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RB powertrain mounting questions


WizardBlack

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I got McKinney mounts for my RB25 powertrain in my 280Z. Something is a bit odd. I mounted the powertrain with the oil pan off to see what kind of clearances I was going to have for the oil pan. With no pan on, my main girdle is ~3/8" from the steering rack. Do you guys typically get them that close and make the front of your oil pan that close to the girdle? I am not sure I got the right mount set as the funky 280z trans mount isn't even close to fitting. No way, no how (yes, I know how to orient it, etc.)

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are you trying to use a front or rear sump oil pan? IIRC it needs a rear sump pan.

 

Clearly a rear/mid sump. The engine came with a front sump and it's only 3/8" clearance from the front end of the girdle to the power steering rack without the pan on there. I mounted it without the pan on to get an idea how I would need to make the new pan.

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I used the same kit with similar results. With my RB20 rear sump pan it almost touches the steering rack. I am switching to a RIPS custom pan so I'm gonna have to get some thicker isolators to raise the engine up. With the McKinney mounts you have to raise the engine to R&R the 200zr pan. I'm not sure if dropping the steering rack will give you enough room and with the limited access to the linkage it might be just as much of a PITA as raising the engine.

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I used the same kit with similar results. With my RB20 rear sump pan it almost touches the steering rack. I am switching to a RIPS custom pan so I'm gonna have to get some thicker isolators to raise the engine up. With the McKinney mounts you have to raise the engine to R&R the 200zr pan. I'm not sure if dropping the steering rack will give you enough room and with the limited access to the linkage it might be just as much of a PITA as raising the engine.

 

Yeah, I didn't want to mess with the rack and alter bumpsteer by moving it down/forward.

Did you end up with enough room for the electronic speedo sensor? I have a 280Z and I had to remove the original trans mounts from the trans tunnel, but there is still a hoop of additional reinforcement there that is somewhat in the way of the sensor. My McKinney trans mount would not lay up against the car at all; not sure what is going on; calling Mack today. :evil:

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I forgot to mention that I had to drill new holes in the trans mounts because they were a little too far forward. It wasn't a big deal it was only about 3/8" difference and I didn't have room to scoot the engine further back because of the fittings on the top of the RB26 valve cover were gonna hit the hood latch w/the RB25 that shouldn't be an issue. If you do end up having to drill on those try to use a drill press I used a hand drill and it was very difficult. Also, the speed sensor is fairly easily accessable. Sounds like you might have the mounts for the earlier S30s.

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I forgot to mention that I had to drill new holes in the trans mounts because they were a little too far forward. It wasn't a big deal it was only about 3/8" difference and I didn't have room to scoot the engine further back because of the fittings on the top of the RB26 valve cover were gonna hit the hood latch w/the RB25 that shouldn't be an issue. If you do end up having to drill on those try to use a drill press I used a hand drill and it was very difficult. Also, the speed sensor is fairly easily accessable. Sounds like you might have the mounts for the earlier S30s.

No, I have a 280Z. You don't get to reuse the factory trans mounts. You have to cut them off. The trans mount they give you is basically two pieces of angle iron (that you bolt through the floorboard) connected to each other with a round tube bent to an inverted "U" and a tab on it (in the center) to bolt the poly mount onto. McKinney said the trans tunnel has a 1/2" tolerance from the factory; thus making this design all but useless. I would have to notch the floorboard-to-trans tunnel transition a good couple of inches for the hoop as it arcs down to meet the angle iron.

I am going to make my own trans mount. The factory trans mount 'ears' that I had to remove were tack welded to a reinforcement band that runs the perimeter of the trans tunnel (in an inverted 'U'). I will make a backing plate with nuts welded onto the back of it, drill holes in the band for the nuts to stick down into and then tack weld it on. That'll give me a mounting point that should be pretty tough and looks way more factory.

As an aside, the band is also what it almost interfering with the speedo sensor. I may end up notching it a tad to get a bit of clearance.

How far below your trans tunnel shifter opening is the top of the shifter plate on the RB25 trans in your install?

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As an update, I called Mack at McKinney and he said sometimes they get an oddball that doesn't have a standard trans tunnel. They have a specialized mount that would work for my situation. They are going to send it out for me to try.

In the meantime, I guess I will dive into the electrical and oil pan stuff.

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Hey wizard.

I am also located in central ohio, doing RB swap. :mrgreen:

I had the same issue with steering rack and block clearance using the McKinney mounts. I ended up shimming engine mount. Everything fitting together now. PM me if you want to come over and have a look.

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Hey wizard.

I am also located in central ohio, doing RB swap. :mrgreen:

I had the same issue with steering rack and block clearance using the McKinney mounts. I ended up shimming engine mount. Everything fitting together now. PM me if you want to come over and have a look.

 

I may have to do that. The main issue seems to be getting pinion and offset for the driveshaft. I have a 280, so I am stuck with a really funky trans mounting option. What year is yours? BTW, I live in Marysville. :-)

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Good information. Would you happen to have pictures? I just ordered my set of mounts from McKinney.

 

Sure, no problem. I just gotta get it located properly.

 

Mack said you should shim the engine mounts to suit your needs, but you have almost enough engine mount bolt length to shim the valve cover up into the hood.

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Do they make it sit higher, then? Interesting website, but the pics weren't really detailed. :-)

 

must be higher than yours, if yours hit the rack. Just sits in well with no height issues any where. Have seen it on a few over here and always ok - no shims required.

The ones McKin make are obviously not right, given the other comments as well..

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Ive made a few sumps for guys with mckinny mounts and having seen a few pictures it appears the exhaust side mount is too short, several of my customers have had to add a shim under the left side mount to get the motor sitting at the correct angle which then allows the sump to clear the rack correctly.

 

Rob

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Ive made a few sumps for guys with mckinny mounts and having seen a few pictures it appears the exhaust side mount is too short, several of my customers have had to add a shim under the left side mount to get the motor sitting at the correct angle which then allows the sump to clear the rack correctly.

 

Rob

What angle should the deck of the block be sitting at for proper orientation? By this, I mean the sideways cant that all RB's have. I think I have 13 degrees at the moment. I took an inclinometer and stuck it right on the top of the deck while looking at the face of the motor from the front of the car.

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must be higher than yours, if yours hit the rack. Just sits in well with no height issues any where. Have seen it on a few over here and always ok - no shims required.

The ones McKin make are obviously not right, given the other comments as well..

 

It doesn't actually hit the rack, but it's about 3/8" diagonal distance from it. I don't have the replacement trans mount from McKinney yet to properly set the rear end of the powertrain, though. That will obviously move it about. Once I get that in, the engine mounts will be shimmed to try to get an appropriate pinion angle and offset.

Nice website by the way!

Rob will get a kick out of this, but I had actually just considered going ahead and stuffing a dry sump setup in there for future plans (one look at the crank collar and oil pump design made me think of this). The nice thing is dry sump pumps are easy to find (and buy used or get rebuilt) in USA. Roundy round cars are good for something, see? :burnout::mrgreen: JK.

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The mounts have a 1.5 " stud so you can shim the engine to the correct clearance and angle...We wanted the engine as low as possible so we designed the clearance to be only 1/4 to 3/8 inch...

 

75-78 trans mount are being redesigned to provide better fit do to some problems with fitting on some cars. Expect to have new designed trans mount done asap. will advise when done...

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