Good morning!

[Maxzillian]

Well, morning anyway... I'll know if it was good once 12:00 rolls around.

Anyway, what brings me here is a 1985 Chevy C-10 I converted to fuel injection a few years back. When I bought the truck it had a GM Performance Parts 350HO in it that used a Holley carburetor. The engine ran great, but at the time it was my daily driver and I wanted better manners for cold operation and was interested in swapping in a 4L60E.

Ultimately I built a hodge-podge setup in which I stuck a TPI intake on the Vortec heads using an aftermarket lower manifold and used a 96-97 LT1 PCM to control it all so I could use OBDII logging tools and ultimately integrate the 4L60E at a later time. That said, hindsight has told me that I either should have just used a OBDI PCM or gone with a 0411... would have been easier in the long run and had better documentation!

As of this year I got the 4L60E installed and the whole setup has been working pretty damn well with the driveability of the truck being greatly improved; mileage isn't what I was hoping for, but I think that's because the cam won't play well with the TPI intake... there's always something.

http://maxzillian.com/truck/intake9.jpg

[EagleMark]

:welcome2:

Cool truck! So are you still using the OBDII Lt1 PCM? There is a way to cnvert that to OBDI Lt1 PCM...

:welcome:

[Maxzillian]

Cool truck! So are you still using the OBDII Lt1 PCM? There is a way to cnvert that to OBDI Lt1 PCM...


I am. I do have a OBDI PCM as well, but I've been sticking with the OBDII since I already have cash and tools invested in it. That said, it looks like a lot more development has been made with the OBDI setup as of lately.

[Fast355]

Well, morning anyway... I'll know if it was good once 12:00 rolls around.

Anyway, what brings me here is a 1985 Chevy C-10 I converted to fuel injection a few years back. When I bought the truck it had a GM Performance Parts 350HO in it that used a Holley carburetor. The engine ran great, but at the time it was my daily driver and I wanted better manners for cold operation and was interested in swapping in a 4L60E.

Ultimately I built a hodge-podge setup in which I stuck a TPI intake on the Vortec heads using an aftermarket lower manifold and used a 96-97 LT1 PCM to control it all so I could use OBDII logging tools and ultimately integrate the 4L60E at a later time. That said, hindsight has told me that I either should have just used a OBDI PCM or gone with a 0411... would have been easier in the long run and had better documentation!

As of this year I got the 4L60E installed and the whole setup has been working pretty damn well with the driveability of the truck being greatly improved; mileage isn't what I was hoping for, but I think that's because the cam won't play well with the TPI intake... there's always something.

http://maxzillian.com/truck/intake9.jpg

The HO 350 cam makes a ton of torque, that being said your block should be roller cam ready. Just find the lifter retainer tray, the 8 dogbones, the cam retaining plate, the roller cam timing set, the cam and lifters and shorter pushrods and you are golden. Car Craft tested the LT4 hotcam + 1.6:1 rockers in their Humble Pie 330 HP 350 buildup and there was not a place in the RPM curve that the flat tappet cam made more torque than the LT4 Hotcam.

http://www.carcraft.com/projectbuild/116_0403_350_ho_crate_engine_hydraulic_roller_cam_ package_install/

[1project2many]

The HO 350 cam makes a ton of torque
IIRC, that cam is a newer version of the old 350/327 cam with 212/222 @ .050". It's a good cam and does like a long runner intake.
http://home.metrocast.net/~shannen/efistuff/tpi_truk/tpitruk4.jpg

[Fast355]

IIRC, that cam is a newer version of the old 350/327 cam with 212/222 @ .050". It's a good cam and does like a long runner intake.


I can tell you for certain a CC304 LT1 grind cam, LOVES oversize long tube runners and vortec heads.

http://www.superchevy.com/how-to/0611gm-tpi-355ci-small-block/

[Maxzillian]

Interesting. I'll have to take a screen shot of the fuel map because there is a sharp increase in fuel right around the 2200-2400 rpm mark and it can be felt. Wideband sensor doesn't indicate a change in AFR so that's why I was questioning whether the cam was right for me or not.

[Fast355]

Interesting. I'll have to take a screen shot of the fuel map because there is a sharp increase in fuel right around the 2200-2400 rpm mark and it can be felt. Wideband sensor doesn't indicate a change in AFR so that's why I was questioning whether the cam was right for me or not.

Actually that is just the nature of TPI. That is where the TPI intake starts to resonate and do its thing. A good dual plane intake and TBI will make more low-end torque on the same engine than TPI will. TPI will KILL the TBI in midrange torque.

[Fast355]

I had LT1 injectors in mine at 50 psi and had to add a huge amount of fuel from 2,500-4,500 from 50 kpa through 100 kpa.

http://i243.photobucket.com/albums/ff172/Fast355_album/TPIVortecVE.jpg (http://s243.photobucket.com/user/Fast355_album/media/TPIVortecVE.jpg.html)

[steveo]

Ultimately I built a hodge-podge setup in which I stuck a TPI intake on the Vortec heads using an aftermarket lower manifold and used a 96-97 LT1 PCM to control it all so I could use OBDII logging tools and ultimately integrate the 4L60E at a later time. That said, hindsight has told me that I either should have just used a OBDI PCM or gone with a 0411... would have been easier in the long run and had better documentation!

what are you using for cam positional reference? did you gut an opti?

[Maxzillian]

I managed to squeeze the opti trigger wheel and sensor into a TPI distributor. Ultimately I cut the center out of the opti-spark to yield the bearing carrier and sensor mount. I shaved the top of the TPI distributor flat as well as the bottom of the section cut from the Opti and bolted this assembly onto the platform. I then machined a steel bushing to neck the Opti hub (which was shaved down on a lathe) and press fit plus soldered it to the TPI shaft. Additionally I made a shield for the trigger wheel on the assumption that arcing in the cap could screw with the sensor. Finally I took some brass stock and made a wider tip for the TPI rotor to allow for a wider spark advance range.

Originally I had machined a hub to hold the shield and trigger wheel as an assembled and set-screwed that to the distributor shaft. The sensor was screwed straight to the base of the distributor. However, I had a lot of trouble with keeping the vertical lash in check and the top bushing of the TPI housing was wearing out. The Opti-spark bearing serves as a better means of keeping the shaft from moving around, reducing backlash and timing variance.

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The top of the sensor was cut to intersect with the distributor cap. I preferred this over cutting the cap as any future caps won't require modification.
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