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The block has been dual torque plate honed twice now which brings me to maximum allowable piston to wall I feel comfortable with for my pistons. The bore roundness is still not acceptable to me. Total out of round is .0013" on the diagonal at the piston gauge point depth, and it changes all through the bore as well. I feel like I'd have no hope for ring seal with such bad roundness.
The shop did the second hone at no cost as they saw the same out of round when we brought the block back. This is a premier shop we have a great relationship with and there's no finger pointing in either direction - simply a **** situation.
Some are telling me to just slap it together as the thin LS7 sleeves cannot be held to tight tolerance, and they move around so much while running that it isn't worth losing sleep over.
This has been a 3 year "bucket list" engine build and for the time and money I would hate to put it together and it have excessive blowby or not perform as expected.
I'm at the stage of getting quotes for block sleeving, and am looking at another $4500 for pistons, rings, sleeving and honing - plus I'm out the cost of the piston, rings and machining already done so about a $6000 total re-work just to get acceptable bores.
Has anyone had such **** roundness/hourglass/taper with factory LS7 blocks honed to 4.130 and still had good performance and ring seal when running? Would it be worth assembling the engine knowing it might have to come back apart, or should I just re-evaluate and sleeve the block at this point?
I'm really hoping for some convincing data points at this stage that would make me feel ok with assembling it despite the crap bore measurements.
So Steve at R.E.D. will have my business 100% if I need to go this route. He has already offered me some invaluable advise as to how better measure the bores. He suggested torquing the heads on and checking it from the bottom off the engine stand. I’ll give this a shot and then make a judgement call.
Corona - that’s another interesting option but I’m in the same boat as you if I use my pistons as is I’m 12:1 if I go new pistons it’ll be 14:1 with a dome and 440 vs 429 cubes.
Navy your engine is definitely also a bucket list build Dustin’s name came to mind as someone I can ask for input also but I don’t think he uses too many ls7 blocks.
I was going to ask how it was being measured. When you hone with a torque plate to simulate the heads being torqued, it seems like you need to measure it with the heads torqued. In for results.
I was going to ask how it was being measured. When you hone with a torque plate to simulate the heads being torqued, it seems like you need to measure it with the heads torqued. In for results.
Yeah we bought a torque plate to better measure the bores but it sounds like torquing both heads on can provide a more accurate result for how it’ll be assembled.
Yeah we bought a torque plate to better measure the bores but it sounds like torquing both heads on can provide a more accurate result for how it’ll be assembled.
Definitely. Curious to see if you measure a difference. Seems hard to believe that honing it twice with a torque plate would still have it that far off.
I'm holding on for the moment 😅....Just paid School/Property taxes/Neighborhood dues.
& Works slow.
😇
You've got the Choice of Either or as we've both have something to work with. The question is to what Depths do you what HP = new Dome pistons
& The 🤔 800 to $950 + Difference added to the re-sleeve if needed.
I'm not going back to....the thoughts of the 700 sandlot. That's OVER. 🤔 Depending on cam and induction you could Do Something Crazy Like a Honest 850 to 875 hp Street engine
I drove back to my dad's last night to break the mains loose, torque the mains on the table, torque the heads on the block on both sides, and measured the bores from the bottom. Saw next to no, if any change to the bore shape, size and taper.
I'll be sleeving the block. I'll decide 4.130 vs larger bore and higher compression later. I have no doubt I could assemble and run the engine and I bet it would even perform well, but for the time and money into this already I don't want any "what ifs" in the back of my mind or potential for needing to rework it after it is assembled.
I will also use another shop for the hone on the Darton sleeves who I know has the diamond hones and can hit the correct surface finishes.
When Steve did mine, he bored them out to where they needed honing to get to final size. So, if you tell him you want a 4.125 bore, they'll likely some back to you at 4.120 or very close to that.
Yes he let me know he presses them in, bores them, decks them and stress relieves. Only step remaining when getting the block back is the final hone. I'm just an hour drive from him so I'm lucky there. LA sleeve is also local and I sent them an RFQ as well, but I know Steve is *the* guy and he's also already been very helpful over the weekend no less so he should get my business. It is a ~2 month wait right now, but I'll survive lol.
After calling around and emailing with ~5 shops that install sleeves - 2 local and 3 I'd have to ship the block to - most are recommending starting with a fresh block. MAST won't sleeve LS7 blocks as they've only done one and it didn't go well. TSP also recommends starting with a 5.3 truck block.
Steve @ RED would do it, but can't guarantee when I'd be able to even get on his list. I guess really backed up right now. Waiting 2 months with no guarantee of getting my block done doesn't fit my goals right now.
I'm going to just close my eyes and assemble the engine. Hopefully it seals up and doesn't have a ton of blow-by. It costs nothing but time at this point to put together and I have zero interest in starting with a fresh block right now. It'll be engine dyno'd before it goes in the car at least. I want this to be the end all be all engine, but at this point I just need to move past it and see what it does.
Mast has a sale currently on gen 4 aluminum darton sleeved blocks. You have to add it to the cart to see the price. And they just turned my order around in a couple/few short wks. Order it n sit on it. If you dont need it or want, me or someone else buy it from ya. If RHS credits me my money back, im ordering another one from Mast to make my 427 short block whole again. For sale or as a back up motor. If they replace my RHS block, same scenario.
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LS7 build struggles - bore roundness 
Dustin’s name came to mind as someone I can ask for input also but I don’t think he uses too many ls7 blocks. 
