erikcaso

Hi, I'm new here so pardon the new-guy questions. I've got a crate motor in my 81 Jeep Scrambler that is a Chevy 350 TPI, part number 12486041. I've scoured the internet for documentation on this motor, as I troubleshoot a few things and prepare for a full rewiring of the vehicle. Unfortunately, I can find any complete manual/spec. Is anyone aware of a full manual? This motor was built in 2001, but I know one of the last years it (or the L98, rather) was included in a vehicle was early 90s Camaro. Can I use a Chilton's for that car to get more info on this engine?

Also, can anyone answer these:
1) What year vehicle do I need use to talk to the computer correctly (e.g. smogging the vehicle, getting correct error codes, etc.)? I've tried 91 Camaro, but I'm not sure that is accurate.

2) Does it have a MAF or MAP sensor or both?

Thanks or the help!

TURBOTOMMY

What documentation do you want? its a 4bolt main 350 with vortec heads with a tiny cam in it..I punched the number into google and the 1st site that came up was summit racing,,,you can readabout it there......

erikcaso

I've seen the Summit Racing page and I've got an install manual that includes a basic parts list. But it doesn't provide any schematic around things like the OBD codes, MAP or MAF or both, wiring, etc. So I guess I'm looking for something far more comprehensive to help me through the electrical (need this to get the right harness from Painless) and troubleshooting a potential vacuum leak.

jmd

iTrader: (4)

http://static.speedwaymotors.com/pdf...tallguide1.pdf

The TPI on the engine could be set up a variety of ways.

I would start with grabbing numbers and other identification from the ECM and PROM (chip) inside it. If you start to find it is a 90-92 F-body ECM and PROM, you may have better direction. It is great when a swap is done so it is "just like it was in the donor vehicle" even when some mods are involved.

jmd

iTrader: (4)

If it ran in the first place, you likely don't need a harness from Painless.

erikcaso

Thanks, that's the install guide I've got. I'll check out the ECM and PROM. The whole kit was a Chevy Performance purchase, so I'm not too sure how to determine the "donor". I don't think any vehicles sold in 2001 had an L98, yet that was the build date for this engine. The spec plate on the bottom of the engine has the following:
Part No. 12486041
Bore O.S. TN (might be IN, but looks like TN)
Main Brgs. STD
Thrust Width STD
Rod Brgs. STD
Date 04/17/2001
Serial # 15013725
S/C 7684

erikcaso

Well, they married up the 350 wiring to the 81 Scrambler harness and it is a mess. I'm taking the tub off to get painted, which is a good time fix the mess of wires.

Tuned Performance

iTrader: (92)

Good advice, Tpi maf uses a ecm service number 1227165 , 16198259 or 88999194. Tpi speed density (map) uses 1227727 under hood ecm, 1227730 ,16196344 & 16198262 . Or just posting a underhood pic . Maf if is front of the trottle body mad is suppose to be on the rh rear of the plenum.

erikcaso

I'll try to grab info on the ECM and PROM this weekend, but here are a few photos. Unfortunately, I don't have any of the back of the engine.

Tuned Performance

iTrader: (92)

The map has been relocated on the bulkhead next to the battery. The throttlebody is 85-88 as well as the runners.

GCrites80s

So wait, just the short block is from 2001 right? They weren't making TPI componentry in 2001 I assume.

Tuned Performance

iTrader: (92)

Afaik Tpi was castes last in 91 but installed in f body's until 92. There was a shortage of throttlebody top plates so some 92s do not say tuned Port Injection.

erikcaso

Holy ****, I didn't notice the MAP was relocated. I'm apparently blind. Thanks!

Is the 85-88 throttle body the same for the L98? Apparently, the motor is a crate but the parts are not spec for that year/model?

I'm a novice, so thanks for the help. I really appreciate it.

Tuned Performance

iTrader: (92)

85-92 throttle bodies were all 48mm for 305 & 350. It looks like someone used a Tpi maf setup for speed density. Hopefully the installed a Vss on the speedometer cable at the trans or transfer case.

Drew

iTrader: (58)

That is not a 12486041 crate engine. The 12486041 is a Vortec head equipped engine, and the one in the pictures isn't. The intake bolt pattern is different on Vortec heads, 4 bolts per head vs 6 bolts per head. They're also vertical on a Vortec, not angled. There's really only one Vortec TPI intake offered, SDPC or Edelbrock, both lack the dips between the intake ports like the one in your photos.

Just from the pics, everything matches up closely with an 85-86 TPI. The half V-belt/Half serpentine accessories, the AIR injection, the fuel lines, plenum, runners, throttle body, injectors, even looks like you've got a cold start injector and a large cap distributor.

erikcaso

Hmmm. This is a picture from the bottom of the block.

Drew

iTrader: (58)

Get the casting numbers off the driver's side of the block, behind the head on top of the bellhousing flange. Also look behind the alternator in front of the passenger's side head for a stamping. Those two things will tell you approximately what the block was originally. Next pull the valve covers and check the casting numbers on the heads.

While it's possible to drill and tap Vortec heads for the early SBC intake bolt pattern, a stock TPI manifold base won't even cover the intake ports on Vortec heads without adding material.

GMPP never offered a Vortec TPI crate motor. Scoggin Dickey did the R&D on the first Vortec head TPI base manifold and brought them to market. Edelbrock manufactured them for SD and sold the same intake with their name cast on top, later. If you look on the bottom of Edelbrock's Vortec TPI manifold it still has the Scoggin Dickey part number cast in it. Both versions are flat on both edges parallel to the valve covers.




Note also the bolt patterns, 8 intake bolts vs 12 on a standard SBC.
And the threaded boss in front of the #1 cylinder injector. Notice how on the Vortec intake, that boss is eliminated and replaced with the boss used on the Corvette L98 intake further forward.
Again notice how the Vortec intake uses an external EGR port on the passenger's side by the distributor, because Vortec heads lack an internal EGR provision.

You might have the shortblock from a crate motor with earlier heads, or just the tag from a crate motor, etc but it's anyone's guess. The castings and stampings will give you a clearer picture.

86CamaroDan

Actually GM makes the Ramjet 350 which is with vortec heads. What you have is the GM 350 HO. I have the same tag on mine, Same numbers. 212/222, .435/.460" lift on a 112.5 LSA. Check your left cylinder head, the front should have three triangles facing up (Looks like a mountian range) should indicate 062 heads. Might be hard to see with a alternator in the way though.