It is that time! Tear down starts tomorrow on the 97 Express.

[L31MaxExpress]

The single plane is probably not the most ideal manifold but I have it and it will be the easiest to adapt. Also have a 103mm throttle body that should allow the 383 to get enough air. I may use the Fitech 92mm, up in the air on that. Parts are an Erson custom grind, Lunati short travel lifters, Holley intake manifold and fuel rails, Holley intake elbow, MSD Atomic 103mm 4 bolt LS throttle body, an EFI connection 24x reluctor and Delco D585 coils on relocation brackets. My intent is to mount the coil packs up front, probably on the inside of the frame itself and run the plug wires down low like a LT1 keeping the coils more away from the heat that cooked them the first time I tried the setup on the old 350. I went away from them when I built the 383. I am ready to have a flex fuel sensor on this that actually works. It ia disabled for some reason on a 4x ignition P59 calibration but works fine on a 24x setup. In theory the smaller, wider LSA, higher lift cam and single plane manifold should broaden the actual torque curve. I would use another dual plane but I am actually trying to kill off some midrange cylinder pressure. Trying to get as flat of a torque curve from off-idle to 6,000 as humanly possible from this little 383. Cam was spec'd and ground with a shorter runner Indmar manifold or single plane as the intended manifold of choice.

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[CumminsFever]

So, if I'm understanding correctly, there's nothing wrong with the current setup? This is exactly the type of thing I'd do! In for pics and results, very curious how this affects economy as well. Very cool stuff!

 

[Sean Buick 76]

No turbocharger???

 

[L31MaxExpress]

So, if I'm understanding correctly, there's nothing wrong with the current setup? This is exactly the type of thing I'd do! In for pics and results, very curious how this affects economy as well. Very cool stuff!

I have had the cam and lifters for a year. In cooler weather the LS7 lifters will start acting up pretty badly. One collapses so badly it causes a cold start misfire. The cam itself was just wrong for the setup. The manifold swap is to get away from the plastic vortec air intake hat. It puts a strangle hold on the engine currently at about 5,000 rpm. I modeled the old engine in DD2003 and it was fairly close to what it makes. Modeled the new setup too when I was gathering all the parts a year ago. Ignoring the exact numbers, if it alters the torque curve in a similar manner in real life as the software model predict, will make me extremely happy with the difference, especially considering the new cam has almost has 20* less overlap at 0.006". Modeling seems to suggest that the only place it will give up anything is at 3,500 rpm.

Current setup
RPM-----HP------TQ
2,000---166----437
2,500---221----464
3,000---280----490
3,500---347----521
4,000---400----525
4,500---446----521
5,000---475----499
5,500---492----470
6,000---495----433

New Setup
RPM------HP------TQ
2,000----172----451
2,500----222----467
3,000----280----491
3,500----345----518
4,000----408----536
4,500----466----544
5,000----511----536
5,500----531----507
6,000----534----467

 

[CumminsFever]

No turbocharger???

It might perk up that little flat spot at 3500rpm? Lol!

 

[L31MaxExpress]

It might perk up that little flat spot at 3500rpm? Lol!

As fun as that would be, would be a nightmare. If I had settled on boost it would have a LSA blown LQ9 6.0L with rectangle port heads in it now. I still have the LQ9 6.0L and rectangle port heads but sold the LSA setup. I made over $1,000 buying the LSA and parts cheap and reselling them when I decided to build the 383. LS would have needed the floor and firewall cut and the LS equivalent sheet metal welded into place. Same thing that stopped the 8100 swap on it years ago. The LSA setup would have needed a ~2" body lift as well as completely redesigning the ac system. I actually set the 6.0L into the frame before I decided to build the 383. Had to remove the valve covers and coil packs to even get the engine into place and there was no room to re-install them with the engine sitting on the mounts and mated to the 4L80E. 2" body lift probably would have given adequate clearence for both. A 2" body lift would have given the Camaro LSA lid approximately 3/4" clearence off the tunnel in the firewall and engine cover.

 

[CumminsFever]

I did forget how space limited the vans are. My brother and I once stuffed twin turbos under the dogbox of a 6.5 equipped van, I believe it was a '95. What a plumbing nightmare. I can well imagine you've got no room for spinny thingys!
It is downright amazing what you're getting from the n/a engine. I can't wait to see what these changes bring. Is it safe to assume there will be some dyno vids?

 

[Road Trip]

The single plane is probably not the most ideal manifold but I have it and it will be the easiest to adapt.

I sincerely appreciate your reasoned approach to powerplants. It's one thing to build something
that fits in the dyno room, another one entirely to fit into a van's cramped engine bay.

After reading through your parts selection reasoning, I tried to find the correct Holley single-plane
EFI manifold. In the first attachment, I think I'm close but not exact? Anyway, the side view
showing how the injectors are mounted looks good.

But my question is centered on the plenum in that single plane intake. Have you ever considered
running a turtle in that? I realize that turtles are generally used to cure fuel distribution issues on
a wet-flow intake, but your setup will be dry.

Even so, I'm just wondering if they offer a turtle to help turn the air make the turn towards the
runners instead of the turbulence that might occur as the incoming air crashes down on that flat
floor? Probably wouldn't want to try to live on the difference it makes, but I'm interested in your
thoughts.

Nice build. What a sleeper that van already is/will be.

 

[L31MaxExpress]

I sincerely appreciate your reasoned approach to powerplants. It's one thing to build something
that fits in the dyno room, another one entirely to fit into a van's cramped engine bay.

After reading through your parts selection reasoning, I tried to find the correct Holley single-plane
EFI manifold. In the first attachment, I think I'm close but not exact? Anyway, the side view
showing how the injectors are mounted looks good.

But my question is centered on the plenum in that single plane intake. Have you ever considered
running a turtle in that? I realize that turtles are generally used to cure fuel distribution issues on
a wet-flow intake, but your setup will be dry. Even so, I'm just wondering if they offer a turtle
to help turn the air make the turn towards the runners instead of the turbulence that might
occur as the incoming air crashes down on that flat floor? Probably wouldn't want to try to
live on the difference it makes, but I'm interested in your thoughts.

Nice build. What a sleeper that van already is/will be.

It is a discontinued manifold. Bought it last year during the Holley clearence sales. It is the Projection line. Powerband claim was 2,500-6,000 for the manifold.

https://www.holley.com/products/discontinued_product/parts/550-701?srsltid=AfmBOoq0lSnbw9VyI-6JZSf9lAWvyCGH0zZVtUZ_nlr8B4GxlxbFihs6

 

[L31MaxExpress]

I will take a shot down the intake later. Seems to have a fairly nice shape to it as is. I need to measure the runner length as well. I have a large mixture of rocker arms at my disposal. Have considered 1.6s on the intake of the outer cylinders and 1.5s on the center 4 cylinders. To help even out the flow and powerband with the inner/outer runner length differences as well. It will either run better or run worse, should not hurt anything either way. I have a V6 set of the Comp steel 1.5s like Supercharged has in 1.6s on his 1500. I have a full set of Scorpion 1.6s and 1.7s as well. Engine currently has the 1.7s on the intake and the 1.5s on the exhaust. The 1.7s are out on this Erson cam because they will exceed the safe lift capacity of the springs. I tested borrowed 1.3 break in rockers on the exhaust and found substantial low-midrange torque gains but was afraid to leave them long term and they were not mine. Hence why I have a single pattern grind this time around.

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