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| FieroGT/4E introduction (Page 4/13) |
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dobey
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JUN 28, 09:44 AM
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| quote | Originally posted by lou_dias:
the new 99 mm (3.9 in) bore required offsetting the bores by 1.5 mm away from the engine centerline of each bank
so yes, some are 6X degrees and others are 5X degrees
my engine rebuilder has one of these LZ4 engines for sale...I almost bought it until I noticed the cam phaser, I was mistaking it for an LX9...
for some reason, the wiki links the LX9 engine on the same page as the LZ4 and LZ9...
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They are all high value platform engines. Why would one be on a different page?
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ericjon262
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JUN 28, 10:13 AM
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I'm 99% sure the bank angle is still a straight 60*. I have a transmission support from an LZ4 bolted to my LX9. the support goes from the side of the block to the oil pan, if the angle was changed, it most likely wouldn't sit flush or bolt on like it did.
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fierogt4e
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JUN 28, 11:09 AM
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I see the “the new 99mm (3.9in) bore required offsetting the bores by 1.5mm (0.1in) away from the engine center line” repeated often. (1.5mm =.0590 in)
The bores are at 60 degrees to each other. When the piston are at tdc the rod angel would be more than 60 degrees.
I have never seen any mention of how they compensate for the change in the stock engine.
Some claim the wrist pin is offset “like in the LS motors”. In the LS one bank of pistons have the pin moved 1mm away from center line and the other bank 1mm towards the center line. I have a set. This will increase the difference in geometry from bank to bank when used in the LZ9 if the 1.5 outward is correct.
Should I be using 6 LS pistons all from the same side and turn 3 backwards??? this would reduce pin offsets to .5mm (.0197in) relative to the crank if the crank is ground at 120 degrees. If so I need to throw out 5 of my new Wiseco pistons and buy 3 more of the same side for all 6 to be the same! F***! F***!! F***!!!
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Sincerely
George
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lou_dias
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JUN 28, 12:45 PM
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| quote | Originally posted by dobey:
They are all high value platform engines. Why would one be on a different page? |
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Because the LX9 is basically a bored 3400...
http://www.enginebuildermag...evy-3-4l3-5l-engine/
Here's a pic of a 2.8 head on a VVT block where you can see how the bore was moved:
 [This message has been edited by lou_dias (edited 06-28-2016).]
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exoticse
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JUN 28, 02:32 PM
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George, sent you a PM. 2 actually.
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dobey
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JUN 28, 05:01 PM
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| quote | Originally posted by fierogt4e:
I see the “the new 99mm (3.9in) bore required offsetting the bores by 1.5mm (0.1in) away from the engine center line” repeated often. (1.5mm =.0590 in)
The bores are at 60 degrees to each other. When the piston are at tdc the rod angel would be more than 60 degrees.
I have never seen any mention of how they compensate for the change in the stock engine.
Some claim the wrist pin is offset “like in the LS motors”. In the LS one bank of pistons have the pin moved 1mm away from center line and the other bank 1mm towards the center line. I have a set. This will increase the difference in geometry from bank to bank when used in the LZ9 if the 1.5 outward is correct.
Should I be using 6 LS pistons all from the same side and turn 3 backwards??? this would reduce pin offsets to .5mm (.0197in) relative to the crank if the crank is ground at 120 degrees. If so I need to throw out 5 of my new Wiseco pistons and buy 3 more of the same side for all 6 to be the same! F***! F***!! F***!!!
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If you are using offset wrist pin pistons, then you do not want the offset to both toward or away from center on both banks. You want the offset to be toward the major thrust wall of the cylinder (or opposite the crank rotation direction).
Which pistons are you using? Got a part number?
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fierogt4e
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JUN 28, 11:33 PM
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Dobey
You're 100% exactly right. For an LS and all motors I'm aware of except for LZ9/LZ4.
These engines (probably) have the cylinder moved outward. Opposite directions. Odds towards the major thrust side. Evens toward the minor thrust side.
Using the ls piston in our cyl. #1 and you add the 1mm of the piston to the 1.5mm of the block! (2.5mm = .0984in outward)
Using the ls piston in our cyl. #2 and you subtract 1mm for the piston from the 1.5mm of the block. (.5mm = .0197in outward)
It maybe OK up to 5 or 6000. But at 7,8 or more umm... not good.
Its the odd numbered bank that is bugging me
CH 1.05 -14CC 3.905OD Yes the pin is in the rings.
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Sincerely
George
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sleevePAPA
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JUL 01, 03:26 PM
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Are you using a custom rod with that CH or an OTS set? Ive been looking around for possible OTS solutions for my turbo LZ9 GN build, but haven't found much.
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fierogt4e
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JUL 02, 12:02 AM
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SleevePAPA ;
If OTS means “off the self” than yes (mostly) also a little custom too.
http://www.speedwaymotors.c...-6-125-In,38265.html
That”s the best picture however Jeg's is a few dollars less. I think I have finely found a new set at $60.00 less . I'll keep looking for 2 more weeks.
6.125 C to C, 2.000 big end, .927(?) small end. The big end needs to be thinned to .860. I can do that. The crank needs to be ground down to 2,000 from 2.250. For lightness. And the stroke reduced to3.290 from 3.307 for.010 above the deck. I haven't found high end thin 3900 head gadgets yet. Anyone?
exoticse you have a PM
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Sincerely
George
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fierogt4e
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JUL 02, 01:14 AM
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