I helped my buddy today at his shop. We did the complete top end ( blown head gasket ) on a 1999 SSEI with an L67.
I noticed a HUGE difference in the valve train components from my 1992.
I saw rollers and better rocker arms. Whats the deal here ?
I know the later years had upgrades but I didin't realize it was to this extreme.
EVERY valve component appeared to be an upgrade over my 1992 L67.

What are the differences ? Will they swap out ? I also noticed the 1999 had more ..
ummm... revability than mine after reassembly. A little less low end and MUCH more top end.

JLathem

The 1992 is the 'lowest' grade of valvetrain among all the modern Bonnevilles. Very similar to the 87-91. 1993 was the first year of the more efficient valvetrain. It'* more closely related to the Series 2 in design (but not sequencing) than your 1992. You and I have different heads as well, to accommodate the different design.

Hey now! You should rephrase that, and say "You have the most VINTAGE version of the valvetrain, and 'back in the day' they didn't have roller anything."

I too have wondered about putting on Series II valvetrain components on my car, but it would never work, so I will just live with mine as-is, until I can upgrade to some real performance valvetrain components.


-justin

Will any of this cool vlavetrain stuff swap out ? Can I get a trashed 199* whatever ...
3800 and bolt on the later equipment ?

JLathem

Nope, already talked to Straitor about this. It is possible, however you will need different rods [size unknown], the bolt holding the rockers in place is a different diameter, and I don't remember for sure, but I think he said the lifters were of also different diameter in the S2. Basically, no. My suggestion is to look at the post "Series 1 performance items" by Dr. Jay. There are some AWESOME valvetrain components that are exactly what you are looking for. It'll cost a pretty penny, though.


-justin

Forget Series 2. They're not even remotely close to swapping into a Series 1 for 5 major reasons, valve sequencing (location in the heads) being the major issue.

93-95 L67 heads and valvetrain will swap onto your car. This may gain you 5-10hp.

The rockers in DrJay'* post may not work on the 92 L67, either. That needs to be looked into. Just think of your 92 as being identical to the 93-95 EXCEPT for heads and valvetrain.

Would those valvetrain components [in Dr. Jay'* post] go onto my LN3?


-justin

Probably not. At least not without modification. Most of those parts are for the L27 and L67.

That'* not worth the expense unless I happen upon a good low mileage trashed
body. Now, if I could find a set of '93 -'95 heads and do a little port work it might get interesting. I was just amazed at the difference in the higher RPM'* of the '99.
It was much smoother and seemed to rev better.
I've never had a chance in the past to drive one and then drive the other right after.

JLathem

I think that it would be to costly to try to switch to some newer parts. Too much expense for not that much of an improvement. You could possible port, polish, etc. your current heads, and pay less for more of a gain i think. I'm not that big of an engine guy but thats just what i think.