2g pistons/1g rods combo. Please help.

[packinkimber45]

After researching a lot about pistons, I am wanting to go this route as long as my set up allows for it. 300-400 hp, daily driver, and 20-25 psi on Evo 3 16g on pump gas. Rest of my mods are on my profile. I feel this is the best option for me cost wise and simplicity. I've been researching this for days, and I can't find the answers I am looking for. The rest of my mods are on my profile. Please no hear says, looking for info based on experiences in running this set up.

1. Oil squirters. I read some people were having issues with the 1g oil squirters hitting the 2g pistons and causing them to fall off in the block? I dont know if I read this right but I need to know if there are known issues that are related to the squirters hitting the 2g pistons vs with 1g pistons. Also when I took my block to the machine shop they put it in a spray cabinet since it was really filthy. Do they spray the block with some kind of materials like bead blasting to clean the block off? I forgot to take off the squirters before hand, I dont know if that would in anyway have weaken the squirters, should I buy new ones?

2. I know I have read that the 2g pistons are a little bit harder to tune than the 1g pistons. Later down the road I will be getting dsmlink for tuning and all other supporting mods. However, until I have enough cash for supporting mods, I will be daily driving the car with the stock ecu at stock boost level for several months. Is it okay for me to run the car this way if I go with 2g pistons for a while? Or do I need to go 1g pistons for this reason? I read that the stock 1g maps may be too aggressive for the 2g pistons being 8.5:1 compression ratio.

3. Piston to wall clearance. What piston to wall clearance do I go with, 1g or 2g specs? If 2g specs, can someone point me in the right direction to find this. Unless someone has the specs, can some one tell me?

4. Main bolts. I have brand new main bolts that the machine shop torqued to the block in order to check my main bore housing spec. Should they have align hone/bore my mains before they used them when they checked my mains? Do I need to make sure the mains are align bored/honed since I am going with new bolts? I know you should when changing rod bolts. Also the what is the difference with align honing the main vs align boring the mains? Which one should I have done if I need to?

5. I am having my block bored .020 over. I have a brand new oem crank I will be using, acl race main and rod bearings, new oil pump, water pump, timing components, reusing arp head studs, new oem composite head gasket, new main bolts. Last on my list are pistons and rods. I want to go with the 2g/1g piston and rod combo with dsmgraveyard.

6. Before I took the head off the block, the motor has been sitting in my garage for two years upside down on the motor stand. The crank, oil pan, front case and timing components were taken off before it sat for that long. Do I need to take apart my head to get it cleaned? Any other stuff I need to do, or can I just run it. No issues before I took the car apart. The head is suppose to be pretty new, it is an SBR stage 2 race head with 1mm over sized valves. The previous owner told me he just installed it right before I bought it.

Thanks.

 

[aspekt9]

After researching a lot about pistons, I am wanting to go this route as long as my set up allows for it. 300-400 hp, daily driver, and 20-25 psi on Evo 3 16g on pump gas. Rest of my mods are on my profile. I feel this is the best option for me cost wise and simplicity. I've been researching this for days, and I can't find the answers I am looking for. The rest of my mods are on my profile. Please no hear says, looking for info based on experiences in running this set up.

You're running the exact same setup as I am, I have a few answers to your questions, some of the other questions I'm actually curious about myself.

1. Oil squirters. I read some people were having issues with the 1g oil squirters hitting the 2g pistons and causing them to fall off in the block? I dont know if I read this right but I need to know if there are known issues that are related to the squirters hitting the 2g pistons vs with 1g pistons.

I've definitely heard this before, and I'm expecting to run into the same problem. The 2g piston has a beefier skirt than the 1g and you most likely will have issues with clearance. I would suggest claying the side of the piston closest to the squirters to see if you will have issues or not.

You must be logged in to view this image or video.

Here's a nice comparison of the 2g (left) vs 1g (right) skirt, you can see the 2g is definitely larger, this is where you would most likely hit.

To get around this you have 3 options...

1. Remove the oil squirters and block them off.
2. Bend the oil squirters down so they clear. I do not recommend this. Doing so could possibly weaken the squirter and cause it to break off down the line, squirting oil everywhere but the piston.
3. Lastly, and most likely what I'm going to do, swap in the EVO oil squirters. They have a lower profile and are shorter which should solve your clearance issues. Here's a comparison picture:
   
   
   You must be logged in to view this image or video.
   
   
   EVO on the left, 6 bolt on the right
   
   
   You must be logged in to view this image or video.
   
   
   6 bolt left, EVO right

Also when I took my block to the machine shop they put it in a spray cabinet since it was really filthy. Do they spray the block with some kind of materials like bead blasting to clean the block off? I forgot to take off the squirters before hand, I dont know if that would in anyway have weaken the squirters, should I buy new ones?

For spraying they use a special solution sprayed at a high temperature and high pressure to remove any contaminants. Most setups have multiple spray nozzles that spray the block as it spins. The shop would remove the squirters if there were going to be any issues. They need to be removed to bore / hone the block anyways.

2. I know I have read that the 2g pistons are a little bit harder to tune than the 1g pistons. Later down the road I will be getting dsmlink for tuning and all other supporting mods. However, until I have enough cash for supporting mods, I will be daily driving the car with the stock ecu at stock boost level for several months. Is it okay for me to run the car this way if I go with 2g pistons for a while? Or do I need to go 1g pistons for this reason? I read that the stock 1g maps may be too aggressive for the 2g pistons being 8.5:1 compression ratio.

This is something I'm interested in knowing myself. I don't think it would be a problem running at stock boost if you're not seeing any knock. The big issue is being able to control timing.

3. Piston to wall clearance. What piston to wall clearance do I go with, 1g or 2g specs?

Many shops will tell you with the OEM cast pistons, the bore is built into the piston meaning if you buy .020 over pistons they would typically bore the block to .020 and the clearance should be within the stock clearance. While this is correct, I advise you make sure they measure the piston first. My .020 OEM 2g pistons came smaller than they should have and if just bored .020 would have given me a clearance of .001... way too small for my liking. I decided to go with .002 which is the upper limit of suggested factory clearance. I feel safer this way especially if I slip up and run a little too lean or my tune is a little bit off, it might possibly save my engine.

If 2g specs, can someone point me in the right direction to find this. Unless someone has the specs, can some one tell me?

Just for reference because I don't believe the specs have been posted on this forum:

PTW: 0.0012 - 0.0020
Top Ring: 0.0098 - 0.0138
2nd Ring: 0.0157 - 0.0217
Oil Ring: 0.0039 - 0.0157

Remember, the actual gap on your rings will depend on how much boost you plan to run. Also, don't get lazy many people will say the rings come pre-gapped and you can just run them straight. I can't stress this enough, measure everything!!

4. Main bolts. I have brand new main bolts that the machine shop torqued to the block in order to check my main bore housing spec. Should they have align hone/bore my mains before they used them when they checked my mains? Do I need to make sure the mains are align bored/honed since I am going with new bolts? I know you should when changing rod bolts. Also the what is the difference with align honing the main vs align boring the mains? Which one should I have done if I need to?

Check out this right-up, it will explain everything and more:

http://www.dsmtuners.com/forums/articles-engine-fuel/303225-engine-machine-work-explained.html

5. I am having my block bored .020 over. I have a brand new oem crank I will be using, acl race main and rod bearings, new oil pump, water pump, timing components, reusing arp head studs, new oem composite head gasket, new main bolts. Last on my list are pistons and rods. I want to go with the 2g/1g piston and rod combo with dsmgraveyard.

Just a heads up. I went with DSMGraveYard for my combo as well. I ordered on March 5, 2010. 9 weeks later I received my order. The rods were fine and within spec. The pistons were a nightmare. Firstly they only sent me 3/4 pistons. They sent me NPR pistons instead of OEM and NPR rings instead of the hastings, the pistons were also std. size instead of .020. I called and it took them another week and a half for them to ship me out the correct ones. I even had to pay shipping to ship the wrong ones back and pay to have them ship the correct ones to me. I will never do business with them again. If you need this combo soon, buy everything individually and bring it to a shop unless you want to wait 3 months.

6. Before I took the head off the block, the motor has been sitting in my garage for two years upside down on the motor stand. The crank, oil pan, front case and timing components were taken off before it sat for that long. Do I need to take apart my head to get it cleaned? Any other stuff I need to do, or can I just run it. No issues before I took the car apart. The head is suppose to be pretty new, it is an SBR stage 2 race head with 1mm over sized valves. The previous owner told me he just installed it right before I bought it.

Thanks.

I would check for rusting on the cam gears, if you're running and MLS head gasket, you will need the head and block resurfaced to a mirror finish (RA of atleast 50 microinches is suggested for a metal head gasket). Make sure the shop you're bring it to does NOT use a belt sander... Also make sure you emphasis you wish to run an MLS, else they might assume you're running a composite.

If you're running a composite you might be able to get away with simply cleaning the surface up. Either way I would check the head if it has been sitting that long. Bring it down to the shop let them go over it. Do it once, do it right. I'd rather be safe than sorry.

 

[JayRolla]

I didnt build my motor so I cant tell you about the other stuff but I can say you will be fine on the stock ecu. Just watch knock and dont turn up the boost without some type of timing control. I switched to e85 back in the day on just an safc/maft so I would handle the timing, boost and 2g pistons. Worked out great.

 

[packinkimber45]

You're running the exact same setup as I am, I have a few answers to your questions, some of the other questions I'm actually curious about myself.



I've definitely heard this before, and I'm expecting to run into the same problem. The 2g piston has a beefier skirt than the 1g and you most likely will have issues with clearance. I would suggest claying the side of the piston closest to the squirters to see if you will have issues or not.

I was already set for the 2g pistons on 1g rods combo until I heard this and now that you confirm the same thing it makes it even more complicated. Now I dont know if I want to do this set up anymore. The last thing I want are things to go south because of going with 2g pistons. I just want my car back on the road and not have to keep dealing with finding fixes for issues such as this we are talking about.

You must be logged in to view this image or video.

Here's a nice comparison of the 2g (left) vs 1g (right) skirt, you can see the 2g is definitely larger, this is where you would most likely hit.

Why use shorter and lower profile? If the longer and higher profile hits, wont the shorter and lower profile hit more since the skirt on the 2g's are beefier?

To get around this you have 3 options...

1. Remove the oil squirters and block them off.
2. Bend the oil squirters down so they clear. I do not recommend this. Doing so could possibly weaken the squirter and cause it to break off down the line, squirting oil everywhere but the piston.
3. Lastly, and most likely what I'm going to do, swap in the EVO oil squirters. They have a lower profile and are shorter which should solve your clearance issues. Here's a comparison picture:
   
   
   You must be logged in to view this image or video.
   
   
   EVO on the left, 6 bolt on the right
   
   
   You must be logged in to view this image or video.
   
   
   6 bolt left, EVO right

I'm sorry but your pictures lost me. Is the second picture description correct? I thought the evo is the shorter and lower profile oil jet? Did you accidentally post the description backwards, or am not understanding it correctly? Sorry .

For spraying they use a special solution sprayed at a high temperature and high pressure to remove any contaminants. Most setups have multiple spray nozzles that spray the block as it spins. The shop would remove the squirters if there were going to be any issues. They need to be removed to bore / hone the block anyways.

I understand they would remove them if it were a problem to have the squirters there. However when I went back to the machine shop to drop off my arp head bolts for torque plating they had no clue I left them there. I had to take them off and the block had already been sprayed at that point. Would that have damaged or weakened my squirters? Should I just buy new ones?

This is something I'm interested in knowing myself. I don't think it would be a problem running at stock boost if you're not seeing any knock. The big issue is being able to control timing.

This worries me because I will be running w/o any tuning device until tax time next year. Not having the ability to control the map while driving daily kind of worries me since I dont have the money for any tuning devices...

Many shops will tell you with the OEM cast pistons, the bore is built into the piston meaning if you buy .020 over pistons they would typically bore the block to .020 and the clearance should be within the stock clearance. While this is correct, I advise you make sure they measure the piston first. My .020 OEM 2g pistons came smaller than they should have and if just bored .020 would have given me a clearance of .001... way too small for my liking. I decided to go with .002 which is the upper limit of suggested factory clearance. I feel safer this way especially if I slip up and run a little too lean or my tune is a little bit off, it might possibly save my engine.

Just for reference because I don't believe the specs have been posted on this forum:

PTW: 0.0012 - 0.0020
Top Ring: 0.0098 - 0.0138
2nd Ring: 0.0157 - 0.0217
Oil Ring: 0.0039 - 0.0157

I will talk to the machine shop about ptw clearance when the time comes. I am still debating on pistons. I keep going back and forth.

Are these specs for the 2g then? Thanks for providing these. I could not find them anywhere.

Remember, the actual gap on your rings will depend on how much boost you plan to run. Also, don't get lazy many people will say the rings come pre-gapped and you can just run them straight. I can't stress this enough, measure everything!!

Since I will be running stock boost for a while, how will me setting my ring gaps based on my target boost level affect the car during the time I drive the car (6-8 months). Any harm can occur from this?

Check out this right-up, it will explain everything and more:

http://www.dsmtuners.com/forums/articles-engine-fuel/303225-engine-machine-work-explained.html

I have read the write up, very interesting. My main housing bores are in spec according to the machine shop. I am just wondering if I need to align bore since I am using new oem bolts and not the old one. However like I mentioned they already used the new ones to torque the mains down while they checked if it is in specs.

Just a heads up. I went with DSMGraveYard for my combo as well. I ordered on March 5, 2010. 9 weeks later I received my order. The rods were fine and within spec. The pistons were a nightmare. Firstly they only sent me 3/4 pistons. They sent me NPR pistons instead of OEM and NPR rings instead of the hastings, the pistons were also std. size instead of .020. I called and it took them another week and a half for them to ship me out the correct ones. I even had to pay shipping to ship the wrong ones back and pay to have them ship the correct ones to me. I will never do business with them again. If you need this combo soon, buy everything individually and bring it to a shop unless you want to wait 3 months.

That sucks! I have dealt with a couple of people or companies in the last couple of years with dsm stuff and I can say I too have had issues. It sucks!! I was really set on going through them for either the 2g/1g combo or evo 9/1g combo, but hearing this scares me having issues again. They have reasonable prices too, it's too bad. Oh well, I will just have to find another vendor to deal with since I don't want to run into any issues such as you did.

I would check for rusting on the cam gears, if you're running and MLS head gasket, you will need the head and block resurfaced to a mirror finish (RA of atleast 50 microinches is suggested for a metal head gasket). Make sure the shop you're bring it to does NOT use a belt sander... Also make sure you emphasis you wish to run an MLS, else they might assume you're running a composite.

If you're running a composite you might be able to get away with simply cleaning the surface up. Either way I would check the head if it has been sitting that long. Bring it down to the shop let them go over it. Do it once, do it right. I'd rather be safe than sorry.

Through my research I have read that the composite head gasket has proven itself for high boost levels. I dont plan to run more than 25 psi ever on this rebuild so I am going to stick with it. I just hope that the info I got is correct that for boring .020 over the standard oem composite gasket will work just fine.

I am trying to do things right without cutting corners, just a little harder when it comes to limited funds.

 

[aspekt9]

Just an update for you. I just assembled my bottom end. The 1g oil squirters were very close to hitting the piston. I had a feeling that after warming up they would most likely have hit. I ordered 4 brand new evo oil squirters ($62) and installed them. They have way more clearance than the 1g ones do.

Also, I ran .020 on the top ring, .024 on the 2nd ring. I decided a little loose was better in the case that I do run lean. I also read an interesting article talking about how ring gap differences don't matter as much as people think. Well it was a little more in depth than that but...

 

[packinkimber45]

Just an update for you. I just assembled my bottom end. The 1g oil squirters were very close to hitting the piston. I had a feeling that after warming up they would most likely have hit. I ordered 4 brand new evo oil squirters ($62) and installed them. They have way more clearance than the 1g ones do.

Also, I ran .020 on the top ring, .024 on the 2nd ring. I decided a little loose was better in the case that I do run lean. I also read an interesting article talking about how ring gap differences don't matter as much as people think. Well it was a little more in depth than that but...

Any update? Have you ran the car yet? Can I ask where you read that article about ring gaps? After doing a lot of thinking and as much answers as I could find, I decided to get Mahle pistons and Manley rods on monday. Waiting for my parts to come in so I can finish my car. Thanks.

 

[aspekt9]

Yeah, the car is up and running. I have about 200 miles on the motor, everything seems kosher thus far. No squirters in the oil pan and no blow by and oil pressure is spot on. I can try to dig the article up for you.

 

[packinkimber45]

Yeah, the car is up and running. I have about 200 miles on the motor, everything seems kosher thus far. No squirters in the oil pan and no blow by and oil pressure is spot on. I can try to dig the article up for you.

Right on. What break inn procedure are you using? The traditional break inn or the motoman way? That would be great if you could do that. Thanks.

 

[DSMDirkah]

The deal with the engine management:

The 1g's had much lower compression pistons so the factory had a completely different idea of how to make safe power with them compared to later models. The 1g maps are very different from a 2g map as in the 1g map adds TONS of fuel (9:1 region) with TONS of timing. Alot of timing is ok for lower CR engines, but with the added compression I would advise to be careful. E85 would love the timing, but I would be more careful with adding a lot of boost with pump gasoline. Just pay close attention to knock.

If I were doing a build like this, I would use 2g timing maps as a base with 93 octane and work from there.

It has been a long time since I was heavy into DSM's, but some questions on the oil squirters. Why not just cut the squirter shorter to get the clearance? IIRC there was some sort of check valve in there but it has been several years since I had one to look at. Another thought is why not just block off the oil squirters? One less thing to go wrong and it would also raise oil pressure. Again, not 100% positive, but I think that the oil squirters were to cool the bottom of the pistons for better emissions or gas mileage. Correct me someone if I am not correct on this.

 

[beachbum2185]

instead of mixing up 1g/2g rod/piston combos and worrying about clearance issues, wouldnt it be easier to just go like..eagle wiseco combo?

 

[packinkimber45]

The deal with the engine management:

The 1g's had much lower compression pistons so the factory had a completely different idea of how to make safe power with them compared to later models. The 1g maps are very different from a 2g map as in the 1g map adds TONS of fuel (9:1 region) with TONS of timing. Alot of timing is ok for lower CR engines, but with the added compression I would advise to be careful. E85 would love the timing, but I would be more careful with adding a lot of boost with pump gasoline. Just pay close attention to knock.

If I were doing a build like this, I would use 2g timing maps as a base with 93 octane and work from there.

It has been a long time since I was heavy into DSM's, but some questions on the oil squirters. Why not just cut the squirter shorter to get the clearance? IIRC there was some sort of check valve in there but it has been several years since I had one to look at. Another thought is why not just block off the oil squirters? One less thing to go wrong and it would also raise oil pressure. Again, not 100% positive, but I think that the oil squirters were to cool the bottom of the pistons for better emissions or gas mileage. Correct me someone if I am not correct on this.

When I ordered my pistons and rods I also ordered Dsmlink. I have never dealt with tuning before. This will by my first time learning. When you talk about using 2g maps as a base, do I have the option to choose from 2g maps in dsmlink? Actually as far as the clearance issues I have decided to steer away from the 2g/1g combo and went with Mahle/Manley combo.

instead of mixing up 1g/2g rod/piston combos and worrying about clearance issues, wouldnt it be easier to just go like..eagle wiseco combo?

Actually I already ordered mahle pistons and manley rods for my set up. I didnt want to worry about clearance issues and I wanted forged pistons for extra insurance and be able to handle more.

 

[JayRolla]

Im not a fan of the 2g timing map. There are some posts on the link forums that give you the formula you input into your timing map to match the 2g map. I would just start with the 1g map and low boost. Then down timing through logs till you get the timing where you want it. The 1g stock timing map is awesome for e85.

 

[packinkimber45]

Im not a fan of the 2g timing map. There are some posts on the link forums that give you the formula you input into your timing map to match the 2g map. I would just start with the 1g map and low boost. Then down timing through logs till you get the timing where you want it. The 1g stock timing map is awesome for e85.

I keep hearing this hype about e85. I hope my set up, as far as my piston compression ratio will work out for that, but I hear with e85 it's ideal to run higher comp pistons. I will look into that. Can you point me in the right direction where I might find that, as far as the formula to enter into the timing map to match the 2g map. I wont be upping my boost anytime soon. I dont have any fuel mods in place right now. Just enought to get the car running with the new internals and such. Dsmlink is the only future mod I wanted that was able to acquire right now.

 

[Ryan4dc]

Hi. I was thinking about starting a new thread but came across this one and most of my questions are answered. Thank you for the information. The difference is the block I'm building doesn't come with oil squirters from factory and might use your setup for the block. Still debating on it since I won't have clearance issues with the squirters using the 2g pistions.

 

[poundcake]

It has been a long time since I was heavy into DSM's, but some questions on the oil squirters. Why not just cut the squirter shorter to get the clearance? IIRC there was some sort of check valve in there but it has been several years since I had one to look at. Another thought is why not just block off the oil squirters? One less thing to go wrong and it would also raise oil pressure. Again, not 100% positive, but I think that the oil squirters were to cool the bottom of the pistons for better emissions or gas mileage. Correct me someone if I am not correct on this.

I know this is an old thread but im getting ready to go with the 2g piston 1g rod combo. My question is can you cut the squirter maybe 1/8th of an inch off for that clearance issue? I really hate cutting anything inside of an engine like that but does anyone see problems with it?

 

[eeeric16]

I'm building a turbo engine with 1g rods 2g pistons, and I'm using a n/t block which means no oil squirters, i don't think they will make much difference as a daily driver. Personally if i did have them and thought they might not clear i would just remove them and block the ports.

 

[poundcake]

Thanks for the reply. I really want to keep the oil squirters. After some looking around I found a pic of them when they actually make contact with the 2g pistons. It really looks like you could bend them just a bit out of the way. I also heard of using evo squirters. Where could I get those at if I go that route? Thanks

 

[arrowhead]

Any updates from anyone?

 

[Cruz67]

How do you machine 1g roda.to accept 2g pistons?

 

[93boostedtalon]

I just done a 91 tsi for A freind and I put the 1g rods with the 2g pistons. The car now is at 3,000 miles no problems with the oil sqwirters. And as far as compression at 16lbs of boost the car counted no knocks and the 1g maf was fine. Not going against any thing these guys have told you but my buddys is still running strong. my car is same rods and pistons and and no contact with the oil sqwirters. But who knows i could have just been lucky

 

[Blindmouse]

I'm running until the last 5 years with this 1grods-2gpistons combo, but my oil-jets never heard this rumours.. that's why never touches the pistons

 

[Spoolin98]

How do you machine 1g roda.to accept 2g pistons?

I believe you have to hone the small end from 21mm to 22mm for the 2g wrist pin to fit.

 

[Cruz67]

I believe you have to hone the small end from 21mm to 22mm for the 2g wrist pin to fit.

Could done one confirm this?

 

[viperlp01]

1g wrist pin is 21mm, 2g wrist pin is 22mm

 

[JD336]

what year of evo for the squirters?

im also building a 1990 eagle talon tsi with 1g rods and 2g NPR pistons .20 over
apr head studs
apr rod bolts
acl rod and crank tri bearings
stock head
fmic
smim
2g port and polished exhaust manifold
small 16g with 7cm exhaust housing
external wastgate
mbc
greddy bov
clutchmaster light weight flywheel/3 puck cluch/2500lb pressue plate



and next year the plan is to go with 660s, afpr, and a walbro 255 wired and dsmlink


shooting for a 300 - 350+ daily driver