[WV328]

Does anyone know where to buy forged or some form of aftermarket internals for the N20? I've searched everywhere and swear I can't find anything.

[Stubok]

I investigated this. I wanted a drop in set. So no additional machining. Though you would probably need to have the cylinders lightly honed to properly prep for the new rings.

I only know of ABR Houston who could do the job. Apparently the N20 is very tricky to take apart and rebuilt.

VAC gave me the following numbers. PM me if you want the contact.

- The Pistons and connecting rods are special order so they will take 4-6 weeks to be made.

- The piston set will come with rings pins and locks besides the pistons (CP Forged Piston Set, N20, 84mm bore, 10 to 1 CR, 89.6mm stroke) it will cost $750 for the set.

- The Connecting rods (144.35mm Rod) are $1120 for the set with WMC upgrade rod bolts, (they are comparable tensile strength to ARP).

I later asked for a price for Pauter Rods.
Pauter N20 connecting rods $980, but I'm not sure if that included the upgraded rod Bolts.

High Performance Rod Bearing Set, N20 - $350

[Seraphblade@sg]

This pricing sounds reasonable but I suppose the labour cost probably be the bomb

[WV328]

That's definitely good to know. Thanks man. I'm not ready to order now, I was just hoping someone just offered the parts.

[Polo08816]

Originally Posted by Stubok

I investigated this. I wanted a drop in set. So no additional machining. Though you would probably need to have the cylinders lightly honed to properly prep for the new rings.

I only know of ABR Houston who could do the job. Apparently the N20 is very tricky to take apart and rebuilt.

VAC gave me the following numbers. PM me if you want the contact.

- The Pistons and connecting rods are special order so they will take 4-6 weeks to be made.

- The piston set will come with rings pins and locks besides the pistons (CP Forged Piston Set, N20, 84mm bore, 10 to 1 CR, 89.6mm stroke) it will cost $750 for the set.

- The Connecting rods (144.35mm Rod) are $1120 for the set with WMC upgrade rod bolts, (they are comparable tensile strength to ARP).

I later asked for a price for Pauter Rods.
Pauter N20 connecting rods $980, but I'm not sure if that included the upgraded rod Bolts.

High Performance Rod Bearing Set, N20 - $350

Originally Posted by Seraphblade@sg

This pricing sounds reasonable but I suppose the labour cost probably be the bomb

Originally Posted by WV328

That's definitely good to know. Thanks man. I'm not ready to order now, I was just hoping someone just offered the parts.

Wonder what the total cost would be...

It seems like a 335i/340i would be a better bet when you consider cost.

[Stubok]

I would expect the labor cost to be pretty high. The point of a drop in set, is that you don't have to pull the whole engine/tranny out.

That's a big time saver. Still I would expect it would be quite a big job... Draining fluids, Removing head cover, intake and exhaust manifolds, Pulling the head, dropping the oil pan, removing old pistons/rods, Lightly honing cylinders, installing new pistons/rods/big end bearings and replacing everything, plus new gaskets and fluids.

I would say prob a day to get it stripped, day for the change out and a day to put everything back at the very best. I would prob estimate 30 hours to be safe. So another big number.

In all with parts I bet it's a $5k ticket. Unless of course you are a BMW tech and can do it yourself.

The hard part is finding someone who can do it. ABR Houston rebuilt some hydrolocked engines for insurance claims and apparently they were very tricky with many special tools needed.

Anyway, with 350hp supposedly on the table without forged internals, I guess this would only be necessary if you want to get to 400. At that point I think some other questions need to be asked. Probably Hardened head bolts & Over the top fueling for starters.

Also this block is open decked. So def no 2jz.

[eluded]

I'm hoping 4 320 rwhp stock or bust

[ralphsworldtour]

I don't see why the n20 engine can't handle 350+ hp with stock internals. it has arc wire technology for the cylinder walls and it has an offset crank. shouldn't that mean less stress on the internals??

if I were to take a stab in the dark id say the problem is in running hot(for efficiency), oiling, and tuning.

possible solutions are running on the rich side with added injectors spraying e85, and accusump for the oiling.

can someone help me understand this?

[Stubok]

Originally Posted by ralphsworldtour

I don't see why the n20 engine can't handle 350+ hp with stock internals. it has arc wire technology for the cylinder walls and it has an offset crank. shouldn't that mean less stress on the internals??

if I were to take a stab in the dark id say the problem is in running hot(for efficiency), oiling, and tuning.

possible solutions are running on the rich side with added injectors spraying e85, and accusump for the oiling.

can someone help me understand this?

So the reports that came back from the blown motors were exactly that, oil starvation (particularly on 4 I believe) in high g stop and turns. That combined with lean AFR, high running temps and very high boost (I believe it was 28psi) caused rod bolts to stretch and eventually the rod was thrown through the block.

Given the Pistons and rods are supposed to be the same design as N55, I would think that the engine could get close to 100hp per cylinder.

But the tune (as you correctly have identified) is critical. Running rich and with correct timing.

I also probably only attempt this if you have th hot temp pack which has additional radiators for cooling in hot climates.

Baffles in the sump would prob be a good idea. As would arp Rod bolts & upgraded big end bearings.

My guess is 350 is easily done without the mods, but 400 would be risky for sure.

[WV328]

So if heat is a major issue I wonder if a larger intercooler or different thermostat should be my next mod..

[Stubok]

Originally Posted by WV328

So if heat is a major issue I wonder if a larger intercooler or different thermostat should be my next mod..

I went with a bigger stepped core FMIC (ATM because they really know what they're talking about) as my first mod, but that's because I live in TX and I saw heat soak . I went with parts before tune. But that's just my MO.

[WV328]

Originally Posted by Stubok

I went with a bigger stepped core FMIC (ATM because they really know what they're talking about) as my first mod, but that's because I live in TX and I saw heat soak . I went with parts before tune. But that's just my MO.

Was it a direct replacement?

[Stubok]

Originally Posted by WV328

Was it a direct replacement?

Yes if you keep the stock Charge pipes it's easy enough. It's heavier and a bit tricky to get in by yourself. Much easier with a helper.

If you buy aftermarket charge pipes (I got black anodized ER hot and cold side) then it's more difficult. I had to make a minor adjustment to my FMIC for a perfect fit.

[WV328]

^Ok good deal. What brand did you use?

[Stubok]

Originally Posted by WV328

^Ok good deal. What brand did you use?

Ambient Thermal Management (ATM), but Wagner looks pretty much the same.

[Meat Hammer]

I think you guys are correct in your estimates of the N20's weak points and power threshold. The N55 DME is on the verge of being OBD flash-tunable without initially being bench flashed or removed and modified. When these cars can be accurately remapped in real time using the highly capable OEM DME, we will have a much clearer idea of the N20's stock hardware limitations. With the offset crank, DI and VANOS, an internally stock N20 *should* be capable of a reliable ~350 whp on pump gas and mid 12-second e.t.'s.

[CRJdriver]

Originally Posted by Stubok

I went with a bigger stepped core FMIC (ATM because they really know what they're talking about) as my first mod, but that's because I live in TX and I saw heat soak . I went with parts before tune. But that's just my MO.

I rigged a IC water spray on the front bumper to cool the IC, so far it drops temps way quicker between runs, I don't know what gains during a run thoughI'm surprise no one has done this?

I even bought a subbie IC spray button to put where the rear fogs would go.

I will do some proper logging to see if it's worth it cause it goes through water kinda quick.

you can Try it by relocating the windscreen washer nozzle, pretty easy and cheap mod

[Stubok]

Originally Posted by CRJdriver

I rigged a IC water spray on the front bumper to cool the IC, so far it drops temps way quicker between runs, I don't know what gains during a run thoughI'm surprise no one has done this?

I even bought a subbie IC spray button to put where the rear fogs would go.

I will do some proper logging to see if it's worth it cause it goes through water kinda quick.

you can Try it by relocating the windscreen washer nozzle, pretty easy and cheap mod

I've been doing this for over a year. Responded to the other thread on that.

It works incredibly well down here in TX.

[WV328]

A little off subject but WTH it's my post. I saw on ECS tuning you can get a N20 block and pistons for a little over $2k. Makes my wonder why BMW shows like $16k for all the guys/girls that have blown theirs. I only bring it up bc the people that have blown the N20 is my sole reason for looking into getting new internals.

[cncmastr]

Originally Posted by WV328

A little off subject but WTH it's my post. I saw on ECS tuning you can get a N20 block and pistons for a little over $2k. Makes my wonder why BMW shows like $16k for all the guys/girls that have blown theirs. I only bring it up bc the people that have blown the N20 is my sole reason for looking into getting new internals.

Link?

[Meat Hammer]

Originally Posted by cncmastr

Link?

https://www.ecstuning.com/BMW-F30-32...All/ES2711233/

[cncmastr]

Originally Posted by Meat Hammer

https://www.ecstuning.com/BMW-F30-32...All/ES2711233/

Thank you!

That seems REALLY cheap. What am I missing?!