Engine swap thoughts

[jarrodblake]

I'm using a 01 boxster as the base of my restomod build. The current engine is a good running 2.7 with 120k on it. The engine runs fine. However I don't trust it. I plan on doing the ims bearing upgrade maybe a even a direct oil injection upgrade as well. But I want more power, I was also planing to turbo the engine. But I just don't know if its worth it. Lately I have been thinking about swapping in a Subaru 3.0-3.6 engine or even a V8 LS1 or even an audi?

My thoughts.

If I do the IMS and turbo the engine and It last to 200k then great! but if it kills it self then I have to replace it.

Do I go ahead and replace it with a subaru engine or v8 and not worry about it?

If I sell the 2.7 that is currently in good condition it can almost pay for the swap.

If I don't sell it now it could live to 200k but it could also kill its self and I would have to pay more for a swap.


So do I take the risk and do all the preventive maintenance that I can to the 2.7 or do I swap in something I know will be more reliable?

A pic just because some one will ask Restomod 70 911

[itsnotanova]

I vote for the sub motor and trans. Overall I think it will be your best bang for the buck. I love the idea of LS1 power, but you're already short on space behind the seat and I think the longer V8 motor will make things worse. You would also have to upgrade to a Boxster S 6 speed or try and find an audi 01E 2wd transaxle. That base 5 speed won't easily hold up to that power. I don't like the idea of trying to turbo the 2.7 either. I think you'll be disappointed by the amount of $$ you spend for 300ish hp. Another idea might be a 911 3.6 or 3.8?

[jarrodblake]

The subaru engine is first on my list. As for the boxster trans, do you have a link or data on what its rated at? I can not find any info on how much power they can handle.

[The Radium King]

transmissions - check the kit car sites where these are used a lot. the 986 5-speed is an audi 012 unit not good for much over 300 hp if that. the 6-speed units (either 986 or 987/997) can handle just about anything. go for a 987/997 unit if you can as they are lighter and shorter (resulting in better axle alignment and cv longevity).

for non-Porsche engines I think the subi is the best soln; there are long threads on both conversions on this forum and the Subaru seems to work the best. I think you could alleviate any of your space problems by cutting out the engine compartment and fabricating your own firewall back there. do that and I bet you could fit a Metzger engine in that thing - 450 hp 996 tt Porsche power!

[ルーカス]

If you're considering Subaru engines I recommend going with the JDM EJ207 with the twinscroll turbo. I have enough friends that have done subaru to subaru swaps and that is the preffered motor. It's a two liter that's fairly reliable and pulls like hell!

It also doesn't suffer from the ring land issues that the EJ25's do. Just something to take into consideration if you start modifying it. I had a friend with a 2009 STI hatch (had just about every single bolt on) and it grenaded. After almost two years the car is back on the road now making 430AWHP lol.. It was an interesting build to say the least and I'm pretty sure I'm poisoned by the amount of coolant I got in my mouth when he undid his rad hose LOL.

[flaps10]

I owned an OBXT which I modded to stage 3 and had a ton of fun with it. In fact it was a freak in the snow, dirt, mud, etc. I probably have never owned a car that had as much shove off the line.

While I think a Subaru engine would be fun in a boxster, be forewarned: They are not without their own flaws.

There isn't much oil in the Subaru and the filter is pathetic. It is somewhere between a shot glass and coffee cup in size. It is also located right next to the exhaust so it doesn't exactly stay cool.

Check the forums where I used to frequent and you'll see as many people with boat anchor turbo subaru motors as anyone with an IMS problem here. My own XT had an engine put in at 57k miles, immediately before I bought it. The small filter clogs easily and goes into bypass mode. Next up, a small filter screen on the way to lube the turbo gets plugged. From there the turbo comes apart and the engine ingests the pieces.

The invoices I had for the short block and new heads (you can't buy a long block from Subaru) was $11k, so let's set aside any illusion that you can get a great engine for a few grand.

The same engine is also known to have the oil pickup tube fall off, causing immediate oil starvation. I didn't experience this problem but it happens.

Now, all of this is something you can mitigate if you really want to go with the Subaru. First change the oil a lot to prevent the joke of an filter from being clogged. You can run the filter from an RX-8 mazda for slightly increased volume but it is a small effort.

Next, remove the filter screen. Dirty oil to the turbo is way better than no oil.

Next, ditch the factory turbo. There is a hybrid turbo available for around $700 that puts great low/mid range power down and is far more durable than the factory unit.

Seek the aftermarket oil pick up. Fresh timing belt, tensioner and waterpump.

If you go above the 16psi that I ran your intercooler will let go. Plenty of welded aluminum aftermarket solutions there. Go much above stage 3 and it gets very expensive.

Not saying it wouldn't be a really fun project, just do it with your eyes open.

[woodsman]

$11000! I could have a Porsche for that....

[Jamesp]

The LS1 seems like a good choice from a bang for the buck, and long term reliability standpoint.

[ルーカス]

Originally Posted by Jamesp

The LS1 seems like a good choice from a bang for the buck, and long term reliability standpoint.

You make a valid point, American heart in a German car... Although on paper it sounds great, I wouldn't want the Porsche gods to hate me lol.

As for the EJ's those engines have problems just like ever other engine, the 2.5's suffer from the ring land failures and head gaskets. The whole oil starvation is easily fixed with an oil pressure gauge. Keep an eye on it and you will be okay. The only other oil starvation i've ever seen is guys running VERY stiff suspension with R-compounds on exceptionally long turns (the sweeping right at mosport park for example). There's pros and cons to every engine I suppose. I'd like to stay in the Porsche family.

[Porsche9]

Stick with a Porsche motor. Go find yourself a low miles 3.4 or 3.6, take care of the IMS and any other know weakness and sell the old 2.7l to help pay for it all.

[itsnotanova]

I'm thinking about going with the Audi 2.7T for my mid-engine 911. This is what sparked my interest in that motor.
https://www.youtube.com/watch?v=lEtNMxVKegM
They did a single turbo conversion on the one in the video, but they come with twin turbos from the factory. It's a pretty stout motor in stock form and not too hard to get 600hp out of them with some bolt-on parts. The more I read up on the 2.7T, the more I like it. Heck I'm half tempted to put one in a boxster. The biggest reason I'm leaning toward the 2.7T, is their size. It's only roughly 18 inches long and they're dirt cheap. You can pick one up for just a few hundred $$. I had the chance today to see one in person and get some measurements. I took a 6 speed along with me so I could see how well they mate up.


The dowel pins are just a hair too big and keep the engine and trans from mounting flush together. That would be an easy fix by just drilling out the dowel holes.

This is another problem when trying to mate the Porsche 6 speed to the 2.7T. The starter is in the bottom right corner. Still not a hard fix. Just cut out an area for the starter nose and weld on a cover.

[ルーカス]

Originally Posted by itsnotanova

I'm thinking about going with the Audi 2.7T for my mid-engine 911. This is what sparked my interest in that motor.
https://www.youtube.com/watch?v=lEtNMxVKegM
They did a single turbo conversion on the one in the video, but they come with twin turbos from the factory. It's a pretty stout motor in stock form and not too hard to get 600hp out of them with some bolt-on parts. The more I read up on the 2.7T, the more I like it. Heck I'm half tempted to put one in a boxster. The biggest reason I'm leaning toward the 2.7T, is their size. It's only roughly 18 inches long and they're dirt cheap. You can pick one up for just a few hundred $$. I had the chance today to see one in person and get some measurements. I took a 6 speed along with me so I could see how well they mate up.


The dowel pins are just a hair too big and keep the engine and trans from mounting flush together. That would be an easy fix by just drilling out the dowel holes.

This is another problem when trying to mate the Porsche 6 speed to the 2.7T. The starter is in the bottom right corner. Still not a hard fix. Just cut out an area for the starter nose and weld on a cover.

You had my interest but now you have my attention.
Build thread anywhere?

[Smallblock454]

@ itsnotanova:

What Audi engine are you talking about. There are different 2.7 Audi Biturbo engines out there. Especially if you are talking about engines prior 2001 - they have a lot of problems if they are getting older:
Turbochargers
Y Hose / pipeignition coils
Lambda sensors
Crankcase ventilation system
Manifold
Throttle
Camshaft actuator leaking / broken
F-hose at the engine Conditions
Control lines to the wastegate doses
Exhaust gas temperature sensor
Power Amplifiers ECU

So maybe you can get them cheap, but very often you have to put a lot of money into them.

I would recommend to search some Audi forums.

Regards from germany
Markus

[Bigsmoothlee]

That looks like a fairly rust free 1970 911.

Please dont kill it. There are a million boxsters but only a few early 911s.

If you are... Can you cut the nose in front of the wheels and sell it to me?

[Qmulus]

I have owned an Audi A6 2.7T 6speed for 14 years and an Audi owner for over 25 years, even making a business in automotive electronics. I know the 2.7T very well. Some of what Markus mentions are common issues with them. I have dealt with most of those issues myself and don't consider any of it to be a big deal.

I don't know what he means about manifold and throttle issues. The rest are pretty minor, especially as compared with M96 issues. The Audi 2.7T issues are mostly in the annoying category. Turbo failures are almost exclusively on tuned cars, especially with intake leaks that result in the turbos overspinning. Cam adjuster seals leak (pretty simple fix), but they rarely if ever fail. O2 sensors fail (I replaced two of mine at 110k), but they fail on all cars, especially turbos. The plastic PCV hoses fail, which is annoying, but not serious nor expensive to fix. Later cars with the secondary air injection have problem with combi valves, leading to failed pumps. That repair is probably the worst IMO, but that system can be coded out and the ports plugged. My car is a '00, so it has no secondary air injection. One problem he did not mention was the auxiliary coolant pump, which Audi decided to put in the valley under the intake manifold.

Personally, I don't think I would put a 2.7T in a Boxster for a few reasons. First, the intake plumbing would be a big issue. You will need to find a place for the intercoolers with good airflow. If you look at the front of an Audi with the front bumper off, it is all coolers. Maybe you modify the sides with big scoops to accommodate those. So, you end up with the same issues you would run into trying to put a 996TT Mezger engine in it. The intercoolers are critical to making power on the 2.7T, so that is a BIG issue.

Next, to get more than 300hp, you will need bigger than stock turbos, which means added lag. To me, part of the appeal of the Boxster is the naturally aspirated engine. While it would be fast as hell with a 450hp 2.7T, it would have more lag than a 450hp 3.6 Porsche engine.

Then there is the rest of the fitment issues. The Audi engine is short, but it is also tall and wide. I think the height would be more of an issue than the width, but having not fit one, I can't say for sure.

In my opinion, if I was going with an Audi engine, I would go with a 4.2L V8 from an '01 or '02 S6 or S8. You would have 360hp naturally aspirated horsepower in the most reliable engine Audi ever built. Weight wise I believe it is lighter than the 2.7T as it is all aluminum (the 2.7T is a cast iron block), with no turbos and the additional intake plumbing required. You would still need to deal with the height of the V8, which is the same as the 2.7T. You also have a bit more length, but it is considerably shorter than a Chevy LSx. I like the idea of a Boxster with a Spyder conversion (getting rid of the stock convertible top) would open up a bunch of room on the top of the engine.

Concerning the Audi V8s, I would stay far away from the later V8s with timing chains. These are the M96s of Audi engines. Well, maybe not quite that bad, but close. They are short, but the cam adjustment actuators, chain adjusters and guides fail. Fixing that is ~$3k in parts and 40hrs labor.

[jarrodblake]

Anyone have any detailed info on the audi 4.2 v8 swap. I have found a few threads on the swap but not any that go into detail. I know it will bolt up to the trans, but cant find what clutch/ flywheel set up.? Is the auto engine the same as the manual, can I just reflash/ tune the ECU. Did any of the timing belt engine use a Map sensor or did they all use Mass air flow sensors? Anyone know the best year timing belt engine is to get? or anyone know of a year list/ modle list for the timing belt engines? I'm having really bad thoughts about runing a audi 4.2 with individual throttle bodys. Cutting away the engine cover and having an open bay with a fire wall kinda like old 993 mid-engine FABCAR. Walking up to the car peeking into the back of and a V8 with ITBS sitting back there.





Can you imagine this with ITBS



That said I'm still on the fence about doing the swap. I know it has been done I just cant find any info on pluming then engine and the wiring side of the swap. Ideally I would like to buy an engine with a full harness. But I cant find anything on compatibility when It come to doing the two harness or what ECU. or if I should build a standalone harness for a standalone ECU or even which one to use?


Also I have been thinking about posting my engine up on CL, Kinda as a feeler stating the engine is still in the car, but don't know what to ask, any thoughts?

[woodsman]

Whew your a man of action! Wow. I'm tired after looking at it for 5 min. So much work but hey you have a dream and the ambition to do it. Not to mention the cajones. Can't answer any of your questions but I'm pull'in for ya. And I think a V8 would be perfect!

[itsnotanova]

I've been surfing Audizine a lot lately researching the audi engines and transmission for my swap. Another good site is 034motorsports.com because they sell a lot of aftermarket parts for audi's. When it comes to the wiring, you can either buy an aftermarket stand alone system or use the stock wiring system from the donor vehicle. From what I understand, Audi wiring systems are easy to separate the engine harness and useful wiring from the unneeded wiring. I can't answer what 4.2 engines are best because I'm going with the 2.7T but I believe both engine share the same bell housing bolt pattern and flywheel/clutch. This is strictly my opinion and haven't been able to verify yet. I believe you'll need to use an Audi flywheel and clutch no matter what. I don't think the Audi starter reaches far enough to engage the teeth on a Porsche flywheel. Both Audi 2.7T/4.2 and Porsche M96 motors have the pilot bushing in the flywheel. I'm not sure if the transmission shaft is the same distance to reach into the pilot bushing though. From what I can also tell, the 5 speed Porsche tranny should bolt up to the audi without any modifications. The 6 speed from a 2000-2004 will need to be modified for the starter. Starting in 2005, the Porsche 6 speed has the same transmission bolt pattern as the 5 speed. I will be answering these questions for myself at some point. My plan is to buy a 2.7T engine soon and see how well it fits in my chassis with the Porsche 6 speed. I don't think it will fit, so I'll probably end up going with the Audi 01E 6 speed trans.

What's the story with this picture and where did you find it?

Originally Posted by jarrodblake

[itsnotanova]

On my post with the pictures of the 2.7T and the 6 speed together there shows a gap between the two. The guy who was letting me test fit my tans to his 2.7t had forgotten that there was a factory spacer on the AUdi motor. That spacer fills the gap and a 6 speed should bolt up snug with no problem.

[jarrodblake]

Thank you! I found Audizine last night and have been doing a lot reading. I also found the 034Motorsport makes a Flywheel Insert, but I cant find anything on if it will work with the boxster trans or what clutch to use. Also what do you mean by an aftermarket stand alone system? Are talking about a harness or the ECU I have not seen any after market harness that would be nice.

As for the pic I found it on this forum it from the same guy that did the sti swap kit however he does not plan on making a kit for the audi 4.2. The engine in the pic is the ABZ engine. At the moment I plan on using the same engine as the stock 5 speed trans "should" be able to handle the power 300hp. I don't know if he ever finished the swap as I cant find anymore info on it other then finding the same pics on other forums.
http://986forum.com/forums/general-discussions/25697-boxster-subaru-conversion-interest-4.html#post221925

Also wow I don't know why but I had my setting set for display mode set to hybrid mode and I could not see you post to the 2.7t to the six speed, I just changed it to linear mode and now I can see all the post?