Need engine advice

[Dalesun]

Currently I have a U67 head on a l16 block that the p.o. Put on there. I've been wanting to put a 210 casting number head on it. It started to smoke pretty bad a few days ago and still is when ever I bring the rpms up. It is also losing oil and it isn't leaking that bad to be just leaking the amount that it is. Don't know if it is bad ring or my valves. Have not done a compression test on it. Was wondering if I should rebuild my l16 and put the 210 head on or if I should rebuild my l18 block that I pulled from my 620 and put the 210 head on that. Don't want to be without a enine in my truck either cause I need it to drive to work. But I also don't want to have an engine that doesn't rum right. My engine also won't idle consitently and won't idle with out me pumping the gas pedle to keep it from dying under 2500 rpms. Any input on this would be very helpfull

[banzai510(hainz)]

gas pedle to keep it from dying under 2500 rpms??/ Vaccum leak? mixture idle adjustment? idle jet plugged?

 

210 is a stock head for a L16.

 

 

read everything on  oldddatsuns.com the tech section.

 

these are simple trucks should be EZ to keep running.

[Draker]

If you're not burning oil, your leaking it. I'd compression test it first.. and adjust the valves if needed. Look around the engine and see where the oil is coming from. If in doubt just get that L18 build it as needed and drop it in while you baby this one for a while.

[Dalesun]

Thanks for the input guys. I looked around for vacume leeks but didn't find any. I put a weber on and it idled the same way and had to do the same thing to keep it running. I also am running prettty advanced. Tried to brin it down but it wouldn't idle at all or start so I turned it up. Also was wondering if a 210 head would run good on a l18. I pulled it out of my 620 cause the head was all sorts of beat up from somthing smashing around in there. The pistons are also cashed on 1 and 2 but the block is fine. Also want to have a rebuilt motor to do it as a learing process with help from my dad and to make it more reliable

[datzenmike]

A 210 head on an L18 will raise the compression to 9.38. It will run fine (other than compression) but will run out of breath sooner than if you had a larger A87 or even a U67 head.

[laotsu]

wanna sell the U67?

[Dalesun]

So would the smaller valves be starving the engine and not letting enough exhaust out? Would it still have good power for an l18? Also when I put a weber on there was some oil sitting in my intake manifold. Don't remember if there was still any when I went back to my hytachi. Could the oil in my intake manifold be a bad pcv valve?

[Dalesun]

wanna sell the U67?

Sorry man. If I don't use it I'm going to hang on to it if I need it later down the road. Unless you have an a87 head you would want to trade?

[laotsu]

Sorry man. If I don't use it I'm going to hang on to it if I need it later down the road. Unless you have an a87 head you would want to trade?

thanks anyhow.

[Stoffregen Motorsports]

If the smoking started suddenly, and if it is definitely a oil smoke (as opposed to fuel smoke) then you may have broken a ring. If you run a broken ring for too long you can score the cylinder badly and the only way to fix it is to have it bored. If this is the motor you want to rebuild, then stop driving it until you can verify what went wrong.

[banzai510(hainz)]

when installing another carb one usually hav to adjust the mixture screw. this lets it idle.

the mixtue is the screw at the base of carb with the tension spring on there. turn in till it seats then turn out about 1.5 turns and then go in half turn increments and hopefully it idles..


Maybe there is soembody local that can look at it with you.

You didnt change out anything lately did you? coil pooints or anything.

 

your 521 should be a 2nd auto till you know these Datsun. If you need perfect attendence at work you better get a newer vehicle.

 

I daily drive a 521 and its a work in progress.  what I changed in the last 10 years would bankrupt most Ratsun members. Or really dump it on side of house.

[Dalesun]

Work on my truck for a couple of hours last week. Figured out there was a vacume leek around where the carb and intake manifold meet. Don't know for sure which side of the spacer it was on but I cleaned off the old gaskets and got new ones on there. Replaced my pcv valve with one I pulled of my l18 intake cause the one on my 521 intake was hallow and had no valve. After changing the pcv valve it stopped smoking really bad. Now I can't see smoke thru my rearview mirror when I accelerate. Got it to idle consistently around 1000 rpm but when ever I stop the engine starts to die out and I have to give it some gas to not die. Sometimes it doesn't and it will just go down to about 500 rpm. It depends on how hard I am stoping.

[banzai510(hainz)]

try the idle adjustment

Its the screw at the base of the cabr w/ the brass tension spring on the screw.

 

adjust in/ out till it runs the smoothest and readjust the timming also(combo of both)