Engine Swap Clutch/Flywheel Question

[Sleepy_Steve]

I am thinking about putting a BMW engine into my 240. I am also thinking about retaining the Nissan transmission and differential. Unless I want to be gear limited to 118mph, the 1-1 5th gear in the BMW box would require me to also swap to a non OEM final drive ratio, so I figure I'm saving 50 points by retaining the Nissan transmission and final drive. 

 

The engine swap rule:

Quote

4.5.3. Engine swaps include stock long block, OE stock exhaust manifolds, stock induction system, motor mounts, wiring, and transmission adapters

 

The clutch point value rules:

Quote

• Flywheel / Clutch - Aluminum / performance “light-weight” SFI recommended rated flywheels with stock type clutch: 10 pts

• Flywheel / Clutch - Multi-disc and / or smaller diameter clutch/flywheel systems: 50 pts

 

How do I estimate the points value for the clutch / flywheel / pressure plate used with the swap? For the discussion and my wallet, lets assume OEM parts from both sides, will those count as the "transmission adapters" mentioned in the swap rules? 

 

From what I've figured out so far, I would need to use a BMW flywheel, a Nissan clutch disk, probably a Nissan pressure plate (TBD if that'll work), and likely a spacer either between crank and flywheel or one behind the throw out bearing.

 

Do I need to plan to take 10 points if I use a BMW flywheel or pressure plate because its not 'OEM' for the receiving car?

 

 

Yes I know the other option is the BMW engine + trans + non OEM final drive and (I assume) that would let me run an aftermarket LSD as well.

[Team Infiniti]

Funny, doing the opposite with a e30 chassis, we are installing a vq30 grafted to the factory bmw autotragic.

 

You should be fine calling whatever it takes to couple the engine/trans as swap parts included in the $1500 swap math

[mhr650]

Don’t use an aluminum flywheel, or especially a Tilton multi disk and you will be fine. and nowadays you get $2500 allowance for the swap.

[wvumtnbkr]

Yep.  I have a gm v6 with a 4 cylinder flywheel and clutch matched to a camaro v6 from a different engine.  All stock parts.

 

As long as you aren't using cheaty parts and not claiming them,  it falls under the trans swap or engine swap and the 2500$ allowance for engine swap.

[Grufton]

2 hours ago, mhr650 said:

Don’t use an aluminum flywheel...

 

Last I heard, for 2022 that's not an issue either.

[Sleepy_Steve]

7 hours ago, Grufton said:

 

Last I heard, for 2022 that's not an issue either.

 

Well if that's not inviting speed creep, I don't know what is haha. 

 

10 hours ago, Team Infiniti said:

Funny, doing the opposite with a e30 chassis, we are installing a vq30 grafted to the factory bmw autotragic.

 

You should be fine calling whatever it takes to couple the engine/trans as swap parts included in the $1500 swap math

 

I guess that's one way to approach drag races down the straights. 

 

From your stance, I don't think any of the parts I have on hand will be an issue. 

 

[mhr650]

18 hours ago, Grufton said:

 

Last I heard, for 2022 that's not an issue either.

 

I would really like to be able to use a 7.25 Tilton dual disk. having a set it and forget it solution is so attractive.

[Aleric Sanders]

On 8/19/2021 at 11:06 AM, Sleepy_Steve said:

I am thinking about putting a BMW engine into my 240. I am also thinking about retaining the Nissan transmission and differential. Unless I want to be gear limited to 118mph, the 1-1 5th gear in the BMW box would require me to also swap to a non OEM final drive ratio, so I figure I'm saving 50 points by retaining the Nissan transmission and final drive. 

 

The engine swap rule:

 

The clutch point value rules:

 

How do I estimate the points value for the clutch / flywheel / pressure plate used with the swap? For the discussion and my wallet, lets assume OEM parts from both sides, will those count as the "transmission adapters" mentioned in the swap rules? 

 

From what I've figured out so far, I would need to use a BMW flywheel, a Nissan clutch disk, probably a Nissan pressure plate (TBD if that'll work), and likely a spacer either between crank and flywheel or one behind the throw out bearing.

 

Do I need to plan to take 10 points if I use a BMW flywheel or pressure plate because its not 'OEM' for the receiving car?

 

 

Yes I know the other option is the BMW engine + trans + non OEM final drive and (I assume) that would let me run an aftermarket LSD as well.

One can argue the flywheel is part of the engine swap. The BMW engine you are swapping to most likely has a dual mass flywheel.  The 13th bullet of Rule 4.7.2 in the BCCR states:

Quote

• Flywheel - All flywheels must be OE, OE equivalent, or SFI rated. Unmodified, SFI rated steel flywheel with similar dimensions and stock type / single disc clutch are zero points. Dual-mass flywheels may be converted to singlemass meeting above specifications for zero points.

By using this rule, you can find an SFI rated single mass flywheel that is likely just under the OEM dual mass version (not by much weight, but every little bit helps) for zero points.

[Rodger Coan-Burningham]

15 hours ago, mhr650 said:

 

I would really like to be able to use a 7.25 Tilton dual disk. having a set it and forget it solution is so attractive.

 

You can:

 

• Flywheel / Clutch - Multi-disc and / or smaller diameter clutch/flywheel systems: 50 pts

[Sleepy_Steve]

On 8/20/2021 at 11:23 AM, Aleric Sanders said:

One can argue the flywheel is part of the engine swap. The BMW engine you are swapping to most likely has a dual mass flywheel.  The 13th bullet of Rule 4.7.2 in the BCCR states:

By using this rule, you can find an SFI rated single mass flywheel that is likely just under the OEM dual mass version (not by much weight, but every little bit helps) for zero points.

 

Correct, the donor engine had a dual mass flywheel from the factory. The down side is that although free, it didn't come with a clutch / flywheel to pull measurements from.

 

I did find a single mass flywheel conversion kit (clutch kit + single mass flywheel) on RockAuto though, so maybe I'll use that. 

[Aleric Sanders]

11 hours ago, Sleepy_Steve said:

 

Correct, the donor engine had a dual mass flywheel from the factory. The down side is that although free, it didn't come with a clutch / flywheel to pull measurements from.

 

I did find a single mass flywheel conversion kit (clutch kit + single mass flywheel) on RockAuto though, so maybe I'll use that. 

Don't use RockAuto! Trust me, a few years ago, I thought RockAuto was the most cost effective route for quality parts... Turns out some parts are knock-offs or defective from the factory, but reworked.  You will spend more time and money exchanging parts from RockAuto. For BMW parts, go to FCP euro (lifetime warranty on all parts) or Bimmerworld.  ECS tuning is hit or miss, but this conversion kit from them has been good to my team with an M50 engine: https://www.ecstuning.com/b-ecs-parts/performance-flywheel-sachs-clutch-kit/000282ecs01kt/. I got it when there was a sale going on a while back. It's a little costly, but well worth it. Quality parts with a SFI rated machined steel flywheel.  Compare the kit cost to a factory replacement dual mass, and you're still under the 2X rule.

Edited August 23, 2021 by Aleric Sanders

[TiredBirds]

the 240z had a nice mill, why not change your trans instead? 25 points and done. And as the above mentions....RockAuto is a crap shoot. Some of their stuff is ok, some is not. We ordered some control arm bushings, they were NOS alright, made in 1984, they were all cracked up. By the time you factor in shipping costs and how long it takes, you are better off using a local parts store. I like NAPA. A little more expensive but the parts are quality. 

[wvumtnbkr]

1 hour ago, Aleric Sanders said:

Don't use RockAuto! Trust me, a few years ago, I thought RockAuto was the most cost effective route for quality parts... Turns out some parts are knock-offs or defective from the factory, but reworked.  You will spend more time and money exchanging parts from RockAuto. For BMW parts, to to FCP euro (lifetime warranty on all parts) or Bimmerworld.  ECS tuning is hit or miss, but this conversion kit from them has been good to my team with an M50 engine: https://www.ecstuning.com/b-ecs-parts/performance-flywheel-sachs-clutch-kit/000282ecs01kt/. I got it when there was a sale going on a while back. It's a little costly, but well worth it. Quality parts with a SFI rated machined steel flywheel.  Compare the kit cost to a factory replacement dual mass, and you're still under the 2X rule.

Just an fyi that there is no more 2x rule iirc.

[Sleepy_Steve]

49 minutes ago, Aleric Sanders said:

Don't use RockAuto! Trust me, a few years ago, I thought RockAuto was the most cost effective route for quality parts... Turns out some parts are knock-offs or defective from the factory, but reworked.  You will spend more time and money exchanging parts from RockAuto. For BMW parts, to to FCP euro (lifetime warranty on all parts) or Bimmerworld.  ECS tuning is hit or miss, but this conversion kit from them has been good to my team with an M50 engine: https://www.ecstuning.com/b-ecs-parts/performance-flywheel-sachs-clutch-kit/000282ecs01kt/. I got it when there was a sale going on a while back. It's a little costly, but well worth it. Quality parts with a SFI rated machined steel flywheel.  Compare the kit cost to a factory replacement dual mass, and you're still under the 2X rule.

 

I've generally had good luck across a number of brands with them. For $350 shipped vs 900 and not being able to easily re-drill a those light-ish steel flywheels for a different pressure plate, I'm inclined to give it a shot. 

 

40 minutes ago, TiredBirds said:

the 240z had a nice mill, why not change your trans instead? 25 points and done. 

 

Its a '95 240sx, and frankly it did not have a good engine from the factory. 30+ HPDE weekends taught me that much.  Given their prevalence with engine swaps and drift cars, it's harder and harder to find those stock engines. 

 

It's best time with a lot of weight reduction, bolt on suspension parts and 153whp out of the KA (cams + tune + intake manifold + long-tube header) was in the mid-low 2:30's at VIR... With the SR that made 209whp I got it into the 2:14's before it kicked a rod on that engine's 5th event. My guess is that the 189 crank HP out of the M50 will put me into the mid 120's, and that seems appropriate from the times teams were putting in a few weeks ago at the 24. 

 

I could do the swap with the BMW transmission and eat the 25 points, and probably another 10 for changing the length of the drive shaft, and then I'll be looking at  bouncing on the rev limiter down the straights because of the 240's 4.08 final drive and 1-1 BMW 5th gear. Using the stock transmission seems to be better from a points / cost perspective given what I know so far. 

[TiredBirds]

57 minutes ago, Sleepy_Steve said:

 

I've generally had good luck across a number of brands with them. For $350 shipped vs 900 and not being able to easily re-drill a those light-ish steel flywheels for a different pressure plate, I'm inclined to give it a shot. 

 

 

Its a '95 240sx, and frankly it did not have a good engine from the factory. 30+ HPDE weekends taught me that much.  Given their prevalence with engine swaps and drift cars, it's harder and harder to find those stock engines. 

 

It's best time with a lot of weight reduction, bolt on suspension parts and 153whp out of the KA (cams + tune + intake manifold + long-tube header) was in the mid-low 2:30's at VIR... With the SR that made 209whp I got it into the 2:14's before it kicked a rod on that engine's 5th event. My guess is that the 189 crank HP out of the M50 will put me into the mid 120's, and that seems appropriate from the times teams were putting in a few weeks ago at the 24. 

 

I could do the swap with the BMW transmission and eat the 25 points, and probably another 10 for changing the length of the drive shaft, and then I'll be looking at  bouncing on the rev limiter down the straights because of the 240's 4.08 final drive and 1-1 BMW 5th gear. Using the stock transmission seems to be better from a points / cost perspective given what I know so far. 

what rear gears are available for you? 

[Aleric Sanders]

1 hour ago, Sleepy_Steve said:

 

I've generally had good luck across a number of brands with them. For $350 shipped vs 900 and not being able to easily re-drill a those light-ish steel flywheels for a different pressure plate, I'm inclined to give it a shot. 

 

 

Its a '95 240sx, and frankly it did not have a good engine from the factory. 30+ HPDE weekends taught me that much.  Given their prevalence with engine swaps and drift cars, it's harder and harder to find those stock engines. 

 

It's best time with a lot of weight reduction, bolt on suspension parts and 153whp out of the KA (cams + tune + intake manifold + long-tube header) was in the mid-low 2:30's at VIR... With the SR that made 209whp I got it into the 2:14's before it kicked a rod on that engine's 5th event. My guess is that the 189 crank HP out of the M50 will put me into the mid 120's, and that seems appropriate from the times teams were putting in a few weeks ago at the 24. 

 

I could do the swap with the BMW transmission and eat the 25 points, and probably another 10 for changing the length of the drive shaft, and then I'll be looking at  bouncing on the rev limiter down the straights because of the 240's 4.08 final drive and 1-1 BMW 5th gear. Using the stock transmission seems to be better from a points / cost perspective given what I know so far. 

Oh, geez... Definitely going to need a different gear ratio! With the M50/Getrag pair, the 3.38 ratio is the go to for track use. Currently have a 3.15 in the E36. Tried a 3.91 at Nelson Ledges years ago, thinking I would get away with it, as it is a much smaller track, and I had to lift half way down the back straight to keep it from bouncing on the limiter in 5th (and, the Nelson Ledges back straight is plenty shorter than many other tracks).  At VIR with a 4.08, you would likely be at redline in 5th before the uphill esses, before South Course pit out, and before the halfway point of the main pits.

[wvumtnbkr]

I know a lot of e30 that run 4.10 gears in the rear end with 23 inch tires and dont seem to run out of rpms at VIR or similar tracks.

 

Is the gearbox different in an e30?

[Aleric Sanders]

2 minutes ago, wvumtnbkr said:

I know a lot of e30 that run 4.10 gears in the rear end with 23 inch tires and dont seem to run out of rpms at VIR or similar tracks.

 

Is the gearbox different in an e30?

Yes, the Getrag 260 in the e30 has a 5th gear ratio of 0.81:1, where the Getrag 250 in the E36 has a 5th gear ratio of 1:1.

[wvumtnbkr]

Welll.....  that's a bit different then.

 

What wheel size and max rpm are we going for here?

[Sleepy_Steve]

1 hour ago, Aleric Sanders said:

Oh, geez... Definitely going to need a different gear ratio! ...  At VIR with a 4.08, you would likely be at redline in 5th before the uphill esses, before South Course pit out, and before the halfway point of the main pits.

 

Oh yes, it would be highly sub-optimal / hilarious depending on your point of view. 

 

50 minutes ago, wvumtnbkr said:

What wheel size and max rpm are we going for here?

 

I was assuming at least 6800 and at most 7200... I don't remember what the redline of that engine was when I drove it one time at Summit Point years ago in it's initial chassis, but it was in that ballpark. Tire size is likely in the 24.72" - 25.68" range. 

 

1 hour ago, TiredBirds said:

what rear gears are available for you? 

 

Points free? 4.08 and maybe 3.96 on the ABS optioned cars... If I take the 25 points, the worlds my oyster basically.

[wvumtnbkr]

At 7200 rpm and the 3.96 rear end ratio and the 25.68 diameter tire combo, that would max out at 139 mph.  I would think that would be fantastic for everywhere but Daytona.

 

My cars gear limited top speed is 130 mph and we don't ever really touch that at a normal roadcourse.

[TiredBirds]

5 hours ago, Sleepy_Steve said:

 

Oh yes, it would be highly sub-optimal / hilarious depending on your point of view. 

 

 

I was assuming at least 6800 and at most 7200... I don't remember what the redline of that engine was when I drove it one time at Summit Point years ago in it's initial chassis, but it was in that ballpark. Tire size is likely in the 24.72" - 25.68" range. 

 

 

Points free? 4.08 and maybe 3.96 on the ABS optioned cars... If I take the 25 points, the worlds my oyster basically.

those are steep. We currently have a 3.40somthing / the 5 speed.  Never really use 5th. Taller tire might help you guys. Not sure what you can fit on one of those.