Desktop Dyno Cam Compare

[74 Novallac]

You said you have a CTA250TD cam? Do you have the cam specs such as ABDC, BTDC, BBDC and ATDC? I'd like to see what the Desktop Dyno program thinks of that cam. I know, I know, it's not accurate but it still is fun and interesting to goof around with it.

[Chevlac]

Hey "Novallac", did you ever do a "desk top Dyno" on a "Comp Cams (t.m.)" "High Energy" 260 H pt. # 94-302-5 flat tappet Cam? The r.p.m. range is 1k-5k, valve timing is : 0.006, 260* duration @ 110* lobe center angle, adv. duration @ .050": 212* in. & exh. Intake centerline 106* Valve lift, (adv) .481". Also, have you ever been able to try to buy an "Erson cams" cam directly from them? I'm tring to get the best deal on a good cam that'll "wake up" a 425 Caddy engine. I know that MTS has a couple of real nice cams that;ll do the job but I'm on a very tight budget. There prices are just a tad bit too high for me right now. Not to say that they don't have a good line of products, ( 'cause they do), It's just that my budget can't come up to there price standards. Unless they could do some sort of "in house" finance payment plan to allow a "potential" customer to buy on a time payment schedule. Anyway, I like it that you're at least trying to run a "pre run" on cams BEFORE you install it in your engine & give it a run. Cuts down on the cost of constant replacement of gaskets & bolts. Not to mention the extra time taken up by doing all of that wrenchin' to swap cams & then running the engine to find out what the cam does to the engine.

[74 Novallac]

Hey "Novallac", did you ever do a "desk top Dyno" on a "Comp Cams (t.m.)" "High Energy" 260 H pt. # 94-302-5 flat tappet Cam? The r.p.m. range is 1k-5k, valve timing is : 0.006, 260* duration @ 110* lobe center angle, adv. duration @ .050": 212* in. & exh. Intake centerline 106* Valve lift, (adv) .481". Also, have you ever been able to try to buy an "Erson cams" cam directly from them? I'm tring to get the best deal on a good cam that'll "wake up" a 425 Caddy engine. I know that MTS has a couple of real nice cams that;ll do the job but I'm on a very tight budget. There prices are just a tad bit too high for me right now. Not to say that they don't have a good line of products, ( 'cause they do), It's just that my budget can't come up to there price standards. Unless they could do some sort of "in house" finance payment plan to allow a "potential" customer to buy on a time payment schedule. Anyway, I like it that you're at least trying to run a "pre run" on cams BEFORE you install it in your engine & give it a run. Cuts down on the cost of constant replacement of gaskets & bolts. Not to mention the extra time taken up by doing all of that wrenchin' to swap cams & then running the engine to find out what the cam does to the engine.

Well, like I told the others, it's not perfectly accurate but it does give an idea of the power increase and a comparison to other cams. I do need to know the figures I mentioned in the first line of this post to make a run in the program. A lot of the caddy cam makers don't like to give out these figures until you buy their cam.

[Ted in Olympia]

If you would like to play I have two for you. Both are a 10 to one engine. Bored .030 over for a 507. ported heads, Bulldog intake, 1.72 rocker, 1.75 full length headers. This is the T-bird engine and my old cam is number one and the new cam is a roller.

Cam Number 1 - Old T-bird Cam from Torque Inc
Duration at .050" lift 244 244 degrees
Lift at cam lobe 0.344 0.344 inches
Rocker arm ratio recommended 1.72 1.72
Valve lift without lash 0.592 0.592 inches
Centerlines Intake/Exhaust 113 113 degrees
Cam timing @ .050"
Intake opens 9 BTDC degrees
Intake closes 55 ABDC degrees
Exhaust opens 55 BBDC degrees
Exhaust closes 9 ATDC degrees
Lobe seperation angle 113 degrees

Cam Number Two - Roller Cam from MTS
Duration at .050" lift 248 248 degrees
Lift at cam lobe 0.400 0.400 inches
Rocker arm ratio recommended 1.72 1.72
Valve lift without lash 0.688 0.688 inches
Centerlines Intake/Exhaust 108 112 degrees
Cam timing @ .050"
Intake opens 16 BTDC degrees
Intake closes 52 ABDC degrees
Exhaust opens 56 BBDC degrees
Exhaust closes 12 ATDC degrees
Lobe seperation angle 110 degrees

I guess this is advanced 2 degrees? If you can see what it is straight up also I would like to know.

Thanks

TED

[74 Novallac]

I'm on break at work right now but I'll punch everything in this weekend.

[pila78]

The specs on this cam are a big secret, don'cha know!! And if I tell you, I'll have to kill you The only thing the card says is the advertised duration is 274/284, and the intake opens @ 1 degree BTDC , at .050 lift, and lobe centers are 112 degrees @4 advanced. Not much is it!!
lift w/stock ratio= .502/510 ( 1.65 I assume)
In this day and age, keeping secrets about a production aftermarket ( not custom) part is a bit archaic. I could understand a racing outfit guarding a special custom grind, but not a limited production street grind. I just hope it works!

[74 Novallac]

The specs on this cam are a big secret, don'cha know!! And if I tell you, I'll have to kill you The only thing the card says is the advertised duration is 274/284, and the intake opens @ 1 degree BTDC , at .050 lift, and lobe centers are 112 degrees @4 advanced. Not much is it!!
lift w/stock ratio= .502/510 ( 1.65 I assume)
In this day and age, keeping secrets about a production aftermarket ( not custom) part is a bit archaic. I could understand a racing outfit guarding a special custom grind, but not a limited production street grind. I just hope it works!

I'm sorry but I need a lot more to run in through the simulation. To bad too, because that's my cam and I'd like to know what the program thinks of it.

[Chevlac]

Hi "Novallac", I have more info on the "CompCams" High Energy 260 H cam. I hope these specs will help you. Valve timing 0.006 260* duration 110* lobe center angle, 212* adv. duration @ 0.050" lift Valve lift @ .481". Now for the rest of the story, intake opens @ 24* BTDC & closes @ 56* ABDC. Exhaust opens @ 64* BBDC & closes @ 16*ATDC. I hope that will give ya somethin' to go on. I couldn't get the valve "overlap" info though.

[74 Novallac]

Hi "Novallac", I have more info on the "CompCams" High Energy 260 H cam. I hope these specs will help you. Valve timing 0.006 260* duration 110* lobe center angle, 212* adv. duration @ 0.050" lift Valve lift @ .481". Now for the rest of the story, intake opens @ 24* BTDC & closes @ 56* ABDC. Exhaust opens @ 64* BBDC & closes @ 16*ATDC. I hope that will give ya somethin' to go on. I couldn't get the valve "overlap" info though.

That's great! That's the figures I need. I'll run all three cams and let you guys know sometime this weekend. I don't know when because I'm trying to finally get the Nova on the road.

[pila78]

It's too bad there isn't a bigger selection of Caddy cams from Com Cams. I use their cams in Chevys all the time, and have used several different grinds. The duration at .050 seems to me to be a good indicator of how much vacuum the engine will have for power brakes and heater/AC controls for street use. My '74 Malibu currently has a 280 in it , but with Rhoads lifters, to get decent vacuum and better street manners. Still has a nice lumpy gallop though, and great power. The engine is a .040 over 400 (408 ?)

The Caddy build article in Street Thunder Magazine (Jan-Feb 2008) shows the 260H Comp cam making torque beyond the capability of the dyno at low RPM, which is quite impressive for a mild 260 grind. If I didn't already have a cam, I would likely go for that one, with less lift, and a bit easier on the valve train....

[Ted in Olympia]

If you want more cams to play with I have a few; all of these could be for sale (except the LUXLX cam)

This is the cam that Potter uses in his 500hp crate engine;

Duration at .050" lift 233 236 degrees
Lift at cam lobe 0.318 0.316 inches
Rocker arm ratio recommended 1.72 1.72
Valve lift without lash 0.545 0.544 inches
Centerlines Intake/Exhaust 112 112 degrees
Cam timing @ .050"
Intake opens 4 BTDC degrees
Intake closes 48 ABDC degrees
Exhaust opens 50 BBDC degrees
Exhaust closes 6 ATDC degrees
Lobe seperation angle 112 degrees

This is a cam I got for Dave he was going to use in a Turbo application

Duration at .050" lift 226 226 degrees
Lift at cam lobe 0.304 0.304 inches
Rocker arm ratio recommended 1.72 1.72
Valve lift without lash 0.523 0.523 inches
Centerlines Intake/Exhaust 110 118 degrees
Cam timing @ .050"
Intake opens 3 BTDC degrees
Intake closes 43 ABDC degrees
Exhaust opens 51 BBDC degrees
Exhaust closes 5 ATDC degrees
Lobe seperation angle 114 degrees

This is the Cam that LUXLX used

Duration at .050" lift 241 250 degrees
Lift at cam lobe 0.312 0.312 inches
Rocker arm ratio recommended 1.72 1.72
Valve lift without lash 0.537 0.537 inches
Centerlines Intake/Exhaust 110 ? degrees
Cam timing @ .050"
Intake opens 14.5 BTDC degrees
Intake closes 46.5 ABDC degrees
Exhaust opens 59 BBDC degrees
Exhaust closes 11 ATDC degrees
Lobe seperation angle 110 degrees

This is the cam that I have reground out of stock cores (this is based on a Comp 260)

Duration at .050" lift 210 212 degrees
Lift at cam lobe 0.289 0.290 inches
Rocker arm ratio recommended 1.72 1.72
Valve lift without lash 0.499 0.499 inches
Centerlines Intake/Exhaust 110 118 degrees
Cam timing @ .050"
Intake opens -5 BTDC degrees
Intake closes 35.3 ABDC degrees
Exhaust opens 45 BBDC degrees
Exhaust closes -13 ATDC degrees
Lobe seperation angle 114 degrees

Have fun

TED

[dave brode]

pila,

[you may know, but...]

>It's too bad there isn't a bigger selection of Caddy cams from Com Cams. I use their cams in Chevys all the time, and have used several different grinds.

Although I'm not bragging on the lobes, I also wonder why they don't offer their popular magnum grinds. They at least are single pattern, unlike their weird lowish lift and highly split duration biased to exh "thumper" line, that they do offer for the caddy. Pretty darned long duration available, btw.



> The duration at .050 seems to me to be a good indicator of how much vacuum the engine will have for power brakes and heater/AC controls for street use.

LSA has much to do with it too. A tight LSA will sound way "badder" than a wider one.

Note that Comp uses the wrong rocker ratio to calc lift for caddys [unless you happen to have 1.72-1 rockers]. Divide advertised lift by 1.72 to get apx lobe lift, then multiply by correct number. They will grind any lobe or lobes you want, on any LSA, and L/Cs, within the limits of the cores.

I'm paranoid, but I would opt for the nitriding option if having one done. Lunati offers it too, iirc. Combating the soft core problem, imo.

Dave

[Nick Campagna]

Has anyone ever plotted the exact shape of the raw cores used my most grinders so that one can see what is possible ?

[74 Novallac]

Hi "Novallac", I have more info on the "CompCams" High Energy 260 H cam. I hope these specs will help you. Valve timing 0.006 260* duration 110* lobe center angle, 212* adv. duration @ 0.050" lift Valve lift @ .481". Now for the rest of the story, intake opens @ 24* BTDC & closes @ 56* ABDC. Exhaust opens @ 64* BBDC & closes @ 16*ATDC. I hope that will give ya somethin' to go on. I couldn't get the valve "overlap" info though.

That's great! That's the figures I need. I'll run all three cams and let you guys know sometime this weekend. I don't know when because I'm trying to finally get the Nova on the road.

Ok, here's the results for these three cams.

Again, this is with a 9.5 to one 500 c.i. engine with ported heads and 2.11/1.77 valves w/large tube headers and mufflers, 800 cfm carb and good dual plane intake.

the old T-Bird cam = 461 hp @ 4500 rpm

Roller from MTS = 508 @ 5000 rpm

Comp Cams 260 H cam = 497 @ 5000 rpm

Wow, I didn't expect the 260 H cam to make that much power!

As Darth Vader would say, "Impressive, most impressive!"

[74 Novallac]

If you want more cams to play with I have a few; all of these could be for sale (except the LUXLX cam)

This is the cam that Potter uses in his 500hp crate engine;

Duration at .050" lift 233 236 degrees
Lift at cam lobe 0.318 0.316 inches
Rocker arm ratio recommended 1.72 1.72
Valve lift without lash 0.545 0.544 inches
Centerlines Intake/Exhaust 112 112 degrees
Cam timing @ .050"
Intake opens 4 BTDC degrees
Intake closes 48 ABDC degrees
Exhaust opens 50 BBDC degrees
Exhaust closes 6 ATDC degrees
Lobe seperation angle 112 degrees

This is a cam I got for Dave he was going to use in a Turbo application

Duration at .050" lift 226 226 degrees
Lift at cam lobe 0.304 0.304 inches
Rocker arm ratio recommended 1.72 1.72
Valve lift without lash 0.523 0.523 inches
Centerlines Intake/Exhaust 110 118 degrees
Cam timing @ .050"
Intake opens 3 BTDC degrees
Intake closes 43 ABDC degrees
Exhaust opens 51 BBDC degrees
Exhaust closes 5 ATDC degrees
Lobe seperation angle 114 degrees

This is the Cam that LUXLX used

Duration at .050" lift 241 250 degrees
Lift at cam lobe 0.312 0.312 inches
Rocker arm ratio recommended 1.72 1.72
Valve lift without lash 0.537 0.537 inches
Centerlines Intake/Exhaust 110 ? degrees
Cam timing @ .050"
Intake opens 14.5 BTDC degrees
Intake closes 46.5 ABDC degrees
Exhaust opens 59 BBDC degrees
Exhaust closes 11 ATDC degrees
Lobe seperation angle 110 degrees

This is the cam that I have reground out of stock cores (this is based on a Comp 260)

Duration at .050" lift 210 212 degrees
Lift at cam lobe 0.289 0.290 inches
Rocker arm ratio recommended 1.72 1.72
Valve lift without lash 0.499 0.499 inches
Centerlines Intake/Exhaust 110 118 degrees
Cam timing @ .050"
Intake opens -5 BTDC degrees
Intake closes 35.3 ABDC degrees
Exhaust opens 45 BBDC degrees
Exhaust closes -13 ATDC degrees
Lobe seperation angle 114 degrees

Have fun

TED

1st cam= 479@4500
Turbo cam w/0 boost= 468@4500
Luxlx cam= 498@5000
Last cam= 376@4000 w/timing .050 / with timing of seat to seat= 452@4500
I ran the last cam both ways because the hp seemed low.
That help anybody out?

As usual I set it up for the same 9.5 to 1, engine w/ ported heads, 2.11/1.77s, large tube headers, mufflers, 800 carb and good dualplane intake.

[Chevlac]

Wowzers! those are indeed some VERY impressive numbers on the "Comp Cams' 260 H cam. I definently never expected that cam to be so potent. I now will have to start saving up my "pennies & dimes" to order 1 of those for my engine project. Of course that'll have to include a total valve train up grade as well. But, oh what a mighty engine I'll have. That'll most definently surprise the "bejesus" out of alot of folks who'll think that I'm just driving some old "grandpa's Impala".

[Ted in Olympia]

Hi "Novallac", I have more info on the "CompCams" High Energy 260 H cam. I hope these specs will help you. Valve timing 0.006 260* duration 110* lobe center angle, 212* adv. duration @ 0.050" lift Valve lift @ .481". Now for the rest of the story, intake opens @ 24* BTDC & closes @ 56* ABDC. Exhaust opens @ 64* BBDC & closes @ 16*ATDC. I hope that will give ya somethin' to go on. I couldn't get the valve "overlap" info though.

These numbers are not correct. The valve timing is at .006 lift not .050, so it is making the duration at .050 look like 260 instead of 212. Intake 24+56+180=260, exhaust 64+180+16=260

This is why you are getting the very big number that you are. I would expect more like 385 hp with this cam. Very similar to my reground cam, it might have a bit more since it is on a 110 lsa instead of the 114.

376 makes since with the reground cam and this is a nice increase over what you would expect stock of 325.

A 47 hp increase from the roller cam sounds nice though. I was coming out with about 475 ET hp with the old cam so this makes sense. The Potter cam came out a little higher than I expected.

One thing that confuses me is the RPM, I know the old T-bird cam pulled to at least 5,300 and the peak HP seemed to come about here.

Thanks for the work you did.

TED

[Chevlac]

Now, that sounds more like the idea I had about the "Comp Cams'" design. Having that much power out of a cam that's supposed to be a "mild" street cam did sound a little bit high. Especially since I also ran the sound effects option offered by Comp Cams on how a Cadillac engine would run with the 260 H cam in it. It sounded like a street cammed engine, not a drag strip hero. Maybe I did confuse "Novallac" with the numbers I gave him. And besides, I kinda do like the idea of not haveing that much power anyway, as even though it would've been kinda nice, It would've caused a rather not so user freindly a ride as far as gas consuption goes. Ya know, "the more horses you have, the more it's gonna cost you to keep them."

[74 Novallac]

I just re-did the simulation with the 260 cam this time at .006. It came out to 401@4500. Sound better? Remember, this is not as accurate as putting your engine on a real dyno.

[Chevlac]

Yeah, that's more like it. Now I still don't think that my engine will run that strong but even @ 380 h.p. or so will still be alot better than the stock 180 h.p. that the 425 Caddy engine has been known to produce in totally stock form. Anyway, thanks for the rough "ballpark" figure though, it helps with giving me an idea of what to work with.
Gene