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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: Mon Apr 27, 2020 3:28 pm 
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mk e wrote:
I can tell you that you can never open up ports and add duration and expect to improve the bottom end.


That's why I mentioned the lack of cores; if it had aftermarket cores available, maybe a profile with more aggressive ramp rates would be in the offing as well. None of the available profiles can get any more aggressive than the stock ramps, due to being regrinds.

I have a '95 manual, but it's at my dad's house. I can get more cam & valve event data this weekend.

mk e wrote:

The best way to help bottom end...tri-Y headers. When they are properly matched they are pretty much unbeatable when you need a wide power curve, nearly as good as small tube 4-1 down low and nearly as good as big step headers up top, I've never seen a street car that doesn't want them.



Yeah, but Tri-Y's just don't sound like 180 degree collectors. ;)
The X-pipe with the old engine sounded phenomenal.
You're building a Ferrari V12 out of welding rod... don't tell me you don't care how it sounds.


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PostPosted: Mon Apr 27, 2020 4:01 pm 
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TheDarkSideOfWill wrote:

That's why I mentioned the lack of cores; if it had aftermarket cores available, maybe a profile with more aggressive ramp rates would be in the offing as well. None of the available profiles can get any more aggressive than the stock ramps, due to being regrinds.

I have a '95 manual, but it's at my dad's house. I can get more cam & valve event data this weekend.


Again, welding is an option which lets you have any grind you like....but the stock intakes are not bad. You could also up the valve sizes but keep the port size, that acts very similar to more aggressive cams....we can model that.


TheDarkSideOfWill wrote:

Yeah, but Tri-Y's just don't sound like 180 degree collectors. ;)
The X-pipe with the old engine sounded phenomenal.
You're building a Ferrari V12 out of welding rod... don't tell me you don't care how it sounds.


Sure....its hard to make them work well though as the pipes just get way too long. Packaging is also a concern, which often leads to even longer pipes. X-pipes almost always help HP, burns also suggest one for me if I could fit it but they said it was a small gain so not to worry if I couldn't but on a V8 its a bigger gain so tri-Y headers (which sound the same as 4-1 but work better) with an X-pipe exhaust sounds like the winner, get it, SOUNDS like the winner...I just crank myself up :)

But We can model it however you want, DM doesn't deal with 180- or not in the model, so I just need to know how long the primaries will need to be and go from there. Right now I'm showing you "what maybe could be", for header design and final cam selection and such we need to switch to the wave model so I'll need to input more stuff, this is just rough work to give you ideas.

For comparison, here is my engine modeled both ways. Hp is the same basically but everything I did is a little on the edge so the FE model is unstable with generic assumptions, but the specific tuning I use is stable in the wave model....we'll want to switch over to the wave model before making any real decisions is my point.


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PostPosted: Mon Apr 27, 2020 6:45 pm 
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In DM 6 even the FE model uses wave components and they have a screen to tell you what setting they are assuming....nice feature and plugging them into the wave model I get basically exactly the same answer they got. Still the same 266/266 cams, ITB, triY


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PostPosted: Mon Apr 27, 2020 7:01 pm 
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You have basically the same valve sizes as me so if I give you me head, my cams and play with the intake and header lengths...569hp @8000rpm, the 266/266 setup on the same graph to compare. So now you kind of have the range and every else will fall inbetween the baseline setup (266/244 OEM intake) and this one.

The instability in the FE model I get and this optimized version also gets is solved with header design....Burns did my triY design different from how DM does it and it turns out the pros know what they are doing and there design works better for this setup. a 4-1 pretty bad, a standard step header even worse, just kills the bottom end but the Burns header makes it work.


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PostPosted: Tue May 05, 2020 9:06 am 
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Soo... Promar said that blocks are their shortage. I said I have one each of '93, '00-'04 and '06+ blocks. They said they aren't interested in bartering. I replied with a more polite form of "you sure about that?" They can still hone whatever block I provide, even with the torque plate.

They use Federal Mogul "rebuild" bearings, which are +0.25mm on the OD and -0.50mm on the ID. That is the only size those are offered in. My last experience with cutting a crank didn't go well, so I'm no wild about those. Owing to the change of shape of the main bores, I'm wondering if I need to get mine line honed with the heads on. I did that on the '93 block by skim cutting the lower crank case. The surface finish on the top of the '06 lower crank case is VERY coarse... I wonder if this has anything to do with GM's swap to RTV as the sealant of choice for the case halves, although this block still had GM's case half seals.

Anyway, since a solution wasn't forthcoming there, I bought this: https://www.ebay.com/itm/133340495195
It's what I was looking for in the first place, but it wasn't listed when I started looking... besides, seeing how the '06's worked in different ways would have been harder without taking one apart. At least that's what I'll tell myself as I pay the credit card bill.

EJC Performance is an interesting outfit... they do business with a bunch of junk yards around them, taking damaged engines that the yards can't sell as running engines, then breaking those down into major components (blocks, cranks, cylinder heads) to sell. They have stuff from a whole lot of MFGs covering US, Japanese, German and whatever else. Sometimes the engines they get have damage as light as a cracked oil pan, but the yards just don't want to mess with them. EJC also scraps damaged components (spun bearings, etc.) as their business model is to sell usable parts and not have come-backs. I found their website and called them. The guy I spoke to actually went to the block on the shelf while I was on the phone and looked at it for me. No scoring or pitting, just normal wear. Decks didn't look like it had a head gasket problem. I threw down. He said they ship Duramax blocks freight, but the Northstar block would just go UPS ground, which is also pretty wild.

I'll still go to Promar to have the bores honed, but may have it line honed locally... WITH the heads bolted on. I need to get the lower crank case decked a smidge, but prototype guy is trying to invent himself as an engine machinist, so I'll let him take that on.


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PostPosted: Tue May 05, 2020 2:39 pm 
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Or line bored. Out of round or misaligned means boring I thing. Normally they cut the caps and try to keep the crank centerline unchanged....having oversize OD bearing no doubt makes everything simpler and will let you fix much larger problems but if its just a little out of round, you should be fine cutting the caps.

Promar is the place that gets a better quality bore you were talking about as the solution to oil usage? Just looking over their website I didn't see anything that looked like they were anything but a high volume lower cost rebuild shop.....a good speed shop wouldn't be a better choice? Or they have a known good honing process so why look elsewhere?


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PostPosted: Tue May 05, 2020 3:48 pm 
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Promar has the CNC hone, diamond stones, profilometer feedback and process to get the hone right. They're a production rebuild shop. Speed shops tend not to have any of that, with operators relying more on feel, surface appearance and doing tribal knowledge of something that's worked before on similar hardware... meaning they're working mostly on guesswork and that if they've never done a Northstar before, they're probably going to screw it up, as I've found out twice.

The Northstar doesn't have caps; it has a lower crankcase (I see it referred to as a "bedplate" on the interwebs sometimes). That component gets skimmed like a block deck in order to do an on-size line-hone/bore. When the caps/crank case get skimmed, the crank centerline moves up in the block by 1/2 the amount the caps get skimmed.


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PostPosted: Tue May 05, 2020 5:54 pm 
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Yes, you posted cradle pics, I was forgetting that. Once you cut that a hone will go to the center as you say tanking 1/2 from the block, 1/2 from the cradle and will also basically follow the holes so if there is an misalignment or curve that remains after honing for the most part. A line-bore will cut the bore straight and can also be setup to just kiss the bore at the top so virtually all the metal comes of the caps keeping the centerline near original....it just depends a little what you're trying to fix.

On the hone, if promar can deliver the job you want, it sounds like a fine choice. I know you where very concerned (I'd say more concerned than anyone I've know :) ) on the hone finish...but I certainty understand wanting what you want :lol:

Way back I spoke to the local ferrari shop about who they use and they told me these guys

http://www.mardinly.com/machineshop.html

I forget exactly what I had them do last time but they seemed to know what they were doing (they had a TON of work) and are probably driveable for you. I'm going to give them my crank....still undecided if I'll they to do the cylinders in the block of not....the fact that I'm even thinking about it means I clearly don't care quite as much as you :oops:

Have you got any kind of estimate on when it will run again?


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PostPosted: Tue May 26, 2020 8:48 pm 
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I helped my roommate from Afghanistan move over the weekend.

I also got the new block deburred and ported the bay-to-bay breathing windows. My dad's taking it in to the basic machine shop to be cleaned this week. I think the seller probably cleaned it as well, although I suspect that was prior to disassembly. I also made a much of chips and filings. No such thing as too clean for assembly. I'll probably take it to the local race shop next week to be line-bored with the heads torqued up. Probably after that I'll take it to the ceramic coating place to have MC-5100 applied to the exterior surfaces, and then to ProMar for bore honing... although I may swap those last two.


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PostPosted: Tue May 26, 2020 8:50 pm 
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mk e wrote:
Yes, you posted cradle pics, I was forgetting that. Once you cut that a hone will go to the center as you say tanking 1/2 from the block, 1/2 from the cradle and will also basically follow the holes so if there is an misalignment or curve that remains after honing for the most part. A line-bore will cut the bore straight and can also be setup to just kiss the bore at the top so virtually all the metal comes of the caps keeping the centerline near original....it just depends a little what you're trying to fix.

On the hone, if promar can deliver the job you want, it sounds like a fine choice. I know you where very concerned (I'd say more concerned than anyone I've know :) ) on the hone finish...but I certainty understand wanting what you want :lol:

Way back I spoke to the local ferrari shop about who they use and they told me these guys

http://www.mardinly.com/machineshop.html

I forget exactly what I had them do last time but they seemed to know what they were doing (they had a TON of work) and are probably driveable for you. I'm going to give them my crank....still undecided if I'll they to do the cylinders in the block of not....the fact that I'm even thinking about it means I clearly don't care quite as much as you :oops:

Have you got any kind of estimate on when it will run again?


Mardinly is in Broomall, PA, which is west of Philly... it's not that far from where I am, but I'm not wild about making a saga of road trips to get my block prepped.


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