Rear Transmission Mount spacer

[PatO]

Boy, I need some help to see if I'm thinking right. . . . . 

I've spent 2 days fussing with my fan / shroud / radiator  setup on my 340 small block in a 72 Challenger.    Basically the snout of the water pump is pointing at a spot about 2" too high on the radiator.  I have a new OER 26" radiator installed, which fit close but not great, that appears to be correct for the car. The left/right offset is pretty close, but the center of the water pump and the center of the fan is about 8" from the top of the core and 10" from the bottom of the core.  I raised the radiator about 3/4" of an inch and adjusted the shroud mounting points another 1/4". That would work as long as I didn't use a radiator cap! Or, I could just leave the hood off.  Put the radiator back in it's original position. the top of the radiator is about 1 1/2" above the radiator frame which seems to be what I can find on the internet. Comparing lots of pictures this seems correct. I have a 18" fan thanx to SCHU.  It SHOULD work.

So, what else is affecting this?  I double and triple checked the motor mounts. All new, appears to be the correct part numbers and matches pics on the internet and service manual illustrations.  So I go to the rear transmission mount/cross member setup.  OK here's something I think. Do I have the wrong bracket?  Looking at the service manual I see a reference to spacers in addition to the mounting bolts although the illustration seems to be be incorrect, in that the spacer would need to go between the bracket and the mounting point on the transmission  instead of between the bolt and the bracket.  There were no spacers on the bracket when I took it apart.

Am I on the right path questioning if I have the right bracket or if the missing spacers would raise the tail of the transmission and tilt the front of the engine down a bit?  How thick are the spacers?   Any suggestions would be really appreciated!

[PatO]

I'm not sure I'm on the right track . . .  to get a couple of inches at the front of the engine, I'd need to raise the rear of the transmission by 3" or more, no room for that.

[70 Challenger Lover]

I don't have a lot of experience with small blocks and most of my projects have been 71 and earlier so not sure if there is something unique with a 72 small block car.

I seem to recall that my fan is more like 17" but I could be wrong. It is also my recollection that the fan never seems to be centered in the shroud. In fact, I recall the big block shrouds have very large openings and I have always wondered just how effective a shroud really is when the fan is significantly smaller and also off center. As far as the transmission, I'd be hesitant to raise of lower it since it affects the angle of the drive shaft.

I'm wondering if it is something related to motor mounts. I say this because I helped a friend with an A body engine swap (6 cylinder to small v-8). He used Schumacher conversion mounts and they would not sit low enough. In the end, we had to slightly modify the mounts so that we could get the engine to sit lower (in the correct spot). Once we did that, everything worked out beautifully.

[Chryco Psycho]

I agree , the engine mount is near the front wall of the block while the trans mount is 3' back so to lower the fan 2" you need more like 8" at the rear , so something has to be not right at the front of the engine , first thing would be aftermarket mount rubber isolators as I have seen them too thick & it will raise the engine but not 2" , wrong mount brackets but you checked that , K frame modified ??

[PatO]

Yes, there is no way to adjust the rear mount enough.  Stock K frame.  I know it has to be in the motor mounts and I think I have an idea . . . . .   Will report back later today   

[RUNCHARGER]

The trans mount actually is designed to be shimmed, not re-engineered however.

[1 Wild R/T]

I just went & took measurements off my car, the correct fan is a #216 it is 18-18.5 inches to get a better measurement I would need to remove it & that ain't happening...  The fan clears the top of the shroud by 1/2" it clears the sides by 3/4" & it clears the bottom by 1.5"... The shroud is designed so it extends nearly to the top of the upper radiator tank but doesn't extend down onto the lower tank more than 3/4"....

So unless your fan is above the radiator top tank chances are it's close to normal...

[Rich G.]

If you start raising the trans up you'll be changing the driveline angle and might create a different problem

[PatO]

OK, thank you for the responses. 

I did a few thinks to day. Basically I spend a few hours fussing with my engine mounts. I loosened them up a bit and jostled the engine back down a couple of times.  checked the biscuits on the mounts, they are 1" thick which seem right.

OK, now what.  Then I remembered that the instructions for my TTI headers had some dimensions for verification.  Center line of crank is 5 1/4" to top of K frame. I measured 5 1/8", so the engine definitely not to high.  OK - back to square 1.

Service manual says an 18" 7 blade fan. Check.  I have the original radiator shroud with the correct part number. Check. it has the correct left to right offset. The diameter of the opening is 20". The shroud seems to sit a bit low on the radiator.  I re drilled some new holes and moved the shroud up a bit on the mounting tabs. Fan now has a little less than 1/2" clearance  at the top and the sides are even.

Came in and hopped on the website and  saw that 1 Wild RT had posted his measurements!  Thanx and thanx again  1 Wild RT.  I guess I don't understand the why of how some things are, just that that's the way these parts come together.  Have everything centered? I guess not.  anyhow, I'm done for the evening, I'll work on it again tomorrow evening, center up some new holes just a touch higher, trim the shroud a bit so it fits tighter and mount the fan.

Again, I much appreciate this board and the people on it who take time to help with their advice.. 

[1 Wild R/T]

Glad things are looking up..   And happy to help.. As we all are..