1936 Dodge Truck Build, 74 Dart Spool Engine Mounts

[Saltcityslant]

Hey all,

Posted below are some pictures of the engine mounts that I am going to use in my truck. These slant engine mounts have a weird diamond shape hole, they're off of a 74 dodge dart with the Slant. I need to know if there is a sleeve that needs to go inside the bushing, or if anyone can rattle off the best size bolt. I want to make sure I do this correctly so I don't have to go back when the steering and exhaust is in the way. Not only that, but I included a pic of the engine as a whole because it looks dope, and I'm excited to share.

Thanks for the help folks,

- Coop

 

[72bluNblu]

These are small block mounts, but yes, there's a metal sleeve that's supposed to go inside that bushing. I'd also add that based on the look of that bushing, I'd replace the whole bushing before I installed that engine.

This is a reproduction mount

This is an original (with an equally smoked bushing)

 

[junkyardhero]

yes. yes. what 72blu said... but enough about that. tell us more about the truck! i see a rack...

 

[Demonic]

I'm thinking the metal sleeve got coated in rubber, and you're looking right at it maybe?

 

[vitamindart]

if I remember correctly its a 1/2" bolt. factory bolt had two little tabs on it mid way.

 

[Saltcityslant]

These are small block mounts, but yes, there's a metal sleeve that's supposed to go inside that bushing. I'd also add that based on the look of that bushing, I'd replace the whole bushing before I installed that engine.

This is a reproduction mount
View attachment 1716446712
This is an original (with an equally smoked bushing)
View attachment 1716446713

That seems so strange to me, these are brand-new engine mounts that I got off of Rock Auto. That was likely my first mistake, I'm just not understanding why they seem to be missing the inner circular metal sleeve that every other engine mount I've ever seen has. If anyone has a link for these spool type (They might not be spool I'm pretty sure they are though) I'll get a better set.

 

[Saltcityslant]

I see, so I might need to get the factory bolt instead of just some grade fives in whatever diameter?

if I remember correctly its a 1/2" bolt. factory bolt had two little tabs on it mid way.

 

[Saltcityslant]

I'm thinking the metal sleeve got coated in rubber, and you're looking right at it maybe?

Could be, it definitely feels like steel and not rubber on the outside. I just can't for the life of me figure out why it's in the shape of a diamond and not a circle like the other 500 engine mounts I've installed over my career. A half inch bolt feels loose, which is what I found recommended in the Dart service manual. I am going to run to the hardware store later and get a couple bigger sizes in grade five and see what works best. Taking the engine mount off I mean, I need to replenish my shop bolt stores anyway

 

[72bluNblu]

That seems so strange to me, these are brand-new engine mounts that I got off of Rock Auto. That was likely my first mistake, I'm just not understanding why they seem to be missing the inner circular metal sleeve that every other engine mount I've ever seen has. If anyone has a link for these spool type (They might not be spool I'm pretty sure they are though) I'll get a better set.

Maybe it’s just the picture, but that doesn’t look like a new mount to me. More like they sent out somebody’s return by mistake.

 

[Saltcityslant]

yes. yes. what 72blu said... but enough about that. tell us more about the truck! i see a rack...

yes. yes. what 72blu said... but enough about that. tell us more about the truck! i see a rack...

Got myself a mustang II front end that I installed on this truck. It is a 1936 Dodge Truck, I've spent weeks and weeks building the frame and repairing and epoxy-ing the panels and chassis. My grandfather bought this in the 80's in pieces, and he died in 2015. Last year, I picked it up and got to work. I had access to the Slant Six through a cousin which I figured would be cool because it's like an engineering project, and we're not committing atrocities by having a ford or chev block in it. It's not overkill on power, and it fits under the hood which is sweet. I would like it to appear as close to stock (hotrody thought, since the front is lower to the ground). I'm running an 833od on this slant with the 3.55 rear end so it goes down the freeway without screaming for mercy. Slant has balanced pistons from the last owner, and I had the block and head fully machined and redone. The cam lifts at .440 and Im going to run a 390 cfm carb with the four barrel intake so I can actually control the A/F mixture, if I go too big it will f with the idle. It's been a tough project so far, it took six months to get the trans after a promised delivery of 8 weeks. No big deal, just glad we got the damn thing finally.

The end goal is comfortable and sporty 30-60mph, friendly to 80mph (I've welded rebar inside the fenders to make it more stable and less flexible, shoutout BJ), stable on the ground, and reliable as it can be without any quirks. My end goal is for anyone who knows how to drive a classic can get it, turn the key, and take off.

 

[Saltcityslant]

Maybe it’s just the picture, but that doesn’t look like a new mount to me. More like they sent out somebody’s return by mistake.

****, maybe! Never considered that, I'll reach out and see what they say. To clarify though, it doesn't have a circular bushing though, right? Just a tab on the bolt.

 

[junkyardhero]

that is awesome sauce. thanks for not putting a 350/350 or a ferd in it!

 

[72bluNblu]

****, maybe! Never considered that, I'll reach out and see what they say. To clarify though, it doesn't have a circular bushing though, right? Just a tab on the bolt.

Yeah there isn't anything extra compared to say the top picture I posted. The bushing itself that's pressed into the mount is a metal sleeve with the rubber inside of it, and then the metal sleeve for the bolt.

The bolt itself just had a little crimped section. I don't know what the purpose was, to keep the bolt from spinning when you started the nut? To keep the sleeve from spinning on the bolt? Beats me. It's really small, so it's not like it would take much force to spin the bolt in the sleeve. You can kind of see it here, it's like the used a crimper of some kind to make a little tab out of the bolt.

Needless to say a regular bolt would work just fine.

 

[nutz]

would think it would be easier to fab a pin style mount then the newer yoke style that you have ,unless you are allready past that
sweet ride ,so glad your staying all mopar
i have extra pin style mounts on my 67 truck if you need

 

[RedFish]

Bolt would never size up in the sleeve. Would never make a squeak or any noise. There was some engineering involved back then.

 

[lemondana]

Usually slant 6's don't fit well in these narrow engine compertments. A small block will fit better.

 

[vitamindart]

I see, so I might need to get the factory bolt instead of just some grade fives in whatever diameter?

I would personally just use a decent grade bolt. no need to hunt down an OE bolt with the silly tabs.

 

[Woody500]

I would personally just use a decent grade bolt. no need to hunt down an OE bolt with the silly tabs.

Nice truck.
Any other posts about build? Enough mount bolt info.

 

[67Dart273]

Can't you "poke at it" and determine if it's metal? No need for the special bolt. In fact I would think grade 5 (3 point head) would be fine.

 

[Woody500]

Can't you "poke at it" and determine if it's metal? No need for the special bolt. In fact I would think grade 5 (3 point head) would be fine.

Use the corner of a fine file & make a small notch. It will teach you how to tell hardness of bolts, and other steel, like tubing.
Scrap sheet bits thrown in a box, you can tell 4130 from mild steel when you need to. And you'll then learn to tell by sight(not always) too. Always check.
Grade 5 probably ok but I'd bet Attorneys made grade 8s standard for engine mounts, for liability.
Engineering safety factors are usually ten times what an actual load is for that reason.

 

[72bluNblu]

Engineering safety factors are usually ten times what an actual load is for that reason.

This is a poor assumption. Engineering safety factors are tied directly to the materials being used and the application, there's no "all engineering safety factors for cars are X times the actual expected loads". There are dozens of different safety factors that would be used on a single vehicle based on the component being considered.

Metal grades are also tied into more than just the strength of the material, higher grade bolts usually are also more brittle so they are not always used because of the expected or desired number of work/fatigue cycles.

 

[nutz]

Yes grade 8 has no stretch so might come loose from vibrating
Grade 5 will stretch and hold better

 

[Woody500]

Yes grade 8 has no stretch so might come loose from vibrating
Grade 5 will stretch and hold better

Makes sense to me. Was going to suggest grade 5. But saw previous thread that talked about motor mount studs being harder but they are in tension, not shear like this post.
Also what about Arp connecting rod bolts, aren't they stetch measured now. I've never used them, years of old school wrenching & I've only used stretch gauge a couple times on late headbolts. Turn further style, never measured stretch.

 

[nutz]

All the head /rod /main bolts are stretch to yield now......torque then angle
I guess it works cause not many failures