[Steve C.]

Formulas- When Ultradyne went under, for business related reasons not product problems, Harold moved over to Lunati. With him went one set of masters for his grinds where I suspect they are sold under the "Voodoo" brand. There was another set of masters for Ultradyne grinds and it was obtained by John Partridge at Bullet cams thru bankruptcy proseedings, along with the proceedings he obtained the rights to use the "Ultradyne" name & logo.
This is my understanding of the situation.

And my vote.... a custom solid flat tappet cam made for your specific combination and needs, a design thoroughly discussed by a camshaft tech rep at the company of your choice. And if its a "Ultradyne" grind you might find it easier to deal with John at Bullet rather than trying to deal with Harold at the huge impersonal Lunati conglomerate.

I know Geoff has his thoughts on exhaust duration, here is what Harold said on the topic when asked:
"On most cylinder heads, whenever I have around a 75 percent exhaust-to-intake ratio, I use an 8 degree bigger exhaust cam. If the ratio is under 70 percent, I use a 12 degree, and around 80 percent, only 4 degrees additional exhaust. Whenever the ratio gets around 85 percent, single pattern cams seem to work as good as anything. Rarely do reverse-pattern (intake bigger than exhaust) cams work. At the same time, it depends upon what you want the engine to do. Single pattern cams have better bottom-end, dual pattern cams have better top-end. At low RPM, the longer power stroke of a single pattern cam puts more torque into the crank. At high RPM, the most important thing is getting exhaust gas out of the engine. You can't get more charge in if old exhaust gas is stll in the chamber. This is why the torque curve makes a sudden down-turn at peak horsepower. The exhaust cam has suddenly become inefficient about getting the old exhaust out, and some gas is retained and trapped, and the intake cannot fill completly because of this extra exhaust gas hanging around. So, for the best overall power curve, on the AVERAGE you want a dual-pattern cam, and around 8 to 10 degrees more exhaust. However, if a lot of bottom-end is your goal, or you have heads with a high exhaust/intake ratio, a single-pattern cam will work better. This is based on 30 years of cam design and application."

Personally I use a single pattertn cam with the same intake and exhaust lobes because I have a exhaust-to-intake ratio over 80+ percent on my heads. Both John at Bullet & Chris Mays at Comp agreed with my choice.

[Formula8]

Formulas,

Are you running any computer simulations on these cams? Nothing like real testing but perhaps they would help.

The reason I'm aware of the custom Comp profiles is because just as you (and most others on this board), I'm seeking to squeeze as much usable power from a streetable engine on a reasonable budget. I have about 40 cam profiles stored in two different simulation programs. Oddly enough, the best result came from Comps xtreme solid lobes 6055IN and 6089EX on a 112 LSA installed at 108 CL. Overlap @ .050 is 20 degrees which happens to be the same as the 60310 and the larger of the profiles you were originally contemplating.

I saved that profile and installed it in my simulated motor and it did make 4hp and 3ft/lbs more than the 60310. The oddball 6055/6089 made an additional 7 more HP, the same torque and the best volumetric efficiency. All three cams shared 20 degrees of overlap at .050 and peaked at the same RPMs.

Since your orginal post was essentially asking opinions, you got 'em. I would hope you feel anyone that takes the time out to consider your suggestions then post an opinion in response to your question isn't looking to be made out to be some sort of knuckle dragger. Sorry, I intend no offense and no bad feelings but that is how some of your response come off to me.

[Formulas]

Dont sweat it Form8.. no i havnt run any simulations i am basically going from my past experience with bigger and smaller cams that i have run before and i am trying to find a sweet spot.
The best cam i ran so far was the HO Racing..HC-03... ran it in a aluminum rod 440 with ported #48 heads 11.25 compression back in 1982-1985 in a daily driver.. but for everyday driving its sorta over the top for me now at 46 but early 20s it was the bomb.

But now i am dealing with a 462 @ 9.1 compression and less head flow in my driver and have dedicated the HC-03 cam with 1.7 rockers to the 440 with my ported 614 heads in my other Formula, so i am simply trying to squeeze every bit i can from my driver and keep it in the zone where it makes me happy to drive it and extract every bit of power from it in its current build state minus the cam.

Thanks for the info on bullet Steve after looking at their lobe charts again they do have very comparable profiles to the comp`s and would rather give my $$$$ to a smaller company than a large corp.

Steve have you personally run a solid in this range if so what lobe center and how did you like the characteristics of it ?

Form8 does your dyno programs allow you to put duration @.200 in ?? as this is the area in the duration curve that agressive profiles provide more duration at and thats where the real benefit is i believe.. if the dyno program doesnt take this in account it may not be showing the full potential..

[Steve C.]

Formlas- no solid flat tappet experance, just rollers.
But I have a keen interest in going solid flat tappet for a potential future application and have been looking in that direction.

(Will use Crower lifters with the coolface option)

[Formulas]

Yeah i am with you on the cool face.. my intentions as well.

And as far as the newer lobe profiles they are sneaking up on what only rollers cams could deliver in the past.
I would go full roller but i am not convinced on the long term reliability of them with rollers coming apart and the dist gear thing tho the new composite gear seems to be working, i am just not ready to go there.

[slowbird]

We are running a custom solid from Comp use their Tight Lash solid lobes and it working great and making really good power.

[screamingchief]

I do have solid flat tappet experience.

And they are custom ground.

Too bad you pi$$ed on my attempt to discuss a few issues that affect cam lobe designs and valvetrain choices,by choosing to be rude.

Now who underestimated who?

Hope you don't treat everyone that way...

[DiamondJim]

I have a little solid cam experience but I didn't want to input. You catch more Bees with honey Jim

[Formulas]

Ha ha you guys are killing me..
screamins first post was about warnings about longevity without knowing any details about my heads, and had a tone of it isnt worth it and how he has seen alot of people that cant tune their combo, he didnt speak about his experience..

Thats ok i am very capable of defining what i need on my own and i guess i will keep my experience to myself as well thats not a problem..
I will leave all you gurus to yourselves. Later and happy Pontiyacking..

[screamingchief]

Ok,just to prove I'm not full of it,and can handle someone dumping on me without taking it personally I will explain my position.

Now these cams are slightly bigger than those you are considering but as examples they will work.

Four cams,first one is comps off the shelf cam.

Cam number 51-659-5, grind 290-B-6:
specs;adv.dur. 290/304 dur.@.050 255/266 Dur.@.200 160/172 Lobe lift .360/.356 Lift@1.5 .540/.540 106 lsa.
This cam is ground with they're "old school" high torque intake lobe,and high rpm exhaust lobe.

Second cam,the closest lobes in comps XTQ lobes:
lobe # intake 6263, exhaust 6264
This cams specs: adv.dur. 286/290 dur.@.050 256/260 dur.@.200 168/172 Lobe lift .366/.372 Lift@1.5 .549/.558 lsa (lets say 108 for this cam)

And a crower off the shelf grind:cam # 60353, grind 304 fdp
Specs;adv.dur. 304/312 Dur.@.050 255/262 lobe lift .351/.364 lift@1.5 .527/.546 108 lsa NOTE: I cannot get .200 dur #'s for this one at the moment

Fourth cam,one of my crower custom solids,ground with they're high ratio ballnose lobes:
Cam grind number E27941
specs;adv.dur. 288/292 dur.@.050 256/260 dur.@.200 165/167 Lobe lift .360/.365 lift@.050 .540/.548 108 lsa

Now notice that my custom ground crower lobes look more like the XTQ lobes than it does the 290-B-6 lobes or the crower 304-FDP.

STILL think you would have a VERY hard time finding a big difference between them in the same engine,at the most MAYBE 10 hp.

The reason for the custom ground cam was it was intended to go into a serious engine with well ported heads and maximum effort use for that individual build.

Now with your heads(guess)flow numbers in your first post I know for a fact that you just are not going to gain all that much from the small differences between the lobes you are talking about.And that additional porting would ABSOLUTELY make more power and driveability here than pushing the cam envelope.

And I NEVER said it was'nt worth doing,in fact more than once I have said exactly the opposite!

And as far as the spring issues,that was just an opinion,the heads that the custom cam was ground for had springs and clearance for upto .675 lift even though actual lift was going to be in the .600 neighborhood,a very healthy saftey margin both clearance and life wise.

And NEVER underestimate the importance of tuning and traction,if you do I assure you that you will be the one loosing the races!

By my first post you had basically shot down three other peoples input just because you did'nt like it.Have you actually talked to ANY of the people at these cam companies,that is something both myself and Steve C. have recommended and have done when selecting a custom grind for use.

I aint no guru,and I will admit there are some things that I have'nt seen or done.But I can say I did'nt get a degree and become a ASE master tech. by spending my time beating my head against the wall trying to figure out which cam MIGHT give me a couple of ponies,I've always found out by building it then testing it.

I agree on giving all aspects of any project due consideration and thought.And asking for advice and opinions is part of that.But when push comes to shove sometimes the only way to find out for sure what will work is to try things.

And as far as speaking from experience,if you think I'm going to sit here and tell my life story 100 times over just to satisfy someones doubting nature,as they say in NYC fahgadaboutit!

Now if there are any specific questions feel free to ask them,unless your going to keep jumping all over them once answered.I have'nt taken this personally even though I easily could have,I know it can be tough here trying to get a point across when first starting to post.And criticism can be tough to take at first too.

Thats why I said you should get used to people having different points of view...

[screamingchief]

Oh yeah,if you don't like people here assuming things about your specs,you BETTER provide full details! Just the facts,no guesses...

[DiamondJim]

Dang Chief, I'm impressed. Formulas, you got any flow #'s on your heads? Noticed most of the cams you picked are running about 8 degrees more duration @.050 on the exhaust, from that I would assume your exhaust flow is around 75% of your intake? There are many people here, most(OK..all) with a LOT more knowlege than I have. Most are polite and very helpful if you will just let them. Even the big guys will talk cams with you and help you if you treat them nice. Over the years I have had lenthy conversations with Harold Brookshire, Jim Butler, Mark/Jeff Kaufman and others, just to learn a little. I hope this doesn't come off as mean-spirited, I wish you the best of luck. -Jim

[buwalda]

Steve,
Interesting comments from Harold, but I find his concept of the torque curve suddenly nose diving due solely to the exhaust a bit hard to swallow. What about the possibility that the intake ports have run out of flow, & that causes a dive in the torque curve? Frictional losses at higher rpms? Just about every cam company makes single pattern cams, so I don't think they can all be wrong. On Pontiac heads, I have seen exh/int flow ratios of 80+%; seen some at some lift points as high as 88%.
What I find most interesting is the Crower Cams entry in the PHR magazine Engine Masters challenges. In the first challenge, they used a cam with LESS exh duration & as I recall, got a high placing. In this year's challlenge, they have again gone with less exh duration, so I presume they were happy with the output of the first engine; and I guess these guys should know since their in the business. If memory serves, there was at least one other entrant using a cam with less exhaust duration & some were using lower ratio rockers on the exhaust which reduces effective duration. Great topic & comments.