Nissan Pickup Datsun L20S Conversion

[Juscy M]

Hey Guys 

 

I recently purchased a Nissan 1 Tonner 95 model Pickup with the Datsun L20S engine. Had the engine rebuilt from bottom up. ie:. (Mains, Big Ends, Pistons, Valves, gaskets etc...), changed the Carburetor from a 38 Weber to SU Carbs. for Some or odd reason the vehicle is pushing out thick white smoke. The Carb seems to be very rich. Im not a mechanic but I do understand and know how, the final product is supposed to look sound and feel any advise as to where to start troubleshooting will be greatly appreciated. I will post pics of the engine as possible.

 

regards, 

[datzenmike]

Exhaust 'smoke'

 

Over rich........... black, smells of gas

Burning oil......... blue in extreme cases can be white but is bluish when thinned out.

Coolant............. white, has sweet anti freeze smell.

 

 

If it was running just fine with the 38 and now is smoking you can pretty much rule out oil burning. A leaking intake gasket can allow coolant to be sucked into the intake ports. Rad level will drop. I assume your L20B has the coolant in the intake runners?

[Juscy M]

I may have found what the thick white smoke is, I seem to have overthrown the motor oil and the tappet cover gasket seems to be very thin

So the the oil is seeping through onto the exhaust manifold, might need to shoot some heat resistant gasket selant on.

[datzenmike]

A clean new gasket is better. It's reusable and much easier to take apart.

[Juscy M]

Thanks D Mike. any specific brand I should check for?

[DanielC]

You can get individual gaskets at Nissan dealers.  These are usually the best.

[Juscy M]

Hey Mike 

 

So finally sorted the oil leak out and she was running for a while. she is currently stationary again, It would seem that I blew the cylinder head gasket. I also started hearing a loud rattling noise when changing from 2nd gear to any of the other gears. she also seems to die as soon as I hit an incline. not sure where to start looking or tampering. any ideas? The rattling sounds a lot like valves. but hey that's my assumption. please help.

 

regards,

[]2eDeYe]

Typically when rebuilding an L series you will need to retorque the head bolts after about 100 miles. If you haven't made it to 100 miles and the head gasket has blown on a complete rebuild the head bolts were likely never torqued correctly and I would be taking it back to the person that rebuilt it (although in my case that would be me lol) 

[datzenmike]

A blown head gasket will cause it to die on hills.

 

 

I would check the valve lash, then the timing. To be sure it's not just a tune up problem.

 

If you are having to fill the rad often or it overheats or...

If when the rad cap is off while running and it expels coolant...this is another indication of a bad gasket.

 

 

A compression may may show a low cylinder.

 

 

If you remove the head inspect the timing chain guides for wear. This might be the rattling you hear.

 

Setting the valve lash will quiet them (if it's the valves) But valves or timing chain won't know you are shifting from 2nd gear. If it only happens when shifting from 2nd then it could be the transmission. Only thing you can do here is add to or change the oil in it. Two liters of 80w90 GL4. Do NOT use GL5 oil in a transmission.

[Juscy M]

Thanks guys seems like I have my work cutout for me...will keep u updated.