I recently had my engine rebuilt (66 442) and recently removed the carbs to have them rebuilt. When the engine installer assembled the carbs back onto the manifold, he used a slightly different gasket on the center carb, where there is a gap between the bores. I'm planning to reuse these gaskets since they are still new. Is there any significance in the oddball gasket?

 

The center carb is different than the end carbs. For one thing the throttle plates are smaller.
I would advise you not to re-use these gaskets after a carb has been torqued on them, and they are compressed.
You are just inviting a vacuum leak. Gaskets are cheap.

 

The center carb and end carbs all have a 1-5/8" base bore diameter. The center carb is !-3/16 venturi and the ends are 1-5/16 venturi. The center carb throttle plates are thinner than the end carbs. You need to find a new mechanic,the gaskets are on the intake backwards. I also sell new block off valves if you want to make it correct and get rid of those plates.

 

Thanks. Any idea where I can find a set of gaskets?

 

Do you sell the gaskets? Or know where I can get them? Also, I’m not familiar with block off valves. I’m guessing the plates you’re referring to are on either side of the center on the intake. The mechanic who installed the carbs does mostly Mopars. I wouldn’t know the difference whether the gaskets on backwards or not but the carbs seemed to run normal until a float apparently stuck (gas coming from the accelerator pump section).

 

Felpro makes a nice thick gasket. I'll have to find the part #. Yes the block off plugs/valves go where the plates are. I have very nice reproduction of them.

 

I certainly dont pretend to be an Olds expert in any way and please correct me if this is wrong but . . . . both the Fel Pro catalog and the GM parts catalog show the same gasket part number for all three gaskets ? The Fel Pro number is 60113 and the old GM number is 578912 Both say quantity "as required"

 

What is the function of the plugs/ valves?

 

While you are getting the correct Tri-carb parts, check for the tri-carb specific bell crank on the firewall. In my experience with two 66 tri carb cars, the whole throttle assembly needs to be removed from the firewall for maintenance.

Also, in post #, I see a silver throttle return spring on the driver's side. Does your rebuild have 2 return springs on the passenger sides of the outer carbs?

 

No return springs on the passenger side, just linkage. I've had no issues with the throttle assembly from the firewall.

 

I can clearly see the back carb return spring on the passenger side. The front one may be there, but I just cannot see it. Ask Mike, but I do not recall seeing a driver's side return spring on an Olds Tri- carb. (There is the green on the firewall linkage)

If you want it to work correctly, verify the bell crank is correct and not the shorter one used for a 4 barrel. Wear will likely be in the assembly. You will see it after disassembly.

If that is Teflon tape on the fuel line fitting at the passenger side block, get rid of that.

Mike can help with the correct parts.

As a fellow aircraft pilot, I am just trying to assist you before re-assembly. Now is the time to do these things.




see the green spring on the firewall linkage assembly

 

That is correct. I failed to respond to his question about if all 3 gaskets are the same.

 

The only throttle return spring in on the firewall mechanism. The end carbs have springs that close the throttle plates. It does have the correct tri carb bellcrank on the firewall mechanism. You are absolutely correct about the tape on a flared fitting. I never use tape even on pipe fittings. I use teflon plumbers putty or Gasahol pipe thread sealer.

 

The block off plugs/valves are made so they can be rotated to allow hot exhaust air to the crossover passage so the choke stat can work correctly. They can be turned or rotated to block the hot exhaust air from the crossover passage for a cooler air charge for performance. The original thought is to run them in the open position on the way to the track and turned/closed for performance. I sell the pair for $119 shipped. They just look better and make the car more correct than the homemade plates you now have.

 

Thanks Mike. I wondered what those plates were for. I'm not so concerned with originality or performance. I just want the car to run well.

 

Thanks for all the advice on fittings, springs, etc. I will definitely fix those things when I get the carbs back from the shop. I will check on the throttle spring / firewall linkage when I get to the car later today. This engine has obviously had a lot of small mods done to it over the years and you guys know a lot more than me what is correct. I really appreciate your input.

 

Here is what I have. Looks like the same firewall bracket but missing a piece ? Mine has no green spring - the only throttle return spring on my setup is attached to the center carb linkage and engine hoist hook. Does my firewall bracket look like something from a Q-Jet setup or is it the correct one for tri-carb?

 

Here are the (removed) gaskets. I assume that the Fel -Pro 60111 will work on all three carb bases. Available at Auto Zone. O'Reilly, Amazon, etc. have a Walker 15407C kit that has the gasket (with the gap) but it apparently only comes with the whole carb gasket kit.

https://www.oreillyauto.com/detail/c...it/wlk0/15407c

 

Can't see that green return spring? I'm 73 & blind & I can see it. LOL

 

The correct Fel Pro gaskets are 60113, not 60111. You can also use Victor Reinz # G25452 that is equal to the Fel Pro's.
https://www.ebay.com/itm/27347641440...Bk9SR4KfnJbIZQ

 

Actually 60113 Fel Pro. As mentioned above in a couple of replies all three gaskets are supposed to be the same in 66. If you are having the carbs rebuilt the rebuilder will probably send you gaskets back with the carbs. I would wait until you get them back before wasting money on gaskets.

 

Is this the correct bracket for a tri carb? Even if not, the throttle has been working normally as far as I can tell.

 

I just noticed you posted pictures of 2 different firewall throttle mechanisms. One has the correct tri carb bellcrank and one has a 4 barrel bellcrank. The one with the correct tri carb bell crank has the green return spring. Which one is on your car?. Look back in post #17 and you can see the 2 different bellcrank picture you posted. Again, there is only one throttle return spring on a 66/67 firewall mechanism. Even the Q-Jets in 66/67 only had the firewall throttle mechanism return springs. The tri carb end carbs have springs on the secondary rod arms on the passenger side to close the throttle plates. Here's a picture of the 66/67 firewall mechanism from the PIM/Assembly.

 

Thanks!

 

Tri-Carb posted pics of the correct one. Mine appears to have the Q Jet one. Most likely sometime in the life of this car, someone converted to the Tri power setup, maybe even the dealer? Anyway, it all seems to work well with the way it’s setup now.

 

I see now what you did. You quoted Tri Carb and inserted a picture of your mechanism. The thing about using a 4 barrel bellcrank is that it's shorter and may not give the travel needed to open the center carb to wide open throttle when needed. I've seen this many times and you just have to check to make sure it's working or not.

 

Are there any repro tri carb bellcranks available anywhere? I'm sure trying to find an original is likely impossible.

 

Not that it helps you but I had 50 repo's and they are all gone. I have one original that I'm keeping. I might can help find one from a couple of guys.

 

A good welder could fabricate an extension for the 4 barrel bellcrank. It is unfortunate that Mike doesn't have more of them--his reproductions have always been excellent. You should get a pair of the heat riser block offs while he still has some, for example.