Engine mount orientation

[CalgaryChris]

I put on a set of new mounts from summit. I tried dropping the motor in today and found the  little tabs on the crossmember mounts hit the new ones. Do I have the original ones on the crossmember upside down? Or are the new ones incorrect? The block mounts can only be mounted one way. Thanks

 

[rackerm]

You did not indicate what year car or what size engine. Your frame mount orientation is correct and look to be 71-72 mounts since they have a tab. 73 frame mounts do not have that tab. Its hard to tell from the sideways picture but your motor mounts are the captive type used only in 73 and up so they would not be right for a 71-72 car. My 73 convertible with small block mounts does not have a tab. There has been plenty of posts about the difference between 71-72 and 73 frame and motor mounts, as well as, the difference between mounts for convertibles and coupes/fastbacks. The short answer is 73 frame mounts are shorter and do not work with the readily available 71/72 motor mounts. I suspect the same to be true with 71-72 frame mounts and 73 captive motor mounts, which is why Ford shorten the 73 frame mounts and eliminated the tab so they would maintain the correct engine height and clear the newly designed captive motor mounts. Vendors incorrectly state their motor mounts are for 71-73, but they are wrong. look for the post on the topic... https://www.7173mustangs.com/thread-fan-shroud--31440?highlight=perch

Here is a picture of my stock 73 vert frame mount and motor. I used OEM motor mounts (not aftermarket).

 

[CalgaryChris]

Thanks for the reply. I usually only search titles but will have to start digging deeper before asking questions already answered. The car is a 71fb. 351C Will see what I can do today. Considering just grinding off tabs but not positive that will give the desired results

 

[Stanglover]

From checking out Chris's pictures, his car is a 72 I believe. He didn't seem to mention that, but it ain't a 73 for sure.

If the engine is a 72 351C, the mounts he'll need are the ones pictured top right in rackerm's post above.  He can get these pretty cheap, and that worries me!! I bought a set from Rock Auto for next to nothing. They were made in India. The problem was the top mating tabs were NOT flat, but otherwise looked okay. With a bit of flattening of the tabs, I think they would work. I ended up reusing my original ones, so far no problems. Also, on the drivers side, there is a heat insulator plate that goes between the block and the mount. I don't have a pic of that unfortunately.

Maybe Chris can verify exactly what he has and an update on progress overall would be a very nice touch. Looks like it's going to be quite the car when it's done.

Geoff.

I see Chris was writing at the same time as me, Ok it's a 71, not 72

 

[rackerm]

Thanks for the reply. I usually only search titles but will have to start digging deeper before asking questions already answered. The car is a 71fb. 351C Will see what I can do today. Considering just grinding off tabs but not positive that will give the desired results

Removing the tab may allow them to bolt together, but keep in mind the 71-72 vs 73 frame mounts have a difference in height and angle, so make sure you have 71-72 motor mounts to match your 71 frame mount otherwise the engine height will be affected.

 

[CalgaryChris]

I reset and tried again today. Went together as it should. It does potentially look higher but I have not done any measurements to verify yes or no.





These are the mounts.

https://www.summitracing.com/int/parts/ptp-6-503-bl/overview/

 

[Stanglover]

THAT is going to one sweet ride when done. Nice to see someone taking there time and doing it right and what YOU want. What colour will it be?

The only reservation I might have is hood clearance. You may need to mock up the carb/air cleaner before you go too far. Just my thought and what I think I'd do. I don't know exactly what the difference is between the 73 height set-up and 71-72. I was under the impression that as the 73 had an EGR plate under the carb and all else being equal, the engine needed to be set lower to accommodate it. With 71-72 frame mounts, I'm thinking the engine might be 1/2" or so higher............... or I could be talking out the back of my head!! I'm sure the 73 guys will set the record straight.

Keep it up and keep us posted.

Geoff.

 

[delawarebill]

my question is are u going to use a rad shroud?? if so u may find out the fan won't fit and will hit the bottom of shroud. i learned the hard way and rackerm was hugh in getting me straight.. for me with my '73 f/b i wanted the '71-2 mounts and mixing frame and engine mount will not work when u put the shroud on. those clam shell's are pricey so u really need to make sure u have the '73 frame side too.

 

[Stanglover]

my question is are u going to use a rad shroud?? if so u may find out the fan won't fit and will hit the bottom of shroud. i learned the hard way and rackerm was hugh in getting me straight.. for me with my '73 f/b i wanted the '71-2 mounts and mixing frame and engine mount will not work when u put the shroud on. those clam shell's are pricey so u really need to make sure u have the '73 frame side too.

Or, it could be too high and  the fan hit the top of the shroud. It seems to me it's time for Chris to do some mock up work before going any further. Just my thought on it and what I'd do in that situation.

 

[boilermaster]

Been watching this thread, I am wanting to switch from 1971 fb mounts to the 73 fb captive mounts

for my 1971 fastback.

Have oem mounts and pads from a 1973 fastback motor mounts are in remarkably good condition, but would either have them refurbished or go with the poly mounts.

Have heard that some don't like the poly mounts (harshness/ drone/ vibration)

Have broken mounts in the past.

Boilermaster

 

[CalgaryChris]

So I measured the mounts and found no real difference, 3 1/2” for both old and new from top to center of bolt. If the snow ever quits here I will move it up to the shop and hopefully get the transmission and headers mounted up is weekend. Will definitely be checking hood clearance before I go much past that.

 

[EBSTANG]

I reset and tried again today. Went together as it should. It does potentially look higher but I have not done any measurements to verify yes or no.





These are the mounts.

https://www.summitracing.com/int/parts/ptp-6-503-bl/overview/

...on a side note, I see you have the TFS heads. The lower left accessory mount hole (driver side front/passenger side rear) is drilled all the way into the head. The other three holes, on this end of the head, are not. This tapping needs to be plugged/sealed or you will have an oil leak from it. Trust me, I know. It will be alot easier to effectively seal this threaded hole now before it has oil in it. Putting teflon tape on a straight (non-tapered) bolt will not stop it from leaking. Trust me. The other end of the heads (passenger side front/ driver side rear) do not have any tappings which go all the way through.

 

[CalgaryChris]

Thanks. Covering everything in a nice film of oil is not the way I want to begin.

 

[tony-muscle]

I put on a set of new mounts from summit. I tried dropping the motor in today and found the  little tabs on the crossmember mounts hit the new ones. Do I have the original ones on the crossmember upside down? Or are the new ones incorrect? The block mounts can only be mounted one way. Thanks

Those are the same Prothanes i bought. I still had the original ones and after comparing side by side they are almost identical. Maybe an 1/16" lower.

However, the instructions of the Prothane mounts say to trim or bend those tabs.





Edit: fixed pictures

 

[tony-muscle]

PS: i have a 71 and a fan shroud. I did not have any issues.

Sent from my SAMSUNG-SM-G930A using Tapatalk

 

[Stanglover]

Good to know it's going together as it should and the new mounts are the same as OEM for height.

From the pictures, the Prothane ones just look to be higher.

 

[73pony]

So if I am understanding the above information correctly, the Prothane mounts are the same size as the 71-72 mounts but the captive style like the 73?

 

[tony-muscle]

So if I am understanding the above information correctly, the Prothane mounts are the same size as the 71-72 mounts but the captive style like the 73?

Correct. That's the premise I am working under. Sorry the picture is upside down (edit: pictures fixed), but the distance between holes is almost identical. The width of the tab varies slightly which gives an impression of a larger dimensional change. I will try to installing both mounts on the crossmember and measure from a fixed point to get a more accurate reading.

 

[rackerm]

The 71-72 and 73 motor mount are different heights. As you can see from the picture below the holes in a 73 captive mount are 4 1/2" to bolt hole center and on the 71-72 (actually (68-72) the bolt hole is 4" to center. This is why the 73 hardtop small block frame mounts are a different height than the 71-72 hardtop small block frame mounts. Pictures below with Steve's comments from his earlier post.