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2G pistons in 1G

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Spoolio

15+ Year Contributor
730
10
Sep 3, 2003
Port Charlotte, Florida
whats actually involved in putting like 95 pistons in my 91 6bolt?
 
Wrist pin hole has to be bored out on your rods and the small end of the rod has to be narrowed.
 
eh easier then i thought, you think it would be worth it to buy 2g stock pistons new?, or just get a set of good aftermarkets?
 
when i rebuild my motor im just gonna go with some aftermarkets,
 
im gettin used 2g pistons put in my 6bolt swap, and still have a 14b...
I know this swaps been done a thousand times, but as said up above
there really isnt too much of a big increase of power doing it?
I heard from someone else youll make more off boost power, and more torque,
and that you can produce more overall power everything to increase boost or etc.
Sounds like you gain more by using this pistons over stock 1g pistons....any input on this?

( Learned today that you approx gain 4% increase with these pistons and are better choice over 1g pistons... )
 
nightspeed87 said:
( Learned today that you approx gain 4% increase with these pistons and are better choice over 1g pistons... )
Would love to know whom told you this. Remember we are forced induction engines. The lower the compression the more boost can typically be run before onset of knock (pump gas) which can offset any gains thru compression.

A few years back I'd met up with a guy in NJ that was a pretty serious racer and told me that without a doubt, the 2G piston in a 1G was a huge waste of his money w.r.t. performance as he saw zero gains :dsm:
 
Actual you will get better off boost power and you can make a little more power on boost than stock compression. although with the 1g stock pistons you can run higher boost with less of a chance of knock than with the 2g pistons.
 
well take into consideration like i said i wont be ever running more than 23 lbs and thats me stretching it to more of a well maybe id go that high phrase. It will be some time before I even ever got that high anyway, and Ive never heard of 2g guys running into serious problems at 20psi as long as they got their tune... Intially I wont go past 16 lbs anyway, so that 8:5:1 compression ive learned will give me more power at that same timing advance and boost level than the 7:8:1 and im trying to squeeze every hp i can since i dont have money to go big time hp... ( Besides the fact of offboost power ) All these stroker guys are running like 8:8:1 compression and I know a few guys running 9:1 compression and with proper tuning are running a clean 15 lbs making a lot of power... 16 psi on 8:5:1 should give me what im looking for...

( The wiseman i was talking to about this was andymoraitis, he has a 2.3 stroker and 8:8:1 pistons at 22lbs according to him.... )
 
Not bad mouthing you, but for a turbocharged car the best comp. is 8.5:1 it is a proven fact. Not asking for any comments, just stating my fact.
DSM90AWD said:
Would love to know whom told you this. Remember we are forced induction engines. The lower the compression the more boost can typically be run before onset of knock (pump gas) which can offset any gains thru compression.

A few years back I'd met up with a guy in NJ that was a pretty serious racer and told me that without a doubt, the 2G piston in a 1G was a huge waste of his money w.r.t. performance as he saw zero gains :dsm:
 
On 8 cylinder for turbocharged 8:1 is MAX. Maybe a little more depending if it's fuel injected or carb. On smaller displacement 8.5:1 is best. I've even built 2 full out drag motor's running 14-71 superchargers running 6:1 compression.
 
andytalon said:
Not bad mouthing you, but for a turbocharged car the best comp. is 8.5:1 it is a proven fact. Not asking for any comments, just stating my fact.

I invite differing viewpoints, but fact denotes dyno numbers / 1/4 mile times..etc to substantiate a point. I'd love to see a before/after compare with all other things being equal if you have it.

In the conversation I noted above, the gentleman said the following about his buildup (VPC, 18G, FMIC, 660s)... he said his Extrude Honed intake gave him 35HP on TurboTrix Dyno, his 272 cams gave him 25HP on TurboTrix dyno, the 2G pistons gave him zero HP on TurboTrix Dyno but cost about as much as the other mods. He also started going thru headgaskets pretty regularly (higher compression = more succeptable to knock). Granted he did not have a means to control timing, which with the 1Gs can be pretty radical after 5.5K RPMs (big spike at 6K).

I don't dispute that higher compression pistons will help power production if have control over timing/fuel and properly tuned for it. But for the person whom looks to do this swap as a mod to perfectly fine 1G engine, I still say money is best spent elsewhere.

Also spending the money for parts (rings, HG) / machine work (machining rods, honing of bore..bla..bla..bla) to stick in used cast pistons is a bad idea all around. Forged pistons that fit the 1G rods can be had for ~$400 (I'm sure even cheeper) and will stand up to misjudgements in tuning much better-er ;) :dsm:
 
DSM90AWD said:
I invite differing viewpoints, but fact denotes dyno numbers / 1/4 mile times..etc to substantiate a point. I'd love to see a before/after compare with all other things being equal if you have it.

In the conversation I noted above, the gentleman said the following about his buildup (VPC, 18G, FMIC, 660s)... he said his Extrude Honed intake gave him 35HP on TurboTrix Dyno, his 272 cams gave him 25HP on TurboTrix dyno, the 2G pistons gave him zero HP on TurboTrix Dyno but cost about as much as the other mods. He also started going thru headgaskets pretty regularly (higher compression = more succeptable to knock). Granted he did not have a means to control timing, which with the 1Gs can be pretty radical after 5.5K RPMs (big spike at 6K).

I don't dispute that higher compression pistons will help power production if have control over timing/fuel and properly tuned for it. But for the person whom looks to do this swap as a mod to perfectly fine 1G engine, I still say money is best spent elsewhere.

Also spending the money for parts (rings, HG) / machine work (machining rods, honing of bore..bla..bla..bla) to stick in used cast pistons is a bad idea all around. Forged pistons that fit the 1G rods can be had for ~$400 (I'm sure even cheeper) and will stand up to misjudgements in tuning much better-er ;) :dsm:

well I think everyone is right in there own way, but actually its going in a motor ive been building up since april and its a 6bolt swap im doing because my old 93 engine had way too many problems and I got a motor cheaper in the junkyard than fixing my engine, and besides I figured before spending money now is the time to put together a good engine from scratch and run that one, and got a 6 bolt while I was at it... I didnt really care for the 2g pistons for the longest time, and I thoroughly got my new engine reworked, but fell short in funds and still needed new pistons for my setup because the stock pistons in the 6bolt motor were shot, so I found some used 2g pistons for cheap to put as an replacement cheaper than I wouldve found some used 1g pistons at the time, and needed to wrap this engine build up and swap before school starts (and college is expensive) because I wont have much money then... So basically otherwise I wouldve gotten some high performance forged pistons and not some used 2gs, but ran out of money and opted with these, and figured a little more compression couldnt hurt with my set up since I dont plan on every boosting excessively, and actually ive heard from others that the high comp does gain more power on a set boost level and timing advance, just all depends on your setup. Plus I got all my bottom end internals cryotreated for an extra piece of mind... Now do you see where im coming from with this....?

(But also I agree with the other guys, and I think the 8:5:1 is a better compression than stock 1g compression especially if your not going to run over 30lbs or something crazy like that, or why would they mod the 2g with these compression over the 1gs and inevitably the 2g has a good 10 to 15 more hp than the 1g does stock despite the 1g engine has bigger manifold/tb/ports,turbo etc... and I know the 2g didnt get that 10 hp gain from its air sensor, and even evos roll with higher compression, so I believe it is the sweet spot for comp numbers.....
 
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