1.6L with a 3.91 LSD Verdict

[RoccoGilroy]

Well I got a great deal on an 3.91 320is LSD that I couldnt pass up. I had a 76 diff with the pop out flanges so I didnt need the redrill and spacers or the 79 320i inboard CV's. Bolted it all up along with my new suspension and my freshly rebuilt 32/36 weber. Suspension is tight as a drum and its a huge improvement over the original rubber bushings, stock springs, sway bars, and shocks. New IE mechanical distributor with electronic ignition too.

Now for the issues. I have a 1.6L 1600 motor in my 2002. Long story short, bought 2 cars at once. 70 2002, good body shit motor. 71 1600 good motor shit body. Easiest fix was 1.6L motor in the 2002 body. Didnt swap the diffs when I swaped the motor. Iv read all about the fun and high reving characteristics of the 1.6L motor but I never got to enjoy them with the 2002 diff.

So one LSD swap and a whole lot of time, money, and work later,,,,, still dont have the fun 1.6L motor. Makes lots of noise and revs alot but still doesnt pull like I think it should. In all fairness I never got to drive it with the 4.11 diff. It was a 71 short neck 4.11 diff to so it was rare. I sold it stupidly before I knew what I was doing...

I knew the LSD swap wouldnt make much difference if any but for what I paid for it I still dont regret it. Iv got a few 2002 2.0L motors lying around and eventually ill rebuild one of them. It needs to be on the road for now. Ill just have to suffer. lol Just thought id share my experience with everyone just in case anyone was curious about a 1600 LSD swap. Untill next time fella's...

Rocco

[Mike_B]

You can also improve gearing by going to a smaller diameter tire.

[eastsidebimmer]

In my 1600, I went from a 4.10 to a 3.90 and now down to a 3.64...all open. I was not as concerned with speed and acceleration as I was not turning 4,400 RPM at 70 MPH. The 3.90 dropped the clicks down to about 4,200 and the 3.64 has me down closer to 4,000 (ish) I would have stayed with the 3.90 but it had a bad bearing that I only discovered after it was installed. The 3.64 that I got from one of our own FAQers is doing just fine.

If your car is happy and healthy with the 1600 engine...just drive it man!

[RoccoGilroy]

Ya iv been thinking about that too. I have 14" bottle caps right now with 195 60 14's and I have been curious weather or not smaller wheels and tires would make that big of a difference. Anyone with experience is welcome to chime in on this issue. I get some excessive rub too with my current wheel tire set up! I cant turn the wheel hard over without hitting the fender. Chewed up a good set of tires learning that lesson. Havnt got around to rolling the fenders yet. My car is lowered pretty excessively though. the rear tires are tucked under the tirewell about an inch or two and the front fenders are about an inch above the tire. I want to go a little lower in the front too because it sits a little flat to me. I like it slightly lower in the front than the back. I just hate all the 13" wheel options we have. Plus my front springs are already cut. Im afraid to cut any more out of them. When I jack my car up the springs fall out of the purches and I have to guide them back in when I lower it down. Not fun! Even so it still sits high. Yes before everyone chimes in, I did removed the spacer on top of the strut. Just got to keep my eyes open for some cool 13" wheels. Tall order. lol

Rocco

[RoccoGilroy]

Yup thats what im going to do. I was going to buy another 1600 head and put a hotter cam in it. I also have some solex mikuni sidedrafts that need a rebuild. This would add the HP and torch im looking for but I hesitate because I worry about the 2002 intake manifold holes not matching up with the 1.6L head all the way. Iv been told its not that big of a deal but if im going to go through all that trouble Id hate to find out that it does cause problems. I guess I could do a little port matching but I dont want it to screw up all that german engineering. (There smarter than me)lol. Eventually it will come time for a 2.0L and all these little problems will go away. But like you said, for now, DRIVE IT!!! Thanks

Rocco

[scoyote]

Just a question on the 76 diff flanges--i know they sit out a bit which eliminates the need for the spacers--but thought you might need some machining done to provide a circlip locking system--or can you run with them without that step. I would think that if you had the transition year 79--that you would have the best setup with the wide inputs and necessary 10mm bolt pattern to match the lsd. I guess because you would still have to deal with matching up the out cv's o the halfshafts--Sorry--can you see a question in there!!--scoyote

[Mike_B]

Take a look at Michael Dubois malaga car. He has some sweet 13's that he refinished with a rattle can. I'm not sure what suspension he's running, but the stance of his car just looks spot on.

It's the car in front...

[RoccoGilroy]

Well heres what happened. I researched it to death! Thought about 79 320i cv's. To messy and im not that tallented. Thought about redrilled flanges and spacers. Dont like the idea of spacers and I just couldnt bring myself to pay $70-100 for two stupid spacers and a bunch more 10 min worth of work on a drill press for the flanges.

So heres what I did. I got lucky and found that one of my spare diffs was a 76 with the pop out flanges. They hardly took any effort to pop out. I did the same with the LSD flanges. Again, honestly, almost no effort to pop them out. I could have pulled both out by hand almost. I took the 76 2002 flanges down to my local machine shop and asked what it would cost to put the grooves into the flanges. He said "I dont know, $60-100 bucks to try to do it." I said Try? He said " This is hardened steal I dont know if were going to be able to get the grooves as deep as the other ones." I said thanks but no thanks!!!

Hopped on the FAQ and researched some more. Found a guy who did it without the snap rings. He said that he has put 8K without the snapring goorve and has seen no issues. His logic was. " Once its all bolted up, where can those flanges really go?" I agreed with him.

So I put my 76 2002 flanges in the LSD and bolted it all up! Fuck it right?!!! By the way when I poped the flanges in they where tighter and more difficult to remove than the original flanges. Not in a bad way. Point im trying to make is pulling the 76 flanges out of the LSD was just as hard if not harder than the stock flanges with the grooves. I havnt even put a tank of gas on the set up yet but so far so good. corners like a jack rabbit and the 3.90 is a little peppyer than the 3.64. I got the LSD for $300 and spent no money on CV's, flanges, drilling, or spacers. If something goes wrong it wont be that big of a loss. Hope I answered all your questions but if not please feel free to ask... Please pick my brain as I owe for picking all of yours!

Thanks

Rocco

[RoccoGilroy]

Ya the roundy in that pic looks alot like my stance but mine is a little lower in the back and a little higher in the front. So really as im writing this its nothing like that one. lol But kinda. I like the 13" brittain 100+'s. There's a set on Ebay right now and im tempted!!!

[Guest Anonymous]

Drove 1.6L for years with 3.64dif not fun in lower gears not good in higher gears Just too high a gear. Switched to LSD 3.91 much better. better in lower gears for accel and more into good rev range for cruise accel.

Another question was 2L intake manifold into 1.6L head. The 1.6L head can be opened (JUST enough material left to forms a gasket surface) to match a 2L intake manifold. I did it on 2 different heads and it works fine. A 292 cam in a ported 1.6L head with headers and side drafts is a kick, comes on with a distinct surge at 3400rpm and revs easily into the 7000rpm range.

Have fun

[RoccoGilroy]

Drove 1.6L for years with 3.64dif not fun in lower gears not good in higher gears Just too high a gear. Switched to LSD 3.91 much better. better in lower gears for accel and more into good rev range for cruise accel.

Another question was 2L intake manifold into 1.6L head. The 1.6L head can be opened (JUST enough material left to forms a gasket surface) to match a 2L intake manifold. I did it on 2 different heads and it works fine. A 292 cam in a ported 1.6L head with headers and side drafts is a kick, comes on with a distinct surge at 3400rpm and revs easily into the 7000rpm range.

Have fun

Thanks! Thats exactly what I was thinking of doing. 292 regrind and the rebuilt sidedrafts. Im tired of seeing my car sitting still though. Im going to drive it for a while like it is. Probably through the summer. Im searching for a 1600 head for cheap to rebuild over the summer. I found one from an faq'er in ohio but the price was to much for me right now with the shipping. Plus I cant make up my mind. But this is great news to know that the 1600 head can be opened. Thanks now I gotta think even more!!! lol

Rocco

[RoccoGilroy]

This is exactly what my cars stance looks like. Just fyi. Sorry to jack the picture. Id like to go a little lower in ther front on mine.

Rocco