Lets hear from the fabricators and engineering peeps here. I am making new motor and trans mounts for the Jetta project. Streetability isnt on the list. Looking for the next closest thing to solid.
From what I see there are 2 main types of motor mounts.
V8 style cradle type with a horizontal type bushing on each side holding the block to the frame. only allows up/down and a little side to side movement.
thanks google images for this wonderful example of superior welding skills: lol
FWD style 360 degree bushing style. Usually a single vertical bolt, pin what ever. then the motor side mount hangs off the side like a flag on a flag pole. These allow the motor to move up/down/side/side/front/back.
In a front wheel drive the motor and trans want to twist perpendicular to the car (facing the front of the car), that’s why a lot have a dog bone mounted 90deg to the block to control this twisting. With squishy mounts above that dog bone the motor still twists, it just changes the fulcrum point up higher.
I am thinking of making a set of V8 style mounts for the jetta. What do you guys think?
MAKING being the key word here… I am not going to buy some $500 VF engineering mounts, MK4 30R! :lol
so my idea is a v8 style mount with a bushing point running 90’deg to the side of the motor/trans… running front to back if you looked down on the mount in the engine compartment. That way the motor cant really twist back as much as a “flag pole” motor mount like the VF one I pictured above.
i modified my lower with 1/8" plates to prevent excess rocking , jammed 1/8" washers on my upper dog bone mounts thats all i had to do, all cars are different i guess.
Werd. I am looking for a little more involved modification that your fix though.
Dog bone will be made from scratch too. one little bushing and a billet adjustable heim at the other end to adjust the “preload” if you would call it that.
OE mounts are done for compliance. Compliance is necessary to prevent metal fatigue and cracking. If you lock things up with billet mounts, shit WILL crack guaranteed. Same thing when changing the type of mount and how it transmits the torque to the body. With that said…
If you’re going the route of changing the mounts you MUST reinforce the unibody. Engine mount compliance is factored into the stampings and spot welds and if you remove the compliance from the mount, it WILL source to the next weakest link, which are the welds in the unibody(or the stampings themselves).
I sheared the passenger engine mount area of the unibody twice on the avenger before having to make a larger surface area mount(due to a solid delrin bushed mount). Distributed the force across a wider area and more or less “solved” the issue. And when that was all said and done, boom, starting breaking passenger axles like clockwork
The “V8” style mount would reduce the twist no doubt. I would not go as far as to make it completely solid though. I would still sleeve it with a decent durometer nylon or urethane.
OEM motor mounts (location, geometry, and material) are designed with front impacts in mind. Many are designed to shear and allow the motor to slide underneath the firewall. I would be careful with what you decide to do depending on the use of the car and what interior protection you already have.
Mounts are one of the few things I have NOT fucked with on my car. The engine is designed to actually come OUT of the cradle during specific impacts, making the car allegedly safer.
I’ll gladly take wheel hop and broken axles vs no legs, thanks.
No the car isnt going to see daily street use, it will 100% still be on the street, but its going to be a bumpy ride! lol 80% track %20 street is what we are shooting for.
Car will be caged inside with harness’s. Front subframe will be strengthened and the front unibody legs will be gusseted for strength too. Like adam mentioned the mounting surfaces on the car will be strengthened, prior to the new mount going on. like he said to spread the load out.
its all 1/4" plate sides 3/8" mounting flanges. 2.5" dia 1/4 wall tube for bushing, 5/8" grade 8 bolt through bushing, 8’s for motor and chassis mounting too.
I built a jig for them last night. lucky for me VW engies made the height and spacing the same for the trans side and the motor side, so one jig will do both. the only difference is the engine/trans mount flange is off set a little different per side… no biggie, just drill 4 holes instead of 2 on the jig for the top flange placement.
Tonight I will be burning up some metal and should have them tacked together… just need a argon refill for the tig tomorrow to finish welding them.
^^i couldnt agree more,seriously. and if the mounts “sheared” in your dumpy dodge its because its a dumpy dodge. your constant barrage of overly complicated unwarranted useless commentary becomes obnoxious over time.
dave and i completely solid mounted a 30 year old rabbit with 30 year old stressed metal with no problems. the vibrations will annoy you thats a guarantee. just an example. also filling the stock mounts is always a cost effective and quick solution.
