[Stan65]

Scream n fly,

I would say that’s pushing the limits. It would require accurate measurements.

Can you measure the base circle on the cam?

Stan

Down to 3 sets.

[67Lemons]

I’m a little confused reading through this if it’s best to use the Sealed Power/Gaterman/Howards version or if you just need an LS7 lifter then why not use the Delphi US made ones that are available online?

Also, is any Sealed Power HT 2148 good including the ones made in China? Seems they made them in the US, Mexico & China.

[Stan65]

67Lemons,

Lifters explained…..

The first step in determining if my dog bones will work for you. It is all dependent on the base circle and lift.

Max lift is when the lifter is on the tallest part of the lobe. The lobe can’t be taller than the bearing journals or the cam could not be inserted through the cam bearings. “Most” cam manufacturers have the lobe as tall as possible to help with the angle of the lobe to the lifter base. Usually just a touch under, like .010” smaller than the cam bearing journal diameter.

The way lift is increased is by reducing the base circle. (Lift is the difference between the base circle and top of lobe)

The issues with running a non link bar lifter is none are made specifically for a Pontiac. Through the years several people have experimented with different OEM lifters.

Lifters proven to work…

I used Sealed Power HT-2148 lifters when I designed the dog bone retainers as I didn’t like the way the ford retainers fit. (This is the lifter folks were using with the Ford spider and Ford dog bones)

In the dimensional drawing below you can see my setup. If you reduce your base circle compared to my base circle, the lifter will drop lower by half the diameter difference and you should be able to subtract that from the amount the oil band is above the bottom of the bore to determine how comfortable you are.

In the picture of the two lifters with the red circled area, the one with the red circle is the HT-2148 lifter. The one on the right in the same picture is what people call the LS7 lifter. The notch for the oil feed hole on the LS7 lifter is higher on the lifter and will raise above the bore at lift and leak oil therefore it cannot be used.

The picture of two lifters without the red circle are on the left, the Howard’s/Gaterman lifter. The Sealed Power HT–2148 is on the right. The issue with the Howard’s/Gaterman lifter is with the oil feed hole lower compared to the Sealed Power lifter. There will need to be modifications to the block with the Howard’s/Gaterman lifter. When this lifter is on the base circle, the oil band/oil feed hole drops completely below the oil feed galley in the block. It’s not by much and will only require chamfering the oil feed hole the slightest amount to maintain oil feed on the base circle. The only issue is the block must be fully disassembled so that you can clean after the modification. It doesn’t require any special tools just a drill and a chamfer bit or even just a half inch drill bit to just to put a chamfer on the opening of the hole.



My retainers will not allow you more lift, less lift or the ability to use any special lifter. They are just designed to keep whatever lifter works in your situation from rotating.

I can’t answer to the quality differences between the USA, Mexico, and China seal powered lifters.

Hopefully this answers some questions.

Thanks,
Stuart “Stan”Landreth

By the way down to three sets

[67Lemons]

Ok, after reading the entire thread & your explanation I think I finally understand. So since the worry is the base circle of the cam & not so much the lift how does one pick out a camshaft? Reach out to the manufacturer for base circle dimension & lobe lift? None of the examples posted in the thread are for the camshaft I want to run (RA4) so to be safe before moving forward I’ll reach out to a few mfrs.

Also, this seller has a few sets left, I grabbed 4 of the 4 packs, they’re made in China but at least they were available at a good price
https://www.ebay.com/itm/40536980102...3Avlp_homepage

[67Lemons]

Looking at the Butler version of the RA4 cam it might not work just based on lobe lift, obviously without measuring base circle diameter it’s just a guess on my part & even still the cam really needs to be mocked up in the block.

[gtobob67]

Make sure to check each lifter bore during mock-up to make sure the lifter oil feed hole isn't exposed at full lift. My 73 455 block had a few bores with deep chamfers as compared to others. Even with my .550 exhaust lift all checked good. I have several hundred miles on it now and it's very quiet.

[Stan65]

gtobob67,

67Lemons,

My 73 455 has the same couple of chamfers. My cam is ground with the top of the lobes .007” under the bearing journal. If they were at the same height as the journal the lifter fill holes still would not have came out the top, other blocks could be different and need verified. The lobes can’t be taller as the cam couldn’t be installed

The biggest issue is the lifter oil bad dropping below the boss on the base circle. As the lift gets bigger the lifter drops lower in the bore on the base circle.

If you can find out the base circle dimension and the lobe lift you can get a 95% chance of figuring it out before buying.

Pontiac cam journal specs are 1.8987 to 1. 8997. Use 1.899 for the diameter.

Lobe below journal = Journal diameter- ((2 x lobe lift) + base circle)

If you run the Howard’s/Gaterman lifters you will not have an issue with the lifter out the top on any block. The tops of the bore/chamfer would have to be an 1/8” lower than I have ever seen.

The only caveat is the modification ls to the oil feed galley.

The biggest area of concern is dropping too low in the bore.

Thanks,
Stuart “Stan” Landreth

[67Lemons]

I’m still waiting to hear back on base circle from Powell & Butler on their RA4 cams but if anyone has a suggestion of a cam for a 455 that works with these lifters I’m all ears. I’m working on a ‘72 455 with 7K3 heads, new valves but waiting to figure out the cam before I purchase new springs. It’s going into a ‘72 GTO with a M20 four speed & 3:23 gears, stock exhaust manifolds (maybe RA manifolds later) with a 2.5” exhaust, just a nice cruiser to hit some shows or grab ice cream with the family. I was going to build this with a RA4 cam so something along those lines but that works with these lifters, let me know if you have any suggestions, thanks!

[Iggy]

As for country of origin on the Sealed Power HT-2148 lifters, impossible to find USA made, what is the quality of the ones made in Mexico?

[67Lemons]

Originally Posted by Iggy

As for country of origin on the Sealed Power HT-2148 lifters, impossible to find USA made, what is the quality of the ones made in Mexico?

I’m not sure on the actual quality but I ordered a set of Chinese ones from Sealed Power this weekend since they were available, not ideal but Federal Mogul/Sealed Power has been around for a long time & I imagine they wouldn’t be selling junk if they can help it. That being said if I get this combo installed & stumble on a set from the USA I’ll probably grab them just in case.

[Stan65]

67lemons,

I can’t even begin to advise on the quality of parts these days. I have the China and Mexico lifters in mine. No problems so far. Be careful with the ones you ordered. Make sure they are the correct design and not a superseded later design. You can look back in this thread and see what I’m talking about.

I will attach a photo of my Comp Cams cam card installed in a 73 455 block. I will also attach a Lunati cam card that Gtobob67 installed in a 73 455 also. He posted about 3 pages back with success and some miles on his setup.

By the way down to 3 Sets.

Thanks,
Stan

[Iggy]

I am looking at the HT-2148 and not the HT2148A

[67Lemons]

I reached out to Butler for a cam recommendation on my potential build. It’s a 455 with TRW/Sealed Power flat tops, 7K3 heads with exhaust manifolds & 2.5” exhaust. The car is a ‘72 GTO with an M20 & 3:23 rear gear, basic street cruiser, no race, blah blah blah. They came back with a recommendation on the Butler with 112 lobe separation. Obviously they don’t know anything about running this lifter set up & I’d have to make sure with measurements that it will work but what’s everyone think of the cam recommendation? I’m not sure I have enough compression to run it but Butler said no problem.

https://butlerperformance.com/i-3164...tegory:1459686

[Jay S]

Originally Posted by 67Lemons

I reached out to Butler for a cam recommendation on my potential build. It’s a 455 with TRW/Sealed Power flat tops, 7K3 heads with exhaust manifolds & 2.5” exhaust. The car is a ‘72 GTO with an M20 & 3:23 rear gear, basic street cruiser, no race, blah blah blah. They came back with a recommendation on the Butler with 112 lobe separation. Obviously they don’t know anything about running this lifter set up & I’d have to make sure with measurements that it will work but what’s everyone think of the cam recommendation? I’m not sure I have enough compression to run it but Butler said no problem.

https://butlerperformance.com/i-3164...tegory:1459686

I know of an engine that was ran with those profiles and the 2148 style lifters in a 455. Probably has commented on this thread somewhere, it was Murf. I don’t recall if his was an “S” or a “B”.

[Comanche]

Base circle for Butler RA IV HR cam is 1.168-1.170

[67Lemons]

Originally Posted by Comanche

Base circle for Butler RA IV HR cam is 1.168-1.170

Stan, you listed your base circle below previously in the thread so looking at the Butler base circle as noted above the Butler is a slightly smaller diameter, any idea using rough math if this will work with the Sealed Power lifters? Is there .023 wiggle room in the oil feed without having to chamfer the block? Again, I realize that actual measurements with my block & cam are necessary but trying to have as much information as possible before ordering the cam.

Base Circle 1.191
Lobe Lift .344

[Iggy]

I was able to get a set of ht-2148 lifters made in Mexico.

[Stan65]

Iggy,

That’s good. Can you share where you purchased them?

67Lemons,

That’s only .023” smaller diameter. That only drops the lifter .0115” lower. That would be fine in my block.

Thanks,
Stuart “Stan” Landreth

Down to 2 sets. Need to see how much the materials will go up with all this tariff stuff.

[Iggy]

Through this e-bay vendor

https://www.ebay.com/itm/186930762681