[Cliff R]

Years ago Lee Atkinson changed from a Ultradyne 231/239 at .050"/ 108 LSA hyd flat tappet cam to a Ultradyne solid flat tappet cam with 247/247 at .050"/ 108 LSA and he picked up about 2-tenths and 4 mph ( best of 11.27 at 199.61 mph, I think ).


Steve, is that a "typo" on the 231/239 cam being on a 108LSA?

If it was, not suprising at all that moving up to a flat solid with nearly 250 @ .050" would pick it up considerably......Cliff

[Steve C.]

I'm a one finger typist.... darn thing seems to be swelling a lot these days

119.6 mph

Thanks for the heads up.

Cliff I believe my notes are correct on the 108 LSA for both cams. He worked with Bullet on the cam, they like many others have found a narrow lobe separation can work well in a Pontiac. Dispite the horror stories that permeate our community in doing so. Harold used to use quite a bit of Ultradyne lobes with a 108 lobe separition but not typicaly in a flat tappet lobe, and the others were generaly on cams with more duration. Example, the old Ultradyne catalog suggests solid flat tappet cams from 255 and up were ground with a 108 lobe separation.

Related, Both Chris Mays at Comp and John Partridge at Bullet have both suggested a 108 lobe separation on my cams before. And they seemed to have worked quite well.

[69Goat1]

Mine is on a 108 ls... tickled to death with it!

[Cliff R]

Steve, at some point one simply has to start pulling the LSA in some or you push the power curve beyond the rpm capabilities of the engine.

I've seen poor results in the longer stroke engines with smaller cams pulled down on 108 and 110LSA's, as a general rule. Doesn't mean in a very well set-up car you can't run OK with on, but tiny cams in big engines on tight LSA's punch a LOT of power right in the mid-range, where those engines are already very good at making power. Not to mention they kill off a lot of upper mid-range and top end power.

Probably why we see more power, higher peak power, and more average power using wide LSA's with smaller camshafts instead.

Once again, moving nearly 20 degrees and keeping the 108LSA is no surprise at all that it picked up BIG time everywhere.

Back when I back to back tested the Comp XTQ lobes flat solid (240/248/112) against the Crower 60919 (231/240/113), we LOST power everywhere, and the engine made peak HP 400rpms earlier. To make as much as or more power, I would have needed about 5-8 degrees MORE duration, or a cam up near 250 @ .050"....IMHO.....Cliff

[69Goat1]

I also like 110 LS and have used 106 LS with very good results - Comp 290B-6...

[screamingchief]

This #60311 solid cam is making damn near identical numbers as the RAIV style hydraulic cams do in these sorta combos,which as I recall was Ryan's goal with using that #60311 solid cam in his combo.

If one were to compare Ryan's combo to say Cliff's very similar combo when he first put the KRE heads on his engine in that HPP magazine article,the numbers are so close that any differences could easily be chalked up to them being run on different dynos,and/or having slightly different states of tune or such.

http://www.highperformancepontiac.com/tech/0501pon_kre_aluminum_heads_dyno_results/index.html

And the difference in when the peak torque occured on Ryan's build could easily be explained by a few things,like Ryan using an RPM intake vs. Cliff using his modified OE iron intake,as well as the Ehead having a bit more port volume for roughly similar head flow numbers,as well as the solid cam having that additional "area under the curve" (ie. more .050" duration and such) among other things.

So what that #60311 solid cam might "give up" on the seat numbers to the RAIV style hydraulic cams,it replaces just enough "area" elsewhere on the lobe to make up for that situation.

IIRC in that article Cliff's engine made 549 trq @ 3600 rpm & 494 hp @ 5500/5600 rpm.

Compare those numbers to Ryan's 536 trq @ 4300/4400 rpm & 502 hp @ 5500.

So indeed that #60311 solid cam is a very close solid cam approximation to those RAIV style hydraulic cams.

Not bad @ all IMHO.

And yeah,as Darby pointed out,the AF ratio numbers do indicate that Ryan's combo needs just a bit more fine tuning for optimum results.

But I will say the BSFC numbers with the solid cam look way better than they did with the XE hydraulic cam.

Also,FWIW there was no loss in average torque @ all for Ryan's combo,for both cams that was a dead heat,with the solid making 516 avg.trq. & 440 avg.hp. vs. the XE274 that made 515 avg.trq. & 438 avg.hp.,so likely nothing was actually "lost" at all,it just got shuffled around enough to make that appear to be the case.

Yeah,I think Ryan will be happy with it,and I agree with Draby,almost certainly there is more to be found in it with those further tuning efforts.



Bret P.

[GOAT8U2]

OP, curious on these questions....

What's your launch rpm?
What's your shift rpm?
What rpm does it drop to in the new gear?

[slowbird]

Our 400 pump gas (street driven everywhere) with iron heads runs good with 106LSA (11.4@119mph)
Our 472 with e-heads rans good at hyd cam on a 106LSA (10.0@130mph)

[bobzdar]

Maybe I'm missing something here, but why bother with the solid then? If it performs almost identically to a hydraulic with the same low rpm behavior, there doesn't seem to be any reason to run it.

These cams seem small for e-heads if one is after track performance, but that's jmo. Seems like a stock eheaded pontiac should be in the 550hp range, not 500 even. With the right cam, 6500-7000rpm power peak should be attainable without going crazy on the valvetrain and the heads can support that rpm on a 455 based block, so why build for 5500rpm operation, especially if you're going with a solid cam? I must be missing something...

[screamingchief]

Originally Posted by bobzdar

Maybe I'm missing something here, but why bother with the solid then? If it performs almost identically to a hydraulic with the same low rpm behavior, there doesn't seem to be any reason to run it.

These cams seem small for e-heads if one is after track performance, but that's jmo. Seems like a stock eheaded pontiac should be in the 550hp range, not 500 even. With the right cam, 6500-7000rpm power peak should be attainable without going crazy on the valvetrain and the heads can support that rpm on a 455 based block, so why build for 5500rpm operation, especially if you're going with a solid cam? I must be missing something...

Solid cams & lifters can eliminate certain failure points,have ever seen a hydraulic lifter pump up and spit it's guts out,well I have,and it's not always pretty.

To simplify the answer,no lifter pump up,and better overall valve control.

The solid cam will always do better @ higher RPM than a comparable hydraulic cam will.

A higher peak power like you mention would easily mean more wear & tear in general,shorter spring life just to name one item that would affect.

Remember,Ryan is using the 87cc Eheads,box stock,now thats another thing that was'nt mentioned yet,but he has a fairly conservative CR in his motor,so the thing obviously was'nt put together to be an all out "fire breather" like your talking about.

He just wants a good solid relaible drag car,what's wrong with that?

Some folks dont really want/need a car faster than 11.50's,because that means all the safety stuff is then needed,roll bar @ the minimum,and whole slew of other safety gear as well.

FWIW

Bret P.

[bobzdar]

Gotcha, but at 5500rpm you're not really going to be dealing with lifter pump up or valve control issues, will you?

It seems e-heads and a solid cam are excessive for the power and rpm level, so I'm trying to figure out why they were used.

If I were to try to duplicate this performance in a 400 where the rpms would have to increase to 6200 or so, I would use the solid cam. Still the heads are a question mark, though if it's anything like one of my projects they could have been purchased 5 years ago or so when we didn't have the CNC dports that would easily support that power level...
This is good comparison info, it shows that the need for a solid changes depending on the CID of the engine, another small factor in favor of more cubes. Bang for the buck at the 500hp level would appear to be 4.21 stroke, CNC dports and a raIV hydraulic or similar. To do so on a 428 would be marginal for a hydraulic. 400 would need a solid.

"Some folks dont really want/need a car faster than 11.50's,because that means all the safety stuff is then needed,roll bar @ the minimum,and whole slew of other safety gear as well."

As for that, I'd rather slow the car down than leave power on the table by going small on the cam. If I pay for the airflow, I'm going to use it.

[grandville455]

Bret I noticed that too On the Bfcs Numbers, Definately was happier now, but i believe he added that 850 baseplate after the 274 dyno run? I could be wrong tho. Also It is obvious that the cam now is wanting more Fuel as shown with his A/F. I bet there is close to 10-20 hp out there yet just in A/F. Where was the timing? I say jet it up some more on the secondaries and run her for a baseline at the track.
Ryan
Where did u end up with jetting on this build? Is this a fresh engine Or just a cam swap?

Either Way I think its going to be faster than the 274 when all said and done, which it should if its close in comparison to the RAIV grinds. JMO

[mudbird]

IMHO I think it is all good Ryan. I would like to know your launch rpm and shift points too. R&R is right by my house!
( if I am not there) When are you going?


I do not have my old cam out yet. (got the acc. and rad. and stuff off)


I found the spacer stuff interesting... been thinking of a Jim Hand type spacer as I have run a 4 hole on mine before....

[screamingchief]

Originally Posted by bobzdar

Gotcha, but at 5500rpm you're not really going to be dealing with lifter pump up or valve control issues, will you?

Often folks will shift the car somewhere just above peak hp for best ET's.

Plus what about a missed/late shift or such?

IIRC Ryan's deal is a M/T,and rev limiters can only react so fast,so I dont see any real downside to his using a solid cam in his build.

Originally Posted by bobzdar

As for that, I'd rather slow the car down than leave power on the table by going small on the cam. If I pay for the airflow, I'm going to use it.

Airflow on the "box stock" Eheads or KRE-D's aint all that much,what's that,like 260 - 270'ish cfm or so.

So that's nothing to write home about,that's for sure.

Most people buying/using "box stock" aluminum heads are'nt doing so for the better flow numbers,they're usually doing that to avoid the hassles of messing with 40 yr. old iron heads and their potential issues.

And often they want the ability to run a slightly higher CR safely on pump gas.

Dump the money into ported iron heads or buy some Eheads is usually what they're pondering,and $ for $ common sense says the aluminum heads are money well spent.

Plus the aluminum heads have much better resale value as well.

Plus slowing a car down is'nt always as easy as it sounds...

It all makes perfect sense to me.

FWIW

Bret P.

[ry57pont]

Darby, i ended up jetting 85 rear 75 front, total timing at 36deg. yes i suppose there is some A/F tuning to be had. i was pretty excited to try out my innovate A/F meter until ron at R&R showed me 20 bad senders that he has gone through with the innovate system.

i could regret going bigger on the cam, but i wasn't willing to give it more compression, gear, RPM and i am using a stick so the power band coming in later kind of worried me. plus i never have owned a soild so i wanted to try it out. plus i feel like i might be asking alot of the cast eagle crank

11.50 is the absloute fastest i want to go, and honestly i still probally far from it.

launch rpm - 3500-4K ( at 4k i severed a axle)
drops from shifting- ?
i had been shifting at 5200 (based on the old cam)

Brett- i did have a rev limiter fail, when it jumped 2nd. motor died, got pushed off the track, said various swear words ect..


But what i REALLY WANT. is to have a picture like Darbys hanging on my garage wall. (wheels up)

Steve, already went. couldent you hear the motor from your house?

[mchell]

Originally Posted by ry57pont

Darby, i ended up jetting 85 rear 75 front, total timing at 36deg. yes i suppose there is some A/F tuning to be had. i was pretty excited to try out my innovate A/F meter until ron at R&R showed me 20 bad senders that he has gone through with the innovate system.

i could regret going bigger on the cam, but i wasn't willing to give it more compression, gear, RPM and i am using a stick so the power band coming in later kind of worried me. plus i never have owned a soild so i wanted to try it out. plus i feel like i might be asking alot of the cast eagle crank

11.50 is the absloute fastest i want to go, and honestly i still probally far from it.

launch rpm - 3500-4K ( at 4k i severed a axle)
drops from shifting- ?
i had been shifting at 5200 (based on the old cam)

Brett- i did have a rev limiter fail, when it jumped 2nd. motor died, got pushed off the track, said various swear words ect..


But what i REALLY WANT. is to have a picture like Darbys hanging on my garage wall. (wheels up)

Steve, already went. couldent you hear the motor from your house?

you never know until you try............have fun with it.....and post the results!

[grandville455]

Ryan
I would say more jet maybe 2 in each front and back, and those heads like closer to 38-40 degrees total! What 9 did u go with?

P.s Would u like to buy my picture ?

[tc]

Hope you run 11's, sometime! The photo is from today.

[grandville455]

Tom
Don't be sending that crap up here!

[ry57pont]

Originally Posted by grandville455

Ryan
I would say more jet maybe 2 in each front and back, and those heads like closer to 38-40 degrees total! What 9 did u go with?

P.s Would u like to buy my picture ?

it seemed to fall off a bit at 37? never tried it more. still have not made a 9" purchace yet, probbally go with a Moser. trying to find one used.

yes i will take a signed copy.