Building an LN3 from spare parts plus a Supercharger

[DAVES89]

Looking forward to seeing it on the road. You are getting closer!

[Ronnie]

Looking good. Thanks for taking the time to write about it and for the photos. I enjoy it.

[2seater]

Anyone know why the photos turn themselves on their side in some cases? It seems random because I always hold the phone vertical but it's a crapshoot which way they come out. They appear upright in my phone?

[Ronnie]

I've saw that problem with the photos before. I don't know what causes it. It happens on the other forum to. It uses the same software so I guess the forum software is doing it for some reason.

[2seater]

Not a lot changed in the attached photos but some things did get done. The big bracket on the front is now bolted on with loctite. I did replace the water pump although it took three different FLAPS to find one in stock. It was a good time to add the oil pickup and new oil pan. I have all the pan bolts from the s/c donor but of course the thread size was changed to 1/4” vs 5/16” at some point so I wound up getting socket head screws with washers to install the pan. Not really a big issue, just wasted time. Much of the rest of the time was spent cleaning parts to be reused. The valve covers look pretty good but not perfect by any means. I do not want to paint them and I want to use the ones from the donor because they do not have a grommet hole for the external vent for pvc system. I will recondition the bearings in the idlers and tensioners to get things mocked up but I decided to order new ones as well for $25. 

[2seater]

While cleaning up the power steering pump and remote reservoir, I found the return line nipple is almost completely broken off. There is a plastic reservoir shaped appendage on the side of the pump but rather than a fill cap on top there is a hose nipple for a remote fill reservoir which mounts on the throttle cable bracket. A quick search didn't turn up what I am looking for but will put more time in on that tonight. I did bolt it in place as well as the alternator to check belt alignment, which looks okay. I also added the two heater pipes for mockup purposes. The belt idlers and tensioners are getting replaced so some of these items are less than pristine in the photo. I also found a belt hanging from another stand and guessed at the belt routing, which appears to be correct. Two new ones will be installed and I thought both belts had been cut when the engine was removed but I guess only one was.

 

The supercharger is just sitting loose but the lower manifold is installed and torqued. I also installed the A/C compressor bracket but I am pretty sure that bracket won't work on a Reatta as the front engine mount interfaces with it and this one does not look proper. No matter, the whole a/c compressor and bracket get installed from the previous engine.

 

I started stripping the supercharger of extra items and cleaning it up to be painted. It will get new oil in the drive but otherwise I am going to leave it alone internally. It has a myriad of ports and hoses, probably for various control systems but much of that will be discarded. There are at least eight different hose connections and I only need three or four. I hope to clean it up by tapping a couple of the holes designed for o-ring type connections, similar to the heater pipes, and installing flush pipe plugs. As I have done on other manifolds, I will probably drill and tap directly into the manifold inlet neck. It cleans things up and eliminates that fragile plastic box. Many of the plastic tubes from the hose barbs just crumbled on this engine. I hoped to work something out to adapt our style EGR valve to the mount for the S/C version but it would be way too much work to do so. The biggest issue is the present EGR bolts to the front head where our dogbone mount is located. It also feeds from the front exhaust manifold, which I have but it isn't ceramic coated. It is also UUGLY, ugly with two u's. Easy enough to delete from the programming but that was not my intention.

 

The last item for today was discovering how much larger the throttle body is than similar looking ones from the early TPI manifolds. I included a photo of the two of them side by side. The one from the donor needs a bit of cleaning. The new throttle bore is 2.75" vs 2.25" for both the early TPI and LN3. They have a similar configuration, throttle and MAF combined in one casting but I am not sure if the mounting is the same. 

Edited March 13, 2022 by 2seater

[2seater]

Had appointments today so not much done. I did remove the reservoir attached to the power steering pump, but not having much luck finding a replacement. I can find reservoirs to attach to the pump with a filler cap but not for the remote fill. Anything in the GM parts sites show as discontinued. I contacted Cardone to see if they might have a source. They list a rebuilt pump with integral reservoir for a reasonable price but not the remote fill model. I figured it can’t hurt to ask. 
 

I did more cleanup and an acetone wipe of the supercharger. It will get a Massey Ferguson gray paint job. It won’t match anything but not clash badly with the gray/brown stock color. It turns out the two ports I want to plug are sized just right to tap 3/8” npt so they will be repurposed as a vacuum port and a boost port. 

[DAVES89]

Looks like a run to Gibson's for the reservoir to me. I'd go with you but too busy hanging out by the pool sucking up the suns rays. Only hit 80 today...

[2seater]

2 hours ago, DAVES89 said:

Looks like a run to Gibson's for the reservoir to me. I'd go with you but too busy hanging out by the pool sucking up the suns rays. Only hit 80 today...

Yah, I have been giving that some thought and is my fallback if a new replacement is unobtanium. Are you the same color as your hardtop yet👍

[DAVES89]

8 hours ago, 2seater said:

Yah, I have been giving that some thought and is my fallback if a new replacement is unobtanium. Are you the same color as your hardtop yet👍

Getting brown. Don't burn anymore. 

[2seater]

A little more today. Again it doesn’t look a lot different because some things were out of sight. Pushrods and rocker arms installed and valve covers buttoned up. 
Tapped the two former O-ringed openings in the supercharger for reducers and hose nipples. The opening is plugged below the tap so no debris from the tap gets inside. Bolted the supercharger in place after painting and draining the oil from the drive section. It is actually coming together.

[2seater]

I forgot to mention the recommended GM oil for the supercharger drive snout is $3.15 per oz. Conflicting information on the capacity of between four and six ounces. I guess I had better get on with burning a chip and see about some Bosch III injectors in the appropriate size, guessing about 30# would be appropriate? I also forgot to mention the oil fill cap on the valve cover from the S/C donor engine is labeled 10W-30. A minor change but a little surprise as the years have passed, thinner and thinner oils are recommended.

[Ronnie]

My daughter's Camry uses 0w-20 full synthetic oil. It's like pouring water in it.

[2seater]

8 hours ago, Ronnie said:

My daughter's Camry uses 0w-20 full synthetic oil. It's like pouring water in it.

Yes, my Subaru is the same. I have been going to 0w-30 in my Reatta and Ranger for a few years as well. It appears lots of Euro cars use a 0w-40, somewhat different than what one would expect in the pursuit of mileage.

[2seater]

Well. the engine left the stand, temporarily. There were several items that are impossible to complete while on the stand. I installed the rear frost plugs, the expansion plug for the camshaft and the two pipe thread plugs for the main oil galleries. Next item was the flexplate to the crankshaft. Once that was done it went back on the stand.

Another item that was very time consuming was getting the small screws out of the throttle body to remove the MAF, TPS and IAC for a thorough cleaning. It still looks a little grungy but some of that stuff simply won't move. I also added the arm on the throttle body that operates the throttle valve cable for the transmission. The later model electronic control transmissions don't have that manual control but luckily it is just a bolt on item. It is the black colored small arm at the top center of the photo. The other small item laying just above the throttle body is the remains of the idle stop screw. It took a good hour to get it out without breaking. I noticed the throttle blade was sticking in the bore, even after cleaning and the stop screw was the reason. It is supposed to all thread with a screwdriver slot in the end and a jam nut to lock the adjustment. Someone prior had butchered it badly enough that it was seized and there was no jam nut present. The spare throttle body that donated the arm for the cable also donated a new stop screw. Now the throttle blade closes but not far enough to stick in the bore. I hadn't realized before that the throttle was as large as it was and I posted that before, but that isn't the only thing that is larger. The MAF screen and the outer diameter where the inlet hose connects is also about 1/2" larger. It makes sense, but it isn't obvious until they are side by side.

One item that isn't shown is the fuel rail, which look like many others from 91 and newer. I spent a lot of time cleaning removing the injectors, the pressure regulator and a bunch of rust and dirt inside. The return line from the regulator was completely plugged and it took repeated soaking and air pressure to finally clear things up. It all flushes clear now but it is impossible to see what might still be lurking. Two items of note which I was a bit surprised by: the pressure regulator is marked as 2.7bar or about 39psi. That may explain why when I looked up the injectors that came in the donor engine that I found two different, although similar, flow rates. I found a rating of either 28# or 29# and only the 29# also listed the pressure as 43.5, or three bar. It is likely a somewhat lower pressure and flow is designed in for some reason? I have often noticed injectors used in many Fords are rated at a lower pressure and they in fact do run a lower pressure. Lower pressure is somewhat easier and less electrical load on the fuel pump, but the usual trend has been to go to higher pressures in more recent years to improve atomization. I don't know why they used what they did but I find that refurbed 30# Bosch 3's are fairly common so that is what it will get. I believe I will install a new pressure regulator as well. The nice thing is it can be taken apart completely for cleaning plus it has a filter screen in it, but it just seems prudent to replace, probably with a normal 3 bar.

 

I have decided to install a power steering reservoir with fill cap directly on the pump. That type is readily available and it solves another issue I won't need to deal with. This engine came with a remote fill tank and a hose down to a second tank on the pump, illustrated previously. The remote reservoir mounts and top of the sheet metal piece that anchors the three cables that connect to the throttle. Since this engine didn't have the TV cable, there is no mounting provision to anchor it. Without needing a place for a remote fill, I can use the cable bracket from an earlier model. I am sure it will need modification too, but I can deal with that.

Edited March 17, 2022 by 2seater

[jon L]

I have a power steering reservoir. I might have two.

What is the problem with the one you have?

The tab on the bottom is rarely still there and there are no new ones.

Let me know.

 I would also like to ask you why you taped the hole for the vacuum lines in the supercharger?

 

[2seater]

1 hour ago, jon L said:

I have a power steering reservoir. I might have two.

What is the problem with the one you have?

The tab on the bottom is rarely still there and there are no new ones.

Let me know.

 I would also like to ask you why you taped the hole for the vacuum lines in the supercharger?

 

It's the tank that attaches to the pump with a small return line nipple on the bottom, (broken off on mine), and it has a hose barb on the top, approx. 3/4" diameter for the remote fill by the throttle. I believe you on the lack of replacements available as none have shown up. Autozone does have the correct configuration pump with tank, but I don't need the pump. 

 

I tapped the hole so I can install only what I want rather than that tall cylinder with multiple barbs. That photo with the tap in it is below the S/C so it will see vacuum and boost and I only need a single line that will run to the dash where my gauge is, with a tee off to the fuel pressure regulator along the way so it is boost referenced. The inlet hole from the deleted EGR is also tapped and will be to the transmission modulator and the S/C bypass valve. I am debating tapping directly into the intake plenum on the back side to feed the cruise and HVAC or tap a plate for a fitting that covers the original vacuum block opening. I don't use a charcoal canister as my intercooler piping runs through there but that isn't really vacuum anyway just a sort of ported affair.

[2seater]

Well, I tried something when I took the photo below. The first is with the phone vertical, and the third one in this post is with the phone horizontal, 90 deg to the way the forum displays it. It still rotates it but at least winds up the way I intended. Both photos appear upright in my photo library but the horizontal one is cropped in my phone. I don't know but I give up. In any case, the photo below is of a replacement vacuum block for the intake. I made it from a block of nylatron which cuts and taps easily. There is one hole on the front side as well which will be for the vacuum canister on the S/C bypass butterfly,  but neither is tapped just yet. It will be 1/8" pipe for hose barbs. I figured I had to cover the opening in the manifold anyway so may as well kill two birds.

The photo below is of the throttle cable bracket I adapted from my engine with the TPI manifold in the far background. The original cable bracket is sort of perched on top and is a fair bit larger. It extends further forward to where that small bolt head is visible between the water outlet from the thermostat and the vacuum canister to the right. The actual position of where the cables snap into the brackets is exactly the same.

This view was for comparison with the first photo but I see it also clearly shows where the fuel pressure regulator is located. It is the large opening just below the fuel line connections. I had already removed the regulator which is a small cartridge that is retained by a snap ring. I did order a new regulator and the cartridge for the 95 S/C engine is indeed a different part number than the three bar regulator on that same TPI engine in the background. The internal PCV system valve is located under the black cover just to the right of the fuel lines. 

Edited March 17, 2022 by 2seater

[jon L]

I took the pressure regulator out and cut off the small tube, reinstalled it and mounted an adjustable pressure regulator on the cross brace.

It works very well with the supercharger. Also, you can disconnect the bypass and you will get more boost.

[2seater]

Thanks for the ideas. I do have an adjustable on my present turbocharged engine but wasn’t sure of how to get there on this s/c variant. I am new to that game so input is much appreciated.

I wondered about just keeping the bypass closed but I don’t know enough about how it will work in semi stock form to make a decision.