Fri Guy

Has anyone used one of the Summit Racing 6.0 Bare Blocks?

http://www.summitracing.com/parts/SUM-150105/

EricYJ-TA

iTrader: (10)

I considered using one when I built my 370. The machine shop advised against it stating they had cleaned up several. He also stated they do not use a torque plate when boring the cylinders. Take it for what it's worth I was not taking any chances.

JakeFusion

iTrader: (7)

Damn that sucks to hear. I'd love to be able to buy a machined block for a reasonable price so that I could drop a balanced rotating assembly into it as a cheap way of getting an assembled shortblock.

Fri Guy

I agree, that is what most people will hear from machine shops. I'm trying to find people that have actually used these bare blocks.

PREDATOR-Z

Get a clean used block, that what we call in our lingo 'Seasoned' block. Since it operated before; the casting had time to shift from multiple heat cycles. They end up stronger.

SS67SS

Those blocks Summit is selling are "seasoned."

These are GM used cores re-machined. I can't comment if they use a torque plate but I trust Summit and a phone call to them will answer that.

squirlNUTZ

My Budy bought one. Bought a stroker assembly and dropped it in making a 408. He runs a 300 shot on it. So far so good. Has under 1,000 miles and no track time yet though

bww3588

iTrader: (49)

This is exactly why I wouldn't trust one of these blocks for a performance build. If they sold the block with a rough bore and not a finish hone, it might be a good deal. But it's already finish honed to god knows what exact size. Which any good machinist will tell you, you cannot finish hone a block without the pistons present.

Maybe on a stock rebuild with stock pistons that have a larger window for piston to wall clearance, but not a performance build with better pistons that require a certain piston to wall clearance.

Justhereforinfo

iTrader: (2)

Sure you can. My 347 sbf is running just fine. I makes 360/390. It may not be the right way to do it, but it will work.

bww3588

iTrader: (49)

Not on a true performance build you can't. If I had bought this block and used it on my 370, I'd be tearing it back apart figuring out why the pistons don't fit correctly.

squirlNUTZ

ROSS, JE and I'm sure dimond, wiesco and any other piston manufacturer can will make a set of pistons for what ever you want.
As I posted earlier, my buddy runs a summit block, 408. Built to handle a bunch of nitrous. The engine runs fine. All the measurements came out correct.
"A true performance build". If you use a shelf piston and the clearence is to small then I'm sure a true machinest can hone it out a little more.

bww3588

iTrader: (49)

Which would defeat the purpose of the "pre machined" block wouldn't it? What if it's too big? Could a true machinist fix that?

squirlNUTZ

Don't be an idiot and buy a piston that's to big.
Get the block, measure the bore and "order from a company like Ross ,JE, and dimond the correct piston.
But a "true performance build" will take that into account and I'm sure a true machinst would know that.
Sure it's better (easier) to have the piston in front of the machinst but you don't have to. A competent engine builder will measure the bore and order a piston that is a perfect fit for the given application.
If its that big a deal, order the block with a rough bore and hope your local engine shop doesn't bucher it.
My Budy bought his finished. We measured and ordered the piston, pin and rings for his application.

Fry_

This block would work perfect IF it was made for a specific companies shelf pistons and rings.

bww3588

iTrader: (49)

A competent engine builder wouldn't waste extra money on custom sized pistons to save money on the machine work. Don't be an idiot. Let's waste extra money on pistons to utilize this cheap block...

The right way to do it is measure each piston and size the bore around it.

ironmanLS1

iTrader: (9)

While I know nothing about the Summit block good, bad, or otherwise. Everyone I know sizes the bore to the pistons, not the other way around.

v8pwr

iTrader: (19)

If you search you will find some good info on this block. A reputable builder said the machine work and tolerances are very good. My only complaint is they don't use ARP main studs. It is common practice for an engine machinist to hone the bores to fit the pistons but modern machining tolerances show that you don't need to. Most parts made these days are held within a few tenths. How do you think all of these engines were put together.

bww3588

iTrader: (49)

With a larger window for spec on clearances. Why do you think most ls engines from the factory have piston slap issues?

Busted Knuckles

With today's CNC machining processes on all the big players in the piston business, there's no reason to have the pistons in hand before honing the block. As long as you use good measuring equipment and cylinders are straight and round, piston manufacturers can hit any number you need. Cheaper to hone to a shelf size, though.

I am one of the old farts that can remember this being a MUST, though. The old TRW bricks we used to use on everything were sized and weighted all over the place.

Why would you "trust" Summit? I can call 4 times in a day and ask the same question to each tech and get a different answer every time. Find a builder you can TRUST and let him deal with it - that's why he's in the business.

bww3588

iTrader: (49)

On my wiseco's, the sizes were off by about .001 in either direction from where they needed to be. Some were right on the money, or very close, but when you're shooting for a certain piston to wall, it's what you gotta do.

And my original point was that. The point of the summit block is to avoid machine work...so if you have to touch it, aren't you just defeating the purpose of it?