Contour Enthusiasts Group Archives Forums Modifications 3.0L Duratec which 3.0 u guys using?

The bucket is over the valve spring & valve with a shim for clearence to the cam lobe,cam is mounted directly over the bucket.No, finger followers with hyd lash adj are too weak to handle the rapid 'leverage',for want of a better term, of a cam grind that has a 'fast ramp',the followers are only stamped steel!Not a good design for upgrading........

The heads on the 3.0L Jag S-Type are virtually the same as the Lincoln LS. However, the intake cams are different on the Jag to accomodate the added VCT unit.

BTW, the Taurus, the Jag, and the Lincoln LS all use the same 3.0L Duratech short block.

So these buckets are securely placed over the valve and spring, use a solid pivot in place of the hydraulic lash adjuster, and use a shim to adjust clearance. This shim, is it fixed in place with some kind of retaining clip.
Why is this direct acting lever arm better than having a roller? I understand about the hydraulic lash adjusters, but it seems that the friction of the vavle train would go up without having the rollers. I suppose if the top of the cam lobe were quite wide and relatively low radius of curvature, then the roller could slip on the lobe an close the valve prematurely.
Could you make a good compromise by replacing the hydraulic adjusters with solid adjustible studs?

warmonger

There's no pivot. Picture a bucket with a stem rising up from the middle. Turn the bucket upside down and the stem touches the valve tip. Now place the cam directly above the bucket and you have a gap between the bucket tappet and the cam base circle. Make a bowl in the bottom face of the bucket(which now faces up) and place different size shims in it to adjust your gap. The bucket has a precision OD and rides up and down in a tappet bore.

95-97 2.0L Same size bucket tappets all around with no shims.

98-99.5 2.0L Bucket tappets with shims.

99.5-Present 2.0L Graded bucket tappet, no shim. i.e. the stem to upper surface distance is sized instead of sizing the shims.

Advantages:
1) Less reciprocating mass.
2) Allows more aggressive cam profiles not possible with "slow" hydrailic lifters.
3) Less parts count, easier packaging.
I'm sure there's more...Terry?

The LS & Jag block are NOT machined the same as the Taurus 3.0 Duratec.The water outlets etc have the locations changed.An LS/Jag block needs a little more work to prep than the Taurus....

"Shim adjustmnt is the BEST for DOHC motors, hyd buckets/lash adjusters are a PIA when you want to use radical cam grinds...they fail very quickly"

Terry, I read a tech blurb that said new BMW M3 motor used the finger followers & that puppy spins past 8000RPM. Probably has billet followers though. Could stronger finger followers be fashioned for the Taurus based 3L which are more available than LS/Jag heads?

Is there any way to source the Jag heads TO the US??

So how are the X-type and S-type engines different? And what are the appropriate model years for the S-type? There are plenty of S-type motors available from recyclers, but the X-types are still too new to find. Any drawbacks with the Jag engines vs. Taurus vs. LS in terms of engine management electronics, e.g. does the VCT require extra signal paths not currently in the harness?

Terry, if you're willing to divulge, will the non-Duratec you're doing in 2002 be based on the LS or on one of the Jag engines?

Eric

24 'custom machined finger followers and solid lash adjusters'...$$$$$$$$...no way!
Buckets are DIRECT onto the valve...good enough for Cosworth!,the 2002 project is an LS........

Terry, all of the information that I have shows the exact same block, crank, rods, and pistons going in the 1999 Taurus, Lincoln LS, and Jag S Type.

You are correct about the water outlets. The block has two same diameter core plug holes at the top of the block. LS and Jag plug the rear one and put the water outlet in the middle one. The Taurus just reverses this. Same plug is used in either hole but different water outlets.

Thus, no machining differences. Can you give an example?