[JC455]

Duplicate post

[JC455]

The Gaterman’s may solve any rub-related issues due to more exposed roller.

[pontbil]

What is the goal here using the LS lifters? Morel makes a very nice HYD Roller lifter with link bars for a Pontiac.

[tom s]

The Morel is just a SBC lifter with pontiac linkbars.The Gaterman looks more like a Shaver hyd roller.Tom

[JC455]

For me, the goal is to have a low/no maintenance hydraulic roller- Like the SBF, SBC, LSx, etc. have enjoyed forever- that doesn't cost a fortune to convert to.
Plus, the lifters are a lot lighter, which should improve valvetrain efficiency.

[shermanator2]

My goal would he the longevity and reliability of a factory valve train, without the headaches of flat tappets like cam break in and having to run special oils and ZDDP additives. I also want something that fits under a stock valley pan. I don't like link bars because I have had a link bar pin failure take a really nice engine out of service, so I don't consider those reliable. For me, cost is not a factor. The faster ramp rates and lower friction with a roller cam is a bonus.

[Singleton]

Here’s a 16 pack of Sealed Power HT2148 for $99.99 & free shipping
https://www.ebay.com/itm/124510182649

[tom s]

FYI,link bars have been run since the late 50s with VERY little issue!Hyd roller lifters main isuue has been bad leakdown from what I feel is poor QC.Solid roller have very little issues compared to hyd rollers.Factory lifters seem to live very well because of low spring pressures and very tame cams compared what is needed in HiPo use in our pontiacs.Good luck to all in this venture.Tom

[P@blo]

So much for the fundamental misunderstanding. Looks like the 31-1000 instructions were correct with certain small base circle cams not compatible with the retrofit set-up. Go figure...

My previous questions were leading somewhere.

[P@blo]

Originally Posted by tom s

FYI,link bars have been run since the late 50s with VERY little issue!Hyd roller lifters main isuue has been bad leakdown from what I feel is poor QC.Solid roller have very little issues compared to hyd rollers.Factory lifters seem to live very well because of low spring pressures and very tame cams compared what is needed in HiPo use in our pontiacs.Good luck to all in this venture.Tom

Problem is Tom the Pontiac design link bar has not been around since the 50's and read too many posts of roller lifter failure after not much mileage. Major concern for me we have railroad car weight followers that have not proven themselves to last any longer than a flat tappet cam at 1/5 the cost.

Successful break-in on a FT cam is a risk but a $1000+ roller cam is no guarantee that after 1000K you don't have a more severe problem. The Jim Leheart modification is going to work for a lot of guys and comes with some obvious advantages. The lobe choice is not one of them though as you mentioned.

[pontbil]

I have run link bar solid lifters for years with no link bar issues and have never heard of any. What is failing on the lifters?

[Singleton]

Originally Posted by P@blo

So much for the fundamental misunderstanding. Looks like the 31-1000 instructions were correct with certain small base circle cams not compatible with the retrofit set-up. Go figure...

My previous questions were leading somewhere.

Can you elaborate? Are you saying that Comp has certain cams that has the lobe nose peak on a significantly shorter radius than the cam bearing journal? If so, how much different is the radius?

[JC455]

Originally Posted by pontbil

I have run link bar solid lifters for years with no link bar issues and have never heard of any. What is failing on the lifters?

The solids seem to be way more reliable than the hydraulics.
One of the issues is the link/rivets coming apart.
There’s a guy on YouTube called Fast Monty’s Garage. He’s in the SoCal/SD area. One of his Lunati hydraulic rollers broke the link rivet and ruined his Butler stroker engine.
I drive- a lot- so I want lifters that will last 100K miles without constantly inspecting, shipping them out for rebuilding, etc.
I just don’t see the aftermarket linked lifters doing this, but GM and Ford have proven the spider/dog bone system goes for hundreds of thousands of miles.
That’s what I’m after.

[P@blo]

Originally Posted by Singleton

Can you elaborate? Are you saying that Comp has certain cams that has the lobe nose peak on a significantly shorter radius than the cam bearing journal? If so, how much different is the radius?

No I can not. No I did not say that. You did actually and as such can not comment on the radii.

Why as the confusion added to this topic when we can KIS? The original modification video comments explained a lot of what we are seeing. Also the 31-1000 instructions can be considered a resource to eliminate some confusion.

[JLMounce]

Fwiw I’ve had Lunati link bar lifters on my comp hr for about 15000 miles. I’ve not had any performance or reliability issues with them. They clatter terribly when the engine is warm however. Clearly collapsing.

It’s not just the lifters that are a concern here. The oiling system in basic street builds seems to be an issue as well.

I’ve followed everyone of of these threads and from pulling ideas, thoughts and observations from them all, not only do we need a quality lifter with good internal tolerances and QC, but the engine also needs to be able to supply (by my estimate) 30psi of oil pressure at hot idle.

If like me you have an engine that will only hold 15 psi on a 10/40 oil at 900 rpm hot, and you match the system with a set of lifters that have looser internal tolerances. Well, that’s a recipe for a noisy valve train.

While I haven’t had any reliability issues with my lifters, the constant hammering of the lifter internals at idle as the lifters collapse can’t be good for them.

Given my experience and research I believe that a modernized, well built and blueprinted oil pump, setup to supply 30-40psi at 800 rpm is a requirement to a successful hydraulic roller cam conversion. Along with choosing good quality lifters that have a correct oil band height. Whether those lifters are link bar or using a dog bone as it’s capturing device.

There are obvious cost and weight advantages to this setup being discussed that makes it so intriguing.

[JC455]

I agree with you- that’s what Jim Lehart told me was the biggest improvement using the SP lifters: A piston metered lifter vs. a piddle valve design.

[P@blo]

Originally Posted by JC455

I agree with you- that’s what Jim Lehart told me was the biggest improvement using the SP lifters: A piston metered lifter vs. a piddle valve design.

Thank Jim for us John and let him know his sharing is appreciated.

[Singleton]

I found this info from Comp Cams referring to the instructions for the 31-1000 spider on using a special cam for Ford. They make a special line of Ford roller cams with a -RF, (Retro-Fit), at the end of the part number.

They don’t go into specifics concerning the measurements, but seem to imply that the cam lobe nose is indeed a lower radius than the cam journal to prevent the dogbone from making contact with the lifter body.
However, I’m not aware of any Pontiac camshafts made this way, or if they could be made this way. It would be interesting to test the different manufacturers of Pontiac roller cams by measuring the lobe nose radius against the cam journal radius to see if any of them are significantly different.

[RH68]

So I've been quietly playing around with this as well and think I have come up with a solution for most of the issues. It seems like the issues are:
-The Comp Cams Ford dogbone sits too close to the cam. It will interfere with the lifter at max lift.
-There is not a flat surface for the dogbone to rest on like on the Ford block. The dogbone interferes with the radius in the block casting which makes it want to cock to the side.

By giving the dogbone something to sit on, it can be raised away from the cam so that it remains flat, doesn't interfere with the lifter at max lift, and doesn't interfere with the radius in the casting at the tops of the lifter bores.

The spider needs to go both under and over the dogbone so that it can space it away from the cam and hold it flat. Therefore, it needs to consist of piece the bolts to the 2 valley pan bosses, and then additional pieces that hold each dogbone in place.

The only issue I am still having is that the dogbones are so close to the block that they will still need some material ground off so there is no interference.

I 3D printed the parts shown to mock up the solution. Actual parts would be made out of sheetmetal the the spider would extend the full length of the lifter valley. Attached are a few pictures.

[JC455]

Very nice!
Do you have a source to build the sheet metal spider?