Going to be a bit before I can use the flywheel, so I had it Cerakoted to keep it from rusting and to be able to show it off along the way.



I didn't get a lot done on the Northstar this weekend.
I scraped the anaerobic gasket goo residue off the block and lower crank case.

However, I did fix something that had always been kind of annoying as I work on these engines.
GM doesn't de-burr **** inside a Northstar. They can apparently get away with that as their parts cleaning process is wired tight and their factory is clean enough that they don't have to worry about it... just bolt it together and go.

However, if you are doing a hand build and you handle the major castings a good bit, you wash up at the end of the day and experience the sting of 46 little cuts, scrapes, nicks & minor contusions all over each hand.
On a less wimpy note, the actual engine building reason this is bad is that when you try to clean the engine block lower surface, the lower crank case surfaces or the block or head decks in preparation for assembly, all the burrs just shred whatever kind of wipe/shop towel you're using and capture a lot of lint that you then have to pick out/off before closing up the engine.

So I grabbed a Shaviv tool and a 120 degree countersink and got to work on the bottom of the block and the upper and lower surfaces of the lower crankcase. I countersunk EVERY round hole and any more or less round feature that the countersink would fit against. Then I Shaviv'd EVERY edge on each surface that I didn't already get with the countersink. The only corners I didn't touch were the corners of the main bores where the case halves meet... I didn't want a small chamfer there to compromise the bearing tang's ability to resist rotation. GM had already (just barely) adequately de-burred those edges anyway. Then I bolted the bottom end together using some washers in place of the windage tray. I ran out of time and didn't get to measure the main bores. Next weekend I'll measure the main bores, then bolt up the heads and measure the main bores again to see how they shift, then install the main bearings to get my main bearing measurements. I also need to measure the second forged crank and the titanium piston pins. Of course along with bolting up the heads, I'll de-burr the block decks just like the interfaces I worked on this weekend.

Payoff for all this effort was immediate, as I was able to wipe down and clean the bottom of the block and the top of the lower crankcase, followed by putting the lower crank case in place and cleaning the bottom of it in prep for installing the oil manifold plate... all with the same towel that didn't have any tears or slashes or shred marks in it when I was done... none. Burr-based lint problem: fixed. And the pieces are SOOOOO much easier to handle.

You can see the chamfer I the Shaviv tool made on the front edge of the lower crankcase in this photo.



And here's one of the Coleman hats Cerakoted bolted up to the Wilwood rotor Cerakoted. Bling.

[This message has been edited by Will (edited 04-13-2020).]

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"I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."

cognita semper

http://www.fiero.nl/forum/Forum2/HTML/119122.html

[This message has been edited by Will (edited 04-18-2020).]

quote Originally posted by La fiera: Nice job WIll!

Thanks!

//

The '93-'99 blocks have head bolt holes that are ~3" deep with threads (well... time-serts in my old block) that start at ~1.325 deep.
These engines use 140mm head bolts and the head bolt bosses in the cylinder heads are ~3.010 tall. Head bolt thread engagement was ~1.175 or 2.7 bolt diameters.

I found out that several of the changes I was attributing to '04 actually happened for '00.

In '00, GM reworked the dies that form the sides of the block. They did not rework the valley die, the end dies or the crankcase die.
The side dies have the upper crank sensor boss, the cooling jacket drain bosses, most of the accessory mounting bosses, etc.
The side dies also define the casting features which receive the head bolt threads. Since GM updated these dies for '00, they lengthened the casting features that receive the head bolt threads. The lower/outer rows of head bolt holes in the '00-'03 blocks are ~3.800 deep overall with a starting depth of ~2.025 for the threads.

Since GM was not changing the valley die for the '00 update, they did not extend the casting features for the upper/inner rows of head bolts. However, since they were completely changing the cylinder head castings, they made the upper/inner head bolt bosses in the cylinder heads taller, up to ~3.660. The '00-'03 upper/inner head bolt threads are slightly deeper at ~1.380 starting depth.

Those changes to the block and heads let them increase the bolt length from 140mm to 156mm, though they kept the 11x1.5 thread.

For '04, GM switched to the 11x2.0 thread and further increased bolt length to 161mm. The upper/inner bolt holes couldn't go any deeper, but the threads actually go shallower at 1.150 starting depth. The lower/outer bolt holes got slightly shallower at ~3.600 with threads starting at ~1.800. Thread engagement went up to ~1.525.

LS's use multiple head bolt lengths. All are 11x2.0. <'04 engines use three different lengths, one of which is 155mm. The '05+ LS engines changed the design so that the longest bolt is 100mm.

Soo.... Where does that leave me?
I will be using Cometic MLS gaskets, so the stock torque sequence is out the window.
At Alan Johnson's suggestion, I used 70 ftlbs on my previous engine and had no problems.
I will install thread inserts no matter what.
Because I'm using '<99 cylinder heads, EITHER I'm limited to the 140mm early bolts or my current ARP 204-4204 studs in the upper/inner rows OR I need to machine spacers to use 11x2.0x161mm bolts with the shorter <'99 upper/inner head bolt bosses.

I need to measure out the 'serted and virgin hole diameters to see if the material is in the block to install the 11x1.5 inserts at the <'99 depth in the lower/outer bolt holes. That would let me run my current studs all around again.

I can install the 11x2.0 inserts all around at the '04+ block depths, and machine spacers to use the 11x2.0x161mm bolts in the upper/inner locations as noted above. I still need to figure out torque based on preload and buy a new set of head bolts (not expensive) but I would not be able to reuse my current studs :cry:

I can install the 11x2.0 inserts at the '04+ depth in the lower/outer locations. AND install the 11x1.5 inserts at the <'99 depth in the upper/inner locations. That would let me use 11x1.5x140mm bolts in the upper/inner locations and 11x2.0x161mm Northstar bolts in the lower/outer locations. I'd have to do some math to figure out the torque to get the clamp load right, using 70ftlbs on the 7/16-20 thread at the top ends of the ARP studs as the benchmark. I'll end up with different torques for each row.

If I "split the pitch" as described above I could also use ARP's 11x2.0 LS long studs--which *probably* have 7/16-20 upper threads--in the lower/outer locations... that at least means I use the same torque on both rows.

I need to call ARP about the upper thread and snagging 10 of those long studs, since I need to call them about ordering eight 11x1.5x0.880" LS flywheel bolts anyway.

[This message has been edited by Will (edited 07-10-2020).]