8.1ltr vortec ls1 in a 99t/a
also bmr makes a big block k-member so that shouldnt be a problem. any information would be greatly appreciated. also if anyone knows where I can pickup an 8.1 as well that would be greatly appreciated... http://www.gmgoodwrench.com/perfpartsjsp/home.jsp
Pat
http://www.gmc.com/yukon/enginesxl_p...sp?engine=8100
While the EFI, and coil seem similar the basic motor is quite different. Check out the size and shape of the valve covers. I think they have adapted some of the same external technology used on the Gen III small blocks to the older big block design.
In the old days, Small Block and Big block Chevys could use the same distributor and ignition pieces, and they both could use Quadrajet carbs, but their internal parts and design were totally different. I think the same thing has happened here.
Pat
We've got a brand new 8.1 in stock if you're interested! Fully dressed with harness, computer, accessories, starter, etc. Runs like new (as it should)!


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. And I am pretty sure you wouldnt be able to bolt anything from an 8.1 to an old school bbc. Maybe the header bolts are the same size?? Remington
. And I am pretty sure you wouldnt be able to bolt anything from an 8.1 to an old school bbc. Maybe the header bolts are the same size?? Remington
. Mechanically it shares nothing with the lsx series motors. Just perhaps the electronics and a similar intake manifold design. Being a MK IV any bbc heads should be interchangeable assuming you had an intake manifold to match up to it. Last edited by SmokingWS6; Jan 7, 2005 at 02:36 AM.
Also rods are stronger in the older BBC.
8.1 weak points are in the rod and wrist pin (non-floating type), and piston.
Has anybody compared head gaskets, or have pics of them side by side??
The GM Performance parts ZZ502s use a slightly difference siemesed cylinders Mark VI blocks with aluminum heads. The Vortec 8.1 has a 4.25 inch stroke, while the 502 has a 4 inch stroke. The firing order is also different.
Andrew
Remington
Remington
the 8100 is a makeover of the traditional big block chevy.
the Mark IV (4) lasted untill aprox 1992 replaced by the Mark V (5)
1993 on up were Mark 5 motors, basically the only difference was updated oiling and one peice rear main seals. the main bearings recieved oil in a different fassion. Mark 5 and Mark 6 are very close to the same thing, not sure the difference between them
the Vortec 8100 is classified as a Mark VII (7)
the 8100 is a TALL deck motor, measering 10.2 inches
all bolts in the motor are METRIC threads, nothing has std threads
standard big block chevy headders WILL bolt up, using METRIC bolts
the crankshaft is a different stroke, 4.370, which is the same gm's 572
the bore remains 4.250, stock for the previous 454s
the 8100 makes 496 cuib inch with stock bore, and 4.370 stroke
the common stroked 454 to make 496, is a .060 and 4.250 bore.
the main caps are 4 bolt, they are NOT 6 bolts or cross bolted like the Gen III smallblocks
there are oil cooler lines cast into the block infront of the oil filter boss, older oil cooler adaptors went between the oil filter and block, the 8100 is different there!
the head bolt pattern IS DIFFERENT! i have looked and tried, it will not work.
the firing order was updated to 1 8 7 2 6 5 4 3, same as the Gen III small blocks, but different from traditional chevy small and big blocks.








