Motor Mount Numbers Question

MBW65K_old · February 10, 2009 at 4:51 PM

Hey all.. Picked up the new fastback from Boulder last weekend. It has a few little issues, but overall it seems to be a pretty tight Kar. Hopefully somebody here can shed some light on the first issue I've come across. Upon closer inspection to find an annoying squeak when the Kar is idling, I found that the bottom of the exhaust manifold is in contact with the top of the motor mount on the left side only. I'm pretty sure it's not the original block, but is has the correct hipo manifolds (header style). The engine sits nice and level and there seems to be the correct amount of clearance between the exhaust and the clutch linkage and everything else lines up nicely. It looks like the manifold actually has a divit cast into it to clear the mount, but it's making fairly heave contact with the top end of the metal plate right in that spot. I'm guessing the mounts (or just the left mount) is incorrect. The numbers on the mounts are as follows (at least as best as I could make out under limited lighting):

Right - C30A 6A080-B

Left - C30A 6C041-B

I would love to hear any thoughts on both what these mounts were for and ideas on how to solve the clearance issue.

C6ZZKGT · February 11, 2009 at 9:10 AM Official Post

Congratulations on your new Kar, Marshall. It is unclear to me as to what part of the mount is actually hitting your exhaust manifold. After looking at one of my Kars that has 65 style HIPO mounts it seems most likely that your manifold is hitting on the cast iron part. The first things to know about the cast portions of your mounts is that they are standard and not Hipo mounts. I know that it is tough to see the numbers sometimes however your numbers are actually C3DA 6A030 B and C3DA 6C041 B. Note the C3DA rather than the C3OA prefix to the numbers. If you recheck the numbers on your cast brackets, you will be able to see this. The correct HIPO cast brackets have C4ZA numbers. Regardless of having the wrong mount assemblies, the manifold will still not hit on the cast bracket unless the rubber part on the mount has sagged from time. If you had the correct HIPO upper parts of the mounts, your engine would be stting one inch too high as the C4ZA brackets have a lower saddle to accomodate the complex HIPO upper mount assemblies and your problem would be in the opposite direction. This means that you definitely have standard mounts. The rest of the standard mounts that you have are pretty straight forward as there are only two other pieces per side. You will have a stamped steel angle bracket that has a stud sticking down through the cast bracket with a washer and nut on it. The upper part that attaches directly to the block, has a large rubber block molded to it and another stud that attaches this part to the stamped steel bracket with a washer and nut. The problem is with the rubber block as they tend to sag over time. They start off very square in the beginning and become more of a parallelogram over time. This effectively lowers the engine block closer to the cast frame mount. Usually the first sign of the motor getting lower is the fan hitting the shroud. There are two ways to correct this problem if you are going to continue using standard mounts. One is to replace the rubber mount assemblies with Ford only replacements. The reason that I state Ford only is that, in my experience, the aftermarket mounts have a softer rubber and sag some at the moment you put the engines weight on them. I had occasion at one time to be out of one side of genuine Ford mounts so I used a GYPO, non Ford as known in the Ford parts business, mount on the other side. I ended up with the engine noticeably leaning to one side as I set the engine back down on the mounts. The other correction if you do not wish to buy mounts is to use flat washers between the mounts and the block where the bolts go through and the bolts will hold them in place. This will help to compensate for the mount sag. Of course the correct HIPO mount assemblies would also be good to install at this time however they are tough to come by these days and command some pretty good prices. The rubber blocks on the HIPO monnts can also sag creating a similar problem but it takes a lot longer to show up as they are much beefier.

-Fred-

cobraboy · February 11, 2009 at 11:16 AM

<BLOCKQUOTE id=quote><font size=1 face="Verdana" id=quote>quote:<hr height=1 noshade id=quote>

Congratulations on your new Kar, Marshall. It is unclear to me as to what part of the mount is actually hitting your exhaust manifold. After looking at one of my Kars that has 65 style HIPO mounts it seems most likely that your manifold is hitting on the cast iron part. The first things to know about the cast portions of your mounts is that they are standard and not Hipo mounts. I know that it is tough to see the numbers sometimes however your numbers are actually C3DA 6A030 B and C3DA 6C041 B. Note the C3DA rather than the C3OA prefix to the numbers. If you recheck the numbers on your cast brackets, you will be able to see this. The correct HIPO cast brackets have C4ZA numbers. Regardless of having the wrong mount assemblies, the manifold will still not hit on the cast bracket unless the rubber part on the mount has sagged from time. If you had the correct HIPO upper parts of the mounts, your engine would be stting one inch too high as the C4ZA brackets have a lower saddle to accomodate the complex HIPO upper mount assemblies and your problem would be in the opposite direction. This means that you definitely have standard mounts. The rest of the standard mounts that you have are pretty straight forward as there are only two other pieces per side. You will have a stamped steel angle bracket that has a stud sticking down through the cast bracket with a washer and nut on it. The upper part that attaches directly to the block, has a large rubber block molded to it and another stud that attaches this part to the stamped steel bracket with a washer and nut. The problem is with the rubber block as they tend to sag over time. They start off very square in the beginning and become more of a parallelogram over time. This effectively lowers the engine block closer to the cast frame mount. Usually the first sign of the motor getting lower is the fan hitting the shroud. There are two ways to correct this problem if you are going to continue using standard mounts. One is to replace the rubber mount assemblies with Ford only replacements. The reason that I state Ford only is that, in my experience, the aftermarket mounts have a softer rubber and sag some at the moment you put the engines weight on them. I had occasion at one time to be out of one side of genuine Ford mounts so I used a GYPO, non Ford as known in the Ford parts business, mount on the other side. I ended up with the engine noticeably leaning to one side as I set the engine back down on the mounts. The other correction if you do not wish to buy mounts is to use flat washers between the mounts and the block where the bolts go through and the bolts will hold them in place. This will help to compensate for the mount sag. Of course the correct HIPO mount assemblies would also be good to install at this time however they are tough to come by these days and command some pretty good prices. The rubber blocks on the HIPO monnts can also sag creating a similar problem but it takes a lot longer to show up as they are much beefier.

-Fred-

Fred are you saying if a kar is fitted with standard cast lower mounts and HiPo upper mounts that the engine will be too high? What will be the consequence of this? will the aircleaner contact the hood or will there be other problems?

MBW65K_old · February 11, 2009 at 5:54 PM

Thanks for the input Fred... I was pretty sure the mounts are not original. I seems odd that left side would be sagging so much that the manifold is touching the frame mounted portion of the mount, yet the right side still has at least 1/2" clearance while the engine is sitting dead level in the car. I'll take a couple of photos later today and you can see what I mean. Regardless of that fact, I would like to put some original mounts back in, but I've heard they sell for $1500 plus, and since I'm not planning a concours resto, I'm wondering if there are repops available in the original style, and if so, should they be considered, or are they junk...? I'd also like to know what part numbers other people are using with success. I know most of the motor mount from that era were interchangable, (I once bolted a late 60s vintage 302 into a 58 Ford truck using the same mounts from the late 70s vintage 460 that had been there), but I'm sure there are nuances between different part numbers and some may work better than others for different applications.

MBW65K_old · February 11, 2009 at 5:56 PM

Hey Mark, has your Kar arrived?

cobraboy · February 11, 2009 at 6:09 PM

No Not yet, but I am doing a good impression of a magpie at the moment - picking up anything shiney <img src=images/icon_smile.gif border=0 align=middle>. It cant be far away can it ? how big is this pond anyway ?

MBW65K_old · February 11, 2009 at 8:31 PM

Okay, so I had another look at the mounts and the left one, which where the problem is, is completely different than the right one. In fact the right one looks just like Fred described, with the square piece of rubber that is sqaushing down and actualy starting to seperate from the steel on the block side. However, there is plenty of clearance on this side. The left one has more of a trianglular shaped piece of rubber with the steel on the block side wrapping over the top, and the frame side is much larger. It is on this side where the manifold is sitting right on the steel of the frame side of the mount. I took some photos, but idon't have time to download them right now. Regardless, it looks like I'll be shopping for new mounts for both sides... Assuming I don't have the $$$ for an original set, what should I be looking for.

wlewis_old · February 12, 2009 at 10:09 AM

I have a similar motor mount problem. See my "Exhaust manifold" post below this one. Since I couldn't find parts for the original type, I ordered a set of Ron Morris aftermarket mounts. They're installed now, but not adjusted because tranny is out of car and I'm waiting to get it back from rebuild shop. Hopefully, they will work.

Walter

C6ZZKGT · February 12, 2009 at 1:21 PM Official Post

Marshall, If you send me pictures I can diagnose where you need to go from here. You can most likely fix this by just replacing the mounts that bolt to the block with Ford pieces. There is no reason for the manifold to hit with standard mounts if they are in good condition. I have NOS Ford ones in stock if you need them. I just sent you a PM on this.

-Fred-

MBW65K_old · February 12, 2009 at 9:34 PM

thanks Fred... I sent you an email.

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