GAS - Custom Engine mounts

Guys,

Just finished Mk3 of my engine mounts for my RB26 engine.

Mk1 were a nice mount, but I did not have the engine/transmission in straight. It would have been straight enough as the Universal joints can run out of phase by roughly 0.5 degrees, but I knew I could do better.

Mk2 I did last weekend, but I just rushed the design and implementation too much so was not happy with the design.

For this last mount I did the following in order to make the mount.

- I ran a string line down the centre of the car (lost of measuring to find the centre along a lot of points).

- I then dropped a weighted string off the centre of the transmission output shaft and from the centre of the front of the crank shaft

- I then used a jack to pivot the engine from the transmission crossmember before supporting it on the engine crossmember when it was positioned right.

- I tried to get these within a couple of mm of each other (calculated that they could be 13mm out from each other without causing an issue with UJ alignment). I believe that I got the tolerance to a mm or two which is as best as I could hope for with the methods I was using.

- Made the engine and crossmember plates then used cardboard templates to come up with the connecting ribs. Tacked it all into place on the engine, then welded it hard on the bench.

- I tried to make all the ribs between the plates before putting to much heat into welds as I wanted it to stay straight.

I made the mounts out of 5mm and 4mm plate (RB25 mounts are all 4mm steel, RB26 are a cast aluminium).

Look at all this room for the Turbo Richard.

Got about 12mm clearance between strut tower and intake.

Clearance between sump and rack will be increased with custom sump.

 

Look at all this room for the Turbo Richard.

Noticed you said "turbo" and not turbos. Going big single?

I like the extra effort you go to with your mounts to make them look almost factory.

Thanks. Yes single turbo, but not too big. 

In fact I have been umming and arhing about the 35R 260DET currently has up for sale. (Was originally thinking a T04Z).

Do want a close to equal length manifold though.

Did see a 55r setup come up for sale but only contemplated it for giggles. Too big for my moddest goals.

Nice work! Know how you feel about not being happy when you know something could be better!

Accurate drive train alignment is so important, anyone can drop an engine in and it will likely be OK for a while but will ultimately come back to haunt them.

I wasn't able to follow your description exactly, but are you saying you have a perfectly straight alignment of the tailshaft in both 'x' and 'y' planes? 

The following photos might help Peter.

I currently have the driveline (engine/transmission) parallel to the differential within a couple of mm over the length of the engine/transmission in horizontal plane (or is that vertical? well if you look from the top anyway). To get it parallel with the diff in the vertical plane I have to lower the nose of the diff as it currently points too high.

So the engine is currently offset from the centerline by about 12mm and the diff is about 17mm offset.

You can see the string line running front to back and the weighted strings from the crank shaft to the tailshaft.

This is the distance from crankshaft to centerline.

This is the distance from tailshaft to centerline.

I was going to raise the issue of brinelling of the rollers in the universal if you don't has at least 3-4 degrees angle on the uni. If you are not aware of it then it's probably best you research it for a better explanation than I could provide. Regards

Cheers Peter, read about the minimum angle issue (thought it was smaller then that though).

Mine will have a bit of angle but both should be very close to each other though.

Why I am not too worried about it though is because this car will not be driven enough to worry about wearing the Universals out.

Looks bloody good mate. Did you end up finding a decent sand blaster?

Hey Shaun,

After using your blaster for about half a minute and going through a good half a kg of sand, I decided it would be best that I finish all my mounts first. Then blast them in a cabinet with a harder medium that can be recycled. Or just get someone to blast them for me. Then I will just paint or powdercoat them.

Brad

nice work,

interesting seeing others ideas and work,

i found with engine positioning from factory to be offset slightly to one side, as engine torques it centralises a bit.

i had measurements of about 12mm or soo off centre, but diff is off centre also,

my mounts did centralise the engine at the front and the point the trans directly at the tailshaft flange, howeve the angle where it meets at the diff would be about 2-3 degrees, but i also lowered the engine by 15-20mm and also shifted it back toward the firewall, so only about 20-30mm from back of head to firwall, enough for heater hoses and certain tools.

over all good to see,

like your work,

ps what are you doing for the trans mount, and which gearbox you using?

also wha year is your car an what type of g/box mount dous your car use? ie ear type or hump type?

nat0

This thread will answer all your questions

http://www.viczcar.com/forum/index.php/topic,8777.0.html

and this is the new build thread

http://www.viczcar.com/forum/index.php/topic,9260.0.html

Your mounts sound like my first mount that I made (engine pointing directly at diff at an angle).

I ended up changing it to be parallel as I figured that the engine will be at this position most of the time.

Gearbox is a 300zx with an RB26 bellhousing.

Car is a 2+2 so it has the ears off the side of the tunnel, you will notice I had to remove these as the gearbox will not fit past them.