mrbelvedere

iTrader: (3)

I posted this up a once upon a time but it never got sticky status I found the info n jbody forums
http://www.j-body.org/forums/read.ph...74030&t=474030

OEM ecotecs:

LE5 Ecotec

bore = 88mm
compression height = 28mm
wrist pin diameter = 20mm
stroke = 98mm
rod length = 143.7386mm
rod ratio = 1.46:1
total bottom end height = 220.74mm


LSJ Ecotec

bore = 86mm
compression height = 30.86mm
wrist pin diameter = 23mm
stroke = 86mm
rod length = 145.5mm
rod ratio = 1.69:1
total bottom end height = 219.35mm


L61 Ecotec

bore = 86mm
compression height = 26.75mm
wrist pin diameter = 20mm
stroke = 94.6mm
rod length = 146.5mm
rod ratio = 1.54:1
total bottom end height = 220.55

Now, here are the revised hybrid options. Not a lot of movement is available, but with some custom parts you can build a pretty sweet ecotec engine without sacrificing too much displacement.

2.1 custom rod/ NA
Ingredients:
-LE5 block
-LSJ crank
-LE5 pistons
-Custom Rods (identical to LE5 rods, only 149.5mm in length)

bore = 88mm
compression height = 28mm
wrist pin diameter = 20mm
stroke = 86mm
rod length = 149.5mm
rod ratio = 1.73:1
total bottom end height = 220.5mm

NOTE: I say the above combination is ideal for n/a because if you're using factory LE5 pistons, compression will be up near the 11:1 range if not slightly higher. You CAN use LE5 pistons that lower compression, but this is my reasoning behind saying this would be better for n/a.. plus the rod ratio is a bit higher than the next variation.

2.1 custom piston/ turbo
Ingredients:
-LE5 block
-L61 rods
-LSJ crank
-Custom pistons (Identical to L61, except comp. height = 31mm, and bore = 88mm)

bore = 88mm
compression height = 31mm
wrist pin diameter = 20mm
stroke = 86mm
rod length = 146.5mm
rod ratio = 1.70:1
total bottom end height = 220.5mm

NOTE: I say this one is ideal for turbo because since you are getting custom pistons, you can alter the dome/dish to achieve any compression you want.
Furthermore, this would be a good combination if you have L61 eagle rods hanging around that have not been used yet, and decided to change direction and build an LE5 based engine instead, but still want to use already acquired parts.

which one would be more cost effective depends on what parts you have laying around or have access to, as well as the cost of custom pistons vs. custom rods. Both situations I plan on looking in to tomorrow afternoon.

the reason I'm revising this, is because I recently discovered that the LE5 rods have a tapered end, and the LE5 pistons also have a taper on the inside of their wristpin.

because of this taper, you CANNOT mix LE5 and L61 pistons/rods with one another. GM most likely did this to prevent installation error... or something.

the crank journals and rod journals however across all variants are the same dimensions, so swapping cranks is a no brainer... ASSUMING you take into account that the LSJ crank needs to use an LSJ flywheel and clutch. LE5 and L61 use the same flywheel and clutch, so mixing and matching there is easy.


So NO pistons can be swapped from one ecotec to another
-LE5 wrist pin is 20mm, but taper slot for rod/piston interface
-L61 wrist pin is 20mm, straight slot for rod/piston interface
-LSJ wrist pin is 23mm, straight slot for rod/piston interface
-LNF wrist pin is 23mm, ????slot for rod/piston interface, and also has direct injection dome shape

so mixing and matching IS limited, but you can make some cool 2.1L ecotec combinations using an LE5 block as a good starting point.

this will give you the advantage of having a larger bore (88mm vs 86mm), while retaining lower piston speeds and better rod ratio of the shorter stroke ecotecs (1.70:1 using L61 rods, and 1.73:1 using custom rods are pretty damn good, especially for those looking to build all motor cars... hint hint)


__________________

OneCOLDBIZL272

iTrader: (2)

Nice read...

Staged07SS

iTrader: (25)

Sticky complete!!

Nice info John. Thanks for posting!

Staged07SS

iTrader: (25)

Moved to advanced performance section. Still a sticky though

CptProzak

How much of a difference does the head make?

craigs06ls

yeah........what about the heads.....im interested in doing a build......what kind of power could it handle with stock l61 rods

08baltls

iTrader: (3)

Got a question that I asked in the main part of this subforum, but Im going to ask here too in case some of yall are sub'd to this thread.

I have a 2.2L L61 motor in a 2008 Cobalt that I've been thinking looking into possibly doing a stroker build on as well as a head swap or something of that nature to have a better flowing head, so I will break these down into parts concerning each.

On an L61 stroker, I have read that you can use an LE5 crank and possibly custom pistons and rods, or forged 2.2 rods and custom pistons. Being that my car is an '08 L61 with the 58x reluctor and so is the LE5, and the part number for the PCM is the same between models, would an LE5 crank swap over directly without having to use an external reluctor or anything like that? I know I would have to double check clearance of the crank by the girdle just to make sure it would clear. Also, someone mentioned using off the shelf 2.2 rods and pistons with the LE5 crank, but would that work? And if so, what would it do to compression ratios and would the 2.2 pistons not clear the top of the deck and impact the head and valves? If I need custom pistons, does anyone know what spec pistons would be needed?

As far as the head goes, I was thinking about using an LSJ head, but after looking into the price to upgrade the ignition and make it work, it just doesnt seem feasible. I found JBP heads for like $2,500 fully built, but Im not sure if they will work with an '08 L61. I have found a bare P&P'd performance head from GM (Part# 88958619) but again, Im not sure if it would work on an '08. Could someone clarify that subject for me? And also, if I'm going to do work on the head, I would like to upgrade cams. What would I do about the Cam position sensor? Would it be tuned out? Could I have the sensor pressed off and onto new cams to retain that?

Any help on this would be great. Thanks.

07MetallicSC

iTrader: (16)

Did you also check the thread i think its titled : why no more hybrid builds ? If you came from jbo ~ daflyingskwirl aka pj is the one you want to tall to

mrbelvedere

iTrader: (3)

all of the ecotecs have the same deck height so if you run a 2.4 crank in a 2.2 you would run a 2.4 rod and that will give you 2.3ltr since the 2.2 and the 2.4 use the same wrist pin diameter you should be able to get away with a 2.2 piston on a 2.4 crank and rod setup as for the head I believe your stuck with the head you have I don't know if the 2.2 cps is the same count as the lsj is If it is then you would just need to swap out the plug as for the crank reluctor I don't know if it is clocked the same between the 2 I would ask zzp or someone about it

08baltls

iTrader: (3)

Yeah, I saw it and skimmed over it last night, but havent had a chance to sit down and fully read the whole thread. But its bookmarked for later on this evening. I posted the question on JBO as well and they directed me to ecotecforum and said there was a ton of information over there on the subject. I registered there a few days ago too, so I guess Im gonna have to dig over there. But yeah, theres a few guys that I've seen who seem to really know their **** on this subject. Skwirl, Mrbelvedere, Maven, and one other guy seem to really be knowledgeable about the subject.

Thats awesome info, MrB. I really appreciate that, cause as far as the bottom end, thats pretty much exactly what I was looking for! On the subject of the head, I figured last night that I would probably be better off sticking with a 2.2 head. Now I just need to figure out if it would be better to buy a second '08 L61 head and send it off for P&P, or if the GM Performance L61 head would work with my motor and ignition set up or if its for the older ones. I just assumed LSJ in the beginning because it seemed like a better head that I wouldnt need to P&P.