General Jaguar M112 supercharger questions for the M62

[PanzerShrekd]

Junkyard had an XJR with the supercharger today, got the entire thing for $57, so guess who's 540i is getting supercharged this winter!
Some general stuff if anyone knows, is there a requirement that I run lower compression rods/ gapped piston rings or if I just don't push it will my stock M62 be alright? I have seen JimLevs making 400 something on regular internals.
I am most likely designing my own bracketry and intake adapters to keep this cost effective, does anyone have any insight as to how the blower is mounted to the block and how the intercooler lines are run? I have seen the forum posts of someone else building a M112 M62 but they do not go into a ton of detail.
Do I need to run a standalone ECU or can I run the Stock one and just have it tuned to understand it now makes boost?
IMG_0043.jpg
If someone also has any other insight on supercharging my car, please let me know!

[JimLev]

I’m running 480HP of stock internals, Philly is probably 50+ HP higher.
A little lower compression would help, who you kidding your not going to push it, LOL.
Yes, gap the rings.

[PanzerShrekd]

I’m running 480HP of stock internals, Philly is probably 50+ HP higher.
A little lower compression would help, who you kidding your not going to push it, LOL.
Yes, gap the rings.

Where did you go for the gapped rings? I think 450 is probably where I want to be just to keep it somewhat reliable. If I am doing 450 is the forged lower compression rods still worth the money?

[JimLev]

I didn’t gap the rings. I don’t run the juice long enough for the rings to get hot enough to expand and cause damage to the ring lands and the cylinder walls. There are inexpensive gap tools available from SummitRacing.
Forged conn rods would be nice, depends on the price. Your building HP/Torque as the RPM increases (as I do using a progressive controller to ramp the flow up) so you may not need forged rods.

[Jaaap]

What do you use between the M62 and the M112?
These adapter kits are so expensive:

https://www.partspy.com/collections/adapter-kits

[BimmerBreaker]

I would install a lower temp tstat - and if you are "in there" then it's a good idea to gap the rings but I certainly wouldn't fault anyone for not wanting to open a motor up just to do that. If the power goal is 450hp then I definitely don't think you need ugpraded connecting rods

I think you will want to decide now if this is a budget build or a really proper build, as boosting a BMW - especially a V8 - can get very expensive if you want to "do it right". Just because you bought the s/c for cheap doesn't mean the rest of the stuff will be cheap (or easy). The adapter piece alone is pretty difficult to make - I am not sure how you'd DIY such an adapter using normal fabrication tools, though admittedly I am still learning a lot of that stuff myself. But, just take a look at the existing adapters to get an idea what you'd have to make: https://www.partspy.com/products/com...ar-m112-system (this kit does not fit the S/C you have but gives a general idea what the adapters should look like)

The stock ECU can be tuned to work with an S/C but that's pretty expensive in itself and ideally for a custom build like this you'd rent a dyno and have someone really reputable remote in to tune it



Just as a note... for how often these jaguar S/C builds are talked about and theorized on - I have seen a surprisingly low number of finished products. I can certainly count the number on one hand. Never seen one of those builds dynoed either

[PanzerShrekd]

I would install a lower temp tstat - and if you are "in there" then it's a good idea to gap the rings but I certainly wouldn't fault anyone for not wanting to open a motor up just to do that. If the power goal is 450hp then I definitely don't think you need ugpraded connecting rods

I think you will want to decide now if this is a budget build or a really proper build, as boosting a BMW - especially a V8 - can get very expensive if you want to "do it right". Just because you bought the s/c for cheap doesn't mean the rest of the stuff will be cheap (or easy). The adapter piece alone is pretty difficult to make - I am not sure how you'd DIY such an adapter using normal fabrication tools, though admittedly I am still learning a lot of that stuff myself. But, just take a look at the existing adapters to get an idea what you'd have to make: https://www.partspy.com/products/com...ar-m112-system (this kit does not fit the S/C you have but gives a general idea what the adapters should look like)

The stock ECU can be tuned to work with an S/C but that's pretty expensive in itself and ideally for a custom build like this you'd rent a dyno and have someone really reputable remote in to tune it



Just as a note... for how often these jaguar S/C builds are talked about and theorized on - I have seen a surprisingly low number of finished products. I can certainly count the number on one hand. Never seen one of those builds dynoed either

I have spoken to the Partspy people and actually plan with going with them, I work on CNC mills/ lathes on the side for a family friend and usually a week or so of 12 hour days would cover that adapter set pretty easily. Since this car isn't a daily, I would not have much of a problem opening my engine up to gap the rings, rods I would rather not do because it over doubles the price alone. The tuning thing I would have to call around, but I think there are a few places near Cincinnati that do BMW tuning.

- - - Updated - - -

I didn’t gap the rings. I don’t run the juice long enough for the rings to get hot enough to expand and cause damage to the ring lands and the cylinder walls. There are inexpensive gap tools available from SummitRacing.
Forged conn rods would be nice, depends on the price. Your building HP/Torque as the RPM increases (as I do using a progressive controller to ramp the flow up) so you may not need forged rods.

So for a supercharged setup would you think I would need gapped rings or would a totally stock M62 handle it?

[JimLev]

So for a supercharged setup would you think I would need gapped rings or would a totally stock M62 handle it?

Hard to give you a definite answer.
If your going to drive it like you stole it then gap the rings.
If your only going to beat on it once in a while and not try to break a land speed record then you probably don’t need to gap the rings.
Philly didn’t gap his rings and was OK for 4-5? years until the rings on one cylinder took out the piston. He was fortunate the cylinder was didn’t get damaged.

[PanzerShrekd]

Hard to give you a definite answer.
If your going to drive it like you stole it then gap the rings.
If your only going to beat on it once in a while and not try to break a land speed record then you probably don’t need to gap the rings.
Philly didn’t gap his rings and was OK for 4-5? years until the rings on one cylinder took out the piston. He was fortunate the cylinder was didn’t get damaged.

This car gets the piss beat out of it on a regular basis as it is, so Ill plan on gapping them. I found these rods for roughly $500, do these seem like a good idea or is it a get what you pay for type deal?
I am very dumb when it comes to gapping, is there a set way to gap these, do I need to buy pre gapped or is there a way to figure out what size to file them down to?
https://www.maxpeedingrods.co.uk/pro...s-conrods.html

[JimLev]

Those do look like very good con rods as long as they fir your engine. I didn’t read all the specs.

Here’s some gap info.
http://blog.wiseco.com/everything-yo...about-ring-gap

https://www.summitracing.com/search/...on-ring-filers

[1999 540i m]

The partspy kit looks interesting, I don't know how that throttle body adapter would fit, the zero details from the company is disappointing.

Definitely gap the rings, or ring butt will happen

[BimmerBreaker]

This car gets the piss beat out of it on a regular basis as it is, so Ill plan on gapping them. I found these rods for roughly $500, do these seem like a good idea or is it a get what you pay for type deal?
I am very dumb when it comes to gapping, is there a set way to gap these, do I need to buy pre gapped or is there a way to figure out what size to file them down to?
https://www.maxpeedingrods.co.uk/pro...s-conrods.html

Max Peeding Rods is a meme in the car community because of how bad and cheap their suspensions are. I would never put components from them inside my engine. Or for that matter, anywhere on my car. Engine internal components, more so than other car parts -is definitely a "get what you pay for" game. Upgrading internal components requires starting with good quality materials in the first place which is inherently expensive

I don't think the stock connecting rods are a notable weak link. If you are replacing con rods, you are pulling the heads anyways - if you are pulling heads, you could just install a low comp head gasket to lower compression and run more boost

Personally I think I'd upgrade pistons before I upgraded conrods - you can also lower compression by running aftermarket pistons. I've seen factory pistons melt and burn up before, I've only seen a bent conrod from a hydrolocked motor

Gapping the rings is done by filing down the opening and test fitting it in the combustion chamber, measuring and re-filing as needed. Start by removing just a little material and constantly re-measure. The angle should match (so when squeezed together, it's flat)

Make sure if you buy the partspy adapters to buy the ones for the correct blower. The one I sent a link to is the single, center intake style - yours has the rear intake

[edjack]

Cheaper and easier to fit an appropriate Chebbie engine and a Tremec box.

[jhelgesen]

You have the correct sc and intercooler for the 98-02 kit. How worn do the rotors look?

[PanzerShrekd]

The partspy kit looks interesting, I don't know how that throttle body adapter would fit, the zero details from the company is disappointing.

Definitely gap the rings, or ring butt will happen

I have been in email communication with the company about the throttle body adapter and everything would work. I still am not quite grasping just how much I have to file off of the rings. Is it not a set amount?

- - - Updated - - -

You have the correct sc and intercooler for the 98-02 kit. How worn do the rotors look?

Honestly other than just dirt it looks pretty clean from just eyeballing it so far, once I pull it apart a bit more Ill post some pictures.

[philly98540]

Maybe check out Toolman2's build. He homemade some adapters. He is a machinist. Not sure if he sells them or has any extras. Maybe try to PM him, but he has been pretty silent around here for the last couple of years.

https://www.bimmerforums.com/forum/s...harger-install

For my car, I am still on stock ring gaps, stock connection rods, and stock compression ratio. Totally stock engine. I am a bit over 500 wheel horsepower boosting with 15 psi on a centri blower Vortec V3Si. I use water/meth injection and have a water to air intercooler to help cool things down. I had one piston fail due to ring land fracture a couple years ago. I'm not sure if the rings butted and that caused the lands to break, or if the lands just broke due to fatigue or whatever. The tops of all the pistons looked great. No sign of melting or pitting or anything. I put in a used piston and rings and have been driving it since. No oil consumption and great compression test numbers. My cylinder walls looked great still and all rod bearings looked perfect and are all still original. I'm currently at 192K miles on this engine and been boosted for like the last 60K miles or so. I think the stock M62 is pretty robust and I would not upgrade rods, pistons, or anything unless I has tons of cash to burn and wanted to go even higher boost. With higher mileage, the ring gaps get larger due to wear and yours maybe opened up enough to not need any further opening up. If you are opening up the engine, then I'd pull at least one piston out and check the gaps. If they were on the tight side, I'd pull the other ones and open up the gaps and re-assemble with the thicker head gaskets to lower CR a bit. If you were not opening it up, and your block is over 100K miles and in good shape, I'd just run it.

With the Jag blower, you will come into boost sooner and potentially have higher peak loads on the rods at peak torque rpms. If you keep boost to like 8 or 10 psi, this would give awesome low end torque and decent top end power and limit potential peak loads on the rods to something the M62 should be able to handle without issue. I would just keep it stock and focus on getting the blower setup working. Sinking huge sums of cash into the block does not make sense to me (if the engine is in good shape). The Jag blower has intercooling so that will help cool things down.

For tuning, I'd look around in you area to see who knows your ECU. DudMD knows your ECU very well, but he is far away. Doing remote tuning may be possible. https://dudmd.com/
You will need to upgrade injectors and then tune to make it all work nice and give good AFR numbers and proper timing. This prevents detonation which will kill your motor.

[PanzerShrekd]

Maybe check out Toolman2's build. He homemade some adapters. He is a machinist. Not sure if he sells them or has any extras. Maybe try to PM him, but he has been pretty silent around here for the last couple of years.

https://www.bimmerforums.com/forum/s...harger-install

For my car, I am still on stock ring gaps, stock connection rods, and stock compression ratio. Totally stock engine. I am a bit over 500 wheel horsepower boosting with 15 psi on a centri blower Vortec V3Si. I use water/meth injection and have a water to air intercooler to help cool things down. I had one piston fail due to ring land fracture a couple years ago. I'm not sure if the rings butted and that caused the lands to break, or if the lands just broke due to fatigue or whatever. The tops of all the pistons looked great. No sign of melting or pitting or anything. I put in a used piston and rings and have been driving it since. No oil consumption and great compression test numbers. My cylinder walls looked great still and all rod bearings looked perfect and are all still original. I'm currently at 192K miles on this engine and been boosted for like the last 60K miles or so. I think the stock M62 is pretty robust and I would not upgrade rods, pistons, or anything unless I has tons of cash to burn and wanted to go even higher boost. With higher mileage, the ring gaps get larger due to wear and yours maybe opened up enough to not need any further opening up. If you are opening up the engine, then I'd pull at least one piston out and check the gaps. If they were on the tight side, I'd pull the other ones and open up the gaps and re-assemble with the thicker head gaskets to lower CR a bit. If you were not opening it up, and your block is over 100K miles and in good shape, I'd just run it.

With the Jag blower, you will come into boost sooner and potentially have higher peak loads on the rods at peak torque rpms. If you keep boost to like 8 or 10 psi, this would give awesome low end torque and decent top end power and limit potential peak loads on the rods to something the M62 should be able to handle without issue. I would just keep it stock and focus on getting the blower setup working. Sinking huge sums of cash into the block does not make sense to me (if the engine is in good shape). The Jag blower has intercooling so that will help cool things down.

For tuning, I'd look around in you area to see who knows your ECU. DudMD knows your ECU very well, but he is far away. Doing remote tuning may be possible. https://dudmd.com/
You will need to upgrade injectors and then tune to make it all work nice and give good AFR numbers and proper timing. This prevents detonation which will kill your motor.

I would say my block is in semi decent shape, 150k miles with dealer maintained records to 138k(ish). Car was babied in california and then some college kid got his hands on it in kentucky and now I want to murder the annoying mustangs on campus. Anyways, when I had to do the upper oil pan gasket I did turn it over by hand and inspect my cylinder walls and no scratches or anything that would raise alarm. I am having an extremely difficult time grasping what makes ring gap tight or lose, how do I measure it for our engine? I have read around and have not found anything concrete on what it should be and what would allow me to not bomb the motor if I decide to gap them. From what I can tell the stock Jag blower makes about 8PSI on the XKR but I pulled mine off of the XJR, so I would assume its the same anyways. It has dual air to liquid intercoolers right before the intake so I would agree that it should be able to keep it pretty cool, at the moment I am not wanting insane numbers, but in the future after I get some life things in order I will probably want to push into the high 600s and I will start to look at some more in-depth building then.

The biggest worry for me is thrashing it and then blowing something up because I did not take the time beforehand to solve something that would've been easily avoided. I can probably get my hands on a sub $200 M62 that I could blow apart and throw the charger on it and then swap it into the car, in that case I would probably check ring gaps, but from what you guys are saying I shouldn't have to worry about the rods too terribly much. If I did the thicker head gaskets would I need different head bolts or would stock length be able to handle a non machined head with a thicker gasket?

I have to admit, as a Mechatronics Engineering major, the ring gap thing is really starting to embarrass me on how difficult it is to understand it lol.
EDIT: Scratch the ring gap issues, I figured out the dimensions I would roughly need with a calculator.

I really would like to do this correctly the first time so I can just reliably enjoy it and take it to C&C, new job means no more retail and weekends off (score!)

[philly98540]

See post #563 for ring gaps in my engine.
https://www.bimmerforums.com/forum/s...ock-M62/page27

These gaps seem pretty safe for my engine, but a little wider gap would be safer (if you are taking the engine apart).

The link Jim provided up above about ring gaps is a great article and will give you the info you need so you understand it better. Our blocks are aluminum, not cast iron, so the ring gaps can be tighter vs what that article says since the block expands more than if this was an iron block engine. Maybe do some more googling to see if you can find more info for ring gaps on boosted aluminum block engines.

You can use the same length head bolts with the thicker gasket. Its only a tiny bit thicker. You need to use new head bolts when you re-assemble.

High 600 WHP is not likely going to happen unless you change the cams out (mo mony!!). You can boost and boost and boost more and more, but the engine will just back up and you will get high intake air temps, detonation, and problems. Opening up the breathing with cams will be better than boosting too high to get the same power.

[PanzerShrekd]

See post #563 for ring gaps in my engine.
https://www.bimmerforums.com/forum/s...ock-M62/page27

These gaps seem pretty safe for my engine, but a little wider gap would be safer (if you are taking the engine apart).

The link Jim provided up above about ring gaps is a great article and will give you the info you need so you understand it better. Our blocks are aluminum, not cast iron, so the ring gaps can be tighter vs what that article says since the block expands more than if this was an iron block engine. Maybe do some more googling to see if you can find more info for ring gaps on boosted aluminum block engines.

You can use the same length head bolts with the thicker gasket. Its only a tiny bit thicker. You need to use new head bolts when you re-assemble.

High 600 WHP is not likely going to happen unless you change the cams out (mo mony!!). You can boost and boost and boost more and more, but the engine will just back up and you will get high intake air temps, detonation, and problems. Opening up the breathing with cams will be better than boosting too high to get the same power.

New bolts for assembly are a given, I wouldn't ever reuse something like those. So sounds like if I do gap+ thicker gasket I should have good peace of mind? So after the rebuild you are running stock gap? With the range for stock being .004-.012, The calculation of me needing ~.018 for boost doesn't sound too crazy to me. Id assume I should purchase new OEM rings and just file those down or would you say something aftermarket would be a better application? Thanks so much for your time by the way.

[jhelgesen]

I was able to source a set of I think Raceware head studs a few years back, one of the bmw engine shops. Not sure if they are still available. Refreshed a set of heads and used the .3mm thicker gasket with undecked heads.

[philly98540]

So sounds like if I do gap+ thicker gasket I should have good peace of mind?

Yes. Up to you if you want to take it apart and future proof things for higher boost or just keep boost modest and stay stock. Its only money!

So after the rebuild you are running stock gap?

Well, stock rings that I never opened up the gaps on, but the rings are worn some and the gaps are larger than stock (as I listed in the thread above)

With the range for stock being .004-.012, The calculation of me needing ~.018 for boost doesn't sound too crazy to me.

I never calculated that .018" is correct for my boost. This is just what I found them to be when I opened it up. You should do some more research if you are going to open it up and really spend the money and time on it. Going too large a gap and you get more blowby and lost compression, too small and you can butt rings and blow your motor up.

Id assume I should purchase new OEM rings and just file those down or would you say something aftermarket would be a better application?

You could just re-use your old rings and gap them or buy new OEM ones. I'm not sure what aftermarket one are available actually.

[BimmerBreaker]

Genuine question - do ring gaps open up as an engine ages? And if so, how? I understand the outer edge will wear down, but I don't really see how the gap itself would widen

[PanzerShrekd]

Genuine question - do ring gaps open up as an engine ages? And if so, how? I understand the outer edge will wear down, but I don't really see how the gap itself would widen

If the outer edge wears down, the gap will have to widen to compensate for the lost material against the walls.

[PanzerShrekd]

Yes. Up to you if you want to take it apart and future proof things for higher boost or just keep boost modest and stay stock. Its only money!

I never calculated that .018" is correct for my boost. This is just what I found them to be when I opened it up. You should do some more research if you are going to open it up and really spend the money and time on it. Going too large a gap and you get more blowby and lost compression, too small and you can butt rings and blow your motor up.

You could just re-use your old rings and gap them or buy new OEM ones. I'm not sure what aftermarket one are available actually.

Opening up really doesn't cost me much, I have a lift a family friend lets me use for free, I already own all of the tools and whatnot other than the gap tool. I would be perfectly fine spending a few hundred making the engine a bit more capable to handle boost.

That .018 calculation was one I did while at work, would be for a Gasoline engine running sub 15 psi boost with a 92mm bore. I will do further research eventually when I get closer to actually opening one up.

I will probably end up just measuring my rings and then going from there on purchasing new ones.

Also how do you do the fancy quotes, you're outdoing me on my own thread

[philly98540]

Good to know .018 is likely good as that is where I am. You have a source for the formula? Just curious and if its specific enough for our engine materials.

I have not priced it lately, but I believe its over $1k to just disassemble and reassemble the engine without replacing anything except gaskets, and head/rod/main bolts. They kill you on the rod bolts for some reason. The bolts are TTY so should be replaced, but I hear some don't. Head bolts are not bad. If you need to buy more stuff, the price goes up really fast and steep. BMW tax! That is why LS swaps are so popular. Cheap power.

Hit reply with quote and just copy and paste the entire text sting as many times as you want. Then edit out what you don't want in each text section and put your reply after each.