Max lift with GM dogbone roller lifters

[Darbikrash]

What is the maximum lobe lift that can be used on the dogbone style hyd roller lifters? I'm considering a cam with .395 lobe lift, OK with these lifters?

[rebelyell]

I read some where when using OE L31 lifters, the max lobe lift is about .350"
any more than that & cam may have reduced base circle and allow lifter to drop below dog bones' grasp; boom
There are pricey reduced travel lifters which may help you; I've never used one.

Also, if lifters' oil band rises or falls too far in bores, valve train oiling will suffer.
I certainly wouldn't gamble, I'd setup & measure.

[turbo camino]

Do you mean dogbone-style lifters, or actual OEM factory stock roller lifters? Cause there are drop-in lifters (Morel, others?) labeled as 'high lift' that keep the dogbones, but have a taller body in the flat section so the lifter doesn't drop out the bottom of the dogbones when on the base circle.

https://morellifters.com/products

[Darbikrash]

Neither the cam or lifters have been bought yet, just looking to see if I have to go to a tie bar style lifter. Its a Dart SHP block, so it's ready for the spider and dogbones which I would prefer. The base circle of the cam will be 1.05", and the most likely candidate for lifters would be the Johnson dog bone style.

[url]https://www.johnsonlifters.com/Products ... iption/url]


Any experience with these lifters at .395 lobe lift?

[turbo camino]

If they are not listed as 'high lift' I would assume they have the standard dimension on the flats and could be an issue.

These are Morels, to illustrate the difference in the flats between std and high lift.

screenshot.02-11-2020 00.30.45.png

[mag2555]

GM lifters are terrible!

On some BBC cam lobes and SBC that are not even that wild they will not go over 5800, save yourself I tare down and open your wallet wider for real roller lifters!

[Orr89rocz]

I have used gm ls7 lifters in a sbc oem roller block with a .383 lobe. Worked fine to 7000 rpm

[CamKing]

We do not recommend the dog bone lifters with over .375" lobe lift, or under a 1.100" Base Circle.

[skinny z]

GM lifters are terrible!

On some BBC cam lobes and SBC that are not even that wild they will not go over 5800, save yourself I tare down and open your wallet wider for real roller lifters!

I have used gm ls7 lifters in a sbc oem roller block with a .383 lobe. Worked fine to 7000 rpm

I believe it was Vizard that stated that the Gen 1 OEM lifters (not LS7) which have a cast lifter body would distort at high RPMs (6000+) to the point where the hydraulics would give up leading to component separation.
This was a determining factor in trying to figure out what was up with an original ZZZ crate engine.
At the top end after a pass, while waiting for time slips, it was obvious the valvetrain was clattering away. This would disappear by the time we returned to the pits. A switch to COMP's tool steel lifter (with no other change) solved the problem and the car picked up MPH and went quicker.

[Orr89rocz]

Well just look at the many hundreds of cammed ls motors out there on hydraulic lifters turning 8000 and less rpm. Light valvetrain, proper lobes matched with proper springs you can do a lot. The “LS7” lifters became the gm replacement for a long time. A lot of guys are going to Johnson lifters for drop in replacements with great success. Ls7’s have doubled in price since 2008-2011 when i used them alot lol

[skinny z]

I'm not referring to the LS7 lifter. Or any replacement for that matter. Only what came as original equipment when rollers where first introduced.

[turbo camino]

How many lifters installed at the factory in new engines in 1987 are being re-used today in performance builds?

[skinny z]

Hey man, I'm only the messenger.
And probably more than you might think. Seems that the junk yard L31 is still a popular starting point for many. And I'll bet those engines get recycled everything and this wouldn't necessarily exclude them 6000+ RPM.
Further to that, the ZZZ crate engine referred to in the example has less that 20k miles of combined street and drag strip driving. Hardly worn out and yet the lifters proved unsuitable.
Just saying.

[CGT]

Anyone thinking that the "LS7" lifter and the earlier sbc lifter are drastically different haven't actually looked at them both. There is no difference in material composition to cause "distortion" or whatever that crap is supposed to mean. The only distortion would be the distortion of reality.

I have had the early lifters at 7000 or above with no special considerations, and the LS lifters to 8400. I have taken both types apart, cleaned, inspected and reused. Even old varnished ones . to well above the 6000rpm or 5800, like was mentioned by some here. That is just ridiculous to me. Likely just regurgitation.

From an rpm and noise level perspective, the OE lifters are hard to beat. And I would choose them almost always in a block that has provisions, outside of short or limited travel applications, extreme endurance or pressures etc. I have travel limited the factory type lifters even as far as that goes.

As far as a max lift or base circle requirements, I'd want to mockup and look at that for myself and not just go off what someone says online.

If I had an engine with GM OE hyd roller lifters not wanting to go over 5800 or 6000, the lifters would be several places down on my list of things to look at, barring the lifters weren't previously damaged, abused, or destroyed. The internet

https://www.youtube.com/watch?v=3DZbSlkFoSU

[skinny z]

Talk to Vizard.