I am going to make my own motor mounts in my S13 so i want to get it right. What are some basic things to keep in mind when placing a motor? How do i insure its perfectly center, level (Or does it need to have a few degrees of tilt?) and right where it needs to be?
Motor Mounting Theory? How do you place a motor correctly?
- Thread starter sniper
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The 1UZFE EGR Delete Kit is available for sale here.
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You want the engine set as far back as possible.
To centre the engine I marked the centre of the radiator support and firewall with tape and did the same on the engine. This allowed me to see at a glance if it was running down the centre of the car.
You may find it will fit better with a slight lean to one side or the other. My engine is about 5degrees down on the drivers side at the moment. I'll level it when the new trans goes in.
The flywheel should be parallel with the diff flange so the joint run parallel to one and other.
The drive line MUST not run dead straight and level. Ensure the output shaft of the transmission is at a different height to the diff. This will allow the joints to flex each time the shaft turns and will ensure the roller bearings move which will distribute the grease and stop premature failure.
To centre the engine I marked the centre of the radiator support and firewall with tape and did the same on the engine. This allowed me to see at a glance if it was running down the centre of the car.
You may find it will fit better with a slight lean to one side or the other. My engine is about 5degrees down on the drivers side at the moment. I'll level it when the new trans goes in.
The flywheel should be parallel with the diff flange so the joint run parallel to one and other.
The drive line MUST not run dead straight and level. Ensure the output shaft of the transmission is at a different height to the diff. This will allow the joints to flex each time the shaft turns and will ensure the roller bearings move which will distribute the grease and stop premature failure.
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Sniper,
Not necessarilly.
The transmission output must be at a diferent height to the diff flange.
This stops the shaft running in a perfectly straight line.
The diff flange and (imaginary) output flange on the trans should be parallel in all planes.
What you want is for the shaft to bend up or down at the front uni joint (only a few degrees) then bend the opposite way, by the same number of degrees at the rear uni joint.
Not necessarilly.
The transmission output must be at a diferent height to the diff flange.
This stops the shaft running in a perfectly straight line.
The diff flange and (imaginary) output flange on the trans should be parallel in all planes.
What you want is for the shaft to bend up or down at the front uni joint (only a few degrees) then bend the opposite way, by the same number of degrees at the rear uni joint.
MacroP
Member
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- South West Oz
I've being mounting a 1UZ in a MX83 over the last few weeks.
I didn't have much room so it has fit where it will fit. I have about 5-10mm clearance from the rear of the sump to the steering rack/crossmember. About 10mm clearnace to the bonnet at both the intake plenum and the throttle body cover. The front sump pan sits about 8 mm back from sway bar. So basically there is not much room to play with for me.
For my engine mount brackets, I basically designed them on Autocad and had some prototype bits cut from 8mm mild steel. I tack welded them together to test. I'm using the stock MX83 round rubber type mounts. The have a 12mm stud facing upwards at 15 degrees towards centre. The V8 block is at 45 degrees obviously so my bracket are at exactly 30 degrees. The motor is biased 8mm forward from the bracket centre line.
I had to adjust them to bring the motor back 8mm as it was touching the front sway-bar. I adjusted them again to get the engine height correct.
I had slots cut in the brackets to allow me to roll the engine to get it centre and sitting vertical just right and I took a measurement from there for the final version. The new and final design was emailed to the laser cutter yesterday. They will look quite different though as they will be cut from 6mm 316SS.
Seeing as I'm using a trans from a Soarer/SC400 with the tri-flanged(and rubber donut) output setup one thing was apparent to me when setting up the front and rear engine/trans mounts. That is, that the trans output shaft must be pointed directly to the centre of the centre bearing. There is no slip yoke and uni joint on the output shaft on my setup so this will be important otherwise there will be large virbrations and wear(on the donut) I'd imagine.
I may have to adjust the centre bearing height up or down to keep uni alignment errors down low for the rear prop shaft. I took my two props shafts(one from each car) today to a driveshaft machinist to see what he could do.
What trans are you using?
I didn't have much room so it has fit where it will fit. I have about 5-10mm clearance from the rear of the sump to the steering rack/crossmember. About 10mm clearnace to the bonnet at both the intake plenum and the throttle body cover. The front sump pan sits about 8 mm back from sway bar. So basically there is not much room to play with for me.
For my engine mount brackets, I basically designed them on Autocad and had some prototype bits cut from 8mm mild steel. I tack welded them together to test. I'm using the stock MX83 round rubber type mounts. The have a 12mm stud facing upwards at 15 degrees towards centre. The V8 block is at 45 degrees obviously so my bracket are at exactly 30 degrees. The motor is biased 8mm forward from the bracket centre line.
I had to adjust them to bring the motor back 8mm as it was touching the front sway-bar. I adjusted them again to get the engine height correct.
I had slots cut in the brackets to allow me to roll the engine to get it centre and sitting vertical just right and I took a measurement from there for the final version. The new and final design was emailed to the laser cutter yesterday. They will look quite different though as they will be cut from 6mm 316SS.
Seeing as I'm using a trans from a Soarer/SC400 with the tri-flanged(and rubber donut) output setup one thing was apparent to me when setting up the front and rear engine/trans mounts. That is, that the trans output shaft must be pointed directly to the centre of the centre bearing. There is no slip yoke and uni joint on the output shaft on my setup so this will be important otherwise there will be large virbrations and wear(on the donut) I'd imagine.
I may have to adjust the centre bearing height up or down to keep uni alignment errors down low for the rear prop shaft. I took my two props shafts(one from each car) today to a driveshaft machinist to see what he could do.
What trans are you using?
TOBES
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On the subject of driveshafts...
I am using the rubber donut coupling to an independant rear with, hopefully, a one piece driveshaft. The diff centre is mounted in a subframe and the only movement will be in the engine, trans and rubber diff mounts. I realise the trans coupling needs to line up with the centre of the diff flange to reduce the stress on the coupling but whats the story with the diff end?
Can I use a uni joint on the diff flange or does it need to be a CV type joint?
The uni joint would need some missalignment built in (5 to 7 degrees) to survive. Would this cause a vibration from the rotation of the uni joint?
Interesting info for anyone using the donut coupling - The A350 coupling is substantially larger than the A340. The A340 is 90mm between the three mounting bolts where the A350 is 100mm. The rubber coupling is larger in diameter and approx 5mm thicker. Assuming the output shafts on the two trans are the same the A350 looks much stronger...
I am using the rubber donut coupling to an independant rear with, hopefully, a one piece driveshaft. The diff centre is mounted in a subframe and the only movement will be in the engine, trans and rubber diff mounts. I realise the trans coupling needs to line up with the centre of the diff flange to reduce the stress on the coupling but whats the story with the diff end?
Can I use a uni joint on the diff flange or does it need to be a CV type joint?
The uni joint would need some missalignment built in (5 to 7 degrees) to survive. Would this cause a vibration from the rotation of the uni joint?
Interesting info for anyone using the donut coupling - The A350 coupling is substantially larger than the A340. The A340 is 90mm between the three mounting bolts where the A350 is 100mm. The rubber coupling is larger in diameter and approx 5mm thicker. Assuming the output shafts on the two trans are the same the A350 looks much stronger...
sleeperz
New Member
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its called engine angle of inclination, 4----7 degrees sounds on the money.. front being higher
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If you use a CV joint in the rear it can run pretty well dead straight without wearing itself out.
A uni joint will cause vibration in the doughnut for the amount of angle you need to run for the Uni joint to survive.
A uni joint will cause vibration in the doughnut for the amount of angle you need to run for the Uni joint to survive.
Guys,
Do not use a rubber donut at the end of the gearbox in front of the propshaft if you are not running a support bearing on the propshaft and the diff and gearbox are not perfectly in alignement.
In my BMW engined Cobra I used the rubber donut at the end of the box, connected to a propshaft with UJ at both ends, all as recommended by the propshaft supplier, and what I got in reality was , to quote a fellow Cobra owner and far better engineer , " A bloody skipping rope" which would actually start vibrating like hell at anything over 20 mph.
I replaced the donut with a billet aircraft aluminium spacer and theres no vibration whatsoever.
When i'm fitting the prop to the gearbox in my next builds I'll be throwing the rubber donuts in the bin.
Cheers,
Tony
Do not use a rubber donut at the end of the gearbox in front of the propshaft if you are not running a support bearing on the propshaft and the diff and gearbox are not perfectly in alignement.
In my BMW engined Cobra I used the rubber donut at the end of the box, connected to a propshaft with UJ at both ends, all as recommended by the propshaft supplier, and what I got in reality was , to quote a fellow Cobra owner and far better engineer , " A bloody skipping rope" which would actually start vibrating like hell at anything over 20 mph.
I replaced the donut with a billet aircraft aluminium spacer and theres no vibration whatsoever.
When i'm fitting the prop to the gearbox in my next builds I'll be throwing the rubber donuts in the bin.
Cheers,
Tony
