[grivera]

Originally Posted by tom s

My set are dead quiet.Tom

Thanks - good to know.

I asked about spring pressure and he advised 200# on the seat, #420 open

[chuckies76ta]

I seem to recall Dave supplying 99893 springs. 160 seat somewhere around 380 open. 200 closed seems like a lot for hydraulic roller. High high RPM?

[tom s]

200 on the seats for solid rollers on a hyd roller cam is correct.I run 150 on the seats with hyd roller lifters.Tom

[chuckies76ta]

Sorry about that post of mine Tom. Didn’t realize he had quoted you.

[Formulajones]

I could see that for solids but that seems high for a hydraulic roller.

Typically, with Pontiacs having heavy valve trains similar to BBC's, 150-160 lbs on the seat is common with about 400 open with a hydraulic roller.

In fact I talked to Paul about this when setting up the hydraulic roller in Dad's engine and those are the pressure we went with, using a slightly heavier 2.19 intake valve but light weight retainers. It's been fine.

Not enough pressure with these heavier valve trains can be as much of a death sentence as too much pressure. That's why I prefer to take spring advice from the builder/machinist that has run thousands of these combos on the dyno using certain cam profiles.

[Lee]

The stroked 428 I mentioned awhile back now has 1,000+ miles on it, and the Comp Evolution HR lifters are doing fine. D-port 96's, ported & set up by Dave Bisschop for the HR cam.

[65madgoat]

Been using these PAC springs lately with hyd roller Johnson lifters

https://www.summitracing.com/parts/rsc-pac-1219x-16

[chuckies76ta]

Ya it seems to be two camps on the spring pressures
with solids on HR cams. I have been running the 99893 springs at 160/400 for years and no issues. What I find
Weird about the weight thing is the solids are lighter lifters
I realize it’s about lash and cam profile though. And yes recommend by builder.

[chuckies76ta]

Ya it seems to be two camps on the spring pressures
with solids on HR cams. I have been running the 99893 springs at 160/400 for years and no issues. What I find
Weird about the weight thing is the solids are lighter lifters
I realize it’s about lash and cam profile though. And yes recommend by builder.

[Skip Fix]

"I have been running the 99893 springs at 160/400 for years and no issues."

Did you check they had that much seat pressure? The ones SD sent on my newer heads did not and had to be shimmed to about 1.770 to get there.

[Steve C.]

"...in most applications we use the Crane 99893 valve spring, installed at 1.790-1.810", I set the intakes on the tighter side of the tolerance, I test all the springs and always put the ones with the higher pressures on the intake valves, since the intake valves weigh more and also have the momentum of the charge pushing on the back side of the valve while the exhaust valve if anything has pressure pushing or drawing it closed and the valve is lighter. On my digital InterComp spring tester the seat pressures on a new set of springs will range from 147-157lbs typically @ 1.800" and 380-390lbs @ 1.200" open pressure."

That comment was posted by Dave Bischopp within a discussion of the Old Faithful hydraulic roller cam, but NOT with the use of solid roller lifters.
At that time Crane rated that spring at 1.850 with 130 lbs seat pressure in their catalog.

Today with the Old Faithful 2.0 hyd roller cam Dave is using the Comp 26925 spring rated 141 lbs at 1.810"


.

[darbikrash]

Originally Posted by chuckies76ta

I seem to recall Dave supplying 99893 springs. 160 seat somewhere around 380 open. 200 closed seems like a lot for hydraulic roller. High high RPM?

It's a blower motor which requires more spring pressure than N/A.

The Evolution lifters are rated to 450#.

[chuckies76ta]

Originally Posted by Skip Fix

"I have been running the 99893 springs at 160/400 for years and no issues."

Did you check they had that much seat pressure? The ones SD sent on my newer heads did not and had to be shimmed to about 1.770 to get there.

Yes on my wife’s previous engine I did shim them to increase seat pressure to around 160 I believe.
Haven’t touched my engine though.

[chuckies76ta]

Originally Posted by darbikrash

It's a blower motor which requires more spring pressure than N/A.

The Evolution lifters are rated to 450#.

I wasn’t aware the conversation changed to a blower
Application. !!!

[Cliff R]

As mentioned the HIPPO solid roller lifters and considerably lighter than a retro-fit HR lifter. No need for more spring pressure with them. In my 455 with the 1st version OF cam it would rev to and past 6500rpm's so fast you'd have trouble moving the shifter quick enough to keep it from over-revving.

In my previous 455 with HR lifters it went "dead" at 5800rpm's. I even tried more spring pressure and it made no difference whatsoever, DONE at 5800rpms. Not a big deal because I typically shift at 5000rpm's at the track and went thru around 5200-5300 on top end. Raced the car like that for many years with zero issues anyplace.....

[grivera]

Originally Posted by grivera

Thanks - good to know.

I asked about spring pressure and he advised 200# on the seat, #420 open

Could the high spring pressures cause the bleed down issue?

[Steve C.]

Solid roller lifters on hydraulic roller profile....

https://www.yellowbullet.com/threads...ofile.2680361/


Note tom s post number 11 within that thread.

Opinions vary. Do your homework, this subject has been discussed many times here on PY.

One example of many:
https://forums.maxperformanceinc.com...d.php?t=659422


.

[Formulajones]

Originally Posted by grivera

Could the high spring pressures cause the bleed down issue?

200 lbs on the seat certainly would be approaching that threshold.

It's why I've always advocated spending the money to lighten the valve trains as much as possible so you don't have to get too crazy with springs and still have a hydraulic roller that spins as high as you need.

The blueprint 598 I bought only has about 145 on the seats on the ones I checked which matches the paperwork they sent. Not near enough on a BBC with a 2.30" intake valve. And that's exactly why they stopped the dyno at 6000 even though it was still climbing in HP. I highly suspect they ran into valve control issues and cropped the dyno sheet right there.

[Formulajones]

Originally Posted by grivera

Could the high spring pressures cause the bleed down issue?

I'll elaborate on that further with some experience I've had with that.
Decades ago the 454 bbc I built I used AFR heads. They spec'd the camshaft which was a hydraulic roller. They sent the heads with solid roller spring with 275 #'s on the seats!! The engine actually ran perfectly fine. The Johnson lifters did have a slight sewing machine noise but nothing harsh and hard to hear with the hood closed.
I drove and raced the car for 2 years like that. Until one day it developed a squeak. Sure enough turned out to be a wheel on one of the rollers.
In a nut shell the hydraulics worked ok but eventually it'll eat a wheel with pressures like that, and it did. I checked pressures on disassembly and found the spring problem. I reassembled with new cam, Johnson rollers and springs with 160 on the seats. It's been running fine for the last 26 years and spins to 6500 no problem.


I think when you start really pushing the spring pressure it does have an effect on reliability and the same effect on the other side of that
spectrum too. With every engine
being different there is no good answer but if 160 on the seat is good enough for a BBC to spin a hydraulic roller to 6500 I can't see a reason for needing 200 on the seats. That just sounds like it'll be harder on parts than it has to be.
Maybe other engine builders with more experience spinning heavy valve trains can comment

[Jay S]

I am waiting for someone to put a Pontiac link bar on an Isky HPx needless lifter to run in a Pontiac. Rated for 185 seat, and 535 lbs max lift, and 7500 RPM, and supposedly out lasts needle type lifters by 3X. That would make you cool

FWIW, just and observation, but the drop off that engines often have with HR cams at around 6000 or slightly better is not as much do to the lifters weight, as it is the internal valving doesn’t flow enough to feed the plunger, then the spring pressure ends up overwhelming the plunger. The Hylift Johnson “S” slow bleed lifters have extreme controlled bleed rates, and they still often have that trouble making it much past 6000 with aggressive cams. Johnson’s limited travel (PR) lifters (also my suggestion for what to run for the OP) act similar, as do most all the offering across brands except the short travels. The only way to get around that for more RPM’s seems to be to bottom out the lifter like others have already mentioned. More valve spring pressure makes it worse instead of better. The more acceleration the cams has off and on the base circle the more pronounced it seems to get, the beehive springs are a band aid, and don’t really address the problem. The Comp evolution lifters look to me like they redesigned the piston to help that, making the volume smaller so the valving doesn’t have to feed as much oil to it. I think the better solution was what Isky did (made by Johnson) which was to change the valving so it flows more and tight machining to keep the bleed rates very precisely controlled. I don’t think Comp will be able to run as much spring pressure as Isky’s HPx lifter because they made the piston smaller. Time will tell.

I run around 160 and just over 400 (.6 to .65” lift)on my hybrid cams, if you have to run 200 your likely running too much lash on them, and that gets to be pretty hard on the lifters. You might as well run a mechanical profile with it set up like that.

On hybrids i might mess with the lash for testing, but for operating them on the street I set the lash at zero cold on aluminum heads, for iron heads I zero lash the intake and run .005” on the exhaust, it works great. I think it gains everywhere over a hydraulic lifter, even the best ones. I have done enough thsg way, I don’t even get the feeler gauges out anymore. Iron head hybrid’s are the quietest cams I have heard, actually I think they operate quieter that the hyd flat tappets I have done, rivals any the modern platform’s HR cams for operating noise.