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Building an LN3 from spare parts plus a Supercharger


2seater

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2seater did a great job, it looks good and I am envious. As I told him today 10 years ago and I would be after him to do another one for me, but he [2seater] did give me good advice on the rebuild for the Red to get me additional horsepower.

 Happy driving 2seater!

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39 minutes ago, DAVES89 said:

As I told him today 10 years ago and I would be after him to do another one for me, but he [2seater] did give me good advice on the rebuild for the Red to get me additional horsepower.

Ten years ago when I still had my health I would have been wanting him to guide me in building my own SC engine if I could have found the parts. Too much work for me these days, and I don't have a good place to do it anymore, so I just keep driving and enjoying what I've got.

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I wonder what the points deduction would be at a BCA National😎.  Excellent work there, 2seater!

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1 hour ago, ship said:

I wonder what the points deduction would be at a BCA National😎.  Excellent work there, 2seater!

He would get extra credit!

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I appreciate the comments but am far from a trailblazer in this endeavor. I just followed the path many have done before while I spent my time, energy and money with turbocharging. I don't think that time was wasted either, it has been educational. Others have documented their experience and I have done the same combining it with a bit of improvement (IMHO) in the basic LN3. I tried to be as honest as possible with my mistakes and successes with the purpose of encouraging more experimenting.

 

At the risk of repeating myself, much of the time spent during this thread could be eliminated by simply installing a complete running donor engine. With that in mind, only the heater hoses, power steering pressure and return, and possibly the upper radiator hose need be modified. Even the original air inlet hose can be stretched over the late model L27 Series 1, which is what I have done. The EGR does need to be eliminated due to the location blocking the upper dogbone mount, but that's about it. All of the wiring harness just plugs in as the original, with the possible exception of rerouting some items. The fuel lines do need to be modified which I did with short lengths of fuel injection hose and crimp type clamps. Even the exhaust will bolt on in the original location at the rear of the engine, plus the manifolds from the S/C donor are more streamlined without that pesky rear restriction.  I am pretty certain, a Series 2 engine could be substituted instead, just operate it using the Series 1 sensors and system, Daniel would know for certain.

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  • 2 weeks later...
1 hour ago, Ronnie said:

How's it going with the SC swap. Anything new?

Not this week, I had an implant done in my good eye and vision will take a while to recover and improve without a "helper" eye. No glasses after over six decades of wearing them.

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I hope the work on your eye turns out good. I have a friend that had to wear glasses all his life and no longer needs them after getting the surgery. I've never had to wear prescription glasses. I do keep a pair of reading glasses close by for fine print and low light conditions but I can get by without them.  For many years I had to wear safety glasses most of the time at work and I hated them. That is one of the reasons I jumped at the chance to get an early retirement when the railroad shop shut down where I worked.

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 2seater and I went and had lunch the other day and we discussed his surgery and that I should get my eyes checked. So I did and it turns out I need 225 reader strength and my distance vision is good. All my readers are 250 strength [all bought before eye exam] and I have at least 9 pair [bedroom, desk, basement, garage, living room, all the cars, and camper]. After buying all the glasses I got in the habit of just setting them down where I am at these places. That way while I don't need them for most times I need them at those stations.

BTW the vent on the door makes a great receptacle to put your glasses in for quick and easy access. 

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I'm prediabetic and the first place damage will show up is in your eyes. I get my eyes checked once a year and I always tell them I want a diabetic eye exam as well as a vision exam

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On 8/28/2022 at 1:29 PM, Ronnie said:

I'm prediabetic and the first place damage will show up is in your eyes. I get my eyes checked once a year and I always tell them I want a diabetic eye exam as well as a vision exam

I am with ya on the diabetic concern too. I have been skating along the edge for many years but it seems stable, so not terribly worried. There has never been any mention of problems in my eyes related to diabetes, and I have had many in depth exams.

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At this time, I think this subject can be put to bed for the foreseeable future. I didn't really do a detailed recording and tweaking of the timing table but I did make changes based on some assumptions. In my experience, I have found GM's programming to be pretty well matched to the mechanical attributes of the engine. Sure, it is possible to make gains around the edges, especially if other things have been changed physically. With that in mind, I initially added ten degrees of timing to the entire table just to see if it felt better, and it did in many ways. After some testing it proved to be too much but I reasoned the overall progression had been scienced out pretty well by GM. I then took two degrees out overall, leaving an eight degree advance from stock. I then removed another six degrees from the area around idle speed and load. This appears to be a happy combination. Cold start also has improved on its own as the ECM learned what it wants. In any case, the engine feels nice and responsive, and full throttle while rolling in second gear to the shift shows a handful of knock counts right near the shift point. The S/C makes a very satisfying scream as well. I will monitor this on occasion, but it seems pretty happy.

 

Indirectly related to this thread, I neglected to reinstall a couple of spacer washers under the passengers end of the strut brace when I reassembled after the engine change. This causes intermittent contact of the large Hydac accumulator which is audible in the car. Perhaps a blessing in disguise as it seems the pump runs more often than it should. The brakes work fine and no warning lights. Today I had the chance to check the pressures and volume with my test rig. I found that it took 24 full peddle strokes to finally get a hard pedal, a testament to the large capacity of the Hydac. With the key on the pump operates in the textbook pressure range, 2600 psi off and 2000psi to restart. I also found my high pressure needle valve on the return to reservoir leaks by a bit, but that also seems to be a blessing?? I generally crack the valve just a bit and let the system build pressure while returning a bit to the reservoir so it continuously cycles. It appeared I had to leave the valve in what felt like a closed position to get the pump to build pressure but it was in fact letting some fluid through at all times, so all is well there. What did seem to come from this was the pump seems to build pressure more quickly and can tolerate more leak by to the reservoir after the circulation of fluid from pump to reservoir, almost like it was a bleeding operation. No empirical data to support that, but that was it appeared to be? Testing of the residual gas charge in the accumulator indicates ~900 psi remains after about six years of use. I am going to monitor for a while before I reinstall the spacer washers. 

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This has been a good thread. I've really enjoyed reading it. Sounds to me like you are to the point that you can drive the car knowing that you have the programming about where it needs to be. Good job.

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12 hours ago, jon L said:

BTW it's 4 points off for a different engine.

Thanks for the heads up. The car is far from show quality overall, so I am in little danger of it being an issue😎

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On 8/30/2022 at 1:18 PM, Ronnie said:

This has been a good thread. I've really enjoyed reading it. Sounds to me like you are to the point that you can drive the car knowing that you have the programming about where it needs to be. Good job.

2seater, it was great reading.  I've never torn into an engine before and really enjoyed reading your topic...a great learning experience for me, thanks.  

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I thought this was put to bed but a mystery sound has appeared. I tried a little video from under the car and the rattling sound definitely comes from the front of the engine in the vicinity of the crankshaft. The sound is greatly muted when cold but not gone completely. It is a tinny sound but it isn’t rhythmic so it seems more like something is loosely making contact. You can see the tip of one of the vanes on the balancer but this setup has a complete plastic shield over the area behind the balancer. I cannot tell if the sound is inside the front cover at this point. Nothing else seems amiss otherwise and all internal and external parts are brand new🤨

I also noticed I need one of those little exhaust hanger donuts.

It looks like I can’t add the video due to wrong file type😕

7A65B808-8657-48C4-9C5E-CBBEFFF51843.jpeg

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Don't know what the sound could be but the location of a sound can be deceiving sometimes. Have you checked the heat shields near the spark plugs on the exhaust manifolds. I had one of them on the front rattling and cured it with a hose clamp to tighten it up.

 

I don't think the forum software allows videos to be directly uploaded like you can on facebook. Only youtube videos are allowed as far as I know. Don't know why unless it is a security issue or maybe because video files are so large. If you will tell me the extension of the file you are trying to upload I might be able to override the forum settings to allow it.

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At this point I am going to remove the balancer and shield to see what's going on. It is definitely from the area of the balancer or behind it. The file when downloaded to my computer is a .mov and I can't find any way to convert so I guess it isn't worth the hassle. 

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We found the rattle and I am glad it was pursued. The screws that retain the shutter wheels on the inside of the balancer had backed out allowing the wheels to move in and out, a lot! I didn’t find any actual contact marks but if this had been the LN3 style crank sensor, there is no doubt there would have been contact or outright failure. This is a new balancer so this was a surprise. The screws are now Loctited in place. Nice and quiet.49FE6231-8644-4160-BB45-FAA883983F03.thumb.jpeg.c9c564d6e503aec1b5f1a124dee81847.jpeg

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