When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
History / OriginalityGot a question about 1982-1992 Camaro or Firebird history? Have a question about original parts, options, RPO codes, when something was available, or how to document your car? Those questions, answers, and much more!
So who knows (or can remember) the ORIGINAL orientation of the left side rocker cover on a L98/B2L ??
Did they leave the factory with the oil filler cap located FORWARD or AFT ??
See attached pics - the pic with the oil filler located AFT is of an all original L98 in a 1988 Formula 350 with 3015 miles.
The pic of the oil filler located FORWARD is of an all original L98 in a 1990 Formula 350 with 9200 miles.
Which one is factory correct ???
I guess it could depend on the year, but I highly doubt it.......originality experts, please chime in !!
Re: L98 oil filler cap location - forward or aft ??
I bet we get a 50/50 split on the answers to this - just like a Florida election result
A friend who was a GM tech in the late 80's seems to think he remembers the filler cap located AFT on the new cars ??
If so, my guess is it was flipped around on the 1990 car to make adding oil easier ???
Re: L98 oil filler cap location - forward or aft ??
I'm pretty sure earlier TPIs with the larger oil cap were aft and later TPIs with the smaller oil cap were forward, if you look back at those pics you'll see the different size caps.
Re: L98 oil filler cap location - forward or aft ??
TPI including MY 89 have it AFT, TPI from 90-92 have it forward. There was a slight redesign because of the speed density system.
My 88 GTA with MAF has it also aft and my 92 TA has it forward. Both engines are original.
Re: L98 oil filler cap location - forward or aft ??
On my 90 Formula TPI it's forward and easy to get to. On my 89 Firebird TBI it's buried on the forward passenger side. I have to do some thinking to get to it. I've often wondered if it's in the right place all these years.
Re: L98 oil filler cap location - forward or aft ??
Good info - thanks guys!
In summary, it sounds like the oil filler cap was located AFT 1987 - 1989 L98's
and forward starting in 1990 - I assume this is the same for the LB9 ??
I never knew this, there is incredible expertise on this forum !!
Re: L98 oil filler cap location - forward or aft ??
I never knew this either...or that my valve covers are on the wrong sides...my L98 has the fill on the passenger side, and I never noticed it was wrong.
Re: L98 oil filler cap location - forward or aft ??
Chaz....now you've confused me....
Now I am wondering if there was no set way and it was just how whoever installed the rocker cover on the engine production line did it ???
Re: L98 oil filler cap location - forward or aft ??
I would like to add that the 89 brochure has to older, large cap on it.
I'm guessing they just used all old stock up until the 89 small caps came in but I thought the large caps were 1/4 turn and smalls were screw on.
All my 89s are small fill caps in the rear position.
All my 90 and ups are small caps in the forward position.
Also, I've seen a few veeery late 92s that the covers went to black with small caps in forward position. (these engines have more fun stuff in them, blank TB plate, textured corvette runners, flattop hyper pistons, PM rods, and a bit different oil pan)
Re: L98 oil filler cap location - forward or aft ??
Originally Posted by TTOP350
I would like to add that the 89 brochure has to older, large cap on it.
I'm guessing they just used all old stock up until the 89 small caps came in.
All my 89s are small fill caps in the rear position.
All my 90 and ups are small caps in the forward position.
Also, I've seen a few veeery late 92s that the covers went to black with small caps in forward position.
Wow, never seen black rocker covers on these cars - good info !!
Thanks
Re: L98 oil filler cap location - forward or aft ??
Originally Posted by BizJetTech
Chaz....now you've confused me....
Now I am wondering if there was no set way and it was just how whoever installed the rocker cover on the engine production line did it ???
Re: L98 oil filler cap location - forward or aft ??
Originally Posted by chazman
I think '90 was the transition year.
Agreed, that is what my pics support as well - like JC Denton pointed out earlier, its when they went to the speed density cars
that this change occured
Re: L98 oil filler cap location - forward or aft ??
It might be a dumb question, can the rocker cover be turned around to have the filler in the front?
Are the bolt holes different in a different position?
Re: L98 oil filler cap location - forward or aft ??
Originally Posted by Ct1987
It might be a dumb question, can the rocker cover be turned around to have the filler in the front?
Are the bolt holes different in a different position?
Louis
That's a good question. I'd say yes, but I'm not sure.
Re: L98 oil filler cap location - forward or aft ??
My very late 92 (August 92) also has black valve covers, my 88 GTA has silver/aluminum covers. My 92 has a threaded cap, the GTA has a 1/4 turn cap.
And no, its not possible to turn the cover around. Center screws won't line up anymore. You can switch sides left /right but then the ports for the PCV won't line up with the original hoses.
Re: L98 oil filler cap location - forward or aft ??
Originally Posted by Ct1987
It might be a dumb question, can the rocker cover be turned around to have the filler in the front?
Are the bolt holes different in a different position?
Re: L98 oil filler cap location - forward or aft ??
Originally Posted by TTOP350
I would like to add that the 89 brochure has to older, large cap on it.
I'm guessing they just used all old stock up until the 89 small caps came in but I thought the large caps were 1/4 turn and smalls were screw on.
All my 89s are small fill caps in the rear position.
All my 90 and ups are small caps in the forward position.
Also, I've seen a few veeery late 92s that the covers went to black with small caps in forward position. (these engines have more fun stuff in them, blank TB plate, textured corvette runners, flattop hyper pistons, PM rods, and a bit different oil pan)
Did all the late 92's get these parts? By buddy has one and we knew about the black covers, sand-cast runners and the blank TB plate but did not know about the internals,
We have heard that GM was running out of engine parts late in the model year and was taking parts from wherever they could to finish up that last production year.
11-19-2018, 03:19 PM
