EJ20 Engine Machining/Assembly Cost?

[bnr32jason]

I've got a complete EJ20G broken down to it's individual parts:

- Block (Cylinder walls look great, but I want to do new rings so I think a light honing will be needed, closed deck)
- Heads look good
- Rods and Pistons looks good
- Crank is good but does have some minor surface rust so would need to be cleaned

I'm going to have a go at doing this myself since I've got a lot of time until my delivery date, but if I decide not to re-assemble the engine myself (never done it before), does anyone know what I should expect to pay a competent shop for a the machining and re-assembly of the engine?

I'm trying to see if it's going to be worth it to build it or just buy a brand new 2.0 shortblock ($1900) and sell what I have.


Thanks!

[longislandwrx]

What is your power goal again? with a new shortblock you'd still need to do pistons if you plan on making 400hp. a new heat treated crank is $300... so if its too rusty, just get a new one. Honing should be less than $200 to have it done by machine, but if the walls are in good shape and you just want to put some crosshatching on it to help the rings seat there are plenty of youtube videos about doing it yourself with a drill.

To have a shop do everything? really depends on the shop and how much prep work your parts need, and if they factor in profit made on parts you are buying from them.

If you bring them everything, drop it in a pile and say put this together i'd say $1000-1300 to put it together?

[bnr32jason]

My power goals are moderate, 300-325whp.

$1000-$1300 doesn't seem to bad. I might be able to do it myself with some help, I'm just afraid that it's over my head.

Thanks for the information!

[PhyrraM]

This was my quote from 2009. I don't recall if that turned out to be the exact amount I spent.....most likely not.

I ran into two things that are very important to note.

First, on a Subaru you NEED to make sure the shop uses torque plates for all machine work. Most shops do not have Subaru torque plates and will try to talk you out of it by downplaying their importance. The whole motor is aluminum and moves when things are tightened.

Second, The process of measuring and setting clearances means that the block is assembled and torn down a few times by the machinist. This means there is very little savings in assembling the shortblock yourself. If you want to do it yourself for other reasons, go for it - but don't let budget be one of them.

Also, any builder that doesn't set the clearances based on your anticipated HP is leaving longevity on the table. A 350HP block build and a 500HP block build are not the same, even if all the components are. There are tons of Subaru builders that don't recognize that, build all motors off a formula, and have either loose or tight motors that don't last.



Hope this helps.

[longislandwrx]

exactly... about 1200 in labor if you remove the valve job.

+1 on the torque plate if they are doing a bore... for the price phyrram for the bore/hone how can you not.

if you cant find a shop with one you can bring your own.

http://www.amsperformance.com/cart/a...ing_plate.html

not the highest end but much better than nothing. Champion products makes in my opinion the best one but I can't find a link.

[sponaugle]

exactly... about 1200 in labor if you remove the valve job.
+1 on the torque plate if they are doing a bore... for the price phyrram for the bore/hone how can you not.

Indeed, if you are going to have a block bored out, do it right.

However, I would consider other options before doing that. I have done 15+ EJ engines for my cars, plus worked in/on 30 or 40 others. Rebuilding an engine is an interesting and potentially money sinking experience. Consider that you can purchase a brand new short block for $1900 from the dealer. That new fresh block has full thickness sleeves, the latest casting changes, stock pistons and stock rods. If you were building a 2.5L, that short block can be ran at 300whp if you do it right. If you rebuild an older block you really need to inspect it with it cleaned... I know two people who sent significant $ on a block only to discover something that made the case unusable (ruined head bolt threads, stripped threads on pulley mount)

Obviously there are downsides of using a stock block.. The stock pistons are terrible. They are very fragile and can have the ring lands broken with detonation. If you have an aggressive tune, or get some slightly less octane fuel you will break a land. The stock EJ257 rods are pretty strong. They can be bent, but if you are using a 16G size turbo and reasonable tuning they can work great. You could purchase the short block and remove the pistons and replace them with 2618 units, and that is pretty easy to do. As an alternative you could purchase the case, bearings, crank, rods, and rings.. then add you own pistons. I have done both of these options with good results.

Keep in mind I like a good rebuild. I have done a few short blocks 'the right way'.. every surface polished and measured, balanced crank, individual selected bearings, torque plate bore with many many measurements, etc. While the engine worked great, it really didn't work that much better then a less attention build. Part of that is luck.. I have heard of people getting factory blocks that have real problems.. but on the whole they are pretty good minus the pistons.

If there were a single piece of advice, I would just say be careful spending $10,000 getting the most perfect and kick *** short block. In the end your tune and your fuel will really make the difference in what survives.

Jeff Sponaugle

[BrandonDrums]

Indeed, if you are going to have a block bored out, do it right.

However, I would consider other options before doing that. I have done 15+ EJ engines for my cars, plus worked in/on 30 or 40 others. Rebuilding an engine is an interesting and potentially money sinking experience. Consider that you can purchase a brand new short block for $1900 from the dealer. That new fresh block has full thickness sleeves, the latest casting changes, stock pistons and stock rods. If you were building a 2.5L, that short block can be ran at 300whp if you do it right. If you rebuild an older block you really need to inspect it with the cleaned... I know two people who sent significant $ on a block only to discover something that made the case unusable (ruined head bolt threads, stripped threads on pulley mount)

Obviously there are downsides of using a stock block.. The stock pistons are terrible. They are very fragile and can have the ring lands broken with detonation. If you have an aggressive tune, or get some slightly less octane fuel you will break a land. The stock EJ257 rods are pretty strong. They can be bent, but if you are using a 16G size turbo and reasonable tuning they can work great. You could purchase the short block and remove the pistons and replace them with 2618 units, and that is pretty easy to do. As an alternative you could purchase the case, bearings, crank, rods, and rings.. then add you own pistons. I have done both of these options with good results.

Keep in mind I like a good rebuild. I have done a few short blocks 'the right way'.. every surface polished and measured, balanced crank, individual selected bearings, torque plate bore with many many measurements, etc. While the engine worked great, it really didn't work that much better then a less attention build. Part of that is luck.. I have heard of people getting factory blocks that have real problems.. but on the whole they are pretty good minus the pistons.

If there were a single piece of advice, I would just say be careful spending $10,000 getting the most perfect and kick *** short block. In the end your tune and your fuel will really make the difference in what survives.

Jeff Sponaugle

Well, the stock pistons aren't really CRAP, it's moreso the engine geometry of the 2.5L motor that puts additional stress on the pistons that cause the pistons to fail. On 2.0L turbo motors, you don't really have many piston issues. If something fails, it's usually a rod bearing.

If you don't believe me then just spend some time reading this thread, you'll see most of the abused high-mileage motors are 2.0L's.
http://forums.nasioc.com/forums/show....php?t=2406760

It's not just because the 2.0L pre-date the 2.5L, it's because they hold up to abuse more. Not to say the 2.5L engine is weaker, it's actually just as durable but with a 25% increase in displacement and 0% increase in engine component strength, it's much easier to ABUSE a 2.5L than a 2.0L. For instance: 18psi on a 2.5L engine is WAY more air and WAY more torque and far more heat from an overworked turbo than 18psi on a 2.0L engine. Without getting into it, the overall HP output is only a little higher vs. the 2.0 psi to psi on the 2.5L but that's largely due to the reduced RPM capability from short piston dwell/high approach and descent speeds. The big gains are on the torque side which is where the added side to side piston stresses are seen.

Anyway, for 300-325 hp on a 2.0L WRX engine, you actually don't need to upgrade the pistons. The main thing is getting the build and all of the clearances done right. That means either buying a factory shortblock or having it rebuilt professionally. Getting quality micrometers for all of the required measurements, the machine work you'll need done (honing and potentially boring the cylinders, decking the heads etc.) will run you far more than having the whole thing done at a reputable machine shop and potentially more than buying a brand new warrantied shortblock from Subaru.

Another reason NOT to upgrade the pistons with this power goal is cold gap. Forged pistons usually have additional gap when cold to allow for the differential in heat expansion. The increased piston slap over time can end up wearing out the rings faster resulting in lost compression by 80-100k miles. Some argue that gapless forged pistons (depending on the brand) are actually not much stronger than the stock pistons and the main reason for upgrading is weight and having a more optimal combustion chamber and having the ability to change your compression.

That's up for debate but the main thing is that on a 2.0L motor, you're not going to be gaining much going forged with your power goals and you should look more at long-term assembly strength rather than the re-usability of individual components over multiple re-builds.

In short, a DIY build doesn't save money unless you already have the required tools in-hand. Also; Forged Pistons are actually more likely to reduce the life of the assembled engine when used for modest power goals because of the increased ring and bore wear.

However, there are gapless forged pistons out there, it could well be worth the month for a set of those but they will be a bit pricier than the other options.

All things considered, a new stock shortblock comes with a warranty from Subaru...

Just some food for thought.

[sponaugle]

Well, the stock pistons aren't really CRAP, it's moreso the engine geometry of the 2.5L motor that puts additional stress on the pistons that cause the pistons to fail. On 2.0L turbo motors, you don't really have many piston issues. If something fails, it's usually a rod bearing.
It's not just because the 2.0L pre-date the 2.5L, it's because they hold up to abuse more. Not to say the 2.5L engine is weaker, it's actually just as durable but with a 25% increase in displacement and 0% increase in engine component strength, it's much easier to ABUSE a 2.5L than a 2.0L. For instance: 18psi on a 2.5L engine is WAY more air and WAY more horsepower and far more heat from an overworked turbo than 18psi on a 2.0L engine.

Great input Brandon. I should have been more specific that I was only talking about the 2.5L EJ257. Indeed I have not seen very many failures of that type on the 2.0 platform. I had a couple of Spec C motors (EJ207) which used a different piston then the EJ205 and they appeared to be very strong. I suppose that most people have moved to the 2.5L just to get the additional torque.

Anyway, for 300-325 hp on a 2.0L WRX engine, you actually don't need to upgrade the pistons. The main thing is getting the build and all of the clearances done right. That means either buying a factory shortblock or having it rebuilt professionally. Getting quality micrometers for all of the required measurements, the machine work you'll need done (honing and potentially boring the cylinders, decking the heads etc.) will run you far more than having the whole thing done at a reputable machine shop and potentially more than buying a brand new warrantied shortblock from Subaru.

I did a couple of EJ207 builds, and since I was pushing the RPM limit to 8500 I suspect that balance and tolerance become even more important. You can’t underestimate the need for good measurement tools. I have a set of relatively cheap micrometers and vernier calipers as well as a few slightly better Mitutoyo ones. With the cheap ones if I calibrate and use the same calibration and tool for the piston size and cylinder diameter I can get decent RELATIVE results, but the absolute numbers are never the same/correct. I ended up purchasing some NIST traceable sources to calibrate with, but in the end better tools (that cost >$1k) is really needed.

Another reason NOT to upgrade the pistons with this power goal is cold gap. Forged pistons usually have additional gap when cold to allow for the differential in heat expansion. The increased piston slap over time can end up wearing out the rings faster resulting in lost compression by 80-100k miles. Some argue that gapless forged pistons (depending on the brand) are actually not much stronger than the stock pistons and the main reason for upgrading is weight and having a more optimal combustion chamber and having the ability to change your compression.
That's up for debate but the main thing is that on a 2.0L motor, you're not going to be gaining much going forged with your power goals and you should look more at long-term assembly strength rather than the re-usability of individual components over multiple re-builds.

That is a fascinating perspective, and something I never considered. I think I have for most of the time leaned far too much towards higher hp (>100hp/cylinder) and much less mileage. I have always considered that if a EJ257 with 2618 pistons and appropriately loose gaps is good for 30k miles, but not a lot more. Certainly some people push them more, but you are correct that with that kind of loading on the rings and walls you will not be getting 100k miles. I have one ‘hastily’ built EJ257 with very loose pistons that ran fantastic at 450whp (so >500 crank hp), but in 30k miles it had lost both some compression as well as experienced increased blowby. My current EJ257 in my 08 is using Weisco pistons at 478whp with the EFR7670 turbo, and of course it sounds like a diesel on cold start in cold weather.

In short, a DIY build doesn't save money unless you already have the required tools in-hand. Also; Forged Pistons are actually more likely to reduce the life of the assembled engine when used for modest power goals because of the increased ring and bore wear.
However, there are gapless forged pistons out there, it could well be worth the month for a set of those but they will be a bit pricier than the other options.
All things considered, a new stock shortblock comes with a warranty from Subaru...
Just some food for thought.

Yep…. Of course I am not sure the dealer would ever honor a warranty on a shortblock sold just as that.. so many ways user error can break them.

I wonder if most of these 818s will be EJ205/207s vs 257s? Of course we all know the cool kids will use the EZ30R. 

Jeff

[BrandonDrums]

Yeah, it would be hard getting a stock shortblock warrantied through the dealer but I think on a component like that you don't have to worry about a dealer. You'd go directly through SOA.

However, I guess my point is that a shortblock from subaru is built as well as a stock one and if it has a major defect you just get a new shortblock rather than trying to argue with an engine builder and then waiting weeks for the fix.

[Thorne]

Yeah, it would be hard getting a stock shortblock warrantied through the dealer but I think on a component like that you don't have to worry about a dealer. You'd go directly through SOA.

However, I guess my point is that a shortblock from subaru is built as well as a stock one and if it has a major defect you just get a new shortblock rather than trying to argue with an engine builder and then waiting weeks for the fix.

Don't rebuild a 2.0 buy a EJ257 shortblock for 1800$ and modify the 205 heads. WAY BETTER SOLUTION. I'm currently making 435tq/365hp with my hybbrid motor.

[riptide motorsport]

Don't rebuild a 2.0 buy a EJ257 shortblock for 1800$ and modify the 205 heads. WAY BETTER SOLUTION. I'm currently making 435tq/365hp with my hybbrid motor.

can you please tell me how you got your engine to that level? thanks Steven

[Samiam1017]

I had a bearing knock and was gonna rebuild. Decided against it so I bought a brand new factory ej257 block and a used set of D25 heads (thank mechie) had them resurfaced. It cost me about 600 for my heads, some of the parts that Weren't included with our deal, and the machine work. It would have cost 1100 for the machine work alone to freshen the 2.0 heads includeding the cnc work in the combustion chambers. So hybrids are far from cheap to do right.

[longislandwrx]

Yeah no thank you to a hybrid for me. when I rebuild it will most likely be just new pistons rods and a rebalance. Although I am toying with the idea of a 2.1 stroker.

[papajon1000]

Yeah no thank you to a hybrid for me. when I rebuild it will most likely be just new pistons and a rebalance. Although I am toying with the idea of a 2.1 stroker.

Just curious. Why do you not want to do a hybrid build?

Thanks
Jon

[longislandwrx]

just a personal opinion, I just don't think the cost/benefit is there.

Doing it right, getting the chambers machined and replacing the pistons plus the cost of an oem short block? you've already spent almost $3000
personally I would rather put that money into a built 2.0 and open up the heads so it can really breath at high rpm.

I also think the 2.0 is a more balanced engine, happier to rev.

[papajon1000]

Thanks for the reply.

Jon

[PhyrraM]

I simply think that the lower traction nature of the 818, combined with the *possible* torque liability of the transaxle, suits a lower initial torque, higher revving 2.0 motor better.

2.0 and 2.5 both use the same bearings and con-rods. I see ultimate power generation about the same between each engine design, given the same attention and budget.