M6X swap without subframe spacers and without drivetrain angle

[Etexise30]

it has long been the norm to use subframe spacers while preforming the m60 / m62 v8 swap into an e30. Where did this norm start? Well basically as far as I can tell it started with an old-er swap guide which you will find somewhat translated here. So for the sake of convenience people started following that guide, and because 300mm (a website) was offering the motor mounts and spacers (if you use said motor mounts you have to use spacers), not knowing otherwise people bought said products. Now generally speaking as far as quality im sure 300mm produces a nice product, however I just do not agree with the execution. You see, without the subframe spacers the engine sits on an angle, this angle puts pressure on the guibo and the rest of the drivetrain, and generally reduces the amount of space above the engine for things like strut bar. To eliminate this angle the practice has been to use subframe spacers as such:



The reason why subframe spacers are bad is because it raises the body of the car in relation to the subframe, you alter the cars centre of gravity, suspension dynamics and create bump steer.
So what do you do? Well first and foremost you will not be able to use the 300mm mounts, you will have to make some yourself. You have to make the motor mounts yourself because a. no one is currently offering mounts for the configuration I am about to propose b. the 300mm mounts will not work because you will be lowering the engine in relation to the subframe, and considering the mounts connect the engine to the subframe it is only logical that need mounts that will be shorter in height.
The solution is to notch the oil pan, so you can lower the engine more without it hitting the steering rack. There are some select few people who have done this with success. Here is what a normal oil pan looks like (you will only be modifying the upper oil pan):

You will notice there is a buldge in the middle of the pan just right of the mounting bolts for the lower pan.
Here is what, where, and how you will modify it:





Using this method will eliminate the need for subframe spacers (no bumpsteer, suspension geometry stays correct, center of gravity is not lifted), and will reduce the drive train angle to exactly where it needs to be for long term reliability. Considering your saving money on the subframe spacers and on buying motor mounts this method shouldn’t cost you anymore then the former method. I recommend contacting a competent welding shop to notch the oil pan, these shops are usually plentiful in most towns.

Copied from

http://www.rtsauto.com/mounting-an-m60-m62-without-subframe-spacers-and-without-drivetrain-angle/

This entry was posted on January 22, 2012 at 12:38 pm and is filed under Do it Yourself, Interesting Stuff. You can follow any responses to this entry through the RSS 2.0 feed.

[Jonsku]

ummm... what is the "big news"?


I'm still wondering why people are so afraid of bump steer? I suppose they aren't lowering their cars, as that *dramatically* changes the bump-steer as well ..

[Etexise30]

well imma bag my e30 Courtesy of google/white325is

[robiniscool]

you dont need to use subframe spacers or tweak your oil pan if you think of it your motor mounts go on the subframe itself and lowering will lower the whole motor from the frame. but if your running without subframe spacers make sure you knock the #(*$ out of your firewall cause your heater hoses will heavily kink up there

[Jean]

Thats exactly what I plan on doing, I don't want to affect the suspension in a negative way. I have a spare pan already :)

For most people that just dd the car it probably doesn't matter.....but it all adds up and matters when 0.01 second can mean a difference in racing.

[dirtysix]

Thats exactly what I plan on doing, I don't want to affect the suspension in a negative way. I have a spare pan already :)

For most people that just dd the car it probably doesn't matter.....but it all adds up and matters when 0.01 second can mean a difference in racing.

But, either the engine fits the subframe, or not. Spacing it off the chassis rail makes no difference to engine-subframe clearance. Right?

[robiniscool]

what im trying to say is



that aluminum thing that the hoses go to WILL hit the firewall, so weld a different inlet/outlet so the hoses can go in and your golden cause that middle part where that Y is it will hit your firewall and the line on the left will hit where your booster used to be

[Jonsku]

that aluminum thing that the hoses go to WILL hit the firewall, so weld a different inlet/outlet so the hoses can go in and your golden cause that middle part where that Y is it will hit your firewall and the line on the left will hit where your booster used to be

Yep, but that's not really related to subframe spacers.

Best way to solve that is by paying aluminium welder couple of bucks for his time. No big deal.

[Etexise30]

heard and read somewhere that u pound the firewall a bit and u cut the pipes to the heater core and do custom lines cuz there alum

[E30SPDFRK]

My oil pan is in the pictures up there; I did it for steering rack clearance, not to lower the engine more. If you have a e36 or e46 rack with the spacers on the bottom, the oil pan starts to hit as soon as your engine mounts start to sag. The notch only gives you clearance for that, there's no way you're going to make up the 1' that the subframe spacers give.

And I've said this before and I'll say it again, the engine angle makes basically no difference on guibo wear or drivetrain vibrations. Throw it in without the spacers, enjoy the increased ground clearance and go do some burnouts.

[Etexise30]

Throw it in without the spacers, enjoy the increased ground clearance and go do some burnouts.

:twisted:

[Will_NZ]

I am not using subframe spacers, my sump is standard and my rear hoses do not hit the firewall (but are VERY close to it). I am using the standard M60 mounting arms which mount onto separate mounting brackets which are bolted through the chassis rail, so the engine is pretty solid. (I can remove the subframe without disturbing the motor, was a handy feature when building the exhausts).
When I started researching the swap, I got the impression from various builds that the spacers were used so that the bonnet would close without hitting the engine, this is the reason I decided to mount the motor onto the chassis rather than the crossmember so I could adjust the engine height to allow the bonnet to close, and then see how the crossmember fitted. to my suprise, I only needed a bit of tweaking to get it in without spacers.
It is all very tight in there, more so because I am using the V8 auto box as well, but so far no knocks..

[JFarhanbod]

I was gonna say this sounds exactly like noid then I realized you pulled it from his website lol

[noid]

ummm... what is the "big news"?


I'm still wondering why people are so afraid of bump steer? I suppose they aren't lowering their cars, as that *dramatically* changes the bump-steer as well ..

We had this discussion before in another thread. As BruceBe concluded:

Yep, we simply modified the pan to get the engine as low and level as possible. I've documented the process elsewhere on the forum. In our view, this approach met more of the success criteria for our project than spacers. Since it's a race car, we had no desire to alter the suspension geometry in any manner (beyond what we have already done to achieve acceptable handling response over the last 8+ years).

Keep in mind, that the lower control arm mounts to *both* the body and the subframe. Spacing the subframe alters the angle of the LCA, which can have an impact on any anti-dive built in to the chassis (it will increase anti-dive, in this case). It will have a 2nd-order effect on caster as well. With a lowered car, it will also further place the LCA in unfavorable, non-linear areas of the camber curve.

How much of this is relevant AT ALL to a street car is a matter of opinion, but none of it is directionally correct. However, if modifying the oil-pan is outside the scope of a particular project, it's probably not the end of the world.

-Bruce

I also think your thinking about this in an odd way as far as comparing it lowering a car. When you lower a car you do not lift the body in relation to the subframe, nor lift the center of gravity in relation to the suspension system.

No one is afraid, we are just interested in executing the swap as properly as it should be. There are many ways to do it almost right. No one is saying that if you space your subframe that you will forever have a shitbox or that it will inevitably fly into a tree. However, leaving the suspension and center of gravity in relation to the subframe constant is important in my mind to make it completely correct.

When its nearly the same cost to notch a pan and not pay for spacers as it is to pay for spacers and not notch the pan there is no reason people shouldn't be doing it this way.

Lets put it this way; there is absolutely NO advantage to having spacers. There are MANY advantages to not having spacers and notching the pan.

you dont need to use subframe spacers or tweak your oil pan if you think of it your motor mounts go on the subframe itself and lowering will lower the whole motor from the frame. but if your running without subframe spacers make sure you knock the #(*$ out of your firewall cause your heater hoses will heavily kink up there

As I stated in my article, you do not need spacers, nor do you need to notch the pan but you will be left with two problems:
1. Angle
2. Space under the hood

The engine indeed is mounted to the subframe, hence you would make your engine mounts smaller in height. Making the engine lower in relation to the subframe as opposed to using the 300mm mounts. However to do this you need to notch your pan because if you try to lower the engine anymore then the 300mm mounts it will hit the steering rack.

My oil pan is in the pictures up there; I did it for steering rack clearance, not to lower the engine more. If you have a e36 or e46 rack with the spacers on the bottom, the oil pan starts to hit as soon as your engine mounts start to sag. The notch only gives you clearance for that, there's no way you're going to make up the 1' that the subframe spacers give.

And I've said this before and I'll say it again, the engine angle makes basically no difference on guibo wear or drivetrain vibrations. Throw it in without the spacers, enjoy the increased ground clearance and go do some burnouts.

You did it for other reasons but in general the same area needs to be notched so I found your picture useful :)

There is no need to notch a full inch, its more so around the 0.4-0.75 range. Brucebe did it, its possible. That point is irrelevant though because ANY amount in notching is beneficial. Doesnt matter whether you achieve 0.1" or 0.75"; with appropriate engine mounts you are mitigating the problems to a lesser (0.1") or greater (0.75") extent, both ways you are making it better then having to use taller subframe spacers.

I can appreciate your opinion that the angle makes basically no difference (I would disagree). Even if it made a minute difference, that would still make it minutely incorrect from being correctly done. As long as there is a better way to do something it is always worth doing. Lets also not forget that by notching the oil pan, the engine can sit lower, and that will produce a more natural/lower center of gravity. A lower center of gravity is always better.

I was gonna say this sounds exactly like noid then I realized you pulled it from his website lol

Do I write in a recognizable way? :rofl:

[Jonsku]

Still want to comment on this :)

Lets put it this way; there is absolutely NO advantage to having spacers. There are MANY advantages to not having spacers and notching the pan.

As I stated in my article, you do not need spacers, nor do you need to notch the pan but you will be left with two problems:
1. Angle
2. Space under the hood

Yes, I agree. Spacers are not completely good, but they DO give you two positive things;
a) They lower the engine so you can fit E32/E34 coolant reservoir to the correct place (more or less the best place it can physically be), 20mm drop
b) You don't need to mess up with trying to TIG oil pan oil-proof (i.e. that it would not "sweat" all the time). Yes, can be done but not completely "walk in the park"..

I can appreciate your opinion that the angle makes basically no difference (I would disagree). Even if it made a minute difference, that would still make it minutely incorrect from being correctly done. As long as there is a better way to do something it is always worth doing. Lets also not forget that by notching the oil pan, the engine can sit lower, and that will produce a more natural/lower center of gravity. A lower center of gravity is always better.

And this all is based on assumption that E30 suspension geometry is perfect and does not contain any compromises in the first place.. ? I really wonder what the rest of the car looks like when 10-20mm difference in front subframe height causes so much hassle..

I totally understand your thinking in a way that suspension geometry should not be played around with, but still want to make a point that the starting point is not perfect either..