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Which means "Evil Twin". Lets see your projects where you change boring into fun or create the fun from scratch.
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PostPosted: Fri Apr 03, 2020 7:13 pm 
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I think, for what its worth, that picking the setup you plan to build then building it the best you can with give you the best result and save you time and effort. Designing 2 or 3 trans options is great if you are designing a kit you plan to sell to a market that used these 3 trans packages..but if itd your car, well pick a trans and set it up to work with the fewest parts possible.

Honestly with decent hp V8 is a little fiero 4 or 5 or 6 speed trans doesn't much matter. You know the rpm drop in the gears and just need to make sure the engine is tuned to deliver power over a range wide enough to cover the drop at shift....a 6spd lets you build a peakier engine or is maybe my forgiving at the track with a less peaky engine but at the track more manual shift=slower laps generally so I'm not sure how critical more gear are...a 5 spd seems a great compromise which is way I have never made any effort to replace mine...I have thought at making it a sequential shift but keep the trans.

So then making the clutch linkage as simple as possible is the right answer.....making everything as simple as possible is the right answer.

That said, carry on with the multiple trans options so the thread provided many years of enjoyment ;)


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PostPosted: Sun Apr 05, 2020 8:42 am 
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Here's the modded sprocket... I think I fell into the "machinists work from prints, not instructions" trap again. I think he widened the slot on both sides. However, now that I see it in place, I think I can draw something accurate enough for him to work to... and buy a new sprocket.

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Bottom end just before breaking the main bolts loose... The windage trays were not previously galvanized, but everything else looks the same.

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So here's the big WTF. This is a basic bitch FWD engine... it's even an LD8 making a thunderous 270 HP. GM built it with a forged crankshaft.
I *thought* that GM developed the forged crank for the supercharged RWD engines because that's the first place I heard about it. After a bit more googling, I find references to rolling out the forged crankshaft across all Northstar production in 2004, along with a few other subtle design changes.

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Here's another subtle difference; the case half seal grooves used to go all the way to the RMS bore. The engine needed a dab of RTV to join each case half seal to the RMS. Now they don't I guess that little bit just doesn't leak, even though there's not a seal there.

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PostPosted: Sun Apr 05, 2020 8:44 am 
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mk e wrote:
I think, for what its worth, that picking the setup you plan to build then building it the best you can with give you the best result and save you time and effort. Designing 2 or 3 trans options is great if you are designing a kit you plan to sell to a market that used these 3 trans packages..but if itd your car, well pick a trans and set it up to work with the fewest parts possible.

Honestly with decent hp V8 is a little fiero 4 or 5 or 6 speed trans doesn't much matter. You know the rpm drop in the gears and just need to make sure the engine is tuned to deliver power over a range wide enough to cover the drop at shift....a 6spd lets you build a peakier engine or is maybe my forgiving at the track with a less peaky engine but at the track more manual shift=slower laps generally so I'm not sure how critical more gear are...a 5 spd seems a great compromise which is way I have never made any effort to replace mine...I have thought at making it a sequential shift but keep the trans.

So then making the clutch linkage as simple as possible is the right answer.....making everything as simple as possible is the right answer.

That said, carry on with the multiple trans options so the thread provided many years of enjoyment ;)


There's this thing I want to do called "drive the car" that I can do sooner & more by removing complexity from the initial build and undertaking unit/component replacement at a later date. ;) :lol:


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PostPosted: Sun Apr 05, 2020 8:54 am 
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drive the car? I don't understand?????

Why would you work toward drive the car when you cold, I don't know, say dig for a new patio you don't need?

For sure breaking the work in the winter timeline buckets gets you the most driving time....if the buckets actually happen in the winter.

Almost 9am when its ok to fire up the mowed so I have a cart for dirt...time the get back to digging......


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PostPosted: Mon Apr 13, 2020 2:56 pm 
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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.

Image

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 shit 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.

Image

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

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PostPosted: Tue Apr 14, 2020 7:44 am 
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Do you have a local place that does the coating or did you need to ship everything?

Years ago I worked at a place that did mostly plastics machined and thermoformed. A lot of fixtures were also plastic...cheap and quick and good enough. The tool make had a habit of deburring nothing...I talked to him, showed him my hands from handling the stuff all day...talked to him again....a couple days later he had a large piece he needed a hand moving and the non-deburred edge gave me a cut that needed several stitches....after that stuff started coming out beautifully deburred and I no longer touch anything with bare hands that isn't clearly deburred because it isn't safe. The parts are also much less prone the crack so not only did you make it safer you turned them into race parts :)


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PostPosted: Tue Apr 14, 2020 10:16 am 
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There's a guy locally at a custom gun shop who does Cerakote.

As my "How to keep an engine shiny" thread might indicate, I'm super interested in getting the block coated/protected somehow to keep it nice.

Yeah, deburring is important. I'll still have to do the deck surfaces, but those aren't as intricate as the bottom end. I'll also be installing steel thread inserts in the head and main bolt holes, so I'll be handling it a lot... and then taking it to be honed.

The '93-'03 Northstars used 11x1.5 head bolt threads. WTF GM?
Those engines had problems with the head bolt threads corroding and letting go over time. Installing TimeSerts completely fixed the problem and makes the engine bullet proof, as that's it's only real problem... and that takes 100,000 miles to become a problem.
ARP makes a stud kit for a VW 1.8T that works in the Northstar, so I had the 11x1.5 TimeSerts and a pair of those stud kits in my prior assembly. I also used Cometic gaskets, which, along with the ANSI threads at the top ends of the head studs mean that GM's head bolt torquing procedure went out the window. I tightened the studs to 70 ftlbs per advice from now-closed CHRFab.

For '04 GM switched to the 11x2.0 head bolt threads that LS engines used without problems. The bolts are slightly different lengths from the prior bolts and the threads are at slightly different depths in the block. LS head bolt sets have bolts that are similar lengths, but only a few per set, while most are shorter. I dunno if ARP will sell me 20 of the long studs without buying several stud sets.

All this means I need to take some measurements and figure out WTF I'm doing for cylinder head fasteners.


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PostPosted: Tue Apr 14, 2020 12:31 pm 
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Ferrari used studs that are 14-1.5 in the block, after all the welding I switched to 14-2 and went a bit deeper for more engagement.....same concerns I guess.


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PostPosted: Tue Apr 14, 2020 4:45 pm 
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14mm head studs? Hello 30 psi!

In my limited metallurgical knowledge, I think GM's problem with the Northstar 11x1.5 threads was stress corrosion cracking.
Not sure if the 14x1.5 thread is enough larger in diameter to reduce the stress enough not to have that problem or if the difference in casting alloy would eliminate it.

Do you know what alloy Ferrari uses?


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PostPosted: Wed Apr 15, 2020 7:00 am 
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I have needed odd quantities of ARP studs for unconventional projects and I just call them and tell them what I want and the send it. I had custom studs made years ago, like 1999. The company is top notch, expensive, but top notch. It is much easier now that the tuner crowd has been blowing up stuff and needed more metric stuff. When I started getting custom studs, they would put standard threads on the nut end because they didn't make metric nuts.
Anyway, just call them, they will work with you.

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