anyone? thanks
curious- first year for hydraulic lifters?
- Thread starter barbee6043
- Start date
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Think it was 81
whitepunkonnitro
Well-Known Member
81..and if you ask me, those are the ultimate Slant's to build.
Block is 16 pounds lighter, crank is 22 pounds lighter, and has the smaller bearings.
Block is 16 pounds lighter, crank is 22 pounds lighter, and has the smaller bearings.
slantsixdan
=..=
There was an unusually large-scale production test in '78—those engines were installed in regular production cars sold to the public, and a TSB was issued alerting dealers to the special parts and service procedures (no valve adjustments). There were no '79s or '80s with hydro lifters, but all '81-up Slant-6s are hydro-lifter engines.
Very interesting on the "test" engines...maybe thats why the 78 super six I just sold ran so quiet. Not a single tic to be heard.
whitepunkonnitro
Well-Known Member
The valve cover is a dead giveaway on the hydraulic motors. A little wider with the bolt holes in a different position.
If you're looking at just a block assembly, the distributor hold down is a crow foot design rather than a slotted plate, and it uses a 5/16th bolt instead of the earlier 1/4 20
slantsixdan
=..=
'81-up heads do indeed have the larger valve cover with more bolts than the '60-'80 covers, but '81-up heads swap readily onto '60-'80 blocks and vice versa. The late-type and early-type distributor hold down setups also readily swap. Given that the newest Slant-6 engine (1987 model) is three decades old, these easily-changed external bolt-ons are only a suggestion -- not a reliable indication of what's inside the engine.
Also note that hydro-lifter Slant-6s can be converted to solid lifters and vice-versa without much effort.
Slim pickings in camshaft selection for the hydro-lifter Slant-6, but there are plenty of reliable cam grinders who will put together whatever you want (that's the easy part; the hard part is devising a good specification for such a cam).
The oil feed path for the lifters in the hydro Slant-6 is unusual: oil flows from the block through the rearmost cam journal to the head, into the rocker shaft, through the rocker arms, down through the pushrods and from the pushrods into the tops of the lifters. It works, but it's a whole lot less direct than the block-to-lifter side feed common in the V8 engines. On the Slant, everything in the oil path has to be (and stay) clean-clean-clean or you starve and/or clog the lifters.
As for whether the hydro-lifter slant is the "ultimate", that depends on what you want to do with the engine. The lighter blocks, heads, and cranks and the smaller bearings are weaker than the heavier parts and bigger bearings, so the later engines are not as bulldog-strong as the earlier ones. That didn't matter in production, because the strangulation-and-neglect strategy Chrysler applied to keep the Slant-6 compliant with tightening emissions regulations brought it down to 90 horsepower at the bitter end (85 in California) -- not enough to stress the lightened, weakened parts and the shrunken bearings. Those with sterling reputations for building high-performance Slant motors that work and don't break (e.g., Dutra) generally don't regard the later/hydro motors as the optimal pick.
Also note that hydro-lifter Slant-6s can be converted to solid lifters and vice-versa without much effort.
Slim pickings in camshaft selection for the hydro-lifter Slant-6, but there are plenty of reliable cam grinders who will put together whatever you want (that's the easy part; the hard part is devising a good specification for such a cam).
The oil feed path for the lifters in the hydro Slant-6 is unusual: oil flows from the block through the rearmost cam journal to the head, into the rocker shaft, through the rocker arms, down through the pushrods and from the pushrods into the tops of the lifters. It works, but it's a whole lot less direct than the block-to-lifter side feed common in the V8 engines. On the Slant, everything in the oil path has to be (and stay) clean-clean-clean or you starve and/or clog the lifters.
As for whether the hydro-lifter slant is the "ultimate", that depends on what you want to do with the engine. The lighter blocks, heads, and cranks and the smaller bearings are weaker than the heavier parts and bigger bearings, so the later engines are not as bulldog-strong as the earlier ones. That didn't matter in production, because the strangulation-and-neglect strategy Chrysler applied to keep the Slant-6 compliant with tightening emissions regulations brought it down to 90 horsepower at the bitter end (85 in California) -- not enough to stress the lightened, weakened parts and the shrunken bearings. Those with sterling reputations for building high-performance Slant motors that work and don't break (e.g., Dutra) generally don't regard the later/hydro motors as the optimal pick.
thanks!!
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