Engine Mount Design Collaboration.

9549 Views 128 Replies 20 Participants Last post by MaxPF, 2 d ago

Dougal

Discussion Starter · May 13, 2021

Hi Guys

I know engine mounts are always a hot topic. Which ones work best, which ones fit best, which ones you can actually source.
I have reached out to Barry Controls: https://novibration.com/ and they're keen to design us a standard fitment to help out with vibration isolation and make all this easy.

But we need some info:
Weights. That should be easy.
Standard mounting configurations that work for most swaps. Particularly fore/aft location on the engine.
Space constraints inside frame rails etc.

I'm also going to forward some Isuzu 4BD1T info that can help too.

Reactions: 2

1 - 20 of 129 Posts

Snuggletough

· #2 · May 13, 2021

I would add a requirement the mount is captured or travel limited. Prevents failures from being ripped apart and holds drivetrain in place if mount does fail.

The front of a 4BT is usually the best mount location. There's so much fighting for space and so many packaging options I don't feel there is a good mid-mount position.

I tried many different mounts on 4BT's and have found the big chunk of rubber 1st gen dodge isolators attached to Ford 4BT mount brackets are the best way to go. It sounds cheesy, but drill 3/8" holes through the rubber until your mirrors no longer shake at idle and they work for a long time and are $15 to replace way down the road.

Reactions: 1

irhunter

· #3 · May 15, 2021

Snuggletough said:
I tried many different mounts on 4BT's and have found the big chunk of rubber 1st gen dodge isolators attached to Ford 4BT mount brackets are the best way to go.

Got a pic of that?

Roy

Dougal

Discussion Starter · #4 · May 16, 2021

Snuggletough said:
I would add a requirement the mount is captured or travel limited. Prevents failures from being ripped apart and holds drivetrain in place if mount does fail.

The front of a 4BT is usually the best mount location. There's so much fighting for space and so many packaging options I don't feel there is a good mid-mount position.

I tried many different mounts on 4BT's and have found the big chunk of rubber 1st gen dodge isolators attached to Ford 4BT mount brackets are the best way to go. It sounds cheesy, but drill 3/8" holes through the rubber until your mirrors no longer shake at idle and they work for a long time and are $15 to replace way down the road.

I don't think captive will be a problem. I've had an engine mount fail before and the engine just thrashed around a bit more.

How much space is there between frame rails on the average US conversion? I know all the measurements for mine but it has little in common.

J10Mike

· #5 · May 19, 2021

3

irhunter said:
Got a pic of that?

Roy

I don't know if the brackets pictured below are the same as what Snuggle described. But, here are the motor mount brackets that were for the Ford/Grumman step vans that I used. Yep, using that thick Dodge rubber as well. I wish I had known about the "Drill 3/8 holes in the rubber until the mirror stops shaking" trick beforehand. The 4bt easily installed and bolted down. Furthermore, with these mounts, my 46rh transmission lined up perfectly with the trans crossmember. Installed into a 77 Ramcharger poptop.

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Reactions: 1

scout4bta

· #6 · May 19, 2021

Reducing 4BT vibrations, March of 2014

Josiah1122

· #7 · May 20, 2021

Dougal said:
Hi Guys

I know engine mounts are always a hot topic. Which ones work best, which ones fit best, which ones you can actually source.
I have reached out to Barry Controls: https://novibration.com/ and they're keen to design us a standard fitment to help out with vibration isolation and make all this easy.

But we need some info:
Weights. That should be easy.
Standard mounting configurations that work for most swaps. Particularly fore/aft location on the engine.
Space constraints inside frame rails etc.

I'm also going to forward some Isuzu 4BD1T info that can help too.

www.farmstronginc.com

Cummins 4BT Engine Mounts | FarmStrongInc

Cummins 4BT Jeep Engine Conversion Mounts

www.farmstronginc.com

www.farmstronginc.com

Someoldguy

· #8 · May 20, 2021

I'm going Psyco on this .. If I can get the energy to flow.. almost done with the 4bt overhaul.. looking at using the passanger side mount from a 1998 24 V... and then on Driver side.. i have to engineer because i want to use the Vac-Pump, powersteering pump.. and putting this in a late 70's early 80's Dodge 4x4 150 frame.. I'm going to try use a dual mount on the driver side.. 2 of the single posts gel type .. If It works as envisioned..

Snuggletough

· #9 · May 20, 2021

Someoldguy said:
I'm going Psyco on this .. If I can get the energy to flow.. almost done with the 4bt overhaul.. looking at using the passanger side mount from a 1998 24 V... and then on Driver side.. i have to engineer because i want to use the Vac-Pump, powersteering pump.. and putting this in a late 70's early 80's Dodge 4x4 150 frame.. I'm going to try use a dual mount on the driver side.. 2 of the single posts gel type .. If It works as envisioned..

What is your aversion to utilizing the forward mount location?

I would advise against asymmetrical mounts. The absolute worst 4BT shaker I ever witnessed was one just like you described- One dodge mid-mount and then something completely different other side. It was like the mounts amplified the shakes.

We cut all the mounts out, put front mounts sitting on the Dodge biscuits with a few holes drilled in them and it was like a whole different vehicle.

scout4bta

· #10 · May 21, 2021

Snuggletough said:
What is your aversion to utilizing the forward mount location?
edit..............................

The front mounts are meant to be used in conjunction with the sae housing mounts. The bell housing used on US trucks does not have the pad mounts nor is the bell housing designed to withstand the tension of having to support the engine and transmission via the transmission mount. Dodge used the mid mounts on the 6B in their trucks for that reason. The SAE housing have bolt patterns going all the around the circumference, most US bell housing don't have any bolts on the bottom.

Snuggletough

· #11 · May 21, 2021

Did it not work fine for tens of thousands of breadvans with th400's, SM465's and T-19's?

BobS

· #12 · May 21, 2021

scout4bta said:
The front mounts are meant to be used in conjunction with the sae housing mounts. The bell housing used on US trucks does not have the pad mounts nor is the bell housing designed to withstand the tension of having to support the engine and transmission via the transmission mount. Dodge used the mid mounts on the 6B in their trucks for that reason. The SAE housing have bolt patterns going all the around the circumference, most US bell housing don't have any bolts on the bottom.

What surprises me is that nobody has modified that single front mount by extending the bottom and engine side as to incorporate it being extended to the front frame rails. Then simple cushion type mounts could be added to each of the frame rails as attaching points.

scout4bta

· #13 · May 21, 2021

Snuggletough said:
Did it not work fine for tens of thousands of breadvans with th400's, SM465's and T-19's?

You missed my point. It's a engineering fact that industrial engines (Diesel) use the engine mounts as I stated.
Yes you can get away with mounting the 4B at the front and using just the trans mount but it's not a good idea In my opinion.

The breadvans used the TH475.

Someoldguy

· #14 · May 21, 2021

Snuggletough said:
What is your aversion to utilizing the forward mount location?

I would advise against asymmetrical mounts. The absolute worst 4BT shaker I ever witnessed was one just like you described- One dodge mid-mount and then something completely different other side. It was like the mounts amplified the shakes.

We cut all the mounts out, put front mounts sitting on the Dodge biscuits with a few holes drilled in them and it was like a whole different vehicle.

Someoldguy

· #15 · May 21, 2021

I'm afraid of front mount puts all the weight on the aluminum transmission.. from the 47rh

Someoldguy

· #16 · May 21, 2021

so What Is the Optimal mount configuration???.. these forums are great, but I read til my eyes bleed and get so many opinions... on so many issues.. I ma puting a 4bt in a late 70-mid 80's dodge 4x4 frame.. please tell me what not to do before I try it... it would be greatly appreciated..

scout4bta

· #17 · May 22, 2021 (Edited)

Someoldguy said:
so What Is the Optimal mount configuration???.. these forums are great, but I read til my eyes bleed and get so many opinions... on so many issues.. I ma puting a 4bt in a late 70-mid 80's dodge 4x4 frame.. please tell me what not to do before I try it... it would be greatly appreciated..

I've tried to get the mounts centered alone the length of the block (4BT) between cylinders 2 and 3. And centered (height) about the crankshaft centerline. On my first design I used the Dodge Isolators from a first gen Dodge Diesel. They are a little hard for the 4BT and transmit some vibrations at idle but smoothed out at speed.
4bt engine mounts with AC

Reactions: 1

Dougal

Discussion Starter · #18 · May 22, 2021

My reasoning for why centre mounts are best:

1. It means engine engine mounts carry almost all the engine weight and the transmission mounts out the back just need to stop it flopping.
2. It puts the load on the chassis at roughly the front axle point. Centres the load over the spring supports instead of transferring it to the more flexible front end of the chassis.
3. Takes a lot of bending load from the driveline assembly.
4. Makes maintenance easier. You don't need much support to remove a gearbox.

Dougal

Discussion Starter · #19 · May 22, 2021

Frame Rail Dimensions.

So what's the range of width of frame rails you guys are typically using and are your engines mounted centred or offset?

My 4BD1T in a Range Rover I have:
630mm (24.8") inside the chassis rails.
Engine is offset to the left (US Drivers side) by 37mm (1.5") so it measures 3" closer to the left rail than the right rail. (277.5mm and 352.5mm).

Dougal

Discussion Starter · #20 · May 22, 2021

Josiah1122 said:
Cummins 4BT Engine Mounts | FarmStrongInc

Cummins 4BT Jeep Engine Conversion Mounts

www.farmstronginc.com

I've been there before but they didn't have as many options. Are they Dodge Cummins isolators in those kits?

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