VH45, Z31 and engine mounts

[Ford Falcon]

Does anyone know if the VH45 motor mounts will fit on a 300ZX (Z31), or will they need to be custom fabricated? For those that are getting theirs fabricated, are you all doing solid metal mounts, or are you using something softer?

[Clifton]

Not trying to be mean but if the motor mounts are your concerence, you have no idea how much work there is on a motor swap with an engine never designed for that car, especially one that wide. They will need to be custom as will the trans mount, driveshaft and maybe some cutting ?? to get it in there where you want it. There's alot of VH info here. http://forums.nicoclub.com/zeroforum?id=193

[Ford Falcon]

Hello Clif. Thanks for your reply. I was fishing to see if anyone else out there has a Z31 and is performing the same type of surgery on theirs. Yes, I'm aware that there is more to a swap than merely engine mounts. (These are the simplest). There is also what you listed, possibly custom exhaust manifolds, not to mention modifying the wiring loom and probably a different engine management system as well. I did eventually spy a site that describes some detail on creating them...

http://users.bigpond.net.au/lachlan/tech/mounts.html

 

How to Make Custom Engine Mounts

The story started when I got 2 sets of engine mounts to fit my 4AGE in the KE25 but neither of them sat the engine in a good position. It was too high and sloped back and also the drag link hit the gearbox which isn't a desirable thing when it comes to engine fitting! So I set about making some new engine mounts and one day later I couldn't be happier, thats why I will now share with you the method which I found to be extremely simple and effective and therefore very achievable by the backyard enthusiast.

 

The Rubber Vibration Insulator Thing

First choose the rubber mounts which you wiull use. You may use what comes with the new engine or what was on the old engine. The simpler the better. I used a gearbox mount from a Landcruiser or Land Rover or something. The part number is NRC 2054. This is a very simple mount which fits the car perfectly.

 

Position the Engine

Using a crane or chain block or whatever you can rig up drop the engine and gearbox into the bay. Try and use the original gearbox crossmember position and see if the engine fits in. If not then ignore the gearbox position because it has to be changed anyway and concentrate only on the engine. Measure the centre of the car and place a mark on the swaybar or something to line the centre of the crank up with. Its not entirely necessary to have it dead on centre but the closer the better.

 

Sit it as far back as you can with enough clearance for heater hoses and stuff. Drop it as low as possible without leaving the sump hanging down too low in a vulnerable position. Leave enough room above the crossmember and when you have it right tie it in position with some rope or something. Maybe rest it on some wood or whatever you have lying around. Then check the steering linkages for clearance at full lock and all suspension components. When you are satisfied with the position its now time to move on to the next step.

 

The Template

Choose your steel size. I used 6mm steel as it is very strong but still workable with simple backyard tools. Generally try to stay at least the same thickness as what was on the engine before. When you have your steel size get some MDF the same thickness or as close as you can get. It only comes in 3mm, 6mm, 9mm, 12mm etc. Bolt the rubber block to the mount in the position that you want it to finish up. Bolt the old mounts to the engine and see of any part of them can still be used. If not than move on ahead.

You will then have to make a plate that bolts to the block. use the existing mount holes if necessary or whatever is in line with the mount on the car. Cut out a shape of MDF and trim it untill it is a neat fit, drill the holes in it and bolt it to the block. Now maybe your old mounts will weld to this plate or some more custom work is necessary. Make a plate out od MDF that bolts to the rubber block and is in line with the plate on the engine. Hopefully it will extend out evenly on either side of the rubber block but if no thats still ok.

Now we assume the old mounts are useless so all you have to do is make some more plates out of MDF that fit in between the engine block plate and the rubber block plate. Try and get one on either side of the rubber block to even out the load. Remeber to leave access to the bolts holding the plate to the engine and the plate to the rubber mount. Once you have at least two plates made up you can now take it all off and proceed to the next step.

 

The Mounts

Work out the minimum width steel that you can use to make the plates. Go buy some steel from the local steel merchants. As a guide I got 1m of 6mm X 130mm for $11 and 2m of 6mm X 75mm for $14. Trace the MDF shapes onto the steel and start cutting. I used a 100mm angle grinder and went through 4 cutting blades. There are easier ways but it really wasnt that difficult. When they are cut out, mark and drill the holes for the mounting plates. Bolt it all up to the engine and car and see if it fits as before. Assuming it all lines up grap your welder and tack it into place with enough weld to keep it in shape while you remove it from the car. Take it off the car and weld up all joints thorougly. When done, let it cool and bolt it back up. It should be perfect but might need the holes drilled off centre a bit due to the distortion from the heat when welding. Once it fits nicely pull it off and paint it and then bolt it up again and you are halfway there!

 

Finishing off

Now that one is finished the engine should be held in position well and it is just a matter of repeating the procedure on the other side. Remeber that the engine may drop a little when the mounts compress so you can lift the engine higher than you want it while measuring up.

[marcg]

They are the type with a stud on either end. They reminded me of the ones from my Z32TT. I should be able to get my hands on a pair of Z31 mounts. Do you want to look for them and confirm?

[Ford Falcon]

Hey Marcg,

I will as soon as I can get an engine hoist. It sux to be tight on money sometimes. I noticed your signature shows 450Z. So you have already performed this swap? I want to do it with a Z31, mostly because I already have the car, but also, because I've not found anyone who has. Not to my knowledge.

[marcg]

I guess in the rush of responding to your message I didn't make myself clear. Do you want me to go confirm if the mounts are similar? I have Z31, Z32 and Q45 mounts somewhere in my pile of parts. I know the Z32 and Q45 are very similar if not indentical (I'd have to measure to confirm). As for my 450Z signature, I'm working on a conversion as well. The conversion is aboout 80% done, but the car still needs alot of work. Check out the progress at http://www.cardomain.com/ride/563982

My son and I looked at putting the VH45DE in his Z31AE. Initial measurements indicated that the brake booster was too big to let the engine sit back against the firewall.

[Ford Falcon]

I would be grateful if you could confirm that. Thanks, mate!

By the way, I'm impressed with what you've been doing to your Z. It sure does make a difference when you have easy access to the equipment for designing and creating some of those custom parts. And so I don't divert from the topic I started here, do you mind if I PM you about a couple of other things to do with this setup?

 

Thanks marc!

[Ford Falcon]

Initial measurements indicated that the brake booster was too big to let the engine sit back against the firewall.

Marc, have you thought about a hydro-boost brake system instead? I have not yet taken measurements, but perhaps replacing the vacuum booster with something else might help out. I hope to be trying that out next month.