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Gas Cap Differences?
Posted: Tue Feb 07, 2012 8:38 pm
by Alvin
both gas caps are from 67.5 SPLs
vented?
style?

Re: Gas Cap Differences?
Posted: Tue Feb 07, 2012 9:08 pm
by cktrap
I have the one on the left. It's off a '70 1600. pretty sure OE.
Keith
Re: Gas Cap Differences?
Posted: Tue Feb 07, 2012 11:07 pm
by notoptoy
I'm pretty sure I have the one on the right on my 67.5
Re: Gas Cap Differences?
Posted: Tue Feb 07, 2012 11:45 pm
by zippy67roadster
I have the one on the right on my 67, missing the flap though.

Re: Gas Cap Differences?
Posted: Wed Feb 08, 2012 2:34 am
by Phred58
Alvin,
I've looked into gas caps quite a bit (don't ask why someone would do that although in this group, it's probably not that weird....). This is what I've been able to determine from comparing NOS samples of each style of cap.
There are 3 aspects that differentiate the caps (ignoring key style); the chrome exterior style, the offset of the locking "ears" (distance from the gasket face) and the venting.
Big "hump" chrome exterior, long skirt is usually early cars (but can be used on later cars) and is vented.
"Flatter" chrome exterior, shorter skirt is usually later cars although it will fit early cars too and is vented.
(The underside view of the locking mechanism, although it looks different, has the same offset on the ears. Early caps tended to have the simpler mechanism. Don't know why Nissan changed it but I have both types NOS and they're both vented as there is a casting gap in the metal to allow for the venting.)
Regarding the comment about the 1970 model; they didn't originally come from the factory with a locking gas cap as far as I know. The 1970 filler neck has 3 differences from the early filler neck: wider notches, a different offset so the early vented caps will not fit properly and a vent fitting that comes out at close to a 90 degree angle whereas the early model filler neck fitting is more of an elbow that points down toward the tank.
Re: Gas Cap Differences?
Posted: Wed Feb 08, 2012 6:57 am
by cktrap
I assumed it was OE based on the fact that one key fits the cap, trunk and doors.
Keith
Re: Gas Cap Differences?
Posted: Wed Feb 08, 2012 9:46 am
by bikermike
In the photo, the cap on the right is mine. I took the photo when Alvin stopped by on Saturday.
I have a separate Nissan key for the cap. The other 5 locks on the car have a matching key of a different series number (1st digit). Does anyone have all 6 locks match? The keys are different sizes.
A question for the purists out there....at what clock position should the ridge on the cap be facing when on the car?
Re: Gas Cap Differences?
Posted: Wed Feb 08, 2012 9:50 am
by sports imports
I know that the 1200 fairladies and some early 1500 came with the taller of the two. When I still had new gas caps a few years back($46 for a new one !!! 17251-25500) they were the shorter of the two and the number implies 67.5 and on for fitting, although they all seem to be interchangeable. PHred58's write up pins down all the variations. I have over 20 gas caps in stock , some with keys, others I can take to my local locksmith to get a key cut.
Ross
sports imports
Re: Gas Cap Differences?
Posted: Wed Feb 08, 2012 10:58 am
by datsun1500
I remember Sid and I discussing the awhile ago. From what I remember, we have only seen the taller ones on the 67.5 cars. I have had a number of 1500's and the all had the shorter ones. This includes a few with matching keys, so I don't think they were changed.
Re: Gas Cap Differences?
Posted: Wed Feb 08, 2012 11:10 am
by spriso
Weird, 3 of the 4 1500s that I have owned all had the taller cap. I just put a NOS taller cap on the wife's 1500 project.
I always assumed that the taller cap was a 1500 part.
Michael
Re: Gas Cap Differences?
Posted: Wed Feb 08, 2012 11:21 am
by Phred58
Keith,
I'd be interested to know if the vent fitting on your gas tank filler neck is the 80 degree angle type or the more parallel type I described above. If it is the 90 degree type (vent line goes over to the charcoal cannister perhaps instead of back to the tank??) and still fits the locking cap, then that is one more variation with the roadsters.
If I had to guess, I'd say someone changed out the filler neck and put an earlier style neck on your 1970.
Re: Gas Cap Differences?
Posted: Wed Feb 08, 2012 11:42 am
by sports imports
My findings agree with Spriso. Most of my 212-213 cars had the taller one and the 1500 were mostly tall. My PL310 1960 sedan had a tall one. it could be that they had two manufacturers and the assembly line grabbed what was in the bin at the time. the last of the new stock with the 25500 number were short ones. the three numbers listed in the parts book show 17251-04100 (1200 spl212 origin but also evapo 1600), 17251-09501 ( PL312 sedan origin) and the last number 17251-25500 which starts at the U20 introduction. 25500 is 67.5, 25600 is 68, 25900 is 68-69, A3300 and up is 69-70... who knows???
Ross
sports imports
Re: Gas Cap Differences?
Posted: Wed Feb 08, 2012 2:11 pm
by Alvin
great info everyone!
I just need to know if my cap(on the left) is correct for my 67.5 SPL, and what orientation the lock flap is pointed
I am taking it to Barret Jackson and it has to be poyfect!
Re: Gas Cap Differences?
Posted: Wed Feb 08, 2012 2:20 pm
by Garm
Re: Gas Cap Differences?
Posted: Wed Feb 08, 2012 2:49 pm
by Alvin
so i think that looks exactly the same as mine