7.4 vortec sending unit + electronic gauge...?

[Rede]

I've got my truck to the point where it starts (not tuned at all and not ready for a road test at all) but I noticed that I'm not seeing any movement on my oil presure gauge.

The factory oil presure sending unit on engine (7.4L out of a K2500, carbed) has a single connector just like the factory 1979 cluster I have.
I connectred them together when wiring the tach and such, but I don't seem to have any movement.


I've done a pile of google searching for the past hour, but all I seem to find is mechanical gauge setups.



Am I missing thinging vital, or are they just not compatible at all...???

[clinebarger]

They are not compatible, You will need a '79 sending unit, Same goes for the temp sender.

[Rede]

Originally Posted by clinebarger

They are not compatible, You will need a '79 sending unit, Same goes for the temp sender.

Since the threads are different front the vortec and the older units, where can I get an adaptor? (proper adaptor name would help too)

The temp sensor I was able to reuse from the EFI intake...looks identical to the older units, but I haven't had the truck running long enough to check to se if it works
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[clinebarger]

Originally Posted by Rede

Since the threads are different front the vortec and the older units, where can I get an adaptor? (proper adaptor name would help too)

The temp sensor I was able to reuse from the EFI intake...looks identical to the older units, but I haven't had the truck running long enough to check to se if it works
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I havent messed with many Gen V BBC's, I know they have a oil port on the back of the block that the Gen IV didnt, I would "assume" it would be 1/8" NPT like a SBC??

On Gen IV BBC's I use the right front oil pressure port (arrow)....Does you Gen V have this?

[Rede]

I did some googling this morning.


Here's what I found incase anyone else is stumbling on this in google-land:

-Gen6 bbc (maybe even the vortec sbc..??) and LS series all use m16x1.5 thread.
-Old school Gen1 (pre LT1 I believe) uses 1/8"x27 NPT
-Autometer and a few other companies make a male M16 X 1/8 NPT female adaptor, #2268...how sad is it that I've remembered the part number(?)
-Summit Racing makes an electronic oil presure sensor for $20 that is 1/8" NPT


$29 in parts and $38 in shipping/estimated duty/tax and those goodies are now on order....
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[clinebarger]

Originally Posted by Rede

I did some googling this morning.


Here's what I found incase anyone else is stumbling on this in google-land:

-Gen6 bbc (maybe even the vortec sbc..??) and LS series all use m16x1.5 thread.
-Old school Gen1 (pre LT1 I believe) uses 1/8"x27 NPT
-Autometer and a few other companies make a male M16 X 1/8 NPT female adaptor, #2268...how sad is it that I've remembered the part number(?)
-Summit Racing makes an electronic oil presure sensor for $20 that is 1/8" NPT


$29 in parts and $38 in shipping/estimated duty/tax and those goodies are now on order....
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I need to brush up on big block lore
The 96-02 Gen 1 SBC used pipe thread.
I didnt know the 99-00 454's used metric straight thread??
I know the 01 & up 8.1L does.

[Rede]

For those interested, here are the Summit part numbers:

Adapter part number is ATM-2268
Sending unit part number is SUM-G2872-1

$29.xx for both
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[Rede]

Gen 1 sbc ran till around 92 I believe.
Gen 2 sbc ran till 99 (5.7L)
Gen 3 sbc started in 2000-current (LS family)

It's interesting on how several aspects of the gen6 bbc motors are just like the LS family... Rocker torque spec , cam install directions, and so on.

My guess is that it was the basis of the gen 3 sbc's as it was phased out by the gas guzzling 6L.

Figures... Gm finally builds a well designed bb, then phases them out =\
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[clinebarger]

Originally Posted by Rede

Gen 1 sbc ran till around 92 I believe.
Gen 2 sbc ran till 99 (5.7L)
Gen 3 sbc started in 2000-current (LS family)

It's interesting on how several aspects of the gen6 bbc motors are just like the LS family... Rocker torque spec , cam install directions, and so on.

My guess is that it was the basis of the gen 3 sbc's as it was phased out by the gas guzzling 6L.

Figures... Gm finally builds a well designed bb, then phases them out =\
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Gen I SBC ran from 55-02
Gen II SBC ran from 92-97
Gen III ran from 97-07

[Rede]

I was WRONG about the adaptor for the sending unti.

It turns out that it's a 1/4" NPT for the engine block and 1/8" for the old school sending unit.

The problem now is that thesending unit against the block before you can even get an 1/8 of a turn.....

I bought a couple of different fittings that I'll try when I get time.

One is a short 1.5" straight piece to lift over the casting where it slopes out to meet the lip for the bell housing, and the other has a 30º bend which I hope will let me angle the sending unit towards the passenger or driver side.