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JEFFTATE
05-09-2012, 05:59 AM
Last weekend , I went to Run to the Ole South Event in Kershaw , SC .
My car has had a small oil leak for a long time , more like an " ooze " around the front of the engine .
It never dripped on the ground , but enough oil was oozing to run back and make a mess of the oil pan , clutch cover and transmission .
I thought it was either the fuel pump itself , or the front crank seal or the oil pan gasket .

My Camaro has a GEN 1 small block Chevy .
There are two drilled , tapped holes on the passenger side front of the block , adjacent to the fuel pump .
The upper of these two holes is tapped deep enough to go into the oil galley where the fuel pump pushrod lives ..
There's no pressurized oil here , but rather a gravity feed to lubricate the fuelpump pushrod and fuelpump itself .

That upper hole has to have a 3/8" X 1/2" bolt in the hole or it will leak .

I've had at least 30 SBC's over the years and never remember seeing this problem before ( or I just forgot ).
Thanks to James Harrel for pointing it out at the event .

Either way , I plugged the hole and now my powertrain is a lot cleaner ..
https://static1.pt-content.com/images/pt/2012/05/p159196_image_large-1.jpg


Most small-blocks feature four 3/8-inch threaded holes (two per side) at the front of the block. The upper hole adjacent to the fuel pump passes into the crankcase area and if left open will allow oil to leak out from the block. Be certain to plug this hole only with a short 3/8-inch bolt (1/2-inch long). Because this hole aligns perfectly with the fuel pump’s pushrod, a longer bolt will contact and seize the pushrod during engine operation.

Read more: http://www.chevyhiperformance.com/tech/engines_drivetrain/shortblock/83818_block_plug_basics/index.html#ixzz1uNWXTKfv

Norwoodx55
05-09-2012, 07:18 PM
That hole makes it easier to change the fuel pump. Before you remove the old pump, lightly seat a longer bolt against the push rod to prevent it from falling out while you R&R the pump.

TheJDMan
05-10-2012, 05:39 PM
Yep, SBC 101. Those four holes are the engine mount locations for the Tri-5 Chevys.

JEFFTATE
05-12-2012, 04:47 PM
It's funny , I had forgotten all about that ...
We learn every day , I guess .

I hope this info may help someone someday .

Pro Stock
05-18-2012, 09:31 PM
And all of them don't leak either, just the one's with a little bit of core shift or hole that has been drill a little bit too deep.