63 exhaust manifold french locks?

[Rob M.]

Hi all,

I'm building up my engine for my 63 FI car and while putting the exhaust manifolds on I was wondering if these should be fitted with French locks. The TJM is stating this but I have a series of pictures of a very authentic engine I once found on e-Bay and this is not using French locks (only washers).

Who's right, who's wrong???

Aonther thing I'm puzzled about is the TJM stating the exhaust manifold shouldn't have holes in the exhaust manifold for the choke heat tubes while this engine clearly has the choke tube going into the exhaust manifold???

Note: for those who are interested, I have many more pictures of this engine...

regards,
Rob.

[Jack H.]

Re: 63 exhaust manifold french locks?

Pictures shown are of a USED engine and NOT one factory fresh from Flint... If the exhaust manifolds were ever removed (whatever reason), it's rather common for mechanics to have taken off and discarded the factory original French locks. They were intended to be installed once and not re-used...

Also, we visually ID exhaust manifolds based on their casting number since the actual GM final PN appears nowhere on the part. After casting, secondary operations (drill, tap, mill, Etc.) took a given cast number (XYZ) from a raw casting to a finished GM PN.

My experience tells me there WERE two different versions of certain exhaust manifolds with the same common cast number. One with provision for the fresh air tube used to speed the warm up process of carb based engines and another without the fresh air tube. Of course, the later version of the part is harder to find because of its limited use...

My advice is to go with the descriptive text of the JG book, Rob...

[Rob M.]

Re: 63 exhaust manifold french locks?

Ok, but how were the french locks fitted icw the ignition shielding (under the bracket or over it) and if under what purpase has the french lock then)?

Secondly, if the exhaust manifold hasn't got holes how was the choke then measuring the engine temperature?

regards,
Rob

[Edward J.]

Re: 63 exhaust manifold french locks?

Rob, I think the french locks have to go on the outide of bolt so they can be secured with the tangs bent over.

[John H.]

Re: 63 exhaust manifold french locks?

Ok, but how were the french locks fitted icw the ignition shielding (under the bracket or over it) and if under what purpase has the french lock then)?

Secondly, if the exhaust manifold hasn't got holes how was the choke then measuring the engine temperature?

regards,
Rob

Rob -

The french locks were used - they go under the bolt head (between the bolt head and the bracket) so the tab can be bent against one flat on the hex on the bolt head.

The description in the JG is poorly worded for the choke heat tube hole; what it means is that the manifold on the passenger side on an F.I. engine (3797902) should NOT have a hole drilled in it for the choke heat tube. That same manifold casting number was used on the passenger side on carbureted engines WITH a hole drilled for the choke heat tube (same casting, machined differently depending on its application).

[Alan D.]

Re: 63 exhaust manifold french locks?

Rob,
For 64 (check for 63) the bolt at #5 cylinder which holds the warm air bracket for the tube going into air meter area should be a stud, 3814568. It then uses the washer and nut - same pn as the fuel filter. Just found such out from these guys during an exhaust bolt thread.

If you verify 63 is the same then it would appear the exhaust manifolds have been off. Alan

[Jack H.]

Re: 63 exhaust manifold french locks?

Since the plug/wire shields result from the radio option, flip your copy of the AIM book to back, UPC, U69, and you'll see the assy stack-up nicely defined for bolts, French lock, sheild brackets, washers...

Others beat me to the punch on the issue of the FI vs. non-FI RH exhaust manifold. But, they gave you the correct info (two versions of the finished part using the same manifold cast number)!

[John D.]

Re: 63 exhaust manifold french locks?

Rob, As far as the LH exhaust manifold once in a while you might see one from a passenger car that does not have the hole for the choke tube.

Now with these posts I am sure you realize that on a 63 to 65 FI car there definitely should be a choke tube hole. Here is where you have to be careful. Seems that my FI customers don't pay attention to this detail enough.
You may want to replace the heat tube going thru the LH exhaust manifold as so often this tube is rusted out. Thereby permitting tons of carbon and soot to really clog up the choke housing. Then the choke operation fails. Then it's my fault. You haven't lived until at a show when someone complains their choke doesn't work and you take off the choke cover and it's full of carbon.
Story: I think the quilty person checks in this forum once in a while. One time "he" brought his FI unit back to me at Knoxville and said choke doesn't work. Well I took the 63 choke cover off and about screamed. In fact I did. The thing was packed full of carbon.
Used zippo lighter fluid and a box of q-tips trying to get it clean at the show as didn't have squat to clean it otherwise.
The repro catalogs have a nice SS heat tube. Buy it for sure. John

[Michael H.]

Re: 63 exhaust manifold french locks?

Ok, but how were the french locks fitted icw the ignition shielding (under the bracket or over it) and if under what purpase has the french lock then)?


regards,
Rob

Rob,

As others have stated, the manifold bolts at the four end cyl's have lock straps.

Although there are two lock tabs per bolt, only ONE would be bent to contact a flat on the bolt head.

The bolts, washers and straps would be painted orange along with the manifold. The radio shielding brackets would not be painted though.

The fuel injection unit in your pic appears to be very early 63 production. Probably from an October/November 62 built car?

[Gerald C.]

Re: 63 exhaust manifold french locks?

Question on these tabs...How do you bend them over without too much effort and I see from this thread that onlt one of the tabs need to be bent over, correct?

Thanks

[Michael G.]

Re: 63 exhaust manifold french locks?

I'm sure there are other ways, but I just bend them slightly with a chisel, then finish the job with pliers...

[Terry M.]

Re: 63 exhaust manifold french locks?

Question on these tabs...How do you bend them over without too much effort and I see from this thread that onlt one of the tabs need to be bent over, correct?

Thanks

The workers at Flint Engine used a pair of pliers to bend one of the tabs over. I didn't get a good enough look to see if the jaw(s) of the pliers were modified in any way. I wouldn't be surprised that some modification was done to better grab the tab.