Wnts2Go10O

iTrader: (12)

another tiny..small... significant detail about the LT1.. boring it out is going to be very difficult as the deck is all aluminum and the liners are cast into the block underneath that.

Albertan

GM has a LT1 at the Sema show. They announced the engine last week and then hustled it out here to SEMA. I was surprised at how small the mechanical fuel pump was. Sits under the intake to muffle the noise.

-TheBandit-

iTrader: (1)

Interesting. I wonder if that is to keep the top portion of the cylinder more heat conductive. Any idea how far from the deck the liners are?

dmaxvaz

iTrader: (1)

really? the camshaft is not baby, actually its pretty big. Anyways, the factory cyl heads are not bad either, they flow pretty well, and do really well cnc ported. High boost levels are a product of more fuel, more air, more power (double). Yes with higher flowing heads and better cam, boost will go down, but it will like 5psi less.

Wnts2Go10O

iTrader: (12)

id like to amend my last statement: the liners are cast into the blck then the deck is cast over that.

"Cylinder head sealing has been improved through the use of an all aluminum deck surface (cast over liners) and the inclusion of M12 cylinder head bolts."


i think that will play havoc with some wilder setups given the EXTREMELY different expansion characteristics of both metals.

01ssreda4

iTrader: (96)

A buncha BS changes for emissions only. I'm not impressed in the least. I'll be sticking with Gen3/4 platform for performance needs as I suspect 99.9% of others will as well.

dr_whigham

iTrader: (49)

I agree with red. Between the DI, cam and fuel pump, the liners being cast into the block & over, and the rumors of the PCM being locked and direct-linked with GM computers being able to yank your warranty at the blink of an eye, I'm not that excited at all.

GenIII for me.

Wnts2Go10O

iTrader: (12)

DI will be able to do much much more.. youll see 13 and 14:1 compression street motors. the pain in the *** will be the ecm and maybe the strange deck/liners. btw.. the liners have been cast in the block since the ls1 came out..

MSURacing

iTrader: (1)

If you are worried about modding an engine and having the warranty pulled, then maybe you shouldn't be modding in the first place!! If you can't pay, don't play!!!

dr_whigham

iTrader: (49)

I'm aware of that, brother. I'm more talking about boring and decking the block. It's interesting how the deck is cast over the liners themselves now.

I'm sure that's a joke, right? I'm not buying a C7 in the next 15yrs. The point I'm making is the guys that CAN afford these cars will be leery of doing anything with them due to that fact. That PCM is suppossedly some serious **** this time around.

And you're right. I'm afraid to "pay to play" and mod my motor....

sjsingle1

iTrader: (1)

looking at the injectors..........i dont see how they are sealing out ( or in ) the cylinder compression ...........are they threaded or ?

sjsingle1

iTrader: (1)

https://www.youtube.com/watch?v=9E-DQ1qQyJk

Paul Bell

iTrader: (9)

Thanks J-Rod for getting this forum going.

Nice video sjs, thanks!

MSURacing

iTrader: (1)

http://media.gm.com/media/us/en/gm/n...mallBlock.html

http://media.gm.com/media/us/en/gm/n...n5/engine.html

http://media.gm.com/media/us/en/gm/n...omponents.html

http://media.gm.com/media/us/en/chev...olet/gen5.html

tuske427

iTrader: (1)

Sweet engine, but what bothers me is the name. couldn't they have used a different letter sequence?? This is what- the third time "LT1" has been used. (yes, I know one of them had a dash in it)

BTW- here are a few pics of the engine at a media presentation I took Monday night before SEMA

sjsingle1

iTrader: (1)

i see that GM is using a semi synthetic oil for this engine...........what gives?

Gunslinger09

I am wondering why they are only showing 20 HP over the Ls3 after all the expense of development? The torque is nice but I would have expected 500 HP plus out of this motor. The new locked ECM is going to suck because even though DI is great for boost you won't be able to tune for it.

Paul Bell

iTrader: (9)

I'll bet these new heads have way more potential. Like any newly released, output will certainly go up in time.

Has anybody determined if these heads will bolt up to a genIII/IV block?

-TheBandit-

iTrader: (1)

The new heads have the locating dowels (spring pins) relocated and apparently use larger head bolts. I suppose if the bolt spacing and bore spacing is the same, you could make something work, but the chambers were designed for DI and higher compression. Not sure how well they are going to work if you use port injection or carb and I'm not sure how you would retrofit the DI on an earlier block.

I wish they would have driven that tiny high pressure fuel pump off the front of the crank or cam gear instead of all the way at the back.

Paul Bell

iTrader: (9)

Ahh, I see. I suppose the entire engine could be converted to carb or port injection if the DI ports were welded up. The compression could be varied by piston application. All to take advantage of the better heads with a more "user friendly" control system (non-GM LT1/genV ECM).

Agreed. This does seem foolish as it must really load up the entire camshaft. They'd better carve them from 4340 bar stock.