[Cliff R]

Reboxing is commonplace now in the parts industry and likely you'll get something off-shore or low quality if you don't insist on genuine Hylift Johnson lifters.....IMHO.

When all the cam lobe failures started to be commonplace folks blamed just about everything but the lifters. It just so happened that several things happened about the same time. The USA companies making good high nickel content correctly machined lifters went out of business or got bought out. The industry started sourcing out off-shore lifters. We started to see a lot of "reboxing" as well so you never knew exactly where the lifters were coming from even though in fine print someplace on the boxes it may reference "Country of origin", but not always. Federal mandates also went into place to remove some trace metals from lube oil, zinc, etc.

So we start reading about all sorts of lifter failures and folks blaming the oil, not removing inner springs during "break-in" and improper break-in procedures. I can tell anyone reading this that knocking half the lobes right off the cam in less than 20 minutes is NOT the oil that you used or the fact you didn't remove the inner springs.

I knew some very skilled engine builders that had never had the first issue once and were loosing just about every flat cam they installed, and some of them in minutes after start-up. So a few that are pretty dedicated started removing the valve covers despite the mess it made and painting a white stripe on the top of the pushrods and guess what......they were NOT spinning on the initial run-in of the engine. That is a DEATH sentence for that lobe and sure enough when they shut things down and pulled the intake and valley pan off the same lobes where the lifters weren't spinning were either failed or failing.

So what it boils down to is incorrect machining combined with "soft" materials being used to make them. Even if you got thru the break-in without scrubbing a few lobes there were noise issues due to poor plunger to body tolerances (leak down rates all over the map).

IMHO the problems we saw back then and still seeing today are solely related to poor quality lifters being used.

This is why I would use genuine Hylift Johnson lifters if you are building an engine with a flat hydraulic cam in it. Second option is to use Rhoads lifters which far as I know are still nothing more than modified USA made Johnson lifters. No way to really confirm that at this point so if you don't bleed-down type lifters then source out Hylift Johnson lifters. At a minimum you'll get thru the break-in without putting a couple of pounds of ground up cam lobes in your new engines and you'll probably sleep better at night too........Cliff

[Nyairguard]

Order came in from advance, I bought sealed power ht-951 .. made in China and smelled like harbor freight. Bringing them back today and look for a USA set..

[Nyairguard]

Called mike at lunati to discuss the 10510312lk and confirmed the fit and he stated as a very good match for my current setup also guaranteed me the lifters in this kit are made in the USA . So I placed the order even gave me free shipping so for the 216.99 I feel good with this purchase, thanks for the help fellas and will report back my likes and if any dislikes

[Tim Corcoran]

I seriously doubt lifters from Lunati are made in the USA a salesman will say just about anything to get you to buy their product. Lunati makes great cams but they don't make their own lifters and I would bet you a 100 bucks they are not made in the USA. Listen to Cliff Ruggles don't cheap out and save 10 or 20 dollars on a set of lifters only to ruin a $5,000.00 engine. Buy the Top Line Hy-Lift Johnson 951R lifters for a flat tappet hyd cam. Then make sure you are running to correct springs for your installed height and have proper open and closed spring pressures. It's not worth the risk.

[steve25]

Please also note that if you are using the stock 5/16" push Rods that they are only good to spring open pressures of 270 to 280 psi before they start to flex like a blade of grass, and you know what that leads to!

These open pressures should get the motor to 5600 rpm pretty easy with a 2.11" Intake valve depending on the mass of the spring itself , the weight of the retainer and the weight of the rocker arm on the valve side of the valve train.

If you the added funds to run a 21st century Beehive or Conical type valve spring on the heads you can gain the added plus of better valvetrain control, no dips in the power band and atleast 800 more rpm with the same open pressure you would be running with a old style valve spring!

These new type springs also have less seat pressure along with there better overall valvetrain control so the breaking in period of having a new Cam in the motor is far less worrisome!

[Jay S]

The Lunati microtrols are usually our second choice if I can’t buy a hylift Johnson. They at least come with a regular snap ring on the retainer. Other than that I don’t think they are much different than comps lifters.

The Lunati cam you picked and the 995 springs are a bit of a miss match. The springs will work but you don’t need that 400 lb spring rate and the big distance to the coil bind, you should only need a 330 on the rate. You can certainly run it that way and you will likely never know it. Normally you pull the inner springs out when you break in the cam with 995s, at the lift your at it probably will be ok not to do that. Better to pull them though.

[Steve C.]

Both Tim and Jay have again brought up the subject I eluded to in my post number 11, and that's the potential excessive distance from coil bind with a low lift cam used in con junction with your 1.700" installed height.

That said, another subject to consider and that being the amount of pressure your current 995 spring have after being used already. Personally I would remove a few of the springs and have them tested at the current installed height with their retainers in place. Then call mike at lunati again and ask how much pressure they suggest to use with your new cam.


.

[1968GTO421]

Are Lunati's valve springs OK? Wonder since their lifters are suspect. If Lunati springs are OK, I would think they could recommend the best spring for their cam.

[Steve C.]

Lunati 'recommends' online their 73949 dual spring for the 10510312LK cam. It is rated 120 lbs on the seat at 1.650" installed height. BUT the springs coil bind rating is 0.950". Now take into consideration what the pressure would be at a higher 1.700" installed height and with the 0.296" distance away from coil bind at that installed height. In my opinion not a optimum spring package.

"Coil surge is a scenario that takes place when the spring is set up too far away from coil bind giving the middle coils room to bounce back and forth from top to bottom as the spring is closing. This usually takes place with a highly energized spring (fast ramp rate) at high engine speeds. Having a spring with not enough rate can exacerbate the problem and having a spring with both too little rate and not enough seat/nose pressure in conjunction with being set up too far from coil bind is down right deadly."
Darin Morgan
-Induction Research and Development
-EFI Calibration and Tuning
Reher Morrison Racing Engines

.

[Nyairguard]

I will call lunati and get the skinny
looking back I feel I should have reached out to len williams for one of his builds

I called the shop that built this 400 and I told them that I didnt like the way the 1.65 rockers let the push rods rest on the heads I never ran them and put a set of 1.50 on so I can sleep at night. he told me that it would be fine and I read too much. I looked for a good block to build but at the time it made sense to buy a complete engine I figured if I bought an engne for 1000 and tore it down and another 500 for sonic and magnaflux just to find a bought a 1500 min. boat anchor...ugh

[steve25]

If it's ok to have the pushrods rubbing on the heads then I can only assume that this builder is also ok with Bearings rubbing on Crank journals as in zero Bearing clearance!

What BS that guy spews out!!

[Cliff R]

That's because he already got paid and you are now under his best in the industry lifetime blanket coverage "Arkansas Warranty"......

"IF your break it in half........you get BOTH halves!"....LOL

[steve25]

Lol!

[Jay S]

Hopefully we can change your fortune some

The cam you have picked out is an old Ultradyne profile designed to run stock valve terrain. It was designed by Harold Brookshire back in the 80s. You can run that cam with stock valve springs, it was right at coil bind (no spring surge). They worked best on the d port engines like the ra 3’s that ran more seat pressure than 90. The spring rate on most of the mass built oem Pontiac heads ran just under 330, 90 seat and 240 at .45” lift.

Most cams companies list kind of one size fit’s all for their recommended springs. On an odd combo like this there is a very good chance you need to look outside of Lunati to find the best spring package for that cam. The 995s Comps will work, they will abuse the cam more than is needed. Lunati’s recommended spring are a better, but the installed height is off, still somewhat of a mismatch.

[Nyairguard]

Ya bumper to bumper 0 deductible... was looking to pick up a few things from spotts on eBay and last night I looked and all his stuff was removed. Hope things are alright and he relists

[Steve C.]

Adjust the installed height and then find a better spring package for that cam.

The lobes Jay mentioned - H4 and H9 here:

http://www.bulletcams.com/Masters/ultradynemasters.html

Example:
Using the 1.65 rocker arms it would have 0.499" lift.
Lower the installed height to near 1.600".
One option might be the Crower 68404 spring rated 113 at 1.600"
About 0.151" away from coil bind.

Information provided does not represent any product endorsement
And is offered for general interest only.

[1968GTO421]

Originally Posted by Nyairguard

Ya bumper to bumper 0 deductible... was looking to pick up a few things from spotts on eBay and last night I looked and all his stuff was removed. Hope things are alright and he relists

If he doesn't re-list, you can always contact Paul K on this forum as he has tons of stuff. I got my Hy-Lift Johnsons from him. (Paul Knippen)


http://forums.maxperformanceinc.com/...newpm&u=134156

https://www.facebook.com/search/top/...uscle%20motors

[Nyairguard]

Using 1.5 rockers

[Formulajones]

I agree with the others on the spring deal. What caught my attention early on in this thread, I just didn't bother to mention it because it is what it is now, but why would an engine builder set those heads up with a 1.7 install height and spring package just to use the little 068 cam?

I think the cam you picked is worlds better than the 068 but I personally would rather run that at a 1.6 install height with something like a 68404 spring package would be more ideal, and possibly even a 1.65 rocker (just clearance the heads for it).

[Nyairguard]

thats alot of shim under a spring to run the crower 68404 ?? not sure