Duke/Joe...Solid Lifter recommendation please..

[Tracy C.]

My Federal Mogul Speed Pro CS-1145R cam arrived yesterday. I waited 2 months so they could grind one for me. ($104 + shipping,...not bad)

I called to follow up with the status on the AT840R lifters and they have been discontinued.

The sales guy at Jegs is unfamiliar with the "edge orifice" type designation you described as being the original equipment type used with small block solid cams. I couldn't explain it either.....

It's a little late to pursue a "kit" from GMPP.

Any other recomendations?

tc

[Joe L.]

Re: Duke/Joe...Solid Lifter recommendation please.

Tracy------

The GM camshaft kits wouldn't help you, either. They are supplied with Crane mechanical lifters and, I believe, those are the piddle valve type.

The edge-orifice lifter were used on most Chevrolet small blocks with mechanical lifters except 302 cid Z-28 engines. The latter used the piddle valve lifters. The GM edge-orifice lifters have been discontinued for quite some time and the supply of them has pretty well "dried up". I haven't even seen a set of them on eBay for quite awhile. The Federal-Mogul AT840R, if it was a true edge origice type lifter, was the only other lifter of their type on the market that I am aware of.

The primary difference between edge orifice and piddle valve lifters relates to the amount of oil that they direct to the valve train. Edge orifice generate a lesser flow and piddle valve allow a higher flow. Most small blocks do better with a lower flow as provided by the edge orifice and that's why GM used them for most small block applications.

There were never really that many companies that actually manufactured flat tappet lifters. AC Spark Plug, now a Division of DELPHI, was one. Of course, they no longer manufacture the edge orifice mechanical lifters. A company by the name of Johnson was another. They are out of business which may be why the AT840R is now discontinued. I don't remember the name of the third company.

In any event, I would recommend that you use a Comp Cams #813 lifter. This is a piddle valve type, but it's designed for reduced oil flow. So, it should provide some of the benefits of the edge orifice type for your application.

[Tracy C.]

Re: Duke/Joe...Solid Lifter recommendation please.

Thank you for the comprehensive response Joe!

I would have never guessed in a hundred years that "reduced oil flow" to the valve train would be a better thing.

Is it more a function of Pressure vs. Volume? I can envision oil under too much pressure squirting beyond the range of the roller bearing, but lots of oil dribbling onto the rocker bearing area seems to be good to me.

I'll resist the temptation to relate this discussion to things of more personal nature. I'm sure most of us know the dynamics of this pressure/volume thing more than we want to admit!

tc

[Dennis C.]

Tracy, Yes, Much, much more.... DC *NM*

[Joe L.]

Re: Duke/Joe...Solid Lifter recommendation please.

Tracy-----

Excessive oil in the rocker area has at least 2 negative consequences:

1) Too much oil "upstairs" can mean TOO LITTLE oil "downstairs";

2) Too much oil in the valvetrain can exacerbate oil consumption problems.

[Joe L.]

Addendum

By the way, just so there's no misunderstanding, it is NOT my contention that the edge orifice-type lifters are necessary for use in small block engines. They are what GM originally used in PRODUCTION for most small blocks with mechanical lifters, but they ARE NOT what must be used. The piddle valve type lifters, especially the aftermarket variety available from Comp Cams, Crane and others, will work perfectly for most small block applications. Believe me, no judge will ever be the wiser, either.

[Duke W.]

Re: Duke/Joe...Solid Lifter recommendation please.

Ditto what Joe said, plus the following.

The edge orifice type was THE mechanical lifter going back to the early SB days, and meters oil based on lifter OD to bore clearance. It provides adequate oil to the SB rocker boxes. The edge orifice type mechanical lifter is a one piece machined casting.

The piddle valve type was designed to provide additional overhead oiling for BB applications and meters oil with an inertia valve that opens/closes in response to lifter inertial forces, which increases overhead oiling with increasing revs, compared to the edge orifice type. It was first used on the L-78 in '65 and all other subsequent BB mechanical lifter engines. The additional overhead oiling was deemed necessary for the BB valve train.

The piddle valve lifter is a two piece design held together with a snap ring and is easy to misidentify as a hydraulic lifter because of its similar construction architecture.

As previously stated, the more oil that is supplied "upstairs" the less oil available in the pan, which has the potential to cause oil starvation in severe use such as road racing, however, if the engine has the SHP type 5-quart oil pan/6-quart system, I don't think oil starvation will ever be an issue if the oil level is maintained in the normal range. Even a SB with the normal 4-quart pan/5-quart system should not have a problem in normal street use.

Vintage Corvette BBs also use a 5-quart pan/6-quart system, and they move more oil through the entire system. I'm not aware that oil starvation is a problem for BBs in normal street use.

The 302 Z-28 engine was the first SB to use the piddle valve type as OE, and I believe that engine has a 4-quart pan/5 quart system. For the LT-1 engine used in the later Z-28s and Corvette, Chevrolet reverted back to the edge orifice type.

Duke

[Clem Z.]

Re: Duke/Joe...Solid Lifter recommendation please.

when we started to drag race BB corvettes in 65 we would see the oil pressure start to drop at the end of the 1/4 mile. this was because the oil could not return to the pan fast enought. we first used a extra quart of oil but later we just switched to edge orifice lifters to prevent this. F/M only recommeded the use of edge orifice lifters with needle bearing rocker arms because if you tried to use them with new stamped steel rockers you could burn the balls if you were not carefull on the startup of a fresh engine. the heavier the springs the bigger the problem. we welded deflectors over the oil hole on the stamped rockers so all the oil would end up at the ball pivot.

[Steve D.]

Re: Duke/Joe...Solid Lifter recommendation please.

Tracy

I have been looking for a CS-1145R but have come up empty handed. Would you be kind enough to share with me the details (address, phone, ?, ?) of how you ordered it?

Steve

[Steve D.]

PS

My project is a 63 convertible also.

Steve

[Brian Monticello]

Re: Duke/Joe...Solid Lifter recommendation please.

Steve,
I got mine and the AT992 lifters through my local CarQuest. They had it in one week.

Brian

[Tracy C.]

Re: Duke/Joe...Solid Lifter recommendation please.

Steve,

I called both Summit and Jegs (800-345-4545 dial Mark @ extension x536) in search of the Federal Mogul Speed Pro CS-1145R that Duke recommended.

Neither had this cam cataloged, but Jegs took the initiative to call Federal Mogul and see if they would grind one for me. It took about 9 weeks, but I got it this week. Total with shipping/handling was under $115.

I had ordered the AT840R lifters too. The sales guy was more concerned about getting the cam when I ordered. FM has discontinued these lifters so I now have a set of the Comp Cam #813's on the way. ($89) Because I had ordered the lifters intially with the cam, there will is no additional shipping or handling cost.

Good luck with your 63 vert!
tc




Jegs Home Page

[Jim T.]

Re: Duke/Joe...Solid Lifter recommendation please.

My first engine buildup was in 1964. A 348 bored 30, with a 409 solid lifter cam. Remember setting the valves with the engine running would squirt hot oil straight up in the air over the fender. I could not run it at a high RPM very long with out losing oil pressure. I never ruined the engine knowing its limitations. Have no idea what kind of lifters I bought back then.

[Tracy C.]

Re: Duke/Joe...Solid Lifter recommendation please.

Thank you Duke,

Very Helpful! I learn something everytime I visit this place!

I do have the SHP type 5-quart oil pan/6-quart system so an extra quart of oil should allievate any concern with the piddle valve style lifters.

I only plan to "red-line" this engine in all gears except reverse and only on days ending with "y" anyway....

right foot is starting to twitch a little just thinkin' bout it...

left foot has this urge to pump up and back too..

cain't wait to rumpidy rump

thanks again!
tc