I find the idea of spacers on the LSx block to increase displacement funny because I brought this up about a decade ago on this board to do it on the LTx block. The question I have is, can it be done on an LTx block then sleeve it? I'm revisiting the idea ever since the Dart big cube LTx block was canceled. I figured the only drawback is the cam is not high enough. Thoughts?

Is it possible to do this to an LTx block?

 

Advanced Tech is pretty much deceased. There will be some changes soon.

 

I noticed for a while that it's a bit quiet around here lately.

 

The reason you can get away with that on an LS block is because the cam is raised in relation to the crank. In a normal SBC or LT engine, the rods would hit the cam before you got enough stroke to warrant deck spacers.

 

The biggest stroke I've read that fit in an LT1 is the 4.125" but I'm not sure if that's with a small base circle cam or not.

 

I'm hoping Advanced Tech can stay alive!

I brought this idea up with a few other folks when I was at SAM, and they said to try it. Unfortunately, my bankroll couldn't afford it.

That much stroke would definitely require a small base circle cam, but that isn't that bad of a deal.

It gives you the chance to have 454 cubic inches with a 4.185" stroke with plenty of room on the piston for the ring pack and a long enough rod to not have too much sidewall loading.

 

To get that kind of stroke you really would need Honda or Aurora rod journals and you would still be digging VERY heavily into the pan rails and be up into the cam tunnel pretty bad. I don't know that the added inches would be worth it since the small rod journals are going to make the crank quite a bit weaker where the cheek and pin meet and it wouldn't be able to handle a bunch of power. Also, cam grinders will tell you that a small base circle is the opposite of good design. What I'm saying is that it really isn't a good idea unless you had an Iron Eagle block with raised cam tunnel and spread pan rails.