1965 396 Clutch inspection plate bolts ??

[Bill C.]

1965 396 clutch inspection plate bolts, what is correct slotted screws or hex bolts? I have had judges deduct slotted screws at one Regional event and at the next Regional deduct for hex bolts.
Thanks,Bill

[Clem Z.]

Re: 1965 396 Clutch inspection plate bolts ??

slot your hex head bolts and you will be good both way.

[Wayne M.]

Re: 1965 396 Clutch inspection plate bolts ??

Here's my 2 bits.

Since (per the AIM) the clutch inspection cover was installed where the engine was assembled (Flint for SB's and Tonawanda for BB's), and the cover was the same part for both type of motors, there's the possibility that bolts installed differ from one location to the other.

The '65 TIM&JG does not differentiate, claiming recessed hex head bolts for all.

[Carl N.]

Re: 1965 396 Clutch inspection plate bolts ??

Recessed Hex Head on all I'v ever seen which do not appear to have been apart, but slotted could have been used

I would be suprised if very many with more than 10K miles on them still have the original clutch Ass'y so most hve been subject to at least one change out at some point in time.

[Joe L.]

Re: 1965 396 Clutch inspection plate bolts ??

All-------


I think that by 1965 the hex head screws had replaced any slotted screws used on engine assemblies or components thereof except for the waterpump backing plate and the oil pump cover.

Except for the waterpump backing plate I've never understood why slotted screws were EVER used. In the case of the waterpump backing plate, the slotted screws result in a slightly lower profile which helps avoid interference between the screws and the timing cover. In all other cases it would seem to me that the slotted screws would just complicate assembly operations.

Curiously, the slotted screws were used for the oil pump cover into the 70's. That has always mystified me.

[Joe R.]

Re: 1965 396 Clutch inspection plate bolts ??

Joe,

You would not be mystified if you were GM and had 10,000 bolts you had ordered and had no place to put them. Now what would you do? You would stick them in any hole you could find. And that is just what the GM workers did until they reached the bottom of the barrel!

That be the rest of the story!

JR

[Wayne M.]

Re: 1965 396 Clutch inspection plate bolts ??

....I think that by 1965 the hex head screws had replaced any slotted screws used on engine assemblies or components thereof except for the waterpump backing plate and the oil pump cover......

Here's the "pan-head" style slotted screws (with captured star washer) used on early (?) 396 water pumps. Note the perfectly flat backing plate, not the "stamped" plate called for in the '65 TIM&JG, if my understanding of the term is correct. This 3856284 pump is cast E_5_5 (May 5th, 1965). The '65 guide calls for these screws on BB, but recessed hex's on the SB pumps. (different assembly source ?).



m

[Joe L.]

Re: 1965 396 Clutch inspection plate bolts ??

Here's the "pan-head" style slotted screws (with captured star washer) used on early (?) 396 water pumps. Note the perfectly flat backing plate, not the "stamped" plate called for in the '65 TIM&JG, if my understanding of the term is correct. This 3856284 pump is cast E_5_5 (May 5th, 1965). The '65 guide calls for these screws on BB, but recessed hex's on the SB pumps. (different assembly source ?).



m

Wayne------


Yes, there was a different assembly source for the small block and big block pumps------Flint and Tonawanda. During the period when the engines were in PRODUCTION, the water pumps, both PRODUCTION and SERVICE, were actually machined and assembled at the respective engine plants. Of course, Tonawanda also manufactured small blocks although basically none for Corvettes.

The slotted pan head screws continued to be used for awhile on the big block pumps after the pumps went to the later style backing plate during the 1966 model year.

Chevrolet finally solved the interference problem between the backing plate/backing plate screws and the timing cover in 1969 when the went to the "long leg" style waterpumps for most small block and big blocks. However, Corvette was not one of the applications that got the new style waterpumps. It was one of the few exceptions, along with some MD/HD trucks.