Valve clearances

[screamer510]

Guys,

I couldn't find a good thread with what I searched.

I have an L20b with a Racer Brown cam, SS54. .480 lift, stock springs. Dual SUs. Electronic ignition.

Do I use the valve clearance specs off www.olddatsuns.com for a stock L20b, or should they be different with a mild street cam?

Gonna tackle this today, so any good responses are much appreciated!

 

Thanks

Dan

[datzenmike]

I would go with stock clearances on stock springs, valves and rockers. Try Racer Brown site for specs.

[screamer510]

someone said the fuel pump is an excellent source for passenger side oil leaks, right? the oil is mostly around the head, and the firewall up near the hood rod bracket, but not down towards the alternator but coating the whole side of the block?

 

gaskets!!!!!

[datzenmike]

There are two gaskets with a phenolic (plastic/bakelite) spacer between the pump body and the head. Over tightening can crack the spacer and there is a hinge pin through the pump body that can also get wet with oil. I found one of my pumps had been cleaned and a dab of RTV put over each end of the pin to seal it. A good idea. Oil will migrate down hill and be pushed by fan air. This could also be the much higher up valve cover. Pressure wash and clean with carb cleaner and keep an eye on it regularly to see where it really is coming from.

[banzai510(hainz)]

I run a water hose from the airfilter port(valve cover) down by the trans to let any mist go down there instead right out the port.

 

fuelpumps vent seems to always leak. getting the water intake inlet oily. Best to get a eleltric pump.But I like the stock pumps myself

 

I run my LASH at .006 in .008 ex per Schneider cams but stock would be fine also.

[screamer510]

can't get a working link to mklotz's valve adjustment videos???

 

i thought i bookmarked it and they were much better than my Haynes manual

 

any help?

[screamer510]

can't get a working link to mklotz's valve adjustment videos???

 

i thought i bookmarked it and they were much better than my Haynes manual

 

any help?

 

and thanks datzen. i'll get a gasket set in a few days and start going through them to eliminate the leaks.

[hang_510]

I would go with stock clearances on stock springs, valves

im using not stock valves or springs(same cam specs), i run stock clearances.

[datzenmike]

Hi Brian. I figured that the stock parts would expand the same amount so clearances could be the same too. Some clearance is better than no clearance.

[EricJB]

Years ago, I ran an L20 with a Delta 490/290 cam, ( I could get them for $18.00, so I end up with a few of them), Cannon intake w/ 32/36 dgv Stock L16 exhaust manifold, 2 " exhaust. The cam was too much for the rest of the set up, so I advanced the cam timing to tone it down a bit.

 

I was running stock springs, and could still float the valves if I spun it too high. It lived for a long time, but clearly was not right. The rocker should follow the cam. Not use it as a jump ramp,slapping the base circle and slamming the valve shut. This pounds the seats to death.

 

Keep in mind that cam manufacturers are in competition with each other. Even though the #'s are the same, they want to outperform the other. They do this by speeding up the ramp speed.(How fast the valve opens and closes) This puts more demand on the springs to control the valvetrain. As far as springs go, you might want to see what the cam Co. recommends. Only they know how aggresive the ramps are. Running more spring is better than not enough. You will have to be more dilegent with the break in, and some springs create more heat. But valvetrain instability will lead to broken parts.

 

Valve lash can be tightened up a bit (.002) on the intake side, because the intake valve does not get that hot, with the cool charge rushing past it. I would not tighten up the exhaust valve. When it's resting on the seat, is when it's cooling down, the only time hot exhaust isn't rushing past it. tightening it up shortens that cool down time. You might want to consult the cam Co. on that as well. My .02

[screamer510]

I run a water hose from the airfilter port(valve cover) down by the trans to let any mist go down there instead right out the port.

 

fuelpumps vent seems to always leak. getting the water intake inlet oily. Best to get a eleltric pump.But I like the stock pumps myself

 

I run my LASH at .006 in .008 ex per Schneider cams but stock would be fine also.

 

The vent hole is the tiny 1mm hole on the back underside of the pump? I have a major leak, the whole side is covered and I think it's the pump.

 

Can you do the timing cover gasket with the head on or will it rip the head gasket?

 

SOOOOOO glad this is not my DD! This would drive me nuts !

[banzai510(hainz)]

Can you do the timing cover gasket with the head on or will it rip the head gasket?

 

YES.

 

YOu sure thats it???????

 

I loosen the oil pan bolts and slightly drop the pan.

If oil pan gasket rips you can cut a section out of another pan gasket and spliceit in(Victor Renz also made a gasket for that also if still avail.

 

Key is locking the cam up so you can loosen the crank bolt/pully , oil pump,and distributor

[screamer510]

Hainz,

I'm still debating whether or not to just replace individual gaskets and see what works to stop the leak, or just pull the engine and replace everything. I think my rear main is leaking too, oil comes out of the drip hole at the bottom of the trans.

That would be a good weekend project for me and my 8 year old to tackle. I have a cherry picker and engine stand and room for it all and tools and everything else.

 

However the case is...

 

 

[banzai510(hainz)]

If you dont drive the car enough who cares.

[screamer510]

I drive it whenever I can! I want it in perfect running order, so...meh<div><br></div><div>Valves adjusted out OK.  The PO described a time when the #3 exhaust lash pad "jumped out."  The corresponding valve was <i>extremely</i> tight.  Took a lot of loosening to set the clearance.  I don't know if that was part of the problem, or part of a solution, but all the clearances are set now.  Then the huge oil leak happened!  I used common sense in adjusting them; couldn't find the NWDE mklotz videos, and the Haynes manual was lacking in the helpfulness of this procedure.  </div><div><br></div><div>Not as hard as I thought!  Gotta love the L series, right Hainz?  <img src="http://community.ratsun.net/public/style_emoticons/default/wink.gif" alt=";)" class="bbc_emoticon">   Sounds so sweet with the SUs and throaty exhaust.  Much nicer, IMHO, than a KA or SR!</div>

[ggzilla]

Haven't you heard "don't fix what aint broke"? Just fix the leak. There's always the chance if you tear down to fix "everything" it will introduce new bugs.

[screamer510]

Haven't you heard "don't fix what aint broke"? Just fix the leak. There's always the chance if you tear down to fix "everything" it will introduce new bugs.

 

Well, there's a leak on the driver's side, a huge leak on the passenger side, the oil pan leaks, the rear main leaks, there is a fresh sheen of oil on the trans every time it goes somewhere, etc etc

 

What are these bugs you speak of? I've had most of the parts off and back on he engine already, and the car has a pretty good history, I wouldn't foresee any problems.

 

but I totally see your point...head warps, studs, bolts, head bolts break, etc etc but I don't know

 

at what point do you change from pouring oil in to pulling the engine out? This would be my 3rd L series that leaked like a sieve and had to come out. I don't like having oil leaks!!!!! _{(I know this may be against Ratsun code)}

[ggzilla]

at what point do you change from pouring oil in to pulling the engine out?

 

sounds like yours is at that point

[datzenmike]

Oil travels down hill and is pushed by the fan breeze. A leaky $3 valve cover gasket can show up anywhere on the motor. It can travel sideways and along the head/block surface, even work its way down between the block and transmission.

 

Get the motor power washed or shampooed. Use spray on engine cleaner and hose off. Let dry and take for a drive. Keep checking to see where the oil comes from first.

[screamer510]

sounds like yours is at that point

 

My old yellow car was like that...pulled the L16, massaged and rebuilt it, put it back in, wrecked it.

 

My first red 4 door was like that...pulled the L16 and auto trans, and put in a VG30, had my first son and sold it.

 

This red 4 door will be like that...pull the L20, clean and gasket it, and teach that same son, almost 9 years old now, how to do it.

 

A win-win

[screamer510]

Oil travels down hill and is pushed by the fan breeze. A leaky $3 valve cover gasket can show up anywhere on the motor. It can travel sideways and along the head/block surface, even work its way down between the block and transmission.

 

Get the motor power washed or shampooed. Use spray on engine cleaner and hose off. Let dry and take for a drive. Keep checking to see where the oil comes from first.

 

So the valve cover and the fuel pump gaskets would be your first choices to replace

[screamer510]

It leaked/sprayed almost all the oil out when I drove it to work. 90 miles for 4 quarts? I know the valve cover is leaking, and 95% sure the fuel pump and oil pan.

 

Rebuild?

[ggzilla]

Why rebuild it? Just replace all the leaking gaskets. Rebuild suggests new rings and such.

 

Do that if it needs it.

[screamer510]

<br />Why rebuild it? Just replace all the leaking gaskets. Rebuild suggests new rings and such. <br /><br />Do that if it needs it.<br />

<br /><br /><br />

 

Maybe I shoulda said "regasket."

 

Also, should it be running a 185* or 190* or 195* thermostat? I remember a thread about it. I have a 160* in there now.

[ggzilla]

The concensus was that 160 is too cold. Datsun options were 170, 180 and 190, mainly because of the heater. 170 for hot climes, 190 for cold climes so the heater puts out more heat.

 

A guy at the oil company told me 180 is ideal for the oil working the best. He went through training for Mobile I think it was and they were formulating oil for 200 degrees, which works out to be 20 degrees warmer than the coolant for most engines. Maybe it's changed now but it won't be colder as engine now run even hottter than ever.