Understanding my new truck...new crate engine going in.

[peckaldee]

Hi all.

I have an 86 C10.  The motor that was in the truck when I bought it was out of a 80 van after researching the casting numbers.

Bought new crate engine, GM Performance 260 HP from Jets, and have a few questions.

Do I need a knock sensor in the new motor?  The 80 model motor had one.  Not sure about this truck having an ECM but the sensor was plugged in before I pulled the old motor out of the truck.

Beside the distributor on the top of the block is a brass pipe with a T joint.  There are two sensors on each end.  I have been told one is for a oil pressure sender for a dash lamp and the other for the gauge.  Do I need both?  Not sure if I even have a light in the dash.

The new crate motor does not have a pin to locate the flex plate on the crank.  It being internally balanced, does this really matter since the bolts will locate it correctly.

Also looking for some over the valve cover wiring looms if anyone can give me a lead.  The valve covers that came with the motor have what looks like brackets already made for them.

Thanks for any help.

[Fairlane514]

The flexplate bolt pattern allows it to be mounted only one way.  The "T" is for the oil pressure, usually when this is done its for both an electric gauge and a mechanical, so you can choose one, and get rid of the "T."

I can't help you with the knock sensor.  Wire looms, check Summit, Jegs, ebay etc....

[Engineer]

I would put the sensors back like you found them.

It looks like you have the flex plate figured out.

[Captkaos]

Are you still running a Feed back carb?  ESC?  If you aren't you don't need the sensors, if you are, you will need them.

[peckaldee]

Using edelbrock 1406 Carb.

[Captkaos]

did you remove the ESC?  You aren't going to need any of the sensors unless you are running the Carb and timing control.

[peckaldee]

E

did you remove the ESC?  You aren't going to need any of the sensors unless you are running the Carb and timing control.

Removing the ESC along with the knock sensor from the block.  What other sensors are there?

My Edelbrock 1406 Carb isn't a feedback carb as far as I know.  New HEI distrib. with vacuum advance should get me where I need to be right?

[Fairlane514]

Yes, on the new HEI distributor

[Captkaos]

No edelbrock is set as feedback.  With the stock carb and the ESC gone you won't need a number of sensors as it would be just like any other SBC.

[Tx Firefighter]

You can reuse your existing distributor without the ESC function. You have to jumper two wires on the module wiring but otherwise it's good to go as is.

That will save you some money.

[peckaldee]

Good replies all.  Will update as this project moves forward.

Still looking for looms if anyone reads over this and has a suggestion.

[bd]

Still looking for looms if anyone reads over this and has a suggestion.

Summit Racing

[Jason S]

Just to throw out a thought...  If you are reusing the old flexplate (and harmonic balancer), have you checked to make sure the '80 model engine was not a 400? 

[peckaldee]

Just to throw out a thought...  If you are reusing the old flexplate (and harmonic balancer), have you checked to make sure the '80 model engine was not a 400? 

From the block casting number I found it was a 350.  As far as I could tell.  It does have a 1 piece rear main seal and the flex plate was weighted. 

Anyone got a clue?

[Jason S]

An '80 model engine should be a two piece seal crank. The only factory SBC V8's that had weighted flywheels/flexplates were the 400 (two piece seal crank) and the SBC with a one piece seal crankshaft ('86-up SBC). The 400 also had a specific harmonic balancer. 

The flexplate for a 350 engine with a 2-piece seal crankshaft is different than the flexplate for a 350 engine with the 1-piece seal crankshaft.

If the engine you are replacing has a one piece rear main seal, then it is out of an '86-up car, truck, van, etc. 

If you bought this engine:
http://www.jegs.com/i/GM+Performance/809/10067353/10002/-1
-then-
You will need the flexplate for a 2-piece rear main seal 350 (1985 and back), which would be:
http://www.jegs.com/i/B%26amp%3BM/130/20230/10002/-1 or
http://www.jegs.com/i/Eagle/356/FRA104/10002/-1?parentProductId=1688817 (if you have need the 168-tooth flywheel)

The harmonic balancer will swap between the one-piece seal crank and many (but not all) earlier two-piece crank SBC's.  There are caveats to this; but if I am reading correctly, you can use your old harmonic balancer on your new engine.  However, as the rubber in the balancer can deteriorate over time and grooves can be cut into the sealing surface, you may want to just swap on a new one while you're there... The balancer you use install will need the correct timing tab.  The paperwork that comes with the crate engine should have all the information required for the correct harmonic balancer, timing tab and flexplate for that engine.

I hope I didn't create any confusion, like I said before just a thought...  My initial thought was just to check and make sure you weren't mixing parts that might throw off engine balance (i.e., 400 flexplate & balancer on a 350).  If a few simple checks now saves a lot of time and hassle later, then I think it is time well spent...