rshissler Posted February 21, 2005 Report Share Posted February 21, 2005 ok i was talkin with a few friends about my 3.1 turbo i got to rebuild. they asked about gettin it bord to a 3.4 and i said maybe i should. Should I? Any problems that i would have to deal with if i got it to a 3.4?? Quote Link to comment Share on other sites More sharing options...
GutlessSupreme Posted February 21, 2005 Report Share Posted February 21, 2005 Pretty sure a 3.1 can't be bored to 3.4. There's simply not that much cylinder wall material that you can get rid of.. cylinders would be overlapping. Quote Link to comment Share on other sites More sharing options...
slick Posted February 21, 2005 Report Share Posted February 21, 2005 cylinders would be overlapping. Don't you know, thats the new hotness when it comes to boring out engines. Quote Link to comment Share on other sites More sharing options...
rshissler Posted February 21, 2005 Author Report Share Posted February 21, 2005 ok didn't think of that. Stupid question Quote Link to comment Share on other sites More sharing options...
Bossman429 Posted February 21, 2005 Report Share Posted February 21, 2005 I read somewhere in pre-60degreeV6.com days that the most a 3.1 could be safely bored out to was to a 3.2-3.3. The actual 3.4 block was strengthened with steel grid or something like that to make the thinner walls stronger, but it is not the same block used on a 2.8-3.1. EDIT: Heres the site: http://users.spec.net/home/emxjc/block.html There's a chart at the bottom, looks like .060 over bored pistons would yield a 3.3L out of a 3.1/2.8. You might be able to confuse some people I guess, if you tell them you have a 3.3 in your W. Quote Link to comment Share on other sites More sharing options...
slick Posted February 21, 2005 Report Share Posted February 21, 2005 I read somewhere in pre-60degreeV6.com days that the most a 3.1 could be safely bored out to was to a 3.2-3.3. The actual 3.4 block was strengthened with steel grid or something like that to make the thinner walls stronger, but it is not the same block used on a 2.8-3.1.EDIT: Heres the site: http://users.spec.net/home/emxjc/block.html There's a chart at the bottom, looks like .060 over bored pistons would yield a 3.3L out of a 3.1/2.8. You might be able to confuse some people I guess, if you tell them you have a 3.3 in your W. Couldn't have said it better myself. Also, if you go onto 60degreev6.com, it will tell you what each bore over will increase your engine size by. There's charts somewhere. Quote Link to comment Share on other sites More sharing options...
mfewtrail Posted February 21, 2005 Report Share Posted February 21, 2005 If you actually want 3.4 liters displacement, you could always use a late model 3400 pushrod engine in your rebuild/project. Quote Link to comment Share on other sites More sharing options...
Jeorge Posted February 21, 2005 Report Share Posted February 21, 2005 get a 3.4 Stroker kit and bore it .030 over....nothing 2000 in block mods cant fix LOL Quote Link to comment Share on other sites More sharing options...
Aaron Posted February 21, 2005 Report Share Posted February 21, 2005 get a 3.4 Stroker kit and bore it .030 over....nothing 2000 in block mods cant fix LOL There are no stroker kits for 60* engines, other than that of using a 3.1/3.4/3.4 TDC crank in a 2.8 block, which strokes it to 3.1L. All 660s at and above 3.1L used the same stroke, 68mm IIRC. I will hopefully will eb getting my custom crank stroked about 1/4" when I build my Fiero TDC, but it will not be cheap, and will take some minor block machining to work. Also, a stock turbo off of a TGP 3.1 is already on the small side, another .3L is going to kill any dreams you had of power after 5,000rpm. Quote Link to comment Share on other sites More sharing options...
Canada Posted February 21, 2005 Report Share Posted February 21, 2005 84 mm stroke. Quote Link to comment Share on other sites More sharing options...
Jeorge Posted February 22, 2005 Report Share Posted February 22, 2005 get a 3.4 Stroker kit and bore it .030 over....nothing 2000 in block mods cant fix LOL There are no stroker kits for 60* engines, other than that of using a 3.1/3.4/3.4 TDC crank in a 2.8 block, which strokes it to 3.1L. All 660s at and above 3.1L used the same stroke, 68mm IIRC. quote] http://www.engine-parts.com/GMV6/gm2834stkr.html ARI makes a Stoker They make a Kit too. I have contacted them on it for my build up. and they told me I can get a kit for making my 3.1L a 3.4L and I can get oversized pistons... Quote Link to comment Share on other sites More sharing options...
Aaron Posted February 22, 2005 Report Share Posted February 22, 2005 The 3.4L "kit" they sell is not a stroker off of the 84 (thx canada) stroke. It still has the same 84mm stroke, and same crank by carried by some 99% of 60 degree engines. It is simply a large overbore of a 2.8L block, too far IMO. Their kit takes a stock 2.8L, and strokes it to 3.1L using the factory 84mm crank. Their 3.4L kit bores this same 3.1L block to 3.4L. Quote Link to comment Share on other sites More sharing options...
dbtk2 Posted February 23, 2005 Report Share Posted February 23, 2005 With boost, you don't want to bore it out much over .030 over because the cylinder walls are too thin. .030" over is a 3.2L. (as I believe was already stated) I don't know how much you're planning on spending on this, but I would recommend either getting a 3400 or just boring it .030 over and leaving it at that. Also, a stock turbo off of a TGP 3.1 is already on the small side, another .3L is going to kill any dreams you had of power after 5,000rpm. First off, they make other turbo's, it can be upgraded, which obviously is the only way to go in trying to get decent performance out of the LG5. And 2nd, it really won't be that bad if he doesn't want to get tons of power out of it. If he keeps the power around 280 or so, he should be just fine. He just has to keep the exhaust as open as possible and it will flow the air pretty decently. The extra displacement isn't going to help, thats for sure, but unless he tries to extract every little amount of power he possibly can out of the engine, it will do okay. Also Aaron, remember, this is a pushrod engine, its not DOHC like you are used to. Peak power comes at around 5k on a Turbo 3.1 and peak torque is at like 3k or so, it really doesn't need to be wound out that much to make alot of power. You don't really want to spin it past around 5500 or so, so who cares if power does drop off after 5k, he won't be there long. And my STE is making ~280hp and it pulls hard all the way to the limiter, with a stock turbo. Bigger displacement making less power is still going to push out less exhaust then the smaller engine making more power, and since the exhaust housing is the restrictive part of the T25, it shouldn't be a huge problem. Not optimal at all, but useable, and it will have instant spool. I understand that you were pointing out that its and undersized turbo for that setup, and I agree with you, but its not THAT bad. Shawn Quote Link to comment Share on other sites More sharing options...
Aaron Posted February 23, 2005 Report Share Posted February 23, 2005 I've ridden in a few TGPs. I agree with you, but if he is spendign the time and money to turbo the car in the first place, he might as well pick the correct turbo for his application. Quote Link to comment Share on other sites More sharing options...
EurosportZ34 Posted February 23, 2005 Report Share Posted February 23, 2005 If you actually want 3.4 liters displacement, you could always use a late model 3400 pushrod engine in your rebuild/project. or just get yourself some real HP and get a 3.4 DOHC Quote Link to comment Share on other sites More sharing options...
Aaron Posted February 23, 2005 Report Share Posted February 23, 2005 If you actually want 3.4 liters displacement, you could always use a late model 3400 pushrod engine in your rebuild/project. or just get yourself some real HP and get a 3.4 DOHC :withstupid: Quote Link to comment Share on other sites More sharing options...
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