Rebuilding and Supercharging 3.0L

[gavinc69]

Can wait to see how it all goes and when the beast starts and runs (subscribed) Good luck :-)

[Dr J]

Thanks, here are more pics:



Plugged the air injection holes.

[Dr J]

Got the Carrera tensioner and fabricated the spacer to prevent collapse:



Also updated the tensioner idler arm with the supertec arms. Replaced idler sprockets- the old ones were worn.

Setting the cam timing was a pain. Tried to advance to 1.7 mm rather than 1.0 mm to get more bottom end performance (since supercharger would help fill cylinders at the top end). Then did the piston to valve clearance check and had interference. so I set it to 1.5 mm, then had interference on the right bank, then 1.4mm- almost, and had to settle for 1.3mm. This worked with better than minimum clearance.

To help with the clearance check, I put a piece of tape and drew a line at the 0 degree angle to make it easy to count the turns on the rocker screw.





Now installing the intake:



Looked at the dirty tranny and cleaned it up:



After first cleaning pass. Looks even better now.


Ordered and received the Clewett crank pulley and powder coated the fan. Don't have pics now, but will get them in soon.

Meanwhile, I have been stuck with a low fuel flow issue. I've concluded it's OK for the stock 911SC but not for the supercharged version.
Flow test- not getting enough fuel

[JohnJL]

Lookin good. Here's where I've arrived...taking a breather for now...

Smaller pulley, bigger charger, call it done...for now...

All figures are at the wheels, no drivetrain corrections. 30degC ambient temp, IATs maxed at ~40degC with the coolers going.









I think it needs a better exhaust and heads to get much more.

[Dr J]

Excellent John, I have been following your work and glad to see this recovery after your previous setback. I am almost done but haven't had the time to finish it off, doing the small details. Since I tested fuel flow and found it to be low, I just got an LM2 to put it all together and get some data. I was looking at your numbers from the other post and there is good data there. Thanks for posting.

[Northy]

Good work sir - subscribing to follow your progress

[Dr J]

More pics. I have been behind on my pics but trips, and moving have kept me from posting.

Here is a part to mount the electromotive. It's a convertible so no need for the rear window defogger. Also, don't need the heater in Miami so all of that is being disconnected.



Without the console sporting the Clewett pulley and the powder-coated fan.



Two shots ready to mount.





Engine is already mounted in the car and partly connected. I'll have to cut the deck lid but I already knew that...

Also removed the AC condenser. AC will be a later project.

[YZR500]

Very sleek set up Dr J, by curiosity did you stay with the same diameter crank pulley as OEM or increase slightly?

Also, I like the belt tensioner set up, do you mind sharing where you sourced it from,...

Great project very timely and meticulously accomplished

[Kemo]

what compression are your pistons? are they 9.3:1? I cant tell from the pics. Nice work so far!

[Dr J]

For the pulley, I stayed with the same diameter to the alternator/fan. The turbo pulley was too large so I kept the diameter same as stock for the 79. The pulley on the supercharger is rather large, so I can get a smaller one in the future to increase boost.

The belt tensioner was sold together with the supercharger system by the person who had it. I can measure the mounting plate and give dimensions or get a picture from which you can get them. The tensioner itself is from a 1996 Chevy Astro Van. The AC compressor is a Sanden rotary which actually has 7 rather than 6 grooves. It is available through Summit Racing. The crank pulley dimensions were selected by me and fabricated by Clewett Engineering

The piston were stock, but with modifications to the case to get the deck height even and the use of 1mm copper shims, ccing the head resulted in an 8:1 ratio.

[YZR500]

Originally Posted by Dr J

For the pulley, I stayed with the same diameter to the alternator/fan. The turbo pulley was too large so I kept the diameter same as stock for the 79. The pulley on the supercharger is rather large, so I can get a smaller one in the future to increase boost.

The belt tensioner was sold together with the supercharger system by the person who had it. I can measure the mounting plate and give dimensions or get a picture from which you can get them. The tensioner itself is from a 1996 Chevy Astro Van. The AC compressor is a Sanden rotary which actually has 7 rather than 6 grooves. It is available through Summit Racing. The crank pulley dimensions were selected by me and fabricated by Clewett Engineering

The piston were stock, but with modifications to the case to get the deck height even and the use of 1mm copper shims, ccing the head resulted in an 8:1 ratio.

Thanks John, very useful info as I too in the middle of modifying my supercharger. I also have the Clewett Eng. crank pulley I went to 5.5" on the Sc and remained OEM to the alternator fan. I have a 3.25" pulley on my SC which I hope will give me an additional pound or 2 of boost.

I would be very appreciative if you could take a few picture of your serpentine setup with tensioner and idler.


Again great built, .. awesome project.

[Dr J]

Here is a view of the tensioner so you can see where I mounted it in the cross mount.





To space it away from the cross mount I used nuts of larger diameter as the bolts. I found that washers can have different thicknesses to the nuts give a more consistent spacing. If you need an additional washer or so, you can check that they are the same thickness.

[Packy]

Nice, I was planning on doing a similar install before I crashed my car. I'll be jumping back into it once I pull the engine, which may be this weekend.

These sites show my plan...
Plan for (inexpensive) 300+ hp SC motor
Plan for (inexpensive) 300+ hp SC motor

I wouldn't mind your advice. It looks like you are getting good results.

-P

[Packy]

I also have the following in PDF form if you want them:

SoK brochure on both SC kits
SoK installation instructions for the Paxton kit
SoK installation instructions for the Auto-Rotor kit
SoK 3.2 Low-Boost Whipplecharger Install instructions
TPC racing 993/964 Supercharger installation instructions.

Send me a PM or email if you want them.

-P

[Dr J]

Status report:

It started! Electromotive worked fine, seems that preliminary timing and mixture were OK. Tachometer worked fine on the electromotive. Working on breaking it in.

[Don Settergren]

Congratulations! Whoohooo!

[gavinc69]

AWESOME, you've got to post some videos then its on the road ;-)

[FinallyGotOne]

any updates???

[Dr J]

Yes!

Lots of updates. It's running and has some 2,000 miles. I'm in the middle of a conference so I can't post details and pics now, but will try to do so next week. Also will provide some of the difficulties and lessons learned, for posterity.

[Dr J]

Ok, here is a bit of a summary since the last posts:

Mounted engine back and connected everything without the supercharger.
Performed appropriate break-in in N/A mode.
Installed LM2 A/F system (problems with getting a tach signal- fixed much later)
Found A/F ratio too lean for supercharger use (I wanted enough fuel from the FD without using the cold-start injector on boost)
Changed Fuel distributor to a Euro 81/82 with its WUR. Now I have steel fuel lines.
Connected supercharger.
Belt kept coming off. I found that the tensioner was too close to vertical. I drilled a new hole for the locator pin and tilted it more horizontal.
It was very difficult to align the belt once the engine was in the car, since none of the three pulleys originally came with the car. I ended up getting
a Gates laser alignment tool to get it where it was good enough.




Notice how the tensioner is more horizontal than before. Also, the hump hose at the supercharger has since been replaced. There is still some misalignment between the supercharger and the crank pulley which causes a resonance with the tensioner moving forward/aft, at very low rpms but it is felt when you turn the car off and it goes through this range. Also, I had to remove the AC condenser (which was non-functioning anyway) and cut the deck lid.



After everything was running, I found that I had 2psi! What??

Since I didn’t know the capacity of the supercharger, it seems I should have designed the crank pulley to be larger. However, even this little boost already made a noticeable difference.

No problem, based on the boost I was getting, I back-calculated the capacity of the supercharger to be 1.6L then calculated the size of a new pulley, which I obtained from Whipple. Now I’m running 6-7 psi which based on my research on this site and others seems to be the maximum safe value without using an intercooler. There is still plenty of capacity left in the supercharger for future “upgrade” in boost.

The AF ratios was fixed by a used DWUR, which was a whole other learning curve, but I have enough fuel.

Now that I have some boost, my supercharger outlet pipes to the air intake started disconnecting from the rubber elbow/connector. After much research, I decided to have a bead welded to the stainless pipes. These held but the hump connector at the outlet of the supercharger allowed the whole intake to the engine to move, which caused it to pop off from the throttle body. Removed the hump connector and put a straight piece of silicone and everything is holding now.

On tuning, I figured out how to get a tach signal to record AF tables. I should mention that the tach signal from the HPX could not power the car tachometer AND the LM2 and DWUR. I used a transistor as emitter-follower to isolate the tachometer from the other electronics and now everything is playing together nicely.

I also added the MAP sensor and wired it in. The LM2 is recording tach, AF, ignition advance from the HPX, and manifold pressure. The LM2 was installed between the seats, but those details may be best for another thread.

Current state: It seems most bugs have been worked out. The car is driveable. The difference is very significant. Boost is available almost right away. I can be driving at speed, hit it and feel the front start coming up (Oh no, not a suspension upgrade!) The sound is not bad at all. In fact, I like it. When on the expressway, just opening up the throttle a bit and I can hear it engage.

If I want to operate in NA mode, all I have to do is remove the belt and it operates as such. The difference is easy to see.

Now to the never-ending job of tuning:

Had cold start problems (it would take 3 tries to start) and am going through that learning curve. I found that I just need to richen the warm-up cycle of the DWUR. This is now working but needs to be refined for different cold-start temperatures.

Warm AF tuning: this is still in progress. Changes to the intake, and problems with a slipping belt, and a loose ground on the LM2 has caused me to do this several times. Right now it is too rich under boost and I can feel it bogging down. It’s easy to generate a new table with the LM2 and adjust, but I’m considering dyno tuning.

Ignition timing is working fine. I have the MAP sensor on the HPX for vacuum advance. The result is 13 degrees advance at idle, about 28 degrees with no boost at higher RPM, which retards to 18-20 deg at boost.