nevada Posted February 25, 2011 Report Share Posted February 25, 2011 Hi all, So i got my hands on a '71 521 that has a 1.6 in it. the engine had seized and the previous owner took the head off, etc to do a rebuild that never happened. So just the block is in it now. He took the head and carb's with him when he moved out (he lost the rest of the truck in the divorce). The truck has been converted to a 4x4 with what appears to be international running gear under it (front axle and transfer case). the transmission is a 5 speed. its my understanding that year did not come with a 5-speed? so i assume its from a later model. this is all very new to me. i have been lurking on the forum but could use some good, direct, info from people in the know because im not knowledgeable enough about the Datsun trucks to be sure i am even searching properly the forum lol. so it has been suggested i drop an L20b into the truck for a bit more power, etc so that is what I want to do unless i am missing something. will it drop in and bolt up in the same position as the L16 (i.e. engine mounts line up, etc)? what head should i be looking for? i am very, very new to this kind of thing. it will be my first ever engine install so please don't flame me. i am trying to learn and just cant shake the feeling i am missing out on a whole lot of what i need to know to make an informed decision lol the intake looks to be setup for dual carbs (i assume SU's. the intake looks kind of like the one I had on my 67 roadster). so if i get and L20 can i used the same intake or should i do something different? again im sorry if my questions seem stupid but i am really new to this stuff. i appreciate any info you can provide! Quote Link to comment
DanielC Posted February 25, 2011 Report Share Posted February 25, 2011 The L-20 B engine will pretty much bolt right up to everything. Same motor mounts, same transmission bolt location, all the same. The exhaust manifold might be a little different, some L-20 engines has EGR (Exhaust gas recirculation), a pollution control. The L-20 engine is about 3/4 of an inch taller, so you might have to do some changes on the exhaust pipe. I would remove the exhaust manifold, sitting in your engine bay, and get it out of the way. In 1971, Datsuns did not have a five speed. They were not available in 4 wheel drive, from the factory, either. Quote Link to comment
wayno Posted February 25, 2011 Report Share Posted February 25, 2011 Hi there Nevada, a L20b will bolt in, it would be best if you find a running engine from a wrecking yard if possible with rectangular exhaust ports, pre 1977 I think. If you start buying the engine in parts, like buying the head separate from the block, it starts getting more complicated, you definatly need a early L20b head, so you can use your existing exhaust manifold. There are several differant heads to choose from. You need a L block SU setup for a L block, they are out there, I have 2 setups I use, I like them. I need to go to the store, think about anymore questions you might have and I will help you if I can. wayno Quote Link to comment
datzenmike Posted February 25, 2011 Report Share Posted February 25, 2011 The problem with square port L20B motors ('75-'77) is that the intake and exhaust manifolds are bolted together. You could use your L16 exhaust but you will need a separate intake manifold to go with it. Also if going with an L20B your L16 clutch and flywheel won't bolt to it. Post a picture of the 5 speed. Quote Link to comment
nevada Posted February 25, 2011 Author Report Share Posted February 25, 2011 ok thanks guys, once i get it here i will take more pics. interesting info on the clutch. would a L20 clutch bolt up to the L16? i ask because if the tranny is a 5-speed and it has the L16 then something is up as far as the clutch goes? Quote Link to comment
DanielC Posted February 26, 2011 Report Share Posted February 26, 2011 I think there are two different sizes of L-20 clutches, and people please correct me if I am wrong. 225 MM and 240 mm clutch disk. The 225 and 240 will obviously need their flywheel. L-20 flywheels are six bolt, L-16 and L-18 flywheels are usually five bolts. You could sometimes get a L-18 with a six bolt flywheel, if you had a JDM engine put in the truck as some time. If you find a L-16, or a L-18 with six bolts, it is desirable, because it is fully counterweighted. If you have the 200 MM clutch disk flywheel, you can get a pressure place for a 2000 Roadster, and it will bolt on. Your left leg will get a workout using this clutch. JDM (Japanese Domestic Manufacture) Japan has some funny laws about rebuilding cars in an accident, from what I understand. It was common in the early 1980's to import used engines out of Japanese cars into the USA, and sell these engines. You could buy a "gently used" Japanese engine way cheaper that you could rebuild a worn out engine. It would be very difficult to match the tolerances of a slightly used engine anyway. Quote Link to comment
datzenmike Posted February 26, 2011 Report Share Posted February 26, 2011 would a L20 clutch bolt up to the L16? i ask because if the tranny is a 5-speed and it has the L16 then something is up as far as the clutch goes? The clutch and pressure plate from a car L20B will bolt up the the L16 flywheel, yes. No L20B flywheel, car or truck, will bolt to the L16 motor. Quote Link to comment
nevada Posted February 26, 2011 Author Report Share Posted February 26, 2011 just a pic of the transmission. its the only one i have at the moment. when i get it moved here i will take a better one. Quote Link to comment
bonvo Posted February 26, 2011 Report Share Posted February 26, 2011 l20b has a 6 bolt fly wheel l16 has a 5 bolt fly wheel thats the difference if i were you since it is a 4x4 i would find a napz 2.2 and put a u67 head from an l20b on it you will need a timing cover from an l20b and modify the head gasket this will give you higher hp but also more importantly with a 4x4 more torque i found all this out simply by reading and a simple search this thread is a good read http://community.ratsun.net/topic/21285-lz22-engine/ Quote Link to comment
nevada Posted February 26, 2011 Author Report Share Posted February 26, 2011 Do you mean use the u67 head on the 1.6 block? Quote Link to comment
nevada Posted February 27, 2011 Author Report Share Posted February 27, 2011 ok so what model years should i be looking at as far as a suitable L20B goes? Quote Link to comment
nevada Posted February 28, 2011 Author Report Share Posted February 28, 2011 I put up more pics on this thread: My link Quote Link to comment
wayno Posted March 1, 2011 Report Share Posted March 1, 2011 Hey Nevada, he was saying to put a U67 head on a 2.2 napZ block, the problem here is you don't know about this stuff yet, bonvo put a link up with his statement, read it, you will need to educate yourself if you go any route except the L16. There are a lot of routes to take. Are there any ratsun folk near you? You need an educated friend to explain stuff first hand that has done it before, or you have a lot of investigating/reading ahead of you. wayno Quote Link to comment
nevada Posted March 2, 2011 Author Report Share Posted March 2, 2011 what do you think about a Z24 going in? Quote Link to comment
ppeters914 Posted March 3, 2011 Report Share Posted March 3, 2011 what do you think about a Z24 going in? Go back and read Wayno's reply. Sorry, but I wouldn't tell someone who admits they know little or nothing to replace their L16 with a Z. The Z-series transmissions attach at a different angle than the L-series, so if you want to install a Z24, you'll need the tranny, too. Your options IMHO: OPTION A: Get the missing pieces and rebuild the existing L16. OPTION B: Swap in a running L16 or L18. Probably your easiest & cheapest solution. OPTION C: Swap in a running L20b. More power, but, as already mentioned, several gotchas to watch out for. OPTION D: Sell the project and buy a running Datsun. Pete Quote Link to comment
izzo Posted March 3, 2011 Report Share Posted March 3, 2011 Go back and read Wayno's reply. Sorry, but I wouldn't tell someone who admits they know little or nothing to replace their L16 with a Z. The Z-series transmissions attach at a different angle than the L-series, so if you want to install a Z24, you'll need the tranny, too. Your options IMHO: OPTION A: Get the missing pieces and rebuild the existing L16. OPTION B: Swap in a running L16 or L18. Probably your easiest & cheapest solution. OPTION C: Swap in a running L20b. More power, but, as already mentioned, several gotchas to watch out for. OPTION D: Sell the project and buy a running Datsun. Pete or pull the trans out, and swap the bell housing with that of a z24 :D Quote Link to comment
datzenmike Posted March 3, 2011 Report Share Posted March 3, 2011 FS5W71B 5 speed. Look on the block behind the dip stick handle for the engine size. Totally weird that someone would use an L16. Specially in a heavy 4x4. Need at least an L20B. . Quote Link to comment
datzenmike Posted March 3, 2011 Report Share Posted March 3, 2011 Actually if you think about it they are under tension. Steel comes in many strengths but 60,000 PSI wouldn't be very wrong. This would mean a 1/2" rod would be capable of supporting 7.5 tons. Those bolts look about 1/2" round so are only 78.5% the size of a square so a 1/2" round rod would hold 78.5% of 7.5 tons or 5.88 tons and there are 4 of them that's 23.55 tons support or about 8 or 9 521 trucks worth. No they won't break. Quote Link to comment
ppeters914 Posted March 3, 2011 Report Share Posted March 3, 2011 FS5W71B 5 speed. Okay, Mike, how the heck can you tell from that pic? I don't see the speedo mount, trans mount, shifter ears, or anything from your DQ article. :confused: Pete Quote Link to comment
ppeters914 Posted March 3, 2011 Report Share Posted March 3, 2011 or pull the trans out, and swap the bell housing with that of a z24 :D The idea is to make this simple. What's obvious/easy to us may not be to Mr. Nevada....at least not until he gets schooled. B) Pete Quote Link to comment
nevada Posted March 3, 2011 Author Report Share Posted March 3, 2011 ok so lots of replies lol. it was suggested that i could use a napz 2.4 block and put an L series head on it and go with carbs so i could use the intake and header i have already. i was told this would be close to a bolt in operation with some shimming of the motor mounts, etc. I checked the block currently in the truck now previously and it is marked as an L16. i am not going to sell it as i find it interesting and if i cant do the install myself i will find someone who is in the know to do it for me. i have never don't an engine install so i will need some help i am sure. i am not totally in the dark however so i think with some assistance i could pull it off. only one way to find out lol. Quote Link to comment
wayno Posted March 3, 2011 Report Share Posted March 3, 2011 Okay, Mike, how the heck can you tell from that pic? I don't see the speedo mount, trans mount, shifter ears, or anything from your DQ article. :confused: Pete Hi there Pete, it is easy enough to see that it is a pre 1980 transmission(at least I think it is), you see the bolts that hold the front and back case together, see that wire or what ever it is that is hanging in front of one of the bolt heads, see the extra triangular metal bracing above and below that bolt head on the sides that is part of the casing, to me that is a sure sign of a 620 5 spd. tranny, though it may have been put in other datsun vehicles, I learned this from one of my friends, he put one of these trannys in his diesel powered 521 and was unable to do freeway speeds even with 388 gears, and I realize that not all 620 5 speeds are geared the same Datzenmike, but I don't know the differance, so I just use 720 5 spds. and i don't have that problem.:D wayno Quote Link to comment
wayno Posted March 3, 2011 Report Share Posted March 3, 2011 ok so lots of replies lol. it was suggested that i could use a napz 2.4 block and put an L series head on it and go with carbs so i could use the intake and header i have already. i was told this would be close to a bolt in operation with some shimming of the motor mounts, etc. I checked the block currently in the truck now previously and it is marked as an L16. i am not going to sell it as i find it interesting and if i cant do the install myself i will find someone who is in the know to do it for me. i have never don't an engine install so i will need some help i am sure. i am not totally in the dark however so i think with some assistance i could pull it off. only one way to find out lol. Hi there Nevada, I have not heard about the shimming of the motor mounts before, but I have not done this swap yet. I do beleave that you use the L20b engine mounts that bolt to the block so the engine is tilted the correct direction, and I could be wrong, but I beleave that would enable you to use your L block transmission, and the L block head. But there is more involved, you have to use the L20b front timing cover because the L16 cover is not tall enough, there might be a oilpan change also, you need a friend to lead you threw that has done the swap before. I wouldn't put a napZ 2.4 block in the truck, sure they have more power, but there are way better choices. If I was you, since this is your first project, I would find a running L20b engine(with square exhaust ports) which will almost bolt in, which will bolt to transmission that is in your truck, and if your worried about the flywheel apps. then, buy a running L20b engine and 5 spd. transmission together which I beleave will bolt strait into your truck using the existing motor mounts and tranny mount you have. If you use the alt. you have in the truck now, you might even be able to use your existing wiring also. If I had tried to do what your talking about with my first datsun truck, I don't beleave I would have any datsuns today, I would have given up. :( But I didn't, I went with the L20b in the late 1990s, and in the next couple weeks, I will be replacing that worn out engine, I think it lasted a long time, my friend says I beat the shit out of it everyday, and he can't beleave it runs at all. :rolleyes: :lol: wayno Quote Link to comment
ppeters914 Posted March 4, 2011 Report Share Posted March 4, 2011 Word....what wayno said. :thumbup: Quote Link to comment
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