496-on Pump Gas?

[H20MOFO]

Anyone With A Good 496 Formula? Thinkin Roller Rockered-alum. Headed-? Hyd. Cam Vs Solid.
(i'm Not Racing Just Want To Break 90 Without A Blower). On Pump Gas. Dreamin?

[steelcomp]

Anyone With A Good 496 Formula? Thinkin Roller Rockered-alum. Headed-? Hyd. Cam Vs Solid.
(i'm Not Racing Just Want To Break 90 Without A Blower). On Pump Gas. Dreamin?
700-800hp is do-able with a solid roller and the right combination.

[H20MOFO]

I'm All Ears. By The Way That Salt Rod Is Out Of Control.. What Cam-compresion Ratio Would You Recomend?

[H20MOFO]

Alright I Should Get A Blower Huh? Oh Com On ,nothin Else ,last Time I Checked There Were More Opinions Around Here. Mabey Its My Deoderant? Heads(cfm Runners) Cam? I Have Brodix Heads Now. Not To Happy With Have Fewer Bolts.(had To Modify My Ski Pylon) I Knew That Welding Shop Class Would Come In Handy.

[steelcomp]

I'm All Ears. By The Way That Salt Rod Is Out Of Control.. What Cam-compresion Ratio Would You Recomend?There's way more to building that kind of power on pump gas than I'm going into here, just saying it's possible. I can build you one...:idea:
That salt rod IS out of control...wish it was mine! :D

[H20MOFO]

Ok. Maybe I Think My Thread Should Have Said:does Pump Gas,roller Cam(solid Or Hyd.) Go In The Same Breath? (with 496) . I Don't Know, Seems Like All The Roller Cams Call 4 High Compressions Ratio's.

[steelcomp]

Ok. Maybe I Think My Thread Should Have Said:does Pump Gas,roller Cam(solid Or Hyd.) Go In The Same Breath? (with 496) . I Don't Know, Seems Like All The Roller Cams Call 4 High Compressions Ratio's.
OEM production engines have been running roller cams for years now.

[H20MOFO]

Don't Most Of Those Hyd. Oem Cams Have A Wide Lobe Centerline? 110 To 114*? My Machineist Swears By Crower. And Solid Only In A Boat.

[MACHINEHEAD]

Steel is corect with the hp numbers although you probably wont find anyone hear that will be willing to give up their 496/800hp combo if they build engines professionaly. However, 650 hp is totaly do able. 10 to 1 AFR 305 w/cnc chamber, hyd. flat 246/254 @ .050 (crane) single plane dart and a 850 carb. If you must have a solid flat, get something around 254/260 @ .050 to get the same lobe area. Need more, step up to a solid roller 254/260 or so @ .050 and run the larger AFR325 with cnc chamber add some compression (cut head .075" and go to a possitive deck height .006 out of the hole) now your 10.5 to 1. Go to a dominator 1050 and some spacers and you will be knocking on 700 hp at 6500rpm. I stop here!

[H20MOFO]

Thanks. Would A Crate 572 Be A Mistake? The 620 One?

[MudPumper]

Do a search on here. Cyclone posted a recipe for a 700+ hp 502 chevy using a crate short block, al heads and a single carb on pump. Or get a hold of HBJet, he is running a 730hp 496 on pump with iron heads.

[H20MOFO]

Thanks Mudpumper. I'd Love To See The Cyclone 730 Hp-496 Thread.
Sorry For The Dumb Newby Question. To Search A Thread Do You Just Start Clicking In The Prior Threads Here Till You See It Or Is There A Specific Way To Do That?(eaiser) . I Clicked On The Search This Thread Line And That Wasn't Much Help? I Know I'm A Dumb-ass.
I Was A Little Suprised When I Seen The "iron Heads"

[MACHINEHEAD]

A 502 is far better for making power, the key factor being the 4.466 bore and the 4.00 stroke . 4.25 by 4.31 for the 496. I have seen 40hp difference in favor of a 502 with the same combo at 6000 rpm. The 572/620 or 720 would be a mistake. Just read the bottom of the GM performance parts catalogue. "Not for marine use ". However there are a shitload of good parts in that engine. Buy one complete and tear it down. Check everything and put it right back together with a set of Canfields or AFRs and you got 700 easy.

[H20MOFO]

Thanks. 502 It Is. My 454 Block Is 60 Over Anyway. I Was Worried About My Gen 4 Stuff Boltin On To the Gen V 502 But I Guess Most Of It Will Work?. Should I Ditch My Brodix BB2plus Rec Port Heads?
(not The Cnc'd Ones) What's The Best Deal On A 502 Short Block? I'm So Sick Of Buyin 110 Help!!

[ghittner]

There's way more to building that kind of power on pump gas than I'm going into here, just saying it's possible. I can build you one...:idea:
That salt rod IS out of control...wish it was mine! :D
Reliably? Hmmmmmm, Need a blower maybe and some forged pistons and steel rods?????

[cfm]

Anyone With A Good 496 Formula? Thinkin Roller Rockered-alum. Headed-? Hyd. Cam Vs Solid.
(i'm Not Racing Just Want To Break 90 Without A Blower). On Pump Gas. Dreamin?
Sorry to interupt - I just need to come up to speed.
What kind of boat ? I/O / V Drive / Jet
What HP do you need to surpass 90mph ?
What hp do you have now and what mph ?

[hotbo]

i built a 505 last year .100 block,6.385 rod 4.25 stroke.all eagle froged,srp 10.2 at zero deck 18cc dome.i had comp grind me a solid roller cam i liked.254-260,661-668,108ls-106 centerline. team g intake biggs 1050 dominator,well heres the part most dont like pro-comp aluminum heads,320cc intake runner,225-188 valves,119cc combustion chamber,i had my head guy set them all up he thought they were great at the time:idea: still doing good so we will see,anyway.all i know this combo turns 6300 rpm in a tx-19 with a ss a/b agressor impeller.so im guessing 675+ the desktop dyno says 719hp at 6200 but i think its lieing.so hope this helps.later travis.:D

[ck7684]

I have a good cam for you, depending on what exhaust you plan on running...:D

[H20MOFO]

Thanks Again For The Input Guys. Cfm Right Now I'm In A 18' Tahati Panther Energizer B Cut. I Think I'm 600-650 Now And Can't Hit 70. No Diverter Yet.
I Want A Pickle Some Day. After Lookin At Price Tags On 502 Short Blocks ($5700.00)i May Be Stuck With 496. Exaust Wise , Ck7684 I'm Thru-transom Injected Bassetts. I Took Off My Ot's Off This Year. I Got Tired Of Noise Hasseles. I'm All Ears Cam Wise And Exaust Wise. THANKS FOR THE #'S HOTBO. I'D LOVE TO MAKE 700 PLUS ON PUMP GAS.

[cstraub]

A well thought out 496 combination using around 10 to 1, a good set of heads and a matching cam profile to peak around 6200 to 6400 is do able.

[hotbo]

A well thought out 496 combination using around 10 to 1, a good set of heads and a matching cam profile to peak around 6200 to 6400 is do able.
yes you are exactly right chris the right cam profile is the key along with heads but i have no problem believing that 700hp can be reached with a 10.1 motor at 6500 or less.i wouldnt personally go over board on big runners in the heads and play it alittle conseravtive with the cam profile and you will have a torque monster if the torque is high the hp is gonna folllow.later travis.

[H20MOFO]

A Couple Of People Had Recomended That I'd Call Chris. I Assume An Aa-or-a Impeller Would Be A Better Match For A 496 (depending On Cam Grind).i'm In Utah Does Altitude Factor In To What Comp. Ratio I'd Want? Or Not Really. I'd Like To Think I Can Still Use My Brodix Heads. I BELIVE MY RUNNERS ARE 310 OR 320.

[sangervdrive]

Mine is a 10.5:1 496 with .25 longer rods GMPP aluminum heads, solid roller, edelbrock tunnel ram, two holley 600's. two bolt main.
It made 632 horse at around 6200 and 592 ft.lbs, sorry don't have the dyno sheet right in front of me. That was on 91 octane.

[cfm]

The higher in elevation = the stronger the choke hold.
If your, say 6000ft elev, who gives a rats ass about our sea level hp quotes. You'll be nothing near it.
This is where uncorrected vs corrected dyno sheets come into play !!!
Your '700hp' will be way more difficult to acheive than our 700hp.
Yes, you could (depending on actual elevation) run more measured compression than us but you can't back back the lossed oxygen without a supercharger.

[H20MOFO]

I Realize My Locationaly Challenged Enviroment Is Gonna Kill Those # Thats Why I Was Shootin High. If I Can Ever Figure Out How To Post An Avatar, For My Location Its Going To Say Land Of 1/2 Strength Beer & Air.:d Elev Here Is Prox 4500 Ft.

[cstraub]

At your elevation you will be leaving about a 75 to 100 on the table as compared to an equal engine at sea level. So to run your number it will take a "head scratching" build. Will have to over cam the engine somewhat to help stuff the cylinders as much as possible. We need to look at other areas to help make HP.
You may want to consider:
More compression
More inches
A huffer build....

[gn7]

yeah, something like maybe a BLOWER. One things for sure, if you keep the boat up all the time, squeeze it harder, like 11to1, if you come down off Mt. Everest, then throw some 110 at it.

[H20MOFO]

I Live At 4500 Or So, But Most My Family Have Property At Flaming Gorge (6000+), So I Go There Quite A Bit. I Guess I Should Call It Blower Time. Gotta Sell A Car 1st. Thanks All.(i Gotta Quit Scratchin My Head It Hurts Now):)

[widowmaker]

At your elevation you will be leaving about a 75 to 100 on the table as compared to an equal engine at sea level. So to run your number it will take a "head scratching" build. Will have to over cam the engine somewhat to help stuff the cylinders as much as possible. We need to look at other areas to help make HP.
You may want to consider:
More compression
More inches
A huffer build....
This is the man you need to talk to. He just helped me put together my 502 with AFR heads and 9.2 to 1 compression and it made 712hp on the dyno last week at 6200 rpms....oh yeah one more thing corrected elevation that day was 3600'. Not bad for a pump gas motor....

[cfm]

This is the man you need to talk to. He just helped me put together my 502 with AFR heads and 9.2 to 1 compression and it made 712hp on the dyno last week at 6200 rpms....oh yeah one more thing corrected elevation that day was 3600'. Not bad for a pump gas motor....
Edited: I typed hard to understand reply. See my next post.

[gn7]

That means hp #'s where corrected from 3600ft to show what you'd probably have at 0ft.
Therefore you could contribute real good info for this thread if you could show corrected vs uncorrected #'s. This would show what the elevation does to motors - in your case 0ft vs 3600ft.
:D ditto

[cfm]

This is the man you need to talk to. He just helped me put together my 502 with AFR heads and 9.2 to 1 compression and it made 712hp on the dyno last week at 6200 rpms....oh yeah one more thing corrected elevation that day was 3600'. Not bad for a pump gas motor....
My last post above (I just edited it) would lead to confusion as to what I was trying to say for my brain doesn't transfer to my fingers (ie:typing) very well.
So.......let me try it this way and then I'll go further when the below is answered.
Widowmaker, I see you are in San Diego. San Diego is listed at 72ft above sea level. You mentioned your engine was dyno'd at elevation of 3600ft. When and where (what town/state/shop) did you dyno your engine ?

[steelcomp]

The higher in elevation = the stronger the choke hold.
If your, say 6000ft elev, who gives a rats ass about our sea level hp quotes. You'll be nothing near it.
This is where uncorrected vs corrected dyno sheets come into play !!!
Your '700hp' will be way more difficult to acheive than our 700hp.
Yes, you could (depending on actual elevation) run more measured compression than us but you can't back back the lossed oxygen without a supercharger.Don't forget, if you build an altitude specific combination, (depending on how close you're cutting it), if you ever get below a thousand feet, you'll be in trouble without better gas.
Ther are a lot of build specific things that can be done to increase power and reduce detonation. Attention to detail is going to go a long way here. Clearances, piston dome shapes, hand blending, port and chamber work, parts matching and careful assembly. Reducing friction in every way as much as possible, proper valve train geometry, valve job, etc. There's as much as 50hp in just building the engine properly.

[MACHINEHEAD]

I actually lost a engine build up for a 22 schiada because the other engine builder told him he had a "special altitude cam" . Maybe you should give him a try. HaHa. Cant remember the exact name of the shop, but I think it rymes with roostpower. By the way I think its super charger time for you. The build will be about the same price hp for hp and the blower motor will still be better sans fuel consumption!

[widowmaker]

My last post above (I just edited it) would lead to confusion as to what I was trying to say for my brain doesn't transfer to my fingers (ie:typing) very well.
So.......let me try it this way and then I'll go further when the below is answered.
Widowmaker, I see you are in San Diego. San Diego is listed at 72ft above sea level. You mentioned your engine was dyno'd at elevation of 3600ft. When and where (what town/state/shop) did you dyno your engine ?
It was dynoed at Westech up in Mira Loma, taking into elevation, temp and humidity is how the 3600' number was derived.

[lifter]

So to run your number it will take a "head scratching" build. Will have to over cam the engine somewhat to help stuff the cylinders as much as possible. We need to look at other areas to help make HP.
Actually, this post is “head scratching”. Given a fixed C/R, any incremental increase in altitude, and the resulting decrease in atmospheric pressure, will always result in a loss of cylinder pressure. While adding duration (as altitude increases) may seem “logical” (additional time for cylinder fill?), it doesn’t work that way in the real world.
Lengthening duration extends the IVC event, lowering the dynamic compression (and cylinder pressure), resulting in killing off additional mid range power. The negatives in doing so are compounded by the likelihood of moving your TQ/Power bands up and out of your useable range.
Simply put, with a fixed compression ratio and power band, if you go up in altitude, you must go down in duration to maintain reasonable performance levels. While any solution for this scenario is a compromise, it will be less frustrating than trying to “stuff” the charge with additional duration.

[cfm]

It was dynoed at Westech up in Mira Loma, taking into elevation, temp and humidity is how the 3600' number was derived.
Westech ie: Mira Loma is approx 710ft above sea level. Huge difference between 710ft and 3600ft elevation.
How can you change elevation ? You can't, unless you physically change locations.
What where the weather conditions for the day ?
I'll go further with more info and answers.

[cstraub]

Actually, this post is “head scratching”. Given a fixed C/R, any incremental increase in altitude, and the resulting decrease in atmospheric pressure, will always result in a loss of cylinder pressure. While adding duration (as altitude increases) may seem “logical” (additional time for cylinder fill?), it doesn’t work that way in the real world.
Lengthening duration extends the IVC event, lowering the dynamic compression (and cylinder pressure), resulting in killing off additional mid range power. The negatives in doing so are compounded by the likelihood of moving your TQ/Power bands up and out of your useable range.
Simply put, with a fixed compression ratio and power band, if you go up in altitude, you must go down in duration to maintain reasonable performance levels. While any solution for this scenario is a compromise, it will be less frustrating than trying to “stuff” the charge with additional duration.
Can you show me in my post where I say anything about duration?

[widowmaker]

Westech ie: Mira Loma is approx 710ft above sea level. Huge difference between 710ft and 3600ft elevation.
How can you change elevation ? You can't, unless you physically change locations.
What where the weather conditions for the day ?
I'll go further with more info and answers.
They were hot!! It was about 95 outside and very humid!
Anyways, the boat with this motor runs right at 100mph in the quarter mile. ( 10.4 at 99mph )It is a 19' daytona with dual 750's. B impeller, 6000k rpm. Like I said before. Talk to Cstraub about a cam for your application. Work with him and I promise you will be happy with the outcome!

[widowmaker]

I said corrected elevation, not hp numbers.

[lifter]

Can you show me in my post where I say anything about duration?
I believe your exact reference was to "over camming" the engine. What would your definition of "overcamming" be??

[cstraub]

I believe your exact reference was to "over camming" the engine. What would your definition of "overcamming" be??
You have my phone number Bob.

[H20MOFO]

Quite A Few People Have Told Me Chris Is The Man. I Don't Think I'm Ever Going To Be Happy Without A Blower. Having Said That If I Could Spin An- Aa Into The 80's-to 90 Range Without The Expense (blower 2 Carbs Ect) I'd Do It. Thanks All.

[lifter]

You have my phone number Bob.
Correct. I was simply refering to your definition of "overcamming" on Speedtalk where you had this exchange:
Cstraub:
"IMO opinino, the better the heads the less the camshaft. Most cam companies way over cam these heads and it just makes for lazy rpming engines. I cammed a 360 Sprint years ago when the new All Pro head was out. Engine did not make the suspected power, number were reall good. Dyno guy was a customer of mine, he called me. . I had ground something 20 degrees smaller…………"
The response was:
cstraub wrote:
I had ground something 20 degrees smaller and we picked up 60HP and 80#/ft of torque and flattened the torque curve by 800 rpm.
I just got off the phone with French Grimes about his upcoming interview and he made it clear he thinks overcamming is a big problem. In fact, just about everyone that's been on the show and commented on cams has said the same thing. I think it shows missing the duration numbers on the high side is a lot more harmful than missing them on the low side. Reminds me of shift points.
_________________
Don Terrill - www.RacingSecrets.com
Now that we have redefined "overcamming", back to overcamming for altitude.

[gn7]

I'm In A 18' Tahati Panther Energizer B Cut.
well you may want to reconsider this portion of your deal as well, if those are the speeds your after

[cstraub]

Correct. I was simply refering to your definition of "overcamming" on Speedtalk where you had this exchange:
Cstraub:
"IMO opinino, the better the heads the less the camshaft. Most cam companies way over cam these heads and it just makes for lazy rpming engines. I cammed a 360 Sprint years ago when the new All Pro head was out. Engine did not make the suspected power, number were reall good. Dyno guy was a customer of mine, he called me. . I had ground something 20 degrees smaller…………"
The response was:
cstraub wrote:
I had ground something 20 degrees smaller and we picked up 60HP and 80#/ft of torque and flattened the torque curve by 800 rpm.
I just got off the phone with French Grimes about his upcoming interview and he made it clear he thinks overcamming is a big problem. In fact, just about everyone that's been on the show and commented on cams has said the same thing. I think it shows missing the duration numbers on the high side is a lot more harmful than missing them on the low side. Reminds me of shift points.
_________________
Don Terrill - www.RacingSecrets.com
Now that we have redefined "overcamming", back to overcamming for altitude.
Refer to post 42.

[H20MOFO]

Hi Guys. Gn7 I Could Buy Another Impeller? I Guess Asking For A Specific Mph. Is Pretty Vague(spelling) Sorry. JUST READ IT AGAIN GN7 ,ALL I CAN SAY IS I'M WORKIN ON IT.(21' DAYTONA)

[motormonkey]

I understand what chris is saying on the "over camming" for altitude.:) Go with the blower and you will be happier.

[steelcomp]

I believe your exact reference was to "over camming" the engine. What would your definition of "overcamming" be??Not to speak for Chris, but my guess is that he's referring to over-camming in comparison to an ideal grind, which, as stated in further posts (and I completely agree) is typically WAY smaller than most "experts" will tell you is "ideal". I'd say Chris' idea of "overcamming" this engine would still be under-cammed in most people's opinion.
I also know you're noy gpoing to drag him into a pissing match about this. :D

[steelcomp]

Correct. I was simply refering to your definition of "overcamming" on Speedtalk where you had this exchange:
Cstraub:
"IMO opinino, the better the heads the less the camshaft. Most cam companies way over cam these heads and it just makes for lazy rpming engines. I cammed a 360 Sprint years ago when the new All Pro head was out. Engine did not make the suspected power, number were reall good. Dyno guy was a customer of mine, he called me. . I had ground something 20 degrees smaller…………"
The response was:
cstraub wrote:
I had ground something 20 degrees smaller and we picked up 60HP and 80#/ft of torque and flattened the torque curve by 800 rpm.
I just got off the phone with French Grimes about his upcoming interview and he made it clear he thinks overcamming is a big problem. In fact, just about everyone that's been on the show and commented on cams has said the same thing. I think it shows missing the duration numbers on the high side is a lot more harmful than missing them on the low side. Reminds me of shift points.
_________________
Don Terrill - www.RacingSecrets.com
Now that we have redefined "overcamming", back to overcamming for altitude.
This post makaes no sense at all except to say it sounds like someone has an axe to grind, pulling a thread from another website to make a pointless point. (Don dosen't let you get away with much of this kind of stuff on speedtalk, does he.)
Please keep what's on Speed Talk, on Speed Talk.

[MACHINEHEAD]

IVC is adjustable, Just adjust it for peak torque or somthing. I heard a 98 ICL was the hot ticket up in the altitude:)

[cfm]

I said corrected elevation, not hp numbers.
Corrected elevation ? Elevation is what it is.
Anyway, I typed out a long reply and somehow I got jumped out and had to resign back in. It was lost.
Summary to everything I tried to post:
Basically, your engine made approx 630hp that day at Westech. If you took the motor up to H20Mofo's elevation it would make approx 530hp.
That being said, how could we suggest that same motor build up for H20Mofo when he was asking for 700hp ?
This is why the talk about elevation and such. A 700hp engine at 0' elevation will have a much different build than a 700hp engine at 4500ft elevation.