[gtome]

I with ya on the gears! I Went from a 2:56 to 3:42's and have regreted it ever since. Also I never really checked my gas mileage before, but it sure seems to go quicker now! I hate listening to my engine scream........ barely keeping up with traffic on the highways.

Keep plowing through the info, you will find what your looking for. And i totally get where you are coming from. Why replace all good, and liked parts (exhaust etc...). If I were to build another engine, this would be the same sort of route I would take. I just cant use 500 hp on the street. And I have no intention of loosing my car and license to show some dummy in a Honda that my car is fast.

I do think one of those Cont 13" converters would suprise you though!

[BVR421]

"but I am adamant about not wanting a converter that will require higher RPM low-speed starts, the way that higher stall speed converters do"

where are you getting these ideas LOL

the 5500 rpm stall converter in my race car doesnt do that why would a street converter?

[Fullsize455]

Originally Posted by BVR421

"but I am adamant about not wanting a converter that will require higher RPM low-speed starts, the way that higher stall speed converters do"

where are you getting these ideas LOL

the 5500 rpm stall converter in my race car doesnt do that why would a street converter?

Because I've driven more than a few cars with 2400-ish stall speed converters that will roll backwards on the slightest incline when in gear and require noticable(IE too much) throttle input to move the car at all from a stand still, that's where. I'm glad you think it's funny, but it's not at all.

Edit: And having heard MANY cars equipped with higher stall speed converters as they accelerate from stoplights and such, and the rpm jumps way up higher than it would with a stock converter. I want no part of that. Perhaps it's a matter of cheap converter vs. good, high quality converter, and I have no problem spending money on good parts, but I want daily driver manners, in a sleeper package that looks stock on the outside and under the hood, with the only way to know any different being to look at head casting numbers.

It's amazing that so many people don't understand where this quest comes from. I guess some of you have never heard of the Factory Appearing Stock Tire drag races? It's the same concept, only much more mild. Read:

"No matter how you look at them, F.A.S.T. cars appear showroom stock, including the body, interior, engine and all its external components & manifolds, even the wheels and original 1960's style skinny bias ply tires. As a matter of fact, F.A.S.T cars place very well at shows for "restored" cars, and even sound stock at idle.

But get a group of them on the drag strip, and LOOK OUT! You will see F.A.S.T. cars covering the 1/4 mile in 13, 12, 11 and some even in the 10 second range, with the fastest cars posting trap speeds of over 130 MPH! You see, F.A.S.T. cars may look and sound stock, but internal engine modifications are not restricted."

The point is, there is a middle ground between being bone stock and making gobs and gobs of power with headers and all kinds of other high-visibility modifications. Again, I want to make the most power that I can while still retaining the appearance and manners of stock. Difficult? Yes, absolutely, but that is why it must be done. No, I won't be running in the FAST races - I'm not THAT serious - I just want to make a bit more power, that's all.

It has nothing to do with being a cheapskate or wanting to skimp on parts here and there, and everything to do with the true concept of a sleeper. Yes, it is a compromise - I understand that. I'm ok with that. But at the end of the day, the 350 or so horses I should be able to make and 450+ foot pounds will still be a HELL of a lot more than I was making before.

It's amazing to me that some people simply want all or nothing, and don't understand someone having a different goal than yourself. It's not my intention to start an argument or cause trouble or otherwise stir up crap, but seriously guys, accept that some people have different goals and try to understand why they might not be the same as yours.

Bottom line: I want to make the most power that I can with what I have - That's all. As I have made clear, I have no set goal, and won't be disappointed with the result, regardless, because at the end of the day, no matter what I do, I will be making a lot more than I was making before. Period.

If these guys running the FAST races with Hemi Roadrunners on skinny bias plies can dip into the 10s when their cars were in the 13s stock, surely I can make a few more horsepower than I did before while still appearing stock. That's the entire point, the heart of my goal. Nothing more.

[Cliff R]

Folks just don't understand how converters really work. It's a fluid coupling, so without a clutch inside of it, they all have some slippage, even stock ones. When folks see someone mentioning 3200rpms stall speed (for example), they think it takes at or near that rpm to move the vehicle. Some have also had associations with cheap "shelf" converters that are extremely "loose" everyplace, and never do couple worth a crap at any rpm.

A good street converter will act and drive just like a stock unit, yet allow the engine to see some additional rpm's with good traction when hit with full power, over a stock type converter.

Even my 10" unit would work fine in a heavy car with a low (numerical) axle ratio. It move the car right off idle, and doesn't flash up at light load in any gear.

Load stalling it holding the brakes it will overcome the tires at 1900rpm's.

Any heavy throttle in high gear at low vehicle speeds, like climbing a steep grade, the engine will see about 2200-2400rpm's.

At the track with perfect traction, it flashes to apprx 3500rpm's, enough to put my daily driven car DEEP into the 11's in full street trim.

The 13" Continental unit nearly as good as the 10" unit. My old 455 would send one to just over 3000rpm's at the track, it was every bit as tight at every level as the stock converter it replaced otherwise. I couldn't get the engine much past 1700rpm's on the brakes, and about 2000-2200 loading it pretty heavy on the street for passing situations, climbing steep grades, etc. It ran nearly as quick in 60' times as the 10" unit that replaced it!

I mentioned it in association with this thread based on the goal(s) of the vehicle. The converter would be the best place to spend money, especially with this application, where the owner wants to keep most things pretty stock/mild, and still the ability to unleash the big 455 torque when it's needed.

We just helped two customers with very similiar set-ups, one replaced an early 4 speed auto with one of our TH400's. We installed a low 1st gear set, and 13" Continental converter, backed by his 2.56 axle ratio. He now has big car that drives great, gets good fuel economy, and launches hard with a little traction!........Cliff

[taalltheway]

Hmmmmm...this is a very tough nut to crack...

....you want more power but you want to keep ecerything like it is. Your car does act like it does because it is built like it is. If you change something towards more power it will feel a bit different. Well, let me try:

More power usually comes from more compression, larger cams, better intakes, better exhaust and better airflow in the engine.

More compression is out of the question - OK, i even think that is a good decision in a streetbuild.

To keep that engine idling with near stock quality you will need a cam under or at least no higher than 220 degrees duration @0,050....even as a rollercam. If it was a hydraulic cam i would recommend to play with Rhoadslifters but you have ruled this out.

Where you could really get some more power would be to invest in better exhaust RA-manifolds or even -god forbid - headers!

Another big point is the airflow: i would have a real specialist port and polish the heads and portsmatch the intake in the best possible way.

With the better exhaust and maximum airflow with your limited powerband you get at least the best possible.

If you just keep your heads as they are; your intake and carb as they are; the exhaust manifolds as they are then only the little bit hotter camshaft will definetely not make a night and day difference....

If you want noticably more power you need to bite the bullet and at least dump the manifolds, accept a little bit lopey idle and have the heads completey reworked by a Pro!

If not just have a stock rebuild with stock results and be happy with it.

[Steve C.]

Good example of a 455 street engine with a hyd flat tappet, just change it to a similar hyd roller cam.
Stated- "This is a fairly mild working daily driver combination, making approx. 425 hp, in a car that can run 12.40's with stock type suspension, a/c & weighing 3800 lbs."

Too much duration ?? I don't think so !

Camshaft: Comp Cams #XE 268H Hydraulic cam and lifters(this cam works from 1500 to 5500). 224/230 duration @ .050, Lift:.520 intake/.524 exhaust, with 1.6 rockers: advance cam 2 degrees.

http://www.angelfire.com/fl4/pontiac...nebuildup.html


455 Engine Build - New-Age Super Duty
Cam: Comp Cams hydraulic-roller, PN K-51-423-9
Duration at 0.050: 224/230-deg
Lift: 0.552/0.561
Lobe Separation Angle: 110-deg
http://www.highperformancepontiac.co...ild/specs.html

[Steve C.]

210-225 Intake lobe duration @ .050" lift

Daily Driver, Street Performer or Weekender- YES

And this is based on a hyd flat tappet cam not a hyd roller which has the potential for better performance and driveability.

http://www.pontiacstreetperformance....camselect.html

[66bonne]

FWIW: My suggestion would be that at the time you are ready for your cam shaft give P-Dude aka Ken Keefer a call. He can set you up with a cam that fits your application and desires. He KNOWS hydraulic rollers.
In my old P-Dude 455 combo I ran the "Butcher Saturday Night Special". See signature for performance. As Ken's nut hugger I have frequently posted that this cam is the best I have had in any street/strip motor. It idles nicely and has plenty of vacuum for brakes and other accessories. It purrs like a kitten driving around town all day but growls like a tiger at the track all night.
Good luck with your build.
Jim

[Fullsize455]

Originally Posted by 66bonne

FWIW: My suggestion would be that at the time you are ready for your cam shaft give P-Dude aka Ken Keefer a call. He can set you up with a cam that fits your application and desires. He KNOWS hydraulic rollers.
In my old P-Dude 455 combo I ran the "Butcher Saturday Night Special". See signature for performance. As Ken's nut hugger I have frequently posted that this cam is the best I have had in any street/strip motor. It idles nicely and has plenty of vacuum for brakes and other accessories. It purrs like a kitten driving around town all day but growls like a tiger at the track all night.
Good luck with your build.
Jim

Thank you, I'll do exactly that. I appreciate the input!

[grandville455]

Ok so u said in a earlier post u would like a street/ light strip car?.. why not just have dave at SD port your 6x heads and then use the stump puller cam, maybe have it custom ground on a 114 for idle charactoristics. get a nice conti 13" conv or the 10 either one works great in these cars, 2.5 or 3" x system with stock style caddy 2.5 mufflers, use the low gear set from coan in the trans, run your 2.73's and use 26" slicks when u drag and it will be a fun car all around! I can already tell you tho whatever u do it will end up not fast enough for you

[Fullsize455]

Originally Posted by grandville455

Ok so u said in a earlier post u would like a street/ light strip car?.. why not just have dave at SD port your 6x heads and then use the stump puller cam, maybe have it custom ground on a 114 for idle charactoristics. get a nice conti 13" conv or the 10 either one works great in these cars, 2.5 or 3" x system with stock style caddy 2.5 mufflers, use the low gear set from coan in the trans, run your 2.73's and use 26" slicks when u drag and it will be a fun car all around! I can already tell you tho whatever u do it will end up not fast enough for you

I will look into the converter you're talking about, as well as grinding the cam as you suggest, but I've got the head porting covered already. I'm not going to change my exhaust - I am adamant about that. Thanks for your input

As far as not fast enough for me, I bet it will be plenty fast for what I want to do with the car. If I want a really fun, fast car, I'm not going to start with a 4600 pound daily driver!

[BIGBLUE]

Originally Posted by Fullsize455

My basic requirements are simple: As much power/torque as I can make, while still retaining a relatively smooth idle, while keeping it "looking" stock on the outside(heads, intake, exhaust manifolds, etc), and most importantly it MUST run on 87 octane fuel all day long. This motor will be in a full size '71 Bonneville with stock rebuilt TH400 w/stock stall speed converter and 2.73 highway gears. The emphasis should be on low end torque, but with a touch of top end to throw in. Still keeping that smooth idle. No major lope for me!

14's won't be all that hard in my opinion. I am running a very similar car to yours, and my first 455 with an ordinary flat tappet cam and 6X's with a professional 5 angle valve job and headers allowed me to run low 14's with small street rubber and 2.73 open gears. The thing is the combination of parts. Sounds like you already have a pretty good street mix in mind. I would go with the smallest Hydraulic roller you can find, one like this: http://cranecams.com/?show=browsePar...tType=camshaft
, or perhaps the one that I'm using (a similar one if you cannot find the crane) http://cranecams.com/?show=browsePar...tType=camshaft
if you are willing to go a bit higher in compression, but first I would give the nod to the smaller cam.

Either of those cams will idle pretty smooth (the first like a hot stocker, but much better lobes and lift), and can get you into the 14's with the rest of your parts, the bigger one will roar from an idle to 5 grand, the smaller one will pull really hard to 4,500. Either cam will FRY the tires in a 455 with 2.73 gears, even in a 4,500+ lb ride. Your problems will revolve around traction. If you are only using 87 octane, I would keep the compression ratio of your build somewhere in the region of 8.75 to one with those cast iron heads and if you decide to use premium fuel and the bigger cam 9.25 to one, and make sure your advance curve is not coming in too quick. In all honesty I would allow the cam to do the work in filling the cylinders, and they setup the compression and timing of the combination to match. Some people get fixated on using a certain compression ratio, and then matching the cam to that, but for a street torque monster in the ordinary range of a stock V8, you want great volumetric efficiency first on the low end and midrange, and tune everything else based on that premise. Getting the maximum amount of air and gas into the engine at any RPM has the potential for making the most torque at that RPM, and hence the most power at that RPM as well. That's why turbo charged cars are willing to run low compression ratios and retarded timing, but still make big power. Good cylinder filling.

Don't go with the mantra that a big cam will work as long as the compression ratio is high, not for a torque oriented ride with tall gears and an RPM limit of 4,500, it's a mistake based on following the heard. A big cam can be made to work, but by what you outlined you are looking for a superior stock range engine, and too big a cam will handicap your efforts.

[Fullsize455]

Originally Posted by BIGBLUE

14's won't be all that hard in my opinion. I am running a very similar car to yours, and my first 455 with an ordinary flat tappet cam and 6X's with a professional 5 angle valve job and headers allowed me to run low 14's with small street rubber and 2.73 open gears. The thing is the combination of parts. Sounds like you already have a pretty good street mix in mind. I would go with the smallest Hydraulic roller you can find, one like this: http://cranecams.com/?show=browsePar...tType=camshaft
, or perhaps the one that I'm using (a similar one if you cannot find the crane) http://cranecams.com/?show=browsePar...tType=camshaft
if you are willing to go a bit higher in compression, but first I would give the nod to the smaller cam.

Either of those cams will idle pretty smooth (the first like a hot stocker, but much better lobes and lift), and can get you into the 14's with the rest of your parts, the bigger one will roar from an idle to 5 grand, the smaller one will pull really hard to 4,500. Either cam will FRY the tires in a 455 with 2.73 gears, even in a 4,500+ lb ride. Your problems will revolve around traction. If you are only using 87 octane, I would keep the compression ratio of your build somewhere in the region of 8.75 to one with those cast iron heads and if you decide to use premium fuel and the bigger cam 9.25 to one, and make sure your advance curve is not coming in too quick. In all honesty I would allow the cam to do the work in filling the cylinders, and they setup the compression and timing of the combination to match. Some people get fixated on using a certain compression ratio, and then matching the cam to that, but for a street torque monster in the ordinary range of a stock V8, you want great volumetric efficiency first on the low end and midrange, and tune everything else based on that premise. Getting the maximum amount of air and gas into the engine at any RPM has the potential for making the most torque at that RPM, and hence the most power at that RPM as well. That's why turbo charged cars are willing to run low compression ratios and retarded timing, but still make big power. Good cylinder filling.

Don't go with the mantra that a big cam will work as long as the compression ratio is high, not for a torque oriented ride with tall gears and an RPM limit of 4,500, it's a mistake based on following the heard. A big cam can be made to work, but by what you outlined you are looking for a superior stock range engine, and too big a cam will handicap your efforts.

Thank you, finally somebody that understands my goal! Someone that understands that it isn't about max power as it is working within specific, realistic goals. Thanks a bunch for your input!

[Cliff R]

I agree to stick with the 2.73 gears. If you can afford the low gear set for the TH400, it would be a nice upgrade. Even without the low gear set a well thought out combination will still be a strong runner on the street or track.

A few years ago I tested several sets of tires on the same day, back to back runs. I tried 24" slicks, 28" DOT's, and 30" slicks. The car ran almost the same exact ET and MPH with all three sets of tires, just buzzed the engine harder with the 24" tall tires.

My car has 3.42 rear gears, so 30" tall tires wouldn't be too far off of 2.73 gears with 24 to 26" tall tires. The torque converter used is the key to making this happen, you really can "have your cake and eat it too"!......Cliff

[KJL]

Maybe I missed this if it was discussed. Is there any advantage in using a roller tip to minimize the valve side loading and increasing the valve guide wear? I was considering on using roller tips just for that reason. Would it be worth the investment?

[grandville455]

I ran the summit 2801 in my 464 9.3 .1 comp and ran on 87 all day long! and it was a nice cruiser with 2.93 gears and torque to boot with ported heads and shorty headers which drop in the engine bay on the motor,Their nice headers! Manifolds would be fine too, I would look for something close to that duration in a roller and have fun.