Oil Pan Bolts

[Walter R.]

The Tech Manual states the front and back two oil pan bolts on a BB are 1/2 inch. do they have a wire washer like the other bolts which are 7/16 or do they have a split washer?

[Joe L.]

Re: Oil Pan Bolts

The Tech Manual states the front and back two oil pan bolts on a BB are 1/2 inch. do they have a wire washer like the other bolts which are 7/16 or do they have a split washer?

Walter------

The corner bolts are 5/16-18 with a 1/2" wrench size. These bolts have a captured split lockwasher.

[Walter R.]

Re: Oil Pan Bolts

I wanted to make sure. I ordered a set of bolts from a supplier and they were all 7/16. Typically, the parts suppliers are pretty accurate with the bolt size and markings. I ordered the set as I was missing the corner bolts but had all of the correct 7/16 bolts. Any idea how I could acquire these bolts?

[Leif A.]

Re: Oil Pan Bolts

The Tech Manual states the front and back two oil pan bolts on a BB are 1/2 inch. do they have a wire washer like the other bolts which are 7/16 or do they have a split washer?

Walter,
The SB has the larger bolts on the four corners but I don't believe the BB does...BB bolt sizes are all the same. The BB, also, has reinforcements for the four corners. See below.

From Zip:

https://www.zip-corvette.com/66-67-radiator-shroud-mount-bolts.html

https://www.zip-corvette.com/65-74-396-427-454-oil-pan-bolt-reinforcements.html

From Paragon:

https://www.paragoncorvette.com/p-35...lt-kit-bb.aspx

[Michael V.]

Re: Oil Pan Bolts

Call rich Pasqualone at 610 462 4441 in New Jersey if you want original ones. He is the best.

[Gary B.]

Re: Oil Pan Bolts

All

The ‘66 JG is pretty clear when describing the oil pan bolts. At the start of the oil pan section, the JG describes things common to all oil pans, small block and big block. It says “The pan is attached to the block with 7/16” indented hex head bolts with captured serrated washers; except for the bolts passing through the corner reinforcements, which are 1/2” indented head size.” Then, in the the section specific to BB, the JG reads “The same recessed 7/16” hex head bolts secure the pan to the block along the sides and 1/2” hex head bolts secure the front of the oil pan to the left and right of the timing cover and at the left and right rear.” Since SB and BB use a different number of bolts for the oil pan, the repro parts companies sell a separate kit for each. If you look at the old Long Island Corvette website and zoom in on the oil pan bolt kit contents you can see the bolts with the larger head size in each of the two kits, that are intended for the corner locations. So, the LIC kits were consistent with the JG.

in Leif’s first photo, I think the L headmark bolts at around the 5 o’clock position have a larger head size than the nearby E headmark bolts.

Gary

[Ray K.]

Re: Oil Pan Bolts

Walter,

All big blocks use the same bolt size, as described by Joe, 5/16" X 18 thread with 1/2" wrench size for attachment of the oil pan to the block.
At the front corners of the oil pan, they use 1/4" X 20 bolt with a 7/16" wrench size ( 2 required ) for attachment to the front timing cover.

Ray

[Gary B.]

[Gary B.]

Re: Oil Pan Bolts

After looking at the LIC kit photo, I see the mistake I made. Here’s a photo of the LIC BB kit.

29FC4018-7673-400A-A648-C7CE60FC94BC.jpg

The E headmark bolts with a split lock washer must be the corner bolts. The L headmark bolts with the star washer must be the side bolts. There are many more bolts with the star washer in the photo, so those must be the side bolts. The L headmark side bolts look like they have the larger (1/2”) wrench size and the E headmark corner bolts look like they have the smaller (7/16”) wrench size. If so, that is the opposite of what the JG says.

Gary

[Ray K.]

Re: Oil Pan Bolts

Gary,

I looked at my '65 JG ( 6th edition ) and I believe it is incorrect as well as to the bolt sizes. Most likely offers correct info on the head style and identification. I have a 427 on an engine stand and it does not have original bolts with the recessed heads, but I can assure you about the thread and wrench size being correct.

Ray

[Leif A.]

Re: Oil Pan Bolts

Ray,

Wow! Your description is remarkably different from what the ‘66 JG says. And your description seems to exactly match what is contained in the Paragon BB kit based on Leif’s photo. Seems like a correction to the JG is needed.

Gary

If you look closely at the Zip photo, the bolts for the water pump cover are mixed in with the rest of the oil pan bolts...kind of in the center of all the bolts.

[Gary B.]

Re: Oil Pan Bolts

Gary,

I looked at my '65 JG ( 6th edition ) and I believe it is incorrect as well as to the bolt sizes. Most likely offers correct info on the head style and identification. I have a 427 on an engine stand and it does not have original bolts with the recessed heads, but I can assure you about the thread and wrench size being correct.

Ray

[Gary B.]

[Leif A.]

Re: Oil Pan Bolts

Here ya go...

[Gary B.]

Re: Oil Pan Bolts

Thanks Leif.

So, three out of three JGs incorrectly say on a BB that the front corner bolt heads are the larger size? Have I got that right?

Gary