The 510 Realm

Thanks for the input guys. I will bolt it on for now but I am going to order a rebuild and bearing kit and rebuild it when I get around to it. Bert I have read a few if your posts here about the Weber that have been very helpful.

I have it on what I am assuming is a stock L20. Any jet recommendations?

Thanks.

I would just run the thing first and see how it does. What you should maybe do is let us know what jets are in it now. It sucks that the fuel jets require the top to be taken off. You might be able, with a bright flashlight, look down to the air corrector jets and see what number is stamped on the top of them. The idle jets are easy to pull out.

There are so many variables to be considered, might as well start with YOUR baseline.

Make sure you have a fresh set of plugs...I would recommend NGK BPR6ES to start with. You will want to see how it idles number1, then, how it comes off idle with load.

Wide open throttle will be the last to check, with a proper plug check for colour. If you hear ANY pinging...it is too lean right off the gitgo.

Well i pulled the carb and cleaned up the intake pretty good then bolted it all back together. I drained the oil and filled it up with Gastrol GTX 10w30. I got the car to fire up and adjusted the distributor by ear to get it to run decently. I only had it running for maybe twenty seconds then turned it off to make sure everything looked ok in the engine bay.

I discovered that it is leaking a lot of oil which is seemingly coming out between the block and the head above the number one cylinder. I am assuming it's time for a new head gasket? Is there any other gaskets or preventative maintenance I should do while the head is off?

Thanks.

Check timing chain stretch before pulling the head, dictates whether to R&R the chain and gears while the head's off.

Thanks Julian, I will keep researching but do you know where I can find more info on checking the amount of chain stretch? And by R&R do you mean replace, i'm assuming you don't mean Rock & Roll or Rest & Relaxation?

So I just pulled the valve cover and you can see that in the corner near the #1 cylinder the head gasket is sitting in the engine and isn't between the block and head where it belongs. Do you think that might be the problem (heavy sarcasm)? The rest of the top end seems to look good though.

I don't have a handy Realm reference, though I believe Byron's shown it in detail before. It's in good service manuals (How To Keep Your Datsun Alive). The FSM is pretty useless for this. It's been too long for me to give you good instructions. Lemme search...

Thanks Julian, I appreciate you taking the time.

So I read though that thread and and the section in Keeping Your Datsun Alive, and as far as I can tell I am on the 3rd hole (you can see the top of the 3 just above the washer behind the fuel pump cam) and the timing is a little retarded since the V notch is behind the oblong mark. This is with the #1 cylinder at TDC and the crank pulley at the 0 degree mark.

So if I am reading this right since its already at 3, and retarded that there is no more adjustment to be had and I need to replace the chain, do you guys agree?

Dowel position is not the final arbiter of chain stretch. It's really about TDC and the V notch in the cam pulley (which you can see above in your picture). Dowel position can be used to time the cam and move the power band around slightly.

But since it's in hole 3 and the V notch is to the left (drivers side) of the cam line it's a bit retarded right? Do you think it's time to change the timing chain or since the chain seems taut do you thinks it's ok if the cam timing is a bit retarded? Ideally I wouldn't swap it out but if I need to I will.

Thanks.

So I pulled the motor, pulled off the oil pan, removed the timing cover, and pulled the head.

I found a chunk of aluminum in the oil pan as you can see. I'm guessing it's part of the head but I don't see anything missing from the head, and I found that one of the pistons has a chunk taken out as you can see in the photo.

Well crap. I guess this motor is done or will need a full rebuild. What are your guys thoughts? Am I screwed? Like I mentioned before I was hoping to get this motor in the car and have it last for a few months.

All the pitting and the burned side were from detonation in that cylinder, not good as you can see.

I lost a piston in my AE86 from the same sort of thing, then the fire went down the rings lands and burned through.

You can see the slight "dimple" effect on the piston top. In my case one of the injectors was tired...260,000 Km...and I could not hear the slight pinging over time.

I would say you should be either going through that motor, as you have no idea what the other ring lands maybe like, or starting fresh. Your going to need a piston for sure, and at that point, if your in for the long haul, likely better to just try to do it right.

Oof, that sucks. My sympathies. It's times like these that KAs and SRs start to make a little more sense.

Weird semi-open head, too. Seen 'em before, but they're still weird.

Thank you for the input guys. I've thought about doing a KA but since I have a high strung Rebello 2.3 that I eventually want to put in I may keep with an L series for now to make the eventual swap easier. I have some thinking to do.

Might see if there's a running L-series for sale in SoCal.

An L rebuild can easily be $1500+ even if you do most of it yourself. Since the broken piston is pocked so badly, I imagine that cylinder is worse for wear as well. Then it becomes a question of if you can clean up the cylinder with a bore, and can you get pistons for the bore necessary, etc.