Small block exhaust manifold spacer washers, Black phos or Cad?

[Scott S.]

Are the 1/8" thick spacer washers that are used with the four outer/end bolts on each exhaust manifold natural, Cad (or zinc), or Black phosphate? The 1966 JG is not specific, while the older 1967 JG says they're plated black.

What finish is correct for these spacer washers on a 1967 small block?

[Craig O.]

Re: Small block exhaust manifold spacer washers, Black phos or Cad?

Scott ,all that I have seen are blackish, as are mine

[Dan H.]

Re: Small block exhaust manifold spacer washers, Black phos or Cad?

Scott, I vote for burnt engine orange!

[Michael M.]

Re: Small block exhaust manifold spacer washers, Black phos or Cad?

All small block exhaust hardware should be unpainted unlike big block exhaust hardware.

[Alan D.]

Re: Small block exhaust manifold spacer washers, Black phos or Cad?

Scott, (my comments are based upon a 64 C2, but think it was the same up to 67)

So first double check your AIM. Look in the radio section on shielding, you may find that all the exhaust manifold bolts use that washer. As for the finish, these are painted orange along with the exhaust manifold and once heated the orange will turn a black. So if you want to plate them some form of a black that should be fine.

[John H.]

Re: Small block exhaust manifold spacer washers, Black phos or Cad?

Scott, (my comments are based upon a 64 C2, but think it was the same up to 67)

So first double check your AIM. Look in the radio section on shielding, you may find that all the exhaust manifold bolts use that washer. As for the finish, these are painted orange along with the exhaust manifold and once heated the orange will turn a black. So if you want to plate them some form of a black that should be fine.

Alan -

That (painted fasteners) works for '63-'64, but the '67 exhaust manifolds were installed after engine painting.

[Alan D.]

Re: Small block exhaust manifold spacer washers, Black phos or Cad?

Thank you John!

[Dan H.]

Re: Small block exhaust manifold spacer washers, Black phos or Cad?

Thanks John, I might one day get stuck Judging one of those 'newer' cars. When did the engine plant start painting without the exhaust manifolds?
Dan

[Scott S.]

Re: Small block exhaust manifold spacer washers, Black phos or Cad?

Scott, (my comments are based upon a 64 C2, but think it was the same up to 67)

So first double check your AIM. Look in the radio section on shielding, you may find that all the exhaust manifold bolts use that washer. As for the finish, these are painted orange along with the exhaust manifold and once heated the orange will turn a black. So if you want to plate them some form of a black that should be fine.

Alan,

The 1967 AIM (U69-A7) and 1964 AIM (U69-9) both designate these spacer washers as "Existing Washers", and show four on the LH exhaust manifold, only on the outer or 'end' bolts.

[Scott S.]

Re: Small block exhaust manifold spacer washers, Black phos or Cad?

Scott ,all that I have seen are blackish, as are mine

Thanks Craig. From the various replies, it seems that for 1963-64 these spacer washers would have been painted with the engine, and then discolored by engine heat with time.

For 1965-67, if I understand correctly, the exhaust manifolds on small blocks were not mounted at the time of engine paint, so the exhaust manifolds and associated fasteners should not show orange paint, but should have whatever finish GM Engineering determined they would have.

For 1967, according to both the '67 JG and Craig's car, the finish seems to have been black phosphate (or black oxide). If anyone's car has something other than black for the spacer washers on a small block from 1965-67, please do post the information.

Thanks to all for the replies,
Scott

[Gerard F.]

Re: Small block exhaust manifold spacer washers, Black phos or Cad?

Thanks Craig. From the various replies, it seems that for 1963-64 these spacer washers would have been painted with the engine, and then discolored by engine heat with time.

For 1965-67, if I understand correctly, the exhaust manifolds on small blocks were not mounted at the time of engine paint, so the exhaust manifolds and associated fasteners should not show orange paint, but should have whatever finish GM Engineering determined they would have.

For 1967, according to both the '67 JG and Craig's car, the finish seems to have been black phosphate (or black oxide). If anyone's car has something other than black for the spacer washers on a small block from 1965-67, please do post the information.

Thanks to all for the replies,
Scott

Scott,

Here is an exception on my 67 327/300 June 29 67. No spacer washers at all, as well as no french locks. Whether it was a late production change in 67, or some production experiment, my original engine came with special exhaust manifold bolts with an intergral washer head and self locking threads which obviated the use of french locks.

On the one I removed, it has the remnants of black phosphate among the rust. Here's a few pictures:








Here it is cleaned up, notice the funny threads:




From previous threads on the subject, I am not the only one with this anomoly on a 67 S/B 300, but I think most were very late production.

[Michael H.]

Re: Small block exhaust manifold spacer washers, Black phos or Cad?

Are the 1/8" thick spacer washers that are used with the four outer/end bolts on each exhaust manifold natural, Cad (or zinc), or Black phosphate? The 1966 JG is not specific, while the older 1967 JG says they're plated black.

What finish is correct for these spacer washers on a 1967 small block?

I think the spacer/washer was natural, unplated.

I've never found a part number for that washer but I have several near new ones in my misc bolt/nut box that were removed from brand new cars back in the 60's.

[Ronald L.]

Re: Small block exhaust manifold spacer washers, Black phos or Cad?

Michael,
Do you have ab ID.OD on these?

[Michael H.]

Re: Small block exhaust manifold spacer washers, Black phos or Cad?

Michael,
Do you have ab ID.OD on these?

Ronald,

I don't have one handy to measure but if no one else has one laying around, I can try to find them.

[John H.]

Re: Small block exhaust manifold spacer washers, Black phos or Cad?

Do you have ab ID.OD on these?

Ron -

I.D. measures .400", O.D. measures .735".