is there a 383 combo that you can use your stock rods on?

 

Yeah, just get pistons for a 5.7" rod stroker instead of 6"

 

so i could use my stock rods with a 400 crank and have my block machined and get pistons (what size?)and i could have a stroked lt1??? that seems a little to easy. whats the fine print?? whats balancing a assembly like that gonna be like?? lt1 are intenral zero balanced correct??

 

383 pistons are basically just 350 pistons (for .030") with a 400 pin height if you are using stock rods, which are 5.7"

 

Yes, its that easy. Get a stroker crank and pistons, keep your stock rods, and you're set.

 

what does block work run roughly just to get it clearanced?? i think last time i had one balaced it was 130$ i saw a pic of what it was and it looks like someone just goes in and grinds down some metal for clearance. is it possible to do it carefully yourself??



wait.. 400s are 2 peice seal and balanced different... how does that work in a lt1??

 

never had it done so I cant tell you how much it costs.


They make stroker cranks for 1 piece seal.

 

You can't run stock 350 pistons, 350 (5.7") rods, and a 3.75" crank; the pistons will stick out the top of the block .125".

You can however run 350 pistons, 400 rods (5.565"), and a 3.75" crank; that's the simplest 383 to build.

You're right, you can't just plop a 400 crank in a LT1 block. But there are lots of people that sell non-stoick cranks specifically for that combo. Non-stock pistons as well, to allow the use of 5.7" or even 6" rods.

Balancing involves a little more than just some grinding. It works alot better if you know what you need to grins (i.e. what's too heavy), and you have some way of measuring all the weights of all the pieces; including weights to put on the crank journals such that when you spin the crank, it balances.

 

if you use the 5.7 rode then you get pistons with a 400 pin height..that way those lame @ss 400 rods wont have to be used..

i think he was talking about grinding down the main webs for the clearnace

 

Wrong.

350 and 400 pistons both have the same "compression height", or "pin height", or whatever you want to call that; it's 1.56".

Do the math on the total height of the rotating assembly. The sum of that "pin height", plus the rod length, plus the deck clearance, plus half the stroke (which is the rod journal offset), must equal the height of the block, give or take a couple of thousandths.

So: for a 350, that's 1.56", + 5.7", + 1.74" {½ of 3.48"}, + .025"; that gives you the nominal deck height of the SBC, which is 9.025".

And, for a 400: 1.56", + 5.565", + 1.875", + .025" also gives you 9.025".

That means as long as you use the stock pistons, the crank and rods swap together. 350 crank and 350 rods will work together in a 4" bore and give you 350 CID; or, a 400 crank and 400 rods with the same pistons in a 4" block will give you a 383, if the block is bored .030" over.

On the ohter hand, if you take stock 350 OR 400 pistons, with their 1.56" height, and 5.7" rods, and the 400 stroke, you end up with catastrophe:

1.56" + 5.7" + 1.875" + .025" = 9.160" which is clearly too tall to fit in a 9.025" space. Therefore, you CANNOT use stock 350 or 400 pistons and the 400 stroke, with 5.7" rods; that's the very reason that 5.565" rods exist in the first place. And, the existence of 5.565" rods, is the thing that creates the necessity for external balancing; because the rod is so short, that the counterweight can't be made large enough to do the job, and still fit underneath the bottom of the pistons when they're at BDC.This is what he was talking about. I think he's confused as what balancing involves. Balancing has nothing to do with clearance.

 

sorry about the confusion. i was just throwing a rough figure out on how much it cost me last time to have my rotating assembly balanced. the clearance i was talking about was the clearance were the block needs to be machined so the rods dont smack it on there way up. i think its at the lower edge of the cylinder.

 

Yeah, that's a different matter, separate from balancing; in a stroked motor the block usually needs that at the bottom of the cyls, and at the oil pan rails; and sometimes the rods will even hit the cam. It all depends on what rods you use.