Datsun Roadster Forum-311s.org

Hello,

I am so happy I have found this forum. After 13 years, I am putting the family 68 2000 back on the road. I have many questions:
Mechanically the car is strong as it was rebuilt 5000 miles (13 years) ago. But it runs a little rough for the first few seconds until oil pressure builds. There is no tube inside the filter. Should there be one or do modern filters negate the need?
I have a set of Shelby Cal 500 14x6 wheels from a 71 240Z that I would like to use. What size rubber will fit? (The 185R14 that are currently mounted on these wheels look like they will hit in the rear.)
My rear brakes lockup before the front kick in strong. The brake hardware (calipers, cylinders) is working properly. I "solved" the problem by backing off the adjustment on the rear so that there would be more slop in the rear so the front could become pressurized sooner. Is this normal or do I have a problem with the "pressure switch"?

Thank you very much for your help.

Ted928

Ted,
Congratulations on the revival of your car. Your wheels are slightly the wrong offset. They are sweet wheels however. You might try rolling the fenders to clear the tires. As far as the oil tube you DO need one. You can make one out of a piece of aluminum tubing. It just needs to be long enough to keep the filter about 80% full. This tube is very important because you end up drystarting the engine until the oil pressure builds. U20s flow a huge amount of oil. The brake issue sounds like you might need new rear cylinders, but try bleeding the system first. With the front brakes, retract both pistons on each side before bleeding the system. That should help. By the way, where are you?

Will

Will,

Thanks for the info. I will get an oil tube. The rear brakes work well. The system is hard. Perhaps I have a little air in the front. I'll try bleeding them again. I added my address to my signature block (maybe I can find a local expert).

Thanks

The oil tube should still be available from Nissan. I bought one not too long ago...

The oil tubs still seeps back slowly. None to worry so long you don't park your car time (like winter).

You can also remedy this with a built-in antibackflow valave oil filter. I know the WIC and Napa filter has it. I don't of any others.

My original tube was too tall for the new over the counter filter. Rather than cutting it I put the forementioned filter on.

Minh,

I am certainly no expert but I am not sure that a filter with the back flow value negates the need for the tube. The purolator L30042 that I am using has the back flow valve but it still takes 3 seconds to rebuild oil pressure. It appears that the back flow stops the unfiltered oil from flowing back towards the pump but it doesn't seem to stop the filtered oil from draining out of the filter. Once I get a tube and install it I will know if it solved my problem. Perhaps others have already answered this question.

Thanks

I could be wrong. It is not the 1st time

I assumed this was the case since oil kept on seeping out after I had removed the filter.

I'm basing the hypothesis thinking that oil travels in one direction with pan/pump and gallies/block at both ends where the filter is in the middle.

I also have brand new bearings and seals throughout so that might account for something.

I've got both the tube and a Nissan filter with a backflow preventer and mine STILL drains back into the engine. I've tried a few different filters (Fram, Napa & Nissan) and they all seem to do the same thing - it always takes a few seconds for the oil pressure to come up. What's more, my roadster is a 2000 so I hear the timing chain when it starts. I just try & take it easy when I start her up - until the oil comes up to pressure. If anybody out there has a solution to this problem, I'm all ears.

Don't forget - until the pressure builds from the pump to the filter, there won't be any flow out of the filter, whether it has oil in it or not. The only ways I can think of to have instant oil pressure would be to have a pressurized tank with oil in it to flood the system with oil prior to start-up or an anti-backflow valve down at the pump itself.

Otherwise, just don't goose it when it starts. After all, most wear on a normal engine occurs at start-up.

I put a shim on my upper tensioner so the chain is ALWAYS tight. I will also run the shim with the new chains on the new engine (just one instead of 2) My chains never rattle, I can however tell when the car has been sitting for awhile. If I drive the car everyday the oil seems to stay in the filter because the pressure comes up instantly (however the pressure gauge could be wrong).

Will

I think that I know of a relatively simple fix. The main oil gallery runs down the side of the block. There are plugs or fittings at where the main bearing oil gallerys were drilled. The most forward plug could be removed and an external oil line plumbed directly to the tensioner gallery. I have not really investigated this, so I could be all wet, but it seems to be a good answer to quicker pressure.

The shims are a good idea as well. I have a tensioner for another engine in the box of parts that has a great feature. It has a ratchet assembly built into it. It automatically ratchets out as the chain stretches, and does not retract. If repro tensioners are manufactured, that would be a great feature to add.

Sid,

That may be a good idea. For me anyways, I have an oil pressure switch (set a 2 PSI minimum) in that plug hole that closes the ground loop for my electic fuel pump... I may have to get a work around.

Just read Sid's idea on the oil line, had the same thought a few minutes ago after finding the inevitable slot in the Evil L. I have to replace my oil pressure gauge hose, and WILL not pay &70.00 for a 1 foot hose. Since Ihave an extra upper tensioner and will be screwing around with the oil lines anyway, seems like a good time to experiment.

I'm thinking maybe the original passage from the head to the tensioner should be blocked or extremely restricted so pressure will build.

Anyone know the thread size on the oil hose into the block? Looks like 1/8 British pipe to me.

Would appreciate any thoughts.

You could also install an ignition kill switch, then you could turn the motor on the starter till you have pressure, then fire it up. Motor is still turning with little oil, but at least it isn't firing...TR

Only bad thing is with carburetors you can flood it really easily. I saw an oil accumulator a while back holds 2 quarts and lets it flow when ignition is turned on or if pressure drops while driving. If I find it, i'll post info.

I'm also looking into using 1 or 2 remote filters. see where it ends up.