the items (cruise control & MAP sensor) that were normally held on by the intake bolt studs had to be reconfigured to attach somehow.

Started the reassembly by installing the roller cam, followed by the roller lifters, guides (o=o) & hold down retainer (spider).

Once this was installed, I was going to install the camshaft thrust retainer & found that I had a 1st design engine but a 2nd design retainer. The difference between these 2 retainers can be seen in this picture.

The spacing of the 2 bolt holes is different between the 2 designs. The 1st design has wider spacing than the 2nd design. As luck would have it, I had the incorrect spacer at work & the correct spacer at home. Simple quick trip to retrieve the correct retainer & back to reassembling. Installed the beefy single roller chain & sprockets to the correct orientation & timing, which brings us to this point of the assembly.

During this time, Sanja was working on the header modification. The head/intake manifold/header was mocked up together on a bench to figure out the EGR tube orientation. A hole was drilled in the header collector & ground large enough for the EGR pipe to be welded to it. This pipe attached to the semi rigid EGR pipe that screws into the left front corner of the intake manifold & snakes along the intake manifold/head/valve cover joint to the back side of the left head. Once set up properly, the header/EGR pipe set up was taken over to the body shop where one of the body men welded it up for me.
Upon completion of this, the components were disassembled & given a wipe down prior to installation onto the engine.
New head gaskets & bolts were used for reassembly & torqued - torque angled on.

The obvious question is of course "well, how does it run?"

Nice! How does it run? And where is the new smokey burnout video?

Sorry for the delay in the update on this.
To recap this week, I was sick, had a family emergency & my son turned 18. My wife's grandmother (age 96 ) took a turn for the worse during this last week. Currently have 1/2 dozen extra people from all over the country staying at my house during this time. (plus more relatives during the day) She seems to have recovered & is doing well so now it is a big party!

Anyway, back to the upgrade. The van runs good but I have not really given it all 'the beans' to test it out. I have done some minor adjustments as needed after doing an upgrade of this magnitude. Things like rerouting & securing the spark plug wires & wiring harnesses, adjusting the transmission kick down cable, fixing a minor coolant leak at the thermostat/hose joint & fine tuning the amount of EGR bleed.

Thanks to Sanja there are more pics of the progress of the job as it progressed.
Additional thanks to Sanja for coming & helping me get this job done.

FYI, the bolt pattern for the timing chain sprocket has different spacing for the roller cam when comparing it to the flat tappet cam - same bolts can be used, just can't use the same bolt lock plate.

These head have 2 ways of being tightened down - torque-to-yield (angle) spec or torqued to spec. The preferred way of installing the heads is the torque-to-yield method.
This torque-to-yield method uses an initial torque spec of 22 lb ft of all bolts followed with 75 degrees for long bolts, 65 degrees for medium bolts & 55 degrees for short bolts - all done in the correct sequence.
The alternate method is to torque them to an initial spec of 26 lb ft followed with a second spec of 44 lb ft & a final spec of 66 lb ft - all in the correct sequence.
I had all new head bolts for this job & since I had access to some nice torque angle torque wrenches, I opted to do the preferred torque to yield method - during which Sanja snapped a pic.

One obstacle that I knew I had to take care of during the process of this swap was the addition of an egr port to my header. To make this function I had taken a piece of 3/4 inch black pipe & threaded the inside of it with a 3/4 NF tap so it would accept the fitting that would connect it to the egr pipe. The egr pipe & fitting were the factory items from the L31 engine. Once I had the header off of my engine, I mocked up my new manifold, new left head & old left header together on the bench to see where the pipe should be welded to the header. I cut the previously threaded pipe down to the approximate length needed & then Sanja trimmed it to fit properly & made a hole in the header collector to match. This was then welded together as seen. This actually fit really good on the vehicle & looks like it belongs when viewed from below the vehicle.

With all the minor components swapped over, the intake was bolted on. Due to the design of the gaskets for this intake, there is substantially less torque needed on the bolts to install it in comparison to the old intake. Spec for this is 27 lb in, followed by 106 lb in & finished with 11 lb ft. Something to note on this intake manifold - if you look into the throttle body bores of the intake you can see a hole at the bottom of both bores. This 3/8 hole is actually the egr bleed port.

Once all is assembled into the vehicle, almost all the 'pretty, new stuff' is obscured from sight, however it does look quite at home in there. From what I have felt in the short time that I have driven it so far is that it runs good & pulls strong. That being said, anything is better than running an engine with a worn cam! Unfortunately I am not able to try it more this weekend as I am currently driving another vehicle from work that has a driveabilty problem that I am trying to figure out. #-o
Perhaps next week I will be able to give a run down the highway & secluded roads to test the capability of the engine.

LiftedAWDAstro wrote:Nice! How does it run? And where is the new smokey burnout video?

As to a smokey burnout......maybe, but probably not, unless I put on some old tires. :-k