The LS-1 has a pro-stock derived firing order to get rid of an exhaust overlap.

 

[quote]Originally posted by Merlin:
<strong>I know really nothing about LT1's, so this may sound dumb, but it is an honest question. Is the LT1 block the same block as the regular 5.7L that were put in ,say, the trucks of those years and such or is it a completely different casting? One more question is how does the intake on the LT1 compare to the LS1 as far as runner length, etc.?</strong><hr></blockquote>

The LT1 block is only used on the 5.7L in the 92-96 Corvette, 94-96 B-Body, and 93-97 F-Body. The timing cover and water pump mounting are different from a regular small block.

To answer PSJ, there is a difference in the physical dimensions, I dont know exactly but I know that the overall length of the engine is shorter. Its been said that the LT1 will not fit between the steering rack and the firewall on a C5.

Eric

 

[quote]Originally posted by slow:
<strong>

are you sure about the bellhousing? i had heard they're not the same. If they are cool.

for similarities, i hear that there is one bearing that is interchangable...and thats it.</strong><hr></blockquote>

Quite sure. In fact, all RWD-application GM engines share a common bell housing bolt pattern. What differs from application to application is the transmission input shaft length and spline count. <img src="graemlins/gr_cheers.gif" border="0" alt="[cheers]" />

 

Important differences are: Cam core size, and spacing of cam in block from crank. The much larger diameter of LS1 cam allows for much more rigid race application cam strength and larger lobes for much nastier grinds with reliability and more load bearing surface area. The higher placement of cam in block helps with cam lobe to connecting rod clearance, especially with longer stroke ls1's. The Block design with its deep reaching head bolts help minimze cylinder bore distortion when heads are clamped in place, this makes machining more accurate and allowsw for tighter ring end gaps and better control.
Larger mains is strength issue but will hurt as far as hi rpm bearing speeds on Ls1. i can go on but i need to know people are reading this long reply.

 

[quote]Originally posted by Nightclaw:
<strong>

Quite sure. In fact, all RWD-application GM engines share a common bell housing bolt pattern. What differs from application to application is the transmission input shaft length and spline count. <img src="graemlins/gr_cheers.gif" border="0" alt="[cheers]" /> </strong><hr></blockquote>

How about a 3rd gen camaro with a 2.8 (60 degree motor). Or are you just speaking of present-day cars?

 

See i knew people wouldnt be reading my reply, oh well. <img src="images/icons/rolleyes.gif" border="0">

 

LS1derfull,

I'm reading your post and your right that the cam is a very nice upgrade as well. It also shortens pushrods.

 

It is to my understanding that the LS-1 has a different bellhousing. this is evedent by the fact that there is no aftermarket SFI spec housing for the manual trany for the LS-1 do to lack of interest. I may be wrong but that is what i was told by a stock eliminator LS-1 racer.

 

It's the same only missing one bolt near the top compared to the old SBC. The oil passage "plate" on the back of the block sticks out which requires fitting on an afternmarlet bellhousing so that's what won't fit but the patterns the same basically. <img src="graemlins/burnout.gif" border="0" alt="[Burnout]" />

 

[quote]Originally posted by INTMD8:
<strong>How about a 3rd gen camaro with a 2.8 (60 degree motor). Or are you just speaking of present-day cars?</strong><hr></blockquote>
I think all GM cars from the mid-'50s on up. Definitely the 2.8L G3 F-bods.

 

Actually, the LS1 bellhousing has a different bolt pattern than an LT1. If they were the same, i'd slap in a 93 LT1 t-56 in a heartbeat.....Speaking of that, there is another difference......

The 93 LT1 T-56's had a steeper first gear to compinsate for the 2:73 geared M6's <img src="images/icons/rolleyes.gif" border="0"> . But man that would be nice to have in an LS1, especially to help out low end.

 

No, Erik is correct - it is virtually the same with the exception of the one bolt difference

The main reason the bellhousing/tranny's aren't interchangable is the different length of the input shaft.


Chris