ulakovic22

I've got an itch to make a big cube LTx. There have been a few people who have already built them using a 4" stroke and I've searched and read up on those. I am going to pick up a couple LT blocks this month and have more available fairly cheap. My plan is to use a 400 sleeve and then I can decide what stroke I want to use so I don't have to worry about common draw backs of long stroke, short deck blocks, mainly piston and clearance issues.

This is more of a pet project for me and is on the back burner until I get my other two projects complete, but I did want to find out the order of doing my block prep. I plan on sleeving both blocks and then half filling at least one of them. I'm thinking I can get a 3.75, 6, +piston combo to make a 400 and not worry about clearance/piston issues and other than the cost of sleeving should be a straight forward build.

The other one I plan on boring and dropping a 4" crank into and building a 414/427/434 depending on how big a sleeve I can fit. This motor can use off the shelf parts too since Wiseco has come out with several piston choices in there ProTru catalog for 2009.

Finally to my question, lol. I'm thinking I should sleeve them first, then fill them, then clearance them, then finish machining the block. Is that the right order? Why wouldn't I fill the block after it has been machined? I figured the machining process would cause the block to move around and crack the fill possibly?

Thanks.

cnorton

You're thinking along the right lines but it works the other way around. First, stabilize the block with fill. Then, machine it. Sleeving a block with the relatively narrow bore spacing of a modern SB Chevy is tricky. The relatively thin deck and the proximity between bores leaves a minimal amount of material to stabilize the sleeves. It can be done but there's a lot of room for things to go wrong. Choose your machinist with care.

ulakovic22

Are you saying that I should fill the block, then sleeve it or sleeve it then fill it? I'm thinking if I fill it then sleeve it, I will just be cutting out the block fill that I just put in. Won't cutting the fill out for the sleeves crack it?

I hear what you're saying about the bore spacing and one thing I'm wondering about is the max bore I can go, with what will turn into a siamese block. I guess another thing I should think about is cooling issues. I've heard of people half filling blocks and not running into cooling issues with the LTx, but with a siamese block will cooling become a bigger issue with a half fill?

mdacton

it won't work.

ulakovic22

It's already proven to work in both cases. It's just a cost thing with sleeving and being careful about hitting water which is why people half fill.

mdacton

oh, well you know more than I do then.

I didn't think the bore spacing was right....

Is it really worth it to dump 6k in just block work? you could buy a 4.125" dart block for that.

When you get it finished though let me know..... I want to see if it will outrun a 383

ulakovic22

I only know what I've read and heard by talking to machinist and seeing other members on this board build them. All the parts are readily available to build these motors too. I certainly won't be spending 6K on block work either, if I was then I wouldn't be considering this to be a pet project.

Assuming everything else is equal, physics says it will. Hell, one of these blocks will basically be a 383 RA just with a larger bore, which means more power without having to worry about tiny pistons and bad rod angles of a 4" stroke.

Do you know if I should fill then sleeve or sleeve then fill?

mdacton

If you know a machinist that is even willing to try this run.....

If you prove me wrong I will come back and delete all my post, no questions asked

ulakovic22

I don't care if you delete your posts, I'm not some sensitive little ninny. I just want some help in figuring the best way to stabalize the block for the sleeves and in case I hit water.

cnorton

If it is your intent to install wet sleeves, I misunderstood your question, and by all means do the sleeves first. Can it be done? I suppose so. Will it be an optimum outcome? Personally, I've never seen it done so I can't say. In the long run, nothing is ever learned nor is progress achieved by listening to people who say it can't be done. I'll be the first to congratulate you at the end of the day. On my track-only motors I fill them as far up as I can without blocking the water ports. I've never filled a siamesed block.

Good luck,

c

Kevin Blown 95 TA

Does he need torque plates before he fills it?

cnorton

Actually, it's much easier to fill front-to-back if you wait until the fill has been poured before you put on the torque plate. Mains should be torqued. If the block is subjected to the assembled stresses before the fill takes a permanent set, the final hone with a torque plate removes less material.

c

ulakovic22

It's been said that you need to let the fill sit for a few weeks before you do any clearancing or machine work, is that true? Also would the torque plates have to stay on the whole time so there isn't any shifting?

cnorton

I allow a minimum of two weeks in warm weather for the fill to set before machining. I don't think it would be necessary to leave the plate (or a head) torqued for the full time although it couldn't hurt.

During the filling process, I use a dead-blow hammer to rap along the outside of the block from time-to-time to jar loose any air pockets. I can't say that I've ever seen any bubbles work their way to the top but a solid, consistent fill is a plus.

akafred

just get a dart block and run regular sbc stuff, or go lsx.. either way you will end up more reliable, more power, cheaper, ect..