I fully agree with you Ted. Due to the fact that the roller would need to be small, you would probably have to limit the ramp up of the cam, otherwise it would tend to push sideways on the roller instead of up, creating lifter bore wear. Thats why the larger the roller the better all around.

55 Vicky & customline

58 Rack Dump, 55 F350 yard truck, 57 F100

59 & 61 P 400's, 58 F100 custom cab, 69 F100, 79 F150, 82 F600 ramp truck, 90 mustang conv 7 up, 94 Mustang, Should I continue?

Unfortunately the standard run of the mill Y blocks do not have enough material to be safely bored for the larger and already available lifter sizes.  Ford did make a run of large bore hydraulic lifter blocks for the military but these are rarer than hens teeth.  It would be ideal to have the larger roller wheel on the lifter but it's not a show stopper as long as the lifter is built to superior specifications in regards to the axle and the support bearings within the roller itself.  Tolerances just get more critical with the smaller sizes involved.  The motorcycle industry is already there in that regard.

Ideally the camshaft does need to be steel but I have run specially ground 'cast' camshafts with roller lifters without any adverse effects on race engines but I was limiting valve spring seat pressures to 160-175 lbs and over the nose pressures to 425 lbs.  A street engine could get by on less but the weight of the lifter will help to dictate what the valve spring pressures will ultimately be depending upon the usage and application.  Regardless, camshafts are unique for roller lifters in that the lobes are without the bevel that's required to rotate the lifter on a flat tappet design and if trying to capitalize on the benefits that a roller lifter provides, then the ramp or profile is going to be much more aggressive on a roller camshaft than the run of the mill camshafts that are currently available for the Y.

True on losing a roller and the increased chances for some sort of failure in this area.  That comes with the added complexity and more moving parts.  Roller speed would definitely be higher with a smaller diameter roller and with it, the potential for increased wear.  Maintenance or replacement schedule would likely have to be stepped up especially if being run on a street engine.  But, with the OEM's getting 200K+ miles on roller lifters without failures attributed to the roller itself, the matallurgy and tolerances are available.  Failed or damaged roller lifters in a racing engine isn't necessarily attributed to the length of time that they've been run but rather the weakening of valve spring pressures to the point that the roller lifter is allowed to bounce or not stay securely seated on the lobe which then hammers and destroys the axle or bearings within the roller wheel.  I've even seen the wheels split in half as a result.

As far as pushrod lengths being shorter, that's typically not a problem unless there's some angularity problems that must be dealt with at the bottom of the head.  I typically have to alter pushrod lengths anyhow when correcting the valve train geometry so using non-stock length pushrods is not an issue from my standpoint.  I am using some of the 'retro' hydraulic roller lifters that are available for the older engines and some of these are so tall that they can not be removed from the lifter bores without first pulling the heads.  I would rather be able to pull the lifters without pulling the head but that's something that goes with the territory depending upon the engine.

Had an invite to a car show in Crawford and opted for that instead.  I'm planning on being at Kennedale on Sunday the 22nd though.  Hope to see you there.

Lorena, Texas (South of Waco)

I kind of agree with Ketterbro's. For roller lifters in a Y, the lifters are such a small diameter, roller would be limited in diameter, which would limit the ramp up angle of the cam, the cam would need to be special made with flat lobes to prevent the turning affect, and the lifters would need to be very tall to stick out of the casting and accommodate a link bar, and then special length push rods would need to be fabricated.

Then what happens of you loose a roller, it appears to me you would be adding another weak link unless the lifter bores were drilled large enough to accomodate a larger roller.

Just my 2 cents

55 Vicky & customline

58 Rack Dump, 55 F350 yard truck, 57 F100

59 & 61 P 400's, 58 F100 custom cab, 69 F100, 79 F150, 82 F600 ramp truck, 90 mustang conv 7 up, 94 Mustang, Should I continue?

My Brother and I run the 302 HO with hyd lifters, and have no problem twisting to 7K..

It would be great to have hyd lifters for the Y.. Surley someone can drill the block, if your going to go as far as bore the lifter guides.. Just a thought..

Hey Ted, didn't see ya at the Bracket Finals at Texas Motorplex this last weekend.. There was a Red 57 Bird, turning 9.1 ET..

Brother and I own/operate 1957 Ford Fairlane 312/4x2 and two 1963 Falcons 302 rollers carburated 600cfm, FE427 sitting in shed..

Link bars as pictured above is one way of keeping the lifters from rotating.  Another method is a stud or protrusion in the lifter bore with an appropriately grooved lifter.  The SBF and scrubs use the 'dog bone' method with a 'spider' to keep the dog bones in place.

The pushrods not rotating on a street engine doesn't seem to be an issue for the factory equipped hyraulic roller cammed engines.  I'm sure a hardened pushrod tip and the appropriate hardness in the rocker arm would help though.

Lorena, Texas (South of Waco)

Some questions come to mind if going with roller lifters in a Y,

1.) the lifter bore is round and has no provision to keep the roller aligned with the cam, what would need to be done, we wouldn't want the roller turning sideways on the cam. in order to place keepers on pairs of lifters the lifter would need to be much taller to stick out of the block and require shortened push rods.

2.) The lifters turning rotate the push rods, with rollers they would not turn, would this accellerate wear and require more frequent valve adjustment or would they wear less and require less adjustment.

Just some thoughts to stir more minds

55 Vicky & customline

58 Rack Dump, 55 F350 yard truck, 57 F100

59 & 61 P 400's, 58 F100 custom cab, 69 F100, 79 F150, 82 F600 ramp truck, 90 mustang conv 7 up, 94 Mustang, Should I continue?

Would there be an advantage for a "mild" y block, and because of the roller would the  valve adjustment be more critical? Gerry

Lake Forest California  5th inf 77 Armor Div. VN 68/69

If you put your town and state in your signature

help might be closer than you think.

Just for further info on this subject, Verne Schumann (Schumann's Sales & service) said that his company could make roller lifters available if there was enough of a market. This info was in YBM about a year ago or so.  Apparently he had a few made for racing many years ago, but didn't give any details. Is there a connection between them & the current proposal? I don't know...  

Paul

So the lifters would need to be adjusted as often as now but probably less "drag" on the falve train? and some horse power difference?  Gerry

Lake Forest California  5th inf 77 Armor Div. VN 68/69

If you put your town and state in your signature

help might be closer than you think.

Gerry, You're correct in that the Y has no oil feed to the lifters but that's only an issue if trying to run some form of hydraulic lifter.  Roller lifters refers to having a roller wheel at the camshaft side of the lifter which reduces the friction at the point of contact while also allowing for a much more aggressive camshaft profile.  On my Fe's, I block the oil galley that feeds the lifters when running either flat tappet solid lifters or non-hydraulic roller lifters.

Lorena, Texas (South of Waco)