I have just purchased a 84 SJ410. It has the 1.3 motor out of a samuria. It is smoking very bad and has no power so I am going to have to rebuild it. I am currently working with a limited budget but I want to try to crank a few more horses out of the engine and set it up for future upgrades. I am planing on rebuilding with h/c pistons and getting the head shaved. I am wondering about boring it over and putting in a cam. I was advised by a place that rebuilds them not to bore it unless I have to because of wear in the cylinder walls. They also recommended not putting a cam in it but a header. I can't afford to do it all at once as much as I would like to so I was thinking originally to put in a cam and bore the block then add headers and air intake and exhaust at a later time. Now I am not so sure. Any ideas on what would be best?


I am going to pull the motor and trans tomorrow and tear down the motor and see exactly what damage may have been done. After I know for certain I am going to begin ordering parts for a rebuild. Any suggestions and help would be greatly appreciated. I'll try to get some pictures posted as soon as I can get some on my computer.

I'm real excited about being able to purchase this and I am looking forward to building it and getting on the trails. I finally have a good place to ride and looking forward to testing the SJ out when I get it rebuilt.

I would listen to the rebuild shop.  Boring the block can leave you with thin spots that could lead to future failures.  As for H/C pistons and shaving the head, that will up the compression ratio and you will probably have to burn expensive premium fuel.

I would suggest pulling the head and examining the valves.  If you don't have any burned valves, just have the valves ground and reseated, and replace the valve guides if they are worn.  Usually smoking on startup that goes away after the engine warms up indicates worn valve guides.   If it smokes all the time, it is probably a case of worn out rings.  If the cylinder walls are not scored, just hone the cylinders and put in new rings. 

For a little extra power, a header will give you the most bang for the buck.  A K&N air filter setup will also help. 

Beyond that, put your money into a moderate lift and some reasonable tires.

When you are on the trail, ground clearance, reliability and driving skill will get you much farther than horsepower.   

Thanks for the responce. It smokes all the time. I checked the compression and it's running 90. Pour a little oil in the cylinder and it ups to 120 so I know I have worn rings. I'm probably going to pass on the h/c pistons if it requires burning premium fuel. I don't think the HP gain would be worth it for what I am wanting.

The springs have been put over the axle already and it is setting on 31 mudders but they are in poor condition.  If I go without shaving the head and without the h/c pistons I will definatly put the stainless steel headers on.  Since I'm going into the motor anyway I thought I would get a master rebuild kit and put new pistons, rings and seals, timing belt, and oil pump in the engine. That way I know I shouldn't have any worries out of the engine.


 Hopefully if all goes well I will know exactly where I am at by this time tomorrow.

Also is there a good source for reliable gauges that anyone knows of?


Thanks again for all the help.

I got the motor pulled this evening but that is about as far as it got lol. I still haven't gotten into the motor.  Hopefully tomorrow I'll get the head pulled and be able to see where I am at. I'm following a chilton manual for the rebuild process. Everything has went pretty smooth up to this point. The manual says that you need to take the rod out of the rockers before removing the head. The screws that hold the rockers to the rod had no heads at all left on any of them. Three of them I turned out with my finger they where so loose. I finally got the others out. The manual says  to push the rod out with your finger then to pull it out with your hand. I can't get mine to budge!! I tapped on it with a hammer and soft punch and got one side out far enough to get ahold of it but it's going no farther. The other side wont budge at all. Any suggestions for getting them out if there?

Been there with the rockers.  I usually just take it to a machine shop so that they can hot tank it for me.

As far as the rebuild, the 1.3 is a good little, economical engine.  I would try to keep the internals as stock as possible and just add a header.  The real trick is to gear your rig for your tire size.

Been there with the rockers.  I usually just take it to a machine shop so that they can hot tank it for me.

As far as the rebuild, the 1.3 is a good little, economical engine.  I would try to keep the internals as stock as possible and just add a header.  The real trick is to gear your rig for your tire size.

X2

-Eric

Ordered the rebuild kit this evening. I'm going back stock with everything and planning on adding a header as soon as I can. The enternals looked way better than I expected them to. No broke rings, no bent or burned valves, and the cylinders are still in tolarance and are not scarred. Hopefully I'll be able to start putting it back together Mon.

I'm not for sure what gears are in the truck now but I would love to be able to change them out for the recommended size for my 31's. The gear kits are more than I can afford right mow so that's going to have to come as a later upgrade. I don't guess there is much of a chance at finding solid used one are there?


I can't wait to get this little beast on the trails. I seen a stick on chrome emblem at walmart last night that I just had to get for the tailgate. It says "size matters" lol. I couldn't pass it up. I'm going to work on getting the motor compartment blacked out tomorrow and then a camo paint job while waiting on the rebuild kit to get in.

Thanks again for all the help!!

Good news on the engine! 

Do you have Samurai axles?  Post a pic of your rig.  

I wouldn't go with 31" tires without some kind of t-case reduction.  A 4:1 case at the min.  It will greatly reduce the load on the engine/clutch offroad and helps a lot of the street as well.  Trailtough has the 4:1 case on sale for under $400.  

You might still have the SJ410 case though, so you could have a "baby lobster" with gives a 12% high/12% low range reduction.  This t-case, combined with a Samurai one, can be transformed into a 4:1 case.  Rocky Road will cut/weld your counter gear for $125 to make a 4:1 case.  They did a set for me a couple of years ago.  It might be a low cost route for you.  

I'm uncertain what is still the SJ and what has been changed over. Is there a easy way to tell whats under it? I have it up off of the ground right now cleaning in under it. I can't believe there can be so much mud under a vehicle lol. 

I'm normally posting from my phone and it will not let me post pics to here from my phone. I'll try to get on my computer tonight and upload some pictures. Maybe I could post a link to photobucket I have a app that let's me post there from my phone.

The Samurai axles are wider and will stick out considerably.  They are also beefier and have aftermarket support, whereas the SJ410 does not.  Do you have drum brakes all around?

Here is a link to some pictures. [urlhttp://s1180.photobucket.com/albums/x410/Mike_75/SJ410/][/url] It has disk on the front I think drum on the back but I am not for certain. I haven't gotten into the brakes yet. The tires are pretty well even with the fender wells. They don't stick out very far.

I agree about gearing for your tire size, that'll give you just as much boost in " power " as rebuilding your engine.  You are going to replace all that boogered up hardware  right? I suspect from the way you described the rocker assembly, that little engine had some pretty poor maintenence. Personally I'd go through EVERYTHING, never know what kinda pipe wrench vise grip hack jobs have been done to it.

I'm going through everything.  The only sign of anyone ever being in the motor was in the head. After I got past that nothing seemed to have been touched. The only real damage done was to the rocker screws. I have the motor totally disassembled and have ordered a master rebuild kit as well as a few additional parts that I need.

I can't wait to get it back together but now I'm a little concerned about the gearing ratio. I don't want to mess up a fresh motor or a new clutch because of having the wrong size gears. I can't replace the gears at the moment. I can get some smaller good used tires locally cheap. Should I change the tire size before running it any? I don't want to damage anything but I want to get the rig in the woods asap lol. Any further advice would be greatly appreciated.

From the pics, it appears that you have an SJ410 body on a Samurai frame.  Not uncommon.

If the tires are the ones in the pic, I think you'll be ok for now.  Gearing makes all the difference in the world though-especially offroad.

Is there anything I can look for to definatly let me know if it is a samurai frame? I suppose I would be better off if it is a samurai frame right?

I bought this truck not realizing it was a sj410. It is actually titled as a 1984 samurai. After I got to researching it I found out that the earliest Samurai sold in the US was 1986. I've learned a lot in a few days and the more I learn the more I realize how much more I need to know.

I'm just ready to get it running and hit the woods!!