Guy with a Chevy

I was planning on hand honing this block and still intend to find one to do so with to see how long we can make it last but it is getting harder to find them.

Found out I can get my block bored for $200? Hell of a deal I found in Corpus Christi. Just need to order the pistons and I am wondering if the size on the piston link below adds or subtracts to the combustion chamber size. The way they state it as piston head volume suggests that it subtracts from the pistons volume even though they are dome but my intuition tells me it subtracts from the combustion chamber and will put me right about 11:1 compression with a stock L76 rotating assembly. Confirmation that these subtract from the combustion chamber volume would be a start and if these will work only with a balance and wrist pin bushing resize?

The cam will be the Summit Torkinator 205/210 .550 lift int./exh. 113 LSA which should have a higher DCR at lower rpm if I am getting this right




https://www.summitracing.com/parts/wis-pts523a3

Guy with a Chevy

I am almost thinking I would be better off getting these 4.010 Mahle pistons

https://www.summitracing.com/parts/m...make/chevrolet

And save the .030 over for when I can afford a stroker kit. I just can't justify spending a 1000 dollars on some +5.8cc pistons...

How many times should one be able to reuse(bore larger)these aluminum blocks?

1973 STEP A SIDE

iTrader: (4)

http://www.wallaceracing.com/Calculators.htm

My understanding is that - give you more compresion ratio and + give you less

Guy with a Chevy

Thank you for the confirmation I was thinking of stating that way. I ordered the pistons as I am confident they will work with my stock rotating assembly after a bore and rebalance and probably get the wrist pin bushing sized to the pins. I will start a budget build log when I get a chance

LS1Formulation

iTrader: (13)

A lot of aftermarket pistons have a shorter pin height to account for decking the block. My Summit ProLS pistons came this way. If you aren't decking your block at all, it gives up a slight amount of efficiency due to a taller quench area. You can regain the quench by using a slightly thinner head gasket.

As for how many times these blocks can be bored, it depends on how much wear/scoring they have and what specific block. An LS1 block can only go .005-.010 before it's junk. The LH6 block in my Firebird starts at 3.780" and can go to 3.905". Some Gen IV blocks that are 4.065 bore can go to 4.100, some LS2 blocks can go to 4.020, maybe 4.030, I believe.

Guy with a Chevy

I will be comparing the compression height of the pistons when I remove them to see if I want to get the block deck milled. If I have to I will return them. Thank you for the heads up.

So I won't have any issue boring this l76 out to 4.060 in the future running NA?

LS1Formulation

iTrader: (13)

Is it an LS2 block? Or an L76/L77 or something similar? No matter what, you're going to have to get it sonic tested to be certain it can be overbored and by how much. I'm not that familiar with the Gen IV 6.0 aluminum blocks, so I don't know how their liners are installed or what thickness they are. But I doubt they can be taken out to .060 without compromising structural integrity.

Guy with a Chevy

Its a L76. Maybe I should find some different pistons and wait to do the .030 over when I can afford a stroker kit. Finding something between 4.005-4.030 is difficult as the price jumps a good amount. I will be searching this evening...

LS1Formulation

iTrader: (13)

I'm actually going to be building an L76 for a guy pretty soon, stock bottom end though. If I were you, I'd get the 4.010 pistons and wait on boring it out. I believe those Mahle pistons are their "drop in" pistons that weigh the same as stock pistons so you don't have to balance your rotating assembly. I'm not certain if they are designed to be negative deck height or not, however. Not having to balance will save you a bit, so the higher price is negated.

Guy with a Chevy

I was going to match them if they were within 15-20 grams. Are the ones you referring to PowerPak's? I guess I can spend the money right now if they are under 700 and just not even receive the Summit Wiseco pistons I already ordered that would help them get back faster.

Think You can find them cheaper than these>

https://www.cspracing.com/mahle-moto...gjh-930227705/

Or has anyone heard of this shop?

1FastBrick

iTrader: (16)

It shouldn't be that much to deck the block and really is a good option to even it up. They are never flat or straight any way. Plenty of youtube videos showing this.

At .010 over, they will likely just Hone it right to size.

LS1Formulation

iTrader: (13)

Never heard of that shop, I don't know where else you could find the pistons cheaper. However, after looking at Mahle's website, it looks like they only offer the "drop in" pistons in a 5.3 liter configuration. I thought they had them in other sizes. I myself went with Summit ProLS pistons, which are great bang for your buck. Got their rods too, and when my shop went to balance the rotating assembly, it was already spot on.

Guy with a Chevy

You are correct they said they would hone a small amount not bore it. I don't want to come up short on my future stroker build and make it harder to find pistons in the future are the only things holding me back from decking the block.


I did the math 3.622/2+6.098+1.330=9.239 with the piston link below for the C.H. and that is .001 below the deck and I am considering asking the shop to take .002 off the deck, what do you think?

https://www.summitracing.com/parts/mle-930227705

LS1Formulation

iTrader: (13)

The problem with LS blocks is that the decks sometimes are not square to the crank centerline, and you may have to take more material off than you want to in order to bring it back to square. If one corner is .005 lower than the rest, .002 won't touch the whole surface. This is the main reason aftermarket pistons are built the way they are. You may be lucky and not have to machine much off, but if I were building an engine from scratch, I'm going to get everything machined to end up with a .035 - .040" quench area. So, know what head gaskets you're going to use and their compressed thickness, and you can figure out the rest from there. Your engine will be more efficient if you take the time to build it correctly.