hello sl6 sages- trying to improve my knowledge about the late editions of the sl6 with hyd valves. my main question is whether this engine(apparently made 81-87 in cars and 87-91 in p/u trucks) was an improvement over the the original sl6 with solid lifters made from 59-80. my other question is why was this change made-im guessing themain reason for the change was to eliminate the need to periodically adjust valve lash which really wasnt a big job anyway and was only infrequently needed. want to know this since i figure it likely that at some point i will acquire one maybe in a pickup as the older a and f bodies disappear into rust flakes. would appreciate it if sages could clarify the upsides and downsides of these last sl6s. i.e. did they run better, more durable, better mpg, longer lived valve train etc.? two old concerns i wouldhave are that some hyd. valves are generally not adjustable and some hyd. valve lifters collapse . looking forward to hyd. valves 101. thanks for your interest. paladin(still have my 2 rare birds- 80 volare wagon w/3 spd and 76 feather duster)

To my knowlage 87 was last /6 in pickup/van as well as cars.My main slant is a hydro(83) and before rebuilding it had 185k on the odo with no prob ever on the lifters.As to any pro's and con's I'll leave that to true /6 guru's.

_________________
83 B-150 slant 6,4 speed. 79 B-300 360 pathfinder 4x4. 74 W-300 318 4x4 git-r-done 80 B-100 sl6,4speed

My research showed that the main reason the change way made was to get the engine to pass the increasingly tight emissions requirements.
DD

Doc is correct. The change to hydraulic lifters was done because the emissions characteristics of the solid-lifter engine varied with lash adjustment, both initially and over time. The reduced maintenance was a nice benefit to buyers. The cam used in the hydro-lifter slant-6s is a pretty weak smogger grind, often installed very retarded (and very randomly; QC at Chrysler was basically nonexistent in those years), but better cams are available. The most interesting thing about these engines is the "backwards" oil feed path to the lifters. Rather than substantially change the block for conventional side-feed lifters, they increased oil volume to the rocker shaft and piped oil through the rocker arms, down through hollow pushrods, and into the lifters from the top.

And yeah, the last year for the slant-6 in trucks and vans outside Mexico was '87.

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

Dang it, why did Crysler give the best stuff to other countries? Slants lasted longer, the cars looked cooler. Grrr.

_________________
Casually looking for a Clifford hyperpak intake for cheap.

Probably because they moved their tooling there for cheaper 'production' ... A fair amount of the trucks up through the 90's were made at the Alberto Lago plant in Mexico(including my 1992 Ramcharger....)


-D.Idiot

"You know Mexico the heartland of North America...according to Futurama..."

In a related question, how would one go about using a stock cam to the best advantage? For instance, assuming a stock hydraulic cam, where should the cam be centerlined to assure good low-end torque and performance in the 0-3500 RPM range?

_________________
Casually looking for a Clifford hyperpak intake for cheap.

and in a related question,
can a cylinder head from the solid lifter era be used with a block, and valve train components from the hydraulic lifter generation?
specifically is the increased oil flow mentioned above a function of block oil porting only, or is the cylinder head itself a part of the hydraulic lifter package?

thanks

What best stuff? By the time of its discontinuation in upper North America, the poor old slant-6 had been badly neglected, cheapened, and slowly strangled. Several significant engineering upgrades had been studied and prototyped but cancelled before production.

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

I have a hydraulic head on a solid lifter motor. As far as I have been able to tell, the main difference is in the rear oil hole. The hydro head uses a 3/8" bolt that necks down to 5/16", but so did the later solid heads.

As far as bolting one on I use the same head gasket as a solid head. The valve cover and gasket are specific to the type head though.

_________________
Official Cookie and Mater Tormentor.

The increased oil flow is a function of a groove (instead of two oil holes) on the rear cam journal (not the cam bearing). This allows constant oil feed, instead of a "pulse" of oil every cam revolution.

_________________
Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

Some threads to see: here, here.

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

thanks
this forum is superb
how slant six dan knows where all this info is stored is beyond me.
I used the search function for an hour, never came close to either of those two informative posts