[Bluesugar]

Cliff R and Steve C and all the rest, very good info here, very good read!

[Dick Boneske]

Thanks for the comments.

I have never seen the need for a solid lifter cam with a street-driven Pontiac. Our experience with the one Lunati hydraulic roller in a 467, and the experience with the builder who's doing our 434however, made me think about alternatives. T

he Lunati hydraulic roller performs really well, even though, as some have pointed out, it's too mild. The problem is lifter noise after the engine warms up. It's fairly loud.

The builder who has our 434 is has had very favorable experience with the Comp Cams XE solid flat tappet cams (not solid tappets on a hydraulic cam). He likes the Comp Cams lifters with the /012" hole in the cam surface, providing added lube to the cam. He has built four engines for a friend of mine. The friend is very pleased with all aspects of these cams. Performance is awesome.

[Steve C.]

Not directly related to the OP's topic but in line with Stan's comment.

This regarding a hydraulic lifter situation. From their Spintron research results, the engineers at Comp Cams actually see running valve durations decrease as rpm increases due to the increased inertial loading. The faster the cam spins, the harder it hits the lifter like a "shock absorber" effect, and the lifter loses some duration as a result. Their results from the testing indicated a "real world" dimension for a running engine with hydraulic lifters.

Example on Comps testing with a hydraulic flat tappet lobe with a hyd lifter.. At the rated .006" tappet duration it had 283 degrees, under running conditions with a 1.5 rocker ratio it had 5 degrees less duration at .006" tappet lift.. The actual loss in duration on a running engine could be quite a bit as suggested in this comment from a article on the subject:

"As rpm increase on an overhead-valve engine, this can decrease running valve duration by as much as 10 degrees."

Crower also has a solid flat tappet lifter with oil metering that provides added lubrication to the cam and lifter. Dick if you were to change from a hydraulic cam to a solid cam you need to add additional duration with the solid cam.
A 230 degree hyd cam will not act like a 230 degree solid cam.

Edit: Need to also give credit to Jay regarding adding extra duration with a solid in his post number 7


.

[Formulajones]

Originally Posted by Dick Boneske

Thanks for the comments.

I have never seen the need for a solid lifter cam with a street-driven Pontiac. Our experience with the one Lunati hydraulic roller in a 467, and the experience with the builder who's doing our 434however, made me think about alternatives. T

he Lunati hydraulic roller performs really well, even though, as some have pointed out, it's too mild. The problem is lifter noise after the engine warms up. It's fairly loud.

The builder who has our 434 is has had very favorable experience with the Comp Cams XE solid flat tappet cams (not solid tappets on a hydraulic cam). He likes the Comp Cams lifters with the /012" hole in the cam surface, providing added lube to the cam. He has built four engines for a friend of mine. The friend is very pleased with all aspects of these cams. Performance is awesome.

Don't be afraid of solid lifters on the street. If everything is done right and happy together, you really don't need to constantly monitor or reset lash.

Like I mentioned, one of our daily drivers is a solid flat tappet with the very same lifter you're contemplating. It's going on 4 years now this summer it's been together. I started off checking lash every 3-4,000 miles and it never moved. As I got more comfortable with it I'd stretch the time frame. I don't even look at it but once a year now. It still hasn't moved from the day I broke the cam in almost 4 years ago, it's been flawless now for over 30,000 miles.
They aren't as maintenance prone as people make them out to be.

As far as the cam itself, I don't know the lobe profiles, it's a custom grind done specifically for my engine by Mike at Zimmerman Racing Engines. So he basically picked the lobes he likes to use, but it is of the newer stuff with tight lash settings. I also had it nitride coated just for good measure, knowing this thing was going to see daily use. I would assume your engine builder may also pick a custom grind for your combo that suits your needs and not necessarily some off the shelf piece..
The only reason I went solid flat tappet in this particular engine is because it came from the factory with one and I wanted to keep it that way. As far as what you're doing Dick, with a mild Pontiac, a flat tappet hydraulic wouldn't bother me a bit either. Even a hydraulic roller for that matter as I've had excellent results going that route as well.

[Steve C.]

UltraDyne has been mentioned here. This from Harold Brookshire .....

The way I design solid lifter ramps you can loosen them up at least .004", and tighten them down at least .008", on the normal, ie--.017" ramps.
On tighter lash cams, you can run them about .006" looser, and .006" tighter, because they generally have lower opening velocities, because of the tight lash.
On either type of ramp, the closing side is slower and therefore longer than the opening side. About .006" tighter changes the duration about 5 degrees, 2 degrees on the opening side and 3 degrees on the closing.
With real slow ramps, the ratio may be 1 to 2


.

[Stan Weiss]

Dick,
Have you said how high you want to rev the engine.?

Stan

[darbikrash]

As already mentioned, nitriding a flat tappet solid cam is a really good idea. Comp charges about $100 extra and they do it in-house, the resulting hardness increase on the cam lobes is money well spent. Combined with the EDM oil hole on the lifter face, this setup is about as good as it gets for a street build requiring good longevity.

[Jay S]

There is another option to provide similar results to a solid flat tappet cam with the edm oiling on the lifters. Rhoads Vmax lifters with the super lube option give a hydraulic flat tappet cam many of the same quality’s. They have a groove on the outside of the lifter to provide extra oil to the cam. In my opinion it isn’t as good as the edm solids but it is very effective as well. Crower and Howard’s have a similar option. But the Vmax and Vpro do not have the duration loss like what Steve posted and the engine masters dyno testing. This is only on Vmax and Vpro lifters, the original rhoads have the same or similar losses most high rpm lifters have.

Even when there is no need for variable duration lifters, on higher rpm hft engines I strongly suggest running the vmaxs or the vpro super lubes. There are still benifits the the Vmaxs because they pump up and act like solid lifters once they are fully stroked. Where a normal hyd lifter looses duration at higher rpms like what Steve posted vmaxs decrease that shock absorber effect a bunch.. Once the lash is tightened down to .005” or less and they run quieter than most lifters, almost never need to be adjusted and provide high rpm power like solid cam.

Vmaxs even work on solid cam profiles. You need to know what you are doing, but it is not unusual to run them on solid lifter cams in vaccuum restricted class racing and 4x4 off-road classes.

[Skip Fix]

Cryoing lifters and cam is not a bad idea either. Paul Carter here does it.

[77 TRASHCAN]

Originally Posted by Jay S

There is another option to provide similar results to a solid flat tappet cam with the edm oiling on the lifters. Rhoads Vmax lifters with the super lube option give a hydraulic flat tappet cam many of the same quality’s. They have a groove on the outside of the lifter to provide extra oil to the cam. In my opinion it isn’t as good as the edm solids but it is very effective as well. Crower and Howard’s have a similar option. But the Vmax and Vpro do not have the duration loss like what Steve posted and the engine masters dyno testing. This is only on Vmax and Vpro lifters, the original rhoads have the same or similar losses most high rpm lifters have.

Even when there is no need for variable duration lifters, on higher rpm hft engines I strongly suggest running the vmaxs or the vpro super lubes. There are still benifits the the Vmaxs because they pump up and act like solid lifters once they are fully stroked. Where a normal hyd lifter looses duration at higher rpms like what Steve posted vmaxs decrease that shock absorber effect a bunch.. Once the lash is tightened down to .005” or less and they run quieter than most lifters, almost never need to be adjusted and provide high rpm power like solid cam.

Vmaxs even work on solid cam profiles. You need to know what you are doing, but it is not unusual to run them on solid lifter cams in vaccuum restricted class racing and 4x4 off-road classes.

I was reading the Rhoads Lifter website. Was surprised to see them recommending the V-Max could be used with solid lifter cams. Their description of the V-Max: Duration reduced 5-20 degrees, full lift at 4000 RPM's, 2-4" more idle vacuum, and NON collapsible!!! Rhoads calls the V-Max lifters, racing lifters.

Thew newest Rhoads lftter is the V-Pro (for street use), similar to the V-Max. THese are also non collapsible, stated full lift at 3500 RPM's. Says 1-3" more vacuum at idle, AND the V-Pro's can be used with stock cams that have over .380" lift...

I have not heard anyone here that has tried the V-Pro's...yet

[Formulajones]

I have a hydraulic flat tappet build planned in the future if I ever get around to it. I wouldn't mind trying the V-pro's and see how they do. Actually was already thinking of using Rhoads in it to mimic the sound of a solid cam, since this engine is going to be a clone of a factory solid lifter engine.

[steve25]

By a clone of a factory motor are you alluding to a 389, 421 , 303, 366 or a 400?

[TheGrudge]

Originally Posted by steve25

By a clone of a factory motor are you alluding to a 389, 421 , 303, 366 or a 400?

My guess would be 302

[Dick Boneske]

Originally Posted by Stan Weiss

Dick,
Have you said how high you want to rev the engine.?

Stan

It will never see anything over 5,500.

[Stan Weiss]

Originally Posted by Dick Boneske

It will never see anything over 5,500.

Dick,
JMO But I would go with a hydraulic lifter cam. I see no advantage for going solid lifter.

Stan

[tom s]

2X Stan.Tom

[Skip Fix]

288/296 on a 112 UD HFT. I have the 296/304 in my 455 and it is a little rowdy.

[Jay S]

I agree, solid cams seems kind of unnecessary.
FWIW, One solid cam is not like the other from a different cam family. You can’t just look at the .050 tappet lift numbers and say subtract X duration to compare it to a hydraulic tappet cam.

Here are 3 cams with the same .050” durations. Using the advertise lash setting to get specs.

XE solid, 280@.015” 242* @.050.
On the tight side of it’s valve lash range .0135” valve lash it the Intake valve closing at .009 valve lift
IVC= 70*

.0135” lash removes about 7* from .050”, or 235*

Intensity out at the valve from .006 to .050=45*
================•
XTQ solid
272* at .020”, 242* @ .050
Loose side of the lash, .021” lash
IVC = 66*
.021” lash removes 12* from .050”= 230*
Intensity out at the valve. 40*

=================.

Max Area solid
269* at .20, 242* @ .050
.021” lash
IVC = 64*
.050 duration at the valve 230*
Intensity. 35*

===============
Max area solid
283* @ .020, 256 @ .050
.023 lash
IVC=70*
.050 duration at the valve 243*
Intensity 35*


The Intake valve closing IVC at .009” valve lift has as much or more to do with the power band as the .050” durations.

The ratings can be vary misleading on solid cams. The XE 280 has close to the same power band as the MA283. The XTQ 272 and the MA269 would fall 300-500rpm short of either cams power band with less hp even though it appears to have the same 242* at .050”.

Like Cliff said, the XTQ series needs every bit of 15* more duration going from a hydrualic. Max area need more yet. A extreme energy solid needs closer 10*. Each cam is different.

A Ultradyne like Skip’s is probably closer to 8* to make the same power with .050 hydraulics cams. Lol.

Welcome to the World of Solid cams. It is not straight forward...

[Stan Weiss]

Cam selection can be a bag of worms.

What you want is a valve lift curve which meets the engines needs.

Looking at the cam lobe data from a RAIV cam (if my data is correct) and adjusting it to give the same valve lift curve with 1.5:1 rocker ratio I see a problem. The cam lobe would run off of the lifter face. Back when Pontiac designed the RAIV engine / cam there was no option for hydraulic roller lifters. So they went with the 1.65:1 rockers with the lobe design they did. Their only other option to use 1.5:1 rockers would have been been to use a larger diameter lifter.

This is my long around way of saying don't just look at what a cam profile will do for you with only using the stock 1.5:1 rocker arms

Stan

[Tom Vaught]

A FEW Ram Air II engines were built with the Ram Air IV camshaft profile and the 1.5 rockers. You don't see many of the RA-II engines still alive. It makes me think your story might have merit for the failure rates on those RA II engines, Stan.

Tom V.