Help with internals!
Thread Starter
Teching In
Joined: Sep 2024
Posts: 17
Likes: 6
Help with internals! Hey guys. I’m new to this forum so go easy on me. I have a new project on my hands and need some help. I bought an LM7 to swap into my bmw 135i. Main reason why is because I’d like to learn the process to dropping and tearing apart a motor. I’m a mechanic by trade but I work for Tesla so I think I’m capable. I also just want my bmw to be as reliable as possible on track. My N55e motor is prone to oil starvation on long sweepers. And luckily for me Road America is my home track.
If you guys are familiar with bmw motors, I’d like to base my build off the s65: Good noises, high reving (7.5/8krpm), and about 400hp. But I’d like it reliable. If this is dumb then please tell me why. Also some ITBs would be sweet.
So questions are…
Is this dumb?
what internals would I need?
would it be reliable?
what do yall recommend?
what setup would u recommend?
any good info on the idea and internals in general?
any tips on the process in general?
Also the motor has BTR stage 2 cam, BTR rods and dual valve springs. Motor also sat for 3 years before I bought it hence also y I want to take it apart.
Thanks in advanced!
If you guys are familiar with bmw motors, I’d like to base my build off the s65: Good noises, high reving (7.5/8krpm), and about 400hp. But I’d like it reliable. If this is dumb then please tell me why. Also some ITBs would be sweet.
So questions are…
Is this dumb?
what internals would I need?
would it be reliable?
what do yall recommend?
what setup would u recommend?
any good info on the idea and internals in general?
any tips on the process in general?
Also the motor has BTR stage 2 cam, BTR rods and dual valve springs. Motor also sat for 3 years before I bought it hence also y I want to take it apart.
Thanks in advanced!
Joined: Apr 2006
Posts: 3,890
Likes: 1,137
From: Grand Rapids, Michigan
My first thought: Spend money on a good oiling system over anything else. A completely stock bottom end will get you 7000+ RPM, it's the valvetrain that needs to be upgraded, especially for sustained high RPM. A 5.3 isn't the best engine to start with, as the longer stroke and smaller bore can inhibit high RPM breathing. This is why the smaller 4.8 liter engines love to rev, even though they share a bore size with the 5.3. If you're going as far as to put together a forged rotating assembly, why even keep the LM7 iron block? That's going to slow you down and amplify understeer by making you nose heavy. If you want to keep it, have it bored out to LS1 size and it will be a 5.7 liter, which will easily meet your 400 HP goal ( I'm assuming you meant RWHP ). One thing to note, a 4.8 and a 5.3 that are fitted with identical cams, heads, valvetrain and intake manifolds will make within about 10HP of each other, but the 4.8 will peak out around 1200-1500 RPM higher than the 5.3.( the 4.8 makes quite a bit less peak torque, however ). If revs are what you're after, going slightly smaller will make that easier to accomplish. If it were my build? I'd go find an L33 or LH6 aluminum block, bore it to LS1 size and install a 4.8 crank. Install Summit ProLS domed pistons and H-beam rods, then mill a set of 706 heads to 58CC and have them CNC ported with lightweight valves. 312 cubic inches, about 11.7:1 compression, and 8K RPM ability. Should also make over 500 crank horsepower with ease. I'm sure others with more experience in the road race realm will chime in.
Thread Starter
Teching In
Joined: Sep 2024
Posts: 17
Likes: 6
My first thought: Spend money on a good oiling system over anything else. A completely stock bottom end will get you 7000+ RPM, it's the valvetrain that needs to be upgraded, especially for sustained high RPM. A 5.3 isn't the best engine to start with, as the longer stroke and smaller bore can inhibit high RPM breathing. This is why the smaller 4.8 liter engines love to rev, even though they share a bore size with the 5.3. If you're going as far as to put together a forged rotating assembly, why even keep the LM7 iron block? That's going to slow you down and amplify understeer by making you nose heavy. If you want to keep it, have it bored out to LS1 size and it will be a 5.7 liter, which will easily meet your 400 HP goal ( I'm assuming you meant RWHP ). One thing to note, a 4.8 and a 5.3 that are fitted with identical cams, heads, valvetrain and intake manifolds will make within about 10HP of each other, but the 4.8 will peak out around 1200-1500 RPM higher than the 5.3.( the 4.8 makes quite a bit less peak torque, however ). If revs are what you're after, going slightly smaller will make that easier to accomplish. If it were my build? I'd go find an L33 or LH6 aluminum block, bore it to LS1 size and install a 4.8 crank. Install Summit ProLS domed pistons and H-beam rods, then mill a set of 706 heads to 58CC and have them CNC ported with lightweight valves. 312 cubic inches, about 11.7:1 compression, and 8K RPM ability. Should also make over 500 crank horsepower with ease. I'm sure others with more experience in the road race realm will chime in.
Thread Starter
Teching In
Joined: Sep 2024
Posts: 17
Likes: 6
My first thought: Spend money on a good oiling system over anything else. A completely stock bottom end will get you 7000+ RPM, it's the valvetrain that needs to be upgraded, especially for sustained high RPM. A 5.3 isn't the best engine to start with, as the longer stroke and smaller bore can inhibit high RPM breathing. This is why the smaller 4.8 liter engines love to rev, even though they share a bore size with the 5.3. If you're going as far as to put together a forged rotating assembly, why even keep the LM7 iron block? That's going to slow you down and amplify understeer by making you nose heavy. If you want to keep it, have it bored out to LS1 size and it will be a 5.7 liter, which will easily meet your 400 HP goal ( I'm assuming you meant RWHP ). One thing to note, a 4.8 and a 5.3 that are fitted with identical cams, heads, valvetrain and intake manifolds will make within about 10HP of each other, but the 4.8 will peak out around 1200-1500 RPM higher than the 5.3.( the 4.8 makes quite a bit less peak torque, however ). If revs are what you're after, going slightly smaller will make that easier to accomplish. If it were my build? I'd go find an L33 or LH6 aluminum block, bore it to LS1 size and install a 4.8 crank. Install Summit ProLS domed pistons and H-beam rods, then mill a set of 706 heads to 58CC and have them CNC ported with lightweight valves. 312 cubic inches, about 11.7:1 compression, and 8K RPM ability. Should also make over 500 crank horsepower with ease. I'm sure others with more experience in the road race realm will chime in.
Thanks you for the input… I got a lot to look into. I talked to a local tuner and he dumbed it down for me and essentially said that with the mods the motor came with and since I’m new to all this, it makes no sense to build everything out off the rip. I really like the motor idea you have. At this point I think I’d rather spend less time and money in the motor and rather get seat time. So getting the motor built reliably and forgetting about reving the thing to the moon. Once I get seat time and experience building a motor, I’d like to take a crack at building something similar to what you mentioned.
Thread Starter
Teching In
Joined: Sep 2024
Posts: 17
Likes: 6
Refreshing to see a level headed individual on Tech these days. Get the seat time first and foremost…you can mod the engine later, if you even think you need it. It’s gonna be plenty fast as is. Spend your money on chassis, brakes, cooling, safety equipment etc right now.
The thing is right now I’m young and have no family to support and my parents are all for building it in the back yard, part of me wants to build that dream now before I don’t have the time or loose the passion for it as many of my coworkers have.
Thread Starter
Teching In
Joined: Sep 2024
Posts: 17
Likes: 6
My first thought: Spend money on a good oiling system over anything else. A completely stock bottom end will get you 7000+ RPM, it's the valvetrain that needs to be upgraded, especially for sustained high RPM. A 5.3 isn't the best engine to start with, as the longer stroke and smaller bore can inhibit high RPM breathing. This is why the smaller 4.8 liter engines love to rev, even though they share a bore size with the 5.3. If you're going as far as to put together a forged rotating assembly, why even keep the LM7 iron block? That's going to slow you down and amplify understeer by making you nose heavy. If you want to keep it, have it bored out to LS1 size and it will be a 5.7 liter, which will easily meet your 400 HP goal ( I'm assuming you meant RWHP ). One thing to note, a 4.8 and a 5.3 that are fitted with identical cams, heads, valvetrain and intake manifolds will make within about 10HP of each other, but the 4.8 will peak out around 1200-1500 RPM higher than the 5.3.( the 4.8 makes quite a bit less peak torque, however ). If revs are what you're after, going slightly smaller will make that easier to accomplish. If it were my build? I'd go find an L33 or LH6 aluminum block, bore it to LS1 size and install a 4.8 crank. Install Summit ProLS domed pistons and H-beam rods, then mill a set of 706 heads to 58CC and have them CNC ported with lightweight valves. 312 cubic inches, about 11.7:1 compression, and 8K RPM ability. Should also make over 500 crank horsepower with ease. I'm sure others with more experience in the road race realm will chime in.
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Joined: Apr 2006
Posts: 3,890
Likes: 1,137
From: Grand Rapids, Michigan
Basically, you're going to want an oil pan that has trap doors in it and extra capacity if there's one that fits your chassis. A good Melling stock replacement pump will be fine for this engine. I don't know who the "go to" company would be for BMW swaps - You're likely going to have to source the oil pan from there. Any sustained G turns could uncover the pick up if your pan doesn't have any sort of internal oil baffling. Foregoing the high RPM build will give more of a cushion to any oil capacity issues that may arise, but you still should make oil control a priority. My perspective is this: If you go overkill on the oiing now, even if you build a completely new engine, everything swaps over. You'll just have to do some research and see what other people have done. I'm certain you're not the first person to build a road race LS swapped BMW.
As for my opinion on the L33/LH6 blocks, they're lighter, of course, and at least in the case of the LH6, the aluminum block is stronger than the iron block. I used one for my 5.3 turbo build, and it's going to see north of 800 RWHP. The cylinder bores are siamesed, which means there's aluminum between the bores, no water jackets. This stiffens the block significantly. They're well known to handle large power levels, and the liners are so thick they can be bored up to .125 over. You can bore an iron 5.3 just as much, but I don't think they have the same cylinder integrity at that bore size.
As for my opinion on the L33/LH6 blocks, they're lighter, of course, and at least in the case of the LH6, the aluminum block is stronger than the iron block. I used one for my 5.3 turbo build, and it's going to see north of 800 RWHP. The cylinder bores are siamesed, which means there's aluminum between the bores, no water jackets. This stiffens the block significantly. They're well known to handle large power levels, and the liners are so thick they can be bored up to .125 over. You can bore an iron 5.3 just as much, but I don't think they have the same cylinder integrity at that bore size.
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Verdad Gallardo For any oil control mods on any LS or LT engine, I would consult with Improved Racing in Orlando Fla. They work with swap vehicles also. They are the premier oil control guys and their service is great.
Thread Starter
Teching In
Joined: Sep 2024
Posts: 17
Likes: 6
Thread Starter
Teching In
Joined: Sep 2024
Posts: 17
Likes: 6
Basically, you're going to want an oil pan that has trap doors in it and extra capacity if there's one that fits your chassis. A good Melling stock replacement pump will be fine for this engine. I don't know who the "go to" company would be for BMW swaps - You're likely going to have to source the oil pan from there. Any sustained G turns could uncover the pick up if your pan doesn't have any sort of internal oil baffling. Foregoing the high RPM build will give more of a cushion to any oil capacity issues that may arise, but you still should make oil control a priority. My perspective is this: If you go overkill on the oiing now, even if you build a completely new engine, everything swaps over. You'll just have to do some research and see what other people have done. I'm certain you're not the first person to build a road race LS swapped BMW.
As for my opinion on the L33/LH6 blocks, they're lighter, of course, and at least in the case of the LH6, the aluminum block is stronger than the iron block. I used one for my 5.3 turbo build, and it's going to see north of 800 RWHP. The cylinder bores are siamesed, which means there's aluminum between the bores, no water jackets. This stiffens the block significantly. They're well known to handle large power levels, and the liners are so thick they can be bored up to .125 over. You can bore an iron 5.3 just as much, but I don't think they have the same cylinder integrity at that bore size.
As for my opinion on the L33/LH6 blocks, they're lighter, of course, and at least in the case of the LH6, the aluminum block is stronger than the iron block. I used one for my 5.3 turbo build, and it's going to see north of 800 RWHP. The cylinder bores are siamesed, which means there's aluminum between the bores, no water jackets. This stiffens the block significantly. They're well known to handle large power levels, and the liners are so thick they can be bored up to .125 over. You can bore an iron 5.3 just as much, but I don't think they have the same cylinder integrity at that bore size.
With the motor torn apart, any serviceable things you guys recommend? Rod bearings and such?
If you can swing a dry sump kit for your engine, that would be best for track use.
otherwise, snag an oil pan baffle, windage tray, and barbell from improved racing.
not sure which oil pan will fit your chassis best, but they have good pan baffles for just about every stock ls pan.
If you do happen to still see low psi in a hard sweeper, you can opt for a accusump system too. They were the fix used before the improved racing baffles.
otherwise, snag an oil pan baffle, windage tray, and barbell from improved racing.
not sure which oil pan will fit your chassis best, but they have good pan baffles for just about every stock ls pan.
If you do happen to still see low psi in a hard sweeper, you can opt for a accusump system too. They were the fix used before the improved racing baffles.
Thread Starter
Teching In
Joined: Sep 2024
Posts: 17
Likes: 6
If you can swing a dry sump kit for your engine, that would be best for track use.
otherwise, snag an oil pan baffle, windage tray, and barbell from improved racing.
not sure which oil pan will fit your chassis best, but they have good pan baffles for just about every stock ls pan.
If you do happen to still see low psi in a hard sweeper, you can opt for a accusump system too. They were the fix used before the improved racing baffles.
otherwise, snag an oil pan baffle, windage tray, and barbell from improved racing.
not sure which oil pan will fit your chassis best, but they have good pan baffles for just about every stock ls pan.
If you do happen to still see low psi in a hard sweeper, you can opt for a accusump system too. They were the fix used before the improved racing baffles.
TECH Senior Member
Joined: Jun 2016
Posts: 22,291
Likes: 3,615
From: Central Cal.
I am reminded of the old Jalopnick article by Tavarish titled "bmw engines are gigantic pieces of ****". As I recall, the comments section got interesting pretty quickly on that one.