[242177P]

Originally Posted by shermanator2

I have no experience with dog bones like these, but are they upside down?

I was surprised to learn the flat side IS the top....



Thinking about how the ends are tapered leads me to suspect they're actually
supposed to teeter totter at times??

[tom s]

I have a 301 stroker engine going together right now.I asked the builder to order a pair is sealpower lifters to see how they would work in the 301 block,oil holes are diff from reg std deck blocks.Tom

[68hotbird]

The delphi ls7 lifter has the oil hole exposed in the picture the other picture is the sealed power 2148 lifter it has the oil hole .025-,030 down in the bore.

[shermanator2]

First I would like to thank 68hotbird and everyone else for providing some very good information here and on the other two threads on the same subject. I am very intrigued by the possibility of using factory designed roller lifters in a Pontiac. Not because of the cost, which is not high on my priority list, but because of the reliability. All of the aftermarket companies, hobbyists, and racers cannot put the resources into developing reliability that GM can. I personally have had a very nice engine taken out of service by a link bar pin failure on a lifter from one of the top cam companies.

I would like to comment on lobe lift and its effect on oil band location. Any optimally designed cam will have the nose of the cam at the same height (radius from cam shaft centerline) regardless of lobe lift. The difference between a high lift cam and a low lift cam will be in the radius of the base circle, not the radius of the nose. The nose radius should be just less than the radius of the cam bearing journals (just allowing the cam to be installed down the tunnel). Sure, you can design a cam with a smaller base circle and smaller nose radius, but in doing so you are either increasing side loading on the lifter or reducing the ramp rate, or both.

My point in bringing this up is that we should not be considering the lobe lift when determining if the oil band or oil hole relief notch come out of the top of the lifter bore. All proper cams should be the same and essentially the oil band should be inside the lifter bore when the roller is at the radius of the cam journal. If we had a concern about the oil band coming out the bottom or covering up the oil feed hole while on the base circle, then we would need to talk about lobe lift. That seems to not be the case here, or at least has not been brought up yet.

[Will]

Originally Posted by 68hotbird

The delphi ls7 lifter has the oil hole exposed in the picture the other picture is the sealed power 2148 lifter it has the oil hole .025-,030 down in the bore.

Okay, so different manufacturers are putting the oil hole in different places. That's weird.

So which ones do you get if you go to a GM parts counter and order some LS7 lifters?

[68hotbird]

The 2148 sealed power lifter is a small block Chevy lifter that interchanges with some early ls engines. The ls7 uses a different lifter that may fit some older ls engines but won't work in small block chevys either. The ls7 lifter is different from ls 1-2-3 lifters which is why the oil hole is in a different location.

[Will]

Originally Posted by 68hotbird

The 2148 sealed power lifter is a small block Chevy lifter that interchanges with some early ls engines. The ls7 uses a different lifter that may fit some older ls engines but won't work in small block chevys either. The ls7 lifter is different from ls 1-2-3 lifters which is why the oil hole is in a different location.

Okay, this is getting interesting.

There's a video out there about this, and people are talking about putting LS7 lifters in Pontiacs as the solution, and some other places I've read about this have said the LS1-7 lifters all interchange, but you're saying the LS7 has the oil hole too high and you need the 2148 style.

I think there are going to be quite a few people ordering the wrong parts until this all gets firmly sorted out.

So what would an OE application for those 2148 lifters be? You're saying small block but it would be helpful to have an actual OE application to refer to. And, if you go to a GM parts counter to order this type of lifter, what are you getting? Who's it made by?

[JLMounce]

It's my understanding that there were at least 2 variants of the "LS7" lifter. That engine's design parameters with it's offset rocker arms and higher operating rpms, would likely necessitate a different lifter design than your standard truck based LS.

The LS7 engines have known valvetrain issues, so it's not a surprise that there's likely different parts depending on year and revision.

I don't believe that anyone should spec LS7 specific lifters for this application. The HT2148's seem to cross reference to the 4.3 v6, 4.8 and 5.3 v8 LS engines specifically.

[Will]

Originally Posted by JLMounce

...

I don't believe that anyone should spec LS7 specific lifters for this application. The HT2148's seem to cross reference to the 4.3 v6, 4.8 and 5.3 v8 LS engines specifically.

Which brings up concerns of durability/usefulness in a high performance application. One of the reasons to go with an OE lifter is supposedly higher quality, but if GM didn't design these lifters with high lifts and high spring pressures in mind, then they may not be all that great after all.

[JLMounce]

Originally Posted by Will

Which brings up concerns of durability/usefulness in a high performance application. One of the reasons to go with an OE lifter is supposedly higher quality, but if GM didn't design these lifters with high lifts and high spring pressures in mind, then they may not be all that great after all.

Actually, if you look at the uses involved and the operating conditions you see those engines operating in, it’s not that different than what you see for a typical street Pontiac.

[68hotbird]

I have personally done this conversion and I am trying to keep people from making costly mistakes. The 2148 sealed power lifter fits 4.3 v6 roller cam engines, 5.7 chevy v8 roller cam engines and 4.8/5.3 ls engines. The 2148 lifter was on the market before there was even an ls engine in production. The 2148 lifter is a high quality cost effective lifter made by sealed power (or someone for sealed power) that will work in most applications up to 6000 rpm with reasonable spring pressures. You still need to look closely at your block lifter bores and check very close as you lobe lift approached .400. why all the talk about ls7 lifters. My brother is heavy into building ls engines. The ls7 gm Delphi lifters (not copies, or clones, or anyone else's lifters claiming to be ls7) have been proven to be extremely reliable and very cost effective. Have these Delphi running in a 6.0 ls 175-180 on the seat 420-430 over the nose and turning 8000 rpm routinely with no valve float and no lifter failures so if that lifter would work it would be an awesome choice and that is why I tried it out to find out they won't work easily at least. The other thing to remember I did some machining on my dog bones so they won't ride up and down some at max lift (this is what randy repp is working on a solution for). Summary using the comp SBF modified Spyder and dogbones (I do my own machine work) and the cost of the sealed power 2148 lifters I have a nice reliable hydraulic roller set up (lifters/holddown system for less than $180 dollars. Lifters $130.00 and comp Spyder and dogbones $44.00. with a durable lifter that is much lighter than a link bar set up that cost $400 dollars plus. Im running 140# on the seat and 350-360# over the nose and with the lighter lifters I'm running beehive springs and retainers which also saves more mass in the valve train. In closing I will help anyone that wants to try this set up and I want to give a Shout out to my good friend Jim Lehart who set me on the path to this set up a couple years ago. I continue to refine my options and try new things but all and all its a good set up you just have to double check everything and pay attention. The 2148 sealed power is the only lifter I have used successfully. Keep in mind there are also 2148 clones out there make sure you source true sealed power 2148 for your build. Thanks, Paul

[Will]

Thanks VERY much for your input! I for one really appreciate it.

The talk in other circles that gets me concerned is everyone is talking about LS7 lifters, but it doesn't look like those will work.

My biggest concern is how well these lifters will work with aggressive cams. In larger engines, cams with 240+ duration and .377" lobes are just a starting point. Something like the "Road Paver" from SD Performance (246/252 dur @ .050" lift .608"/.608" lift with 1.52 ratio rockers) would seem to be too big. It would be a shame to have to use a heavier lifter in a higher RPM application.

[68hotbird]

The 2148 should work with the road paver but its right at the lift limit will need the dogbone modification and close check to make sure the oil hole doesn't come up to high on any lifter bores that may have a factory chamfer.

[rohrt]

I know Buttler recommends the Johnson short travel and they are around $600 last I looked but currently not available. I have my motor out and really need to make a choice on roller lifters.
Seems they all have 1 of 4 issues.
1. Oil band in wrong spot that leads to...
2. Lifter not pumping up
3. breakage of roller or link
4. Improper bleed down rate
Then throw on top the fact that not all cams are ground the same. Some have a reduced base circle grind in order to increase the lift.
For every person that has claimed they put 1000s of miles on their brand of roller lifter there is one who has had catastrophic failure. I doesn't help that your never dealing with the same setup when it comes to lift or spring ratings.
I'm tending to lean in the direction of the LS7 lifters. The lifter weight, the GM tolerance they must adhere to and the cost are really compelling. However If the johnson short travel lifter is indeed the best I would go that direction without question, but how would you prove it?

[P@blo]

Originally Posted by 68hotbird

The 2148 should work with the road paver but its right at the lift limit will need the dogbone modification and close check to make sure the oil hole doesn't come up to high on any lifter bores that may have a factory chamfer.

Great information, thanks for asking good questions Will. If the HT-2148 lifter will work with the road paver it will definitely work on old faithful.

I pulled the trigger on a set of these lifters but have a question on the length of pushrod being used. The video states 5\8"-11\16" shorter but wanted to ask what you ended up using?

[JLMounce]

What I don't understand about the lobe lift situation, is how the issue is showing regardless? The nose of the cam should not be any higher than the cam bearings. Increased lobe lift typically occurs by reducing the base circle. Compared to a stock camshaft, you would actually expect the opposite to be happening, with the oil band coming out of the bottom of the lifter bore, not the top.

Is it that some camshafts are doing a combination of both? Where a factory cam the nose is bellow the bearing enough that if gives room to increase it's height?

[rohrt]

Originally Posted by P@blo

Great information, thanks for asking good questions Will. If the HT-2148 lifter will work with the road paver it will definitely work on old faithful.

I pulled the trigger on a set of these lifters but have a question on the length of pushrod being used. The video states 5\8"-11\16" shorter but wanted to ask what you ended up using?

I seen it stated that LS7 lifter setup had 8.550 Pushrods length. Stock is 9.130. I was trying to find what my Comp Roller setup is but have yet to find it.

[68hotbird]

I have used various lengths on pushrods. It is not easy to just say you need a certain length pushrod. You need to check your geometry on your set up and see what it needs to get proper rocker to valve tip contact. several variables affect this. (Rockers used, valve length, etc.) I always set them up and check for correct geometry with a length check pushrod and order the length I need for each build. Not all cams are ground with the same cam base circle either which will also effect pushrod length.

[68hotbird]

Cam base circle is a can of worms also. There are 2 ways to increase lift one is decrease the base circle the other is to increase the base circle and raise the the lift accordingly. different cam companies use different base circles. Most try to use as large a base circle as possible as you can control lifter motion better and have more room to change the ramps of the lobe. The limitation is you cant have a base circle plus lift that is larger than your cam bearing bore or you cant install the camshaft. Im not sure what most of the common cam grinders are using as a base circle for pontiac hydraulic rollers i need to look them up and compare. I know they try to stay as large as possible for stability, strength, and valve motion/lifter motion control. I dont currently have 2 cams of the same company with different lift numbers to compare but when I get a chance I will.

[shermanator2]

As I said in the one of the other threads on this same subject, any optimally designed cam will have the nose of the cam at the same height (radius from cam shaft centerline) regardless of lobe lift. The difference between a high lift cam and a low lift cam will be in the radius of the base circle, not the radius of the nose. The nose radius should be just less than the radius of the cam bearing journals (just allowing the cam to be installed down the tunnel). Sure, you can design a cam with a smaller base circle and smaller nose radius, but in doing so you are either increasing side loading on the lifter or reducing the ramp rate, or both. I want neither of these in a cam that I use.

As JLMounce points out, with higher lifts we should be concerned with the oil band coming out the bottom, not the top. And 68hotbird, I appreciate all of the great information that you have been providing, but if you show me a cam with a nose that is significantly lower that the journal, I will call it a substandard cam.

Just for fun, I happened to have a Melling SPC-7 (068) on my bench. I measured the nose radius and found it to be 0.020" less than the journal radius. I am guessing that is typical with production tolerances.