AV8 question: Front crossmember/crank pulley clearance

Hey fellas, somethings got me questioning the safety of this setup. So, I have a couple of questions.....

In Bishop's book, he says to leave as much of the front crossmember as possible. However, running a long pulley on a 59ab comes very close to the front (I know I have build for my needs not follow the book exactly).

1. How much did you cut off/leave of your front cross member? If you don't leave a little bit of a lip, it sure doesn't look very substantial (I've been known to OVER build things, but I sure sleep good!)
2. You can't weld a heavy pc of steel on the sid the spring sets in, and you can't weld one on the side of the engine. Would it be better to order a repop one made of heavier guage steel?

I'm probably gonna have to cut it to where the red line is in my pic.

Some facts about my pics:
* my engine mouts will be flush with the top of the fram rails (they were just easier to c-clamp in from the bottom) it'll set about 3/4" higher
* engine mounts will probably be moved foward to touch the front cross member (like in the pic I stole from Bishop)
*my crank pulley was cut off so this 59AB could be run in a 33 sedan, I have a double pulley for it
*EDIT, I'm splitting my bones and making my own K-member, so I'm not fixed on that end...

 

I set mine up with the BT book also. My pulley almost touched the lip on my AA crossmember (I don't know if AA are different from reg A). I put a chalk mark on the outer cir***ference of the pulley on the crossmember and when I had the engine out I kinda freehanded a long "s" curve, offsetting about 1/2-3/4" to allow belt to come off easliy. I don't think my engine will be jumping around that much so I figured a bit over 1/2" was enough.

But maybe some guru will know better.

 

I cut off anything that got in the way of changing the fan belt.

THere's a spring bolt block with a ring as part of it that locates a hand crank on a stock A. it sits on the X member and the engine crank should be high (or low) enough to line up with that ring, also the corresponding hole in the radiator shell.
In my visual world of what looks right, the crank should line up with those parts even with an engine swap.
The only time it should be higher is if you're building a ground s****er and want the whole oil pan higher than the bottom of the frame rails, (like the Shifter's "Purple People Eater")
I don't think it looks right lower, ever.
Causes problems with carb leveling too.
I think that would put your engine's nose end about 3-4" higher and help a lot with your pulley and lower hose access problems.

 

Thanks for the help! There are some things you mentioned that I didn't consider...

I got a little wordy for only wanting to know something simple. If I cut off all of the lip on the A front crossmember, will the remaining pc. be able to support all the weight and especially if I hit a good chug hole?

If I cut where the red line is.....see pic.....

Thanks!!!

 

I wouldn't. I think that it too much material removed imo.

 

Chug hole= Pot hole...

Try to post the pic again, Nosurf, I'd like to see it....

Ayone else that cars to share a close up of the crank pulley/front crossmember, I'd greatly appreciate it!

Also, I'd like to leave enough room for a 8BA style engine. I have some threads saved that say you need the mounts back another 1 1/2" for the water pump pulleys to clear... this would fix the getting the belt on too!

 

I emailed you the pic.

Can't resize here at work.

Jay

 

Rather than just remove the trough at the rear of the crossmember, section it. Remove a 1-1/2 inch strip from the center of the trough and weld the lip back in place. That should give you the clearance needed to change the belt and peace of mind about the strength of the crossmember.

Mike

 

Your motor is not on rubber mounts, which you'll need to run anyway. Won't that move your pulley to a safe height without much more cutting?

Mike

 

My mounts are flat off the frame with stock rubber mounts and I did'nt have to trim that much. But what you have should be fine.

 

AV8's probably got the best advice, but perhaps this will help.

Measure the thickness of your front crossmember.
The aftermarket crossmembers are 3/16" thick and as you can see - sort of, almost, just barely - in the two pics below there ain't a whole heck of a lot to them.

(One pic shows an aluminum adjustable bracket used to set grill shell height sans radiator.)

 

I have some, they're just not in yet..... They'll give me about another 1" upward....

 

Ok, ok, I was focused on the pulley going foward as it is and not being high enough to clear the trough. Once I put my engine mounts flush with the top edge of the frame (as per the B/T book) and also insert my rubber engine mounts, the pulley may clear the "lip" of the cross member.

Let me take another look at it...

I hate to beat a dead horse, but I REALLY want this part right and safe! It seems like this is where everyone looks to inspect your fab skills.....

 

Is there any reason why you can't box the crossmember? If not, that's what I would do & then it would be stronger than stock even with the lip cut off.
~ Paul
aka "Tha Driver"

America - made in China!

 

If . . . big word there . . . the pulley almost, but not quite clears the rear edge of the crossmember what do you think about heating it and bending it into a nicely curved area that both clears the pulley and leaves the crossmember intact?

Be sure and leave some room for the cushions to compress after a while.
Seems like they always do.
Unless you use something like these.
(UHMW plastic fwiw.)

 

For $65.00 you can get a brand new crossmember thats gets you more clearance and is probably stronger.

 

Where?
I'll take one.

HotRob

 

Box the crossmember????


Mutt

 

You could box the crossmember, but it would be a ***** to fit the spring into it.

 

Thus the reason I asked if there were a reason he couldn't.
I know you think you understood what you thought I said, but I'm not sure you realise that what you heard is not what I meant.
~ Paul
aka "Tha Driver"

Easy on the Giggle Cream!

 

That's a good idea on the cusions....

A buddy stopped by and I had to go get my baby girl at her aunt's so I didn't get a whole lot farther.

I managed to cut more off and put my stock pulley back on.....and I got the fan ***embly all cleaned up and painted so it would be dry for when I get back to it all again. I have to play Mr. Mom tomorrow, so I won't get back on it until Thursday....

Thanks for all your help!

 

I've waited for the proper context in which to say this but I owe C9 an apology. When I first came on here he posted something about people needing to use spaces, paragraphs...nothing fancy, just something so the reader could follow it. I voiced my opposition to this. I know he was intending on making it easier for EVERYONE to read, not to critique someone's mastery of syntax and grammar.

So, and I don't want to beat a dead horse or open a can of worms, just wanted to extend that.

All of you arm-chair argument spe******ts, don't respond- don't waste Ryan's bandwidth....

Sorry.....

Now, let's get back to hotrodding!

EDIT: One more thing....what the heck are those, C9? Are those hockey pucks?

 

Pardon me, Paul. I'm just not clever enough to understand what you've so clearly expressed.

 

I have an a-bone front c-member in my 32 and for all practical purposes it is just a c-channel with a bend in the middle with no extra support anywhere.I would just trim a large curve out of it starting at the rearmost rivets around to the center and back to the rearmost rivets again.
On the other hand in your pics it sure looks like you should raise the motor a bit for hose clearance anyway.
T.OUT

 

What someone else said, install your motor mounts in the mock up stage. You'll find you have plenty room to change out a belt. Your motor is too low now.

 

I have to say, I personally reckon that it is very important to have the motor and box FULLY bolted into position for the final side of this, as until you pull it all down with bolts into its final resting postion you wont know how much clearance you really haveit can just save you headaches of adjusting later , or having to make spacers.

 

Hey Youngin,

The flange at the back of my front crossmember is about 3/8" all the way across. If I remember right I cut that down from stock a bit more in the center. It's kinda hard to see now since that's a busy area but it does still turn up. On my 8BA the rear pulley is centered right over it with just enough clearance to get the belt on/off easy. You will have some more clearance when you put the rubber pads under the motor mounts. I couldn't see the red line you were referring to in the picture. I'd think you could make it work where you have it cut and it'll still be strong enough......just dress it down and make it look purdy.

 

Some of the guys on here do use hockey pucks for cushions.
Pretty sure the first I heard about it was from the Canadians.
Which makes sense with all that hockey playing they do.

Anyhoo - the white plastic 'pucks' shown on the 32 are UHMW plastic.
UHMW stands for Ultra High Molecular Weight.
They're a sliding bearing in some cases from what I understand, but industry uses them in an impact situation.
Machinery slamming to a stop etc.
UHMW is 70% stronger than Teflon and aside from that you wouldn't really want to use Teflon for a motor mount puck.

You can get UHMW at plastics houses, via the McMaster-Carr catalog and fram supply houses in some cases.
It may be at bearing houses and oil field supply houses as well.
It's surprising how much places like these have to offer the hot rod builder.
All you need do it look around.

Another place that handles UHMW is an industrial rubber supply store.
The places that sell sheet rubber in varying thicknesses.
It's usually neoprene and the durometer (hardness) is very close to motor mount rubber durometer. (Fresh motor mounts anyway, old ones can be pretty hard.)
I have used 1/2" thick neoprene for rear motor mount pads in my 50 Plymouth coupe.
That to replace the stock ones.
One had rotted away due to oil and time and the other wasn't a whole lot better.
Stripping the old bonded rubber off the stock rear motor mount and making new ones from neoprene was easy.
Stacked it all back together with the original washers & bolts and it worked fine for a long time and was still in the car when I sold it.

The big trick with neoprene is to cut it out of a sheet - drill press & hole saw - drill a 1/4" pilot hole (which won't show because it will close up although it does mark the center spot) then put it in the freezer overnight for the final to size hole drilling.
In my case, a 1/2" hole.
Be sure you have everything ready to go when you take the neoprene puck out of the freezer.

You can drill them unfrozen, but it's a guessing game as to what size the final hole will be plus it will be ragged.
Freezing makes for a nice clean hole.


UHMW comes in varying thicknesses.
Get several so you can juggle motor height.
Common sizes for hot rod use are 1/4, 3/8, 1/2, 3/4 & 1".

Drill a 1/4" pilot hole and cut the UHMW out with a hole saw - keeping in mind a 2" hole saw cuts about a 1 7/8" OD on the UHMW.
Use low speed and you'll need to clean the melted plastic off the hole saw teeth a couple of times during the process.

I like to drill pilot holes prior to hole sawing for a couple of reasons.
You can tell exactly how much pressure you're putting on the hole saw proper without having to worry about drilling the material as well.
The other reason is, if you're cutting a fairly thick piece with a standard hole saw (deep ones are available in some sizes) you'll have to flip it to drill from the other side.

The pic below shows the underside of the 32 when it ran the stock style rubber biscuits.
Make a UHMW biscuit for the underside as well.
UHMW can machine a bit stringy in a lathe, but you can machine a step in pretty easy.
If no lathe, make a third UHMW bushing for the large motor mount frame center hole and tie the whole thing together with a 1/2" bolt and nylock.

After making the UHMW mounts for the 31 I was wondering how they would work out considering how hard the material is.
Not long after that the 32 picked up a little clicking noise on some turns.
It was obvious the rubber underside biscuit had failed and was allowing the engine to slip from side to side.

A set of UHMW mounts cured that and I found that my other worry - vibration transmitted by the UHMW didn't happen.
If anything, the car is smoother with the UHMW than it was with the rubber mounts.
A subjective opinion to be sure, but I'm pretty critical of my own work and will try something else if the first go-around doesn't do it.

Makes for a nice collection of wall hangers.
We learn more from our failures than we do from our successes....

Try to buy UHMW from the remnant - or cut-off - barrel if you can.
It's usually cheaper that way.

The aluminum plates you see top and bottom are 1/4" aluminum plate turned round with shallow retaining steps on the inside.
I made them to give the mounts a finished look as well as spread the load over the UHMW.
Spreading the load not necessary.

The original UMHW install on the 31 had the complete engine/trans combo sitting on the UHMW for seven months.
When I finally got around to making the spreader/finishing plates I found that the motor mount had not made a dent in the UHMW.

The second pic shows the 31's motor mount setup.
Note that it uses a through bolt where the 32 uses a stud coming in from the bottom and the top of that mount is smoothed off.
I was into the street roadster/nostalgia drag racers/maybe an occasional show with this car when I built it so that's why the stud.
The stud was a mistake and it's a pain in the *** in some situations.
Next time the 32's motor mounts are out they get drilled....

 

Mine is trimmed just how you drew the line across in the first pics... I had the front pulley machined off as there is only one belt now for the fan/generator...