Valve clearances

[dat521gatherer]

The stock aluminum fuel pumps have a ball bearing on the lower left side that will squirt oil and you'll never know where the leak is coming from.

 

The cadmium (gold) can style pumps dont have the ball bearing on the side.

[kneesamo]

It leaked/sprayed almost all the oil out when I drove it to work. 90 miles for 4 quarts?

 

If it leeks that bad you would think you could just,

 

Get the motor power washed or shampooed. Use spray on engine cleaner and hose off.

 

and discover exactly where the leaks are coming from.

[hang_510]

valvetrain instability will lead to broken parts.

 

Valve lash can be tightened up a bit

i should have mentioned i run a cam oiler spray bar too.

[banzai510(hainz)]

MY stock 521 oil sending unit had a diaphrame leak and made it look like a oilpan or rear seal was bad.

I swapped that out then not more leaks.'

If you run a manual oil gauage then this wont be it

[datsunwizard]

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

 

I have been using those cams for over 32 years. DO NOT adjust the valve lash AT THE CAM LOBES AND THE ROCKER ARMS. The correct way with RACER BROWN cams is to set the lash at the valves, between the lash pad and the rocker tip.The specs for the SS-54 is .006 for the intake and .008 for the exhaust, both measurements are hot. The correct spring specs are 105# seated and 255# at max lift. Max engine speed is 7000 rpm with this cam and spring combo.

[screamer510]

I have been using those cams for over 32 years. DO NOT adjust the valve lash AT THE CAM LOBES AND THE ROCKER ARMS. The correct way with RACER BROWN cams is to set the lash at the valves, between the lash pad and the rocker tip.The specs for the SS-54 is .006 for the intake and .008 for the exhaust, both measurements are hot. The correct spring specs are 105# seated and 255# at max lift. Max engine speed is 7000 rpm with this cam and spring combo.

 

OK, so do I trim down my feeler gauge to ~1/4" to fit in the groove for the lash pad/rocker tip? Still set gap at TDC for the valve, assuming there would be no pressure between the lash pad and the rocker tip at that point?

 

I still use the same adjustment nuts on the opposite side? This is new, good news! A definite way!

 

Thnks wizard

 

Dan

[screamer510]

"In all of the Datsun cammer engines, valve lash is measured between the centre of the heel of the cam lobes and the rocker arm pads."

from

Datsport's Racer Brown cam page

[datsunwizard]

Here is a copy of the cam card for the SS-54 cam. Note the red writing on the left side for the adjusting the cam.

 

 

The original article that Datsport is showing was in the first "Datsun bible" which was in 1973 which dealt with the original RB cams, the SS series of cams came out in the late 70's,early 80's. Racer told me why he changed the adjustments, but I am a little short on time right now to explain. Will do later.

[datsunwizard]

Here is a copy of the cam card for the SS-54 cam. Note the red writing on the left side for the adjusting the cam.

 

 

The original article that Datsport is showing was in the first "Datsun bible" which was in 1973 which dealt with the original RB cams, the SS series of cams came out in the late 70's,early 80's. Racer told me why he changed the adjustments, but I am a little short on time right now to explain. Will do later.