rcdynamic88

I am going to be picking up my 455 from the machine shop next week and would like to hear some thoughts on what kind of HP and torque I can expect and how reliable it should be. The shop doesn't have a dyno to run it on, so I was wondering what some Olds 455 builders had to say. Here is a list of whats involved:

455 bored over .040
"N" crank 10/10
ARP main studs
Reconditioned stock rods w/ARP rod bolts
Keith Black Pistons rated at 10.3 to 1 CR w/77 cc heads
Stock Edelbrock cylinder heads w/ upgraded springs for cam
Lunati hydraulic roller cam 228/236 @ .050., .525/.525 lift
Harland Sharp 1.6 rockers
Mondello posi-flow intake (single plane, like Torker)
QFT 780 cfm vac sec carb
DUI HEI distributor w/custom advance curve for application
MSD 6AL ignition box
Doug Thorley #331-C Full Length Headers, 1 3/4" primaries, 3" collector
3" exhaust w/Pypes "X" pipe, Flowmaster 40 series mufflers

Am I going to be close to 500 HP, or is that wishful thinking? What RPM do you think should I be shifting at?

This is going in a 65 Cutlass HDTP, T400 trans w/manual valve body, 2200-2400 stall converter, Moser Ford 9" with 31 spline traction-loc, 3.50 gears, 9.00 x 28 slicks for the strip & 275/60/15 Goodyear Eagle gt's for the street.

firefrost gold

sounds like a nice set up light weight car Should be real close to the 500 mark the non ported heads will hold you back is the only thing I see .

My442

I say about 440 HP.

cutlassefi

X2, 450ish, not enough cam. If you were shooting for 500hp you should have had more lift and duration to take advantage of the heads and compression. The stock Edelbrock springs would have been fine for that cam, maybe shimmed a little but fine nonetheless. Cam's not very aggressive. That and lift is what would have necessitated a spring change.

And IMO you won't be taking advantage of the available torque with the Posiflow. With that cam especially you should have used a Performer.

Eddie Hansen

I was going with a similar set up, added eagle rods, Icon forged pistons
c heads, performer manifold, qjet , stock manifolds and was hoping to get around 400 hp my engine guy told me that set up would make an honest 350-400 ponies... maybe he is conservative?

skryla

Hey Eddie, do you have A/C?

captjim

I agree with the 450-ish number. But, HP is just a function of torque and rpm, and IMO that cam will run out of breath. The good news is that combo (I agree with Mark) with a Performer, and your gear and converter will make gobs of low-mid range. My 10.25 to 1 355 has a similar cam (227/233 .510/.522) and it has great off-idle response.

I am seeing a high 11 shifting at 5200-5400 in your car.

cutlassefi

Well put Jim.

Bottom line, maybe not the best combination for your goals.

dc2x4drvr

Maybe not enough cam for your compression..

cutlassefi

To take it from there, not enough cam and carb for that manifold, to make 500hp. That comp will be o.k. with aluminum heads cuz I run 9.7 with cast iron heads and 89 octane, no issues. But all else staying the same the manifold is wrong for the rest of the combination, or vice versa.

cutlassefi

With the right cam, compression and a good tune you'll make 400.

rcdynamic88

OK, I'm either going to switch back to my Performer intake manifold or get one of the new Edelbrock Air Gap manifolds when they are available. Since the cam wasn't done yet, Lunati is bumping it up to .550 lift., although they think the duration is still right on for my 455.

Limey

I have been researching this as well and if I were you I would check into the new professional products crosswind intake it has a better RPM range than either the Performer and even the Torker.

rcdynamic88

Just went to the Comp cams website to compare the numbers of the custom grind that Lunati was doing for me to some of Comps hydraulic roller cams. here are the specs of one of their cams, It is Comp Cam XR276HR:

Cam StyleHydraulic roller tappetBasic Operating RPM Range1,800-5,600Intake Duration at 050 inch Lift224Exhaust Duration at 050 inch Lift230Duration at 050 inch Lift224 int./230 exh.Advertised Intake Duration276Advertised Exhaust Duration282Advertised Duration276 int./282 exh.Intake Valve Lift with Factory Rocker Arm Ratio0.505 in.Exhaust Valve Lift with Factory Rocker Arm Ratio0.505 in.

This cam has less duration at .050 than the Lunati roller cam I am having made and the lift is less also at .505, and yet this Comp cam states that its good from 1800 -5600 RPM. I think the comments about my cam being all done at 5200-5400 RPM are incorrect. If you plug this Comp #(XR276HR) into their CamQuest software (which is free to download online! which I just did...), it comes up with 506.8 HP@5000 RPM & 566.0 ftlb @4000 RPM.

This CamQuest software allows you to select the intake manifold type, cylinder head data, final CR, exhaust type, CFM of your carb, etc. If I change from a single plane like my Posi-Flow to a Performer, the final numbers change to 492.7 HP@5000 & 566.8 ftlb@2500 RPM.

I think these numbers show that the Lunati cam their tech dept. worked up for me should be a darn good performer even with my single plane intake and that my combination will make 500+ HP since it is more cam than the Comp Cam XR276HR.

cutlassefi

You can't make comparisons like that, might be two totally different cam profiles. And who's to say their software is absolutely correct?

Call me stubborn but if you get near 500 hp out of this combination I'll be EXTREMELY surprised.

Let me give you an example; just did a 436 BBC, 4.165 bore x 4.00 stroke. RPM Air Gap manifold, 770 Avenger carb, Cam was Erson Hyd Roller 234/240 at .050 with .657 lift. 10.5/1 compression, 2.00" headers with out of the box Edelbrock Performer RPM Oval port heads. Compare those flow numbers to yours, night and day. Plus over .100 more lift on the Chevy.

Made 422hp at the wheels, about 515 at the crank. You still think yours will make that same? I sincerely doubt it.

MI455

On my bbo I made 552 hp. and 610 ft.lbs on .565 lift solid flat tappet.
Mildly ported e-brock heads and 12.0:1 compression on e-85.
Holley street dominator intake. This combo made over 520 torque from 2500-5500.

cutlassefi

What was the duration on the cam @ .050? Carb size?

MI455

This is the cam i used http://www.lunatipower.com/Product.aspx?id=1714&gid=284
The carb is a Quick Fuel e-85, 850
There are are a few other tricks that helped make that number as well.

rcdynamic88

Cutlassefi - When I plug the info for your BBC build into the variables with the Comp cams software, it comes up with a couple of hydarulic roller cams that have est HP's of 522 and 531. Thats not a lot different from the number you gave of "about 515 at the crank". So it would seem their software isn't that far off. I must admit, it does show that my 455 would be much better off with a dual plane intake since it would make more torque at a much lower RPM, and thats what I'm looking for anyway. 500 HP or not doesn't matter that much to me. Looks like my fancy, show polished Mondello intake is going to have to go on ebay now. I sure wish Edelbrock would get that new RPM Air-Gap for the Olds 455 out there, it was scheduled for a March 1st release date, but its not available yet!

Limey

yes it is

RPM RANGE IS 1600 to 6500

will get the link tomm

cutlassefi

Not as of last week, I called. They're still saying April.

Why are you showing a Chevy manifold?

cutlassefi

Yes a dual plane would be better for your application. Also did you plug in head data from the Edelbrock website? If so that could be your discrepancy. The flow data on their website is wrong for the Olds head, not even close. And that came right from Edelbrock.

rcdynamic88

cutlassefi - Yes, I clicked on the seperate box that lets you put in the actual valve sizes and flow numbers for the heads you are going to use, rather than the generic list of head types that they also give you to chose from. I had to put them in for each .100 of valve lift from .100 to .600. I went to the Edelbrock website and got the flow numbers for the Olds heads, and then entered them in to the "port flow" data section.

Do you think that the Performer is the best choice for a dual plane, or would you think the new Air-Gap dual plane would be better? I never even considered that one from Professional Products, but it looks like an air-gap dual plane also...

Limey

thats just the general pic they have and summit says they have them In stock ready for delivery @239 bucks each

Eddie Hansen

No a/c the top comes off LOL..... if I need it any colder I'll ask the mother in law to go for a ride!!!

cutlassefi

O.K lets set the record striaght. Just got off the phone with Ron @ Edelbrock. New BBO RPM Air Gap release date has just been moved back to June, so I'd like to see someone get one from Summit before then, especially for $239.00.
Next as I mentioned, if you plugged in the flow date from their website, it's wrong by a bunch. Therefore your results will be skewed. I still say you won't make much more than 450-460 hp. Not enough camshaft and carb. Just look at the BBO build from HP TV. I spoke to Joe Mondello at the recent PRI about that build, It was correct. As compared to yours it had more cam, carb and messaged heads and still only made 455 hp.

And yes, for your application I would definitely recommend the Performer or the PP Air Gap. Their port sizes are similar. Either way you'd be good but not the new RPM. Again you don't have enough cam and carb imo.

I'm doing a somewhat similar build for Panos here. The differences being nearly stock C heads, which according to Joe Mondello himself don't flow much different than the new Edelbrocks, more compression, 11.0:1, more cam, 238/246, .590 lift, and a bigger carb, 830 Quick Fuel. I still only expect to get in the 460-470 range myself. However the torque should be earth moving, and early in the curve. I'll be using a Performer as well but with the some plenum mods.

rcdynamic88

cutlassefi - I talked to Summit, they don't have any idea when that RPM Air-Gap 455 Olds piece will be available, and since you talked to an Edelbrock rep, I would have to say you have the most reliable info out there on that new manifold.

As far as not enough carb and cam, I guess we will have to just disagree.
I switched between a Holley 825 cfm Street Avenger and the QFT 780 cfm several times last summer and finally stuck with the QFT carb because it out performed the Holley. I ran the Lunati BMII #083 hyd flat tappet cam last year with these specs:

Advertised Duration (Int/Exh): 290/300
Duration @ .050 (Int/Exh): 224/234
Gross Valve Lift (Int/Exh): .496/.520
LSA/ICL: 112/108

I also used a ZEX perimeter plate N2O system with a 150 HP shot and took my 455 with that cam and the 780 QF carb up to 6500 RPM on a too many occassions to count. Enough times that I finally hurt the lower end. I tore up the #2 and #4 main bearings. My new cam has more duration, more lift and is a hydraulic roller, so I can't imagine it not being enough cam. I have no intention of using any N2O on my new build, ( sold all of it on ebay! ) and told the Lunati tech that I wanted something that would make power down low and be done by 5800 RPM. ( I'm setting the rev limiter at 5900 rpm too make sure I behave! )He is confident that the grind he designed should do that for me.

As far as the comparison between the Olds "C" heads and the Edelbrocks here is some info from Joe Mondello himself as posted on the Mondello Performance website:

"Joe Mondello feels this is the best performance cylinder head ever built for the 1965 to 1976 big block Oldsmobile engine. This Performer RPM Cylinder Head out of the box will give you much more power and torque over the best heads ever built by Oldsmobile. The 6051 Edelbrock Performer RPM head flows 268 CFM intake port flow and 207 CFM exhaust port flow. The stock intake port flow on a "C" casting cylinder head is 230 CFM and the exhaust is 162 CFM, which is 30% less than the new Edelbrock head. The exhaust to intake flow ratio is 69%. The new double quench design combustion chamber has the spark plug angled at 45 degrees and moved over closer to the exhaust valve for a better and cleaner burning of the gases in each cylinder, producing more power and torque."

I hear alot of stuff about the E-brocks flowing the same as the "C" heads, mainly from the guys that use "C" heads, but obviously Joe M. has stated himself that the E-brocks flow 30% better, and that there are other factors that make them more powerful as well.

I will make every effort to get my Cutlass on one of those chassis dyno's that seem to be showing up at a lot of the car shows that I go to. When I do I will post the numbers. I don't even care about the 500 HP number anymore, just gobs of low end torque will make my day.

The next Olds motor I do will have a forged crank, aftermarket rods, lighter pistons, full main cap girdle system and Rocket Racing heads. Then we will see if I can get to 600 - 700 HP!

Limey

I AM NOT TALKING ABOUT EDELBROCK I AM TALKING ABOUT

Professional Product Crosswind ..............new technology heres the link ships out same day you order it

Cooler air, more power with Cross Wind manifolds.

These CrossWind intake manifolds from Professional Products feature identical plenum and runner designs to the Typhoon. The main difference is that there is an open area under the plenum chamber. This feature is sometimes called an air gap design. The air flowing under the plenum provides a cooler charge for the incoming air with less heat transfer from the engine. This cooler air charge provides additional power.

Engine Block Style
Stock/OEM standard deckCarburetor Quantity
SingleIntake Style
Single plane with dividerBasic Operating RPM Range
1,500-6,500Intake Manifold Height
6.500 in.Intake Finish
NaturalIntake Material
AluminumEGR
NoQuantity
Sold individually.Notes
Manifold is 1.25 in. taller than stock.

cutlassefi

limey - that's not what you posted originally. You posted a SBC Edelbrock manifold. How was I supposed to know you meant a PP Olds manifold?

rcdynamic - it seems you took that editorial from the Edelbrock catalog?
Call Joe and speak to him for yourself as I did. He will tell you the same thing he told me. The Edelbrock head, as it is today, is not what he wanted them to cast. It is only marginally better than a C casting. The flow numbers from Edelbrock are high, and not real world. Are they better then most other Olds heads? Yes! I have a set for my SBO.
C's flow around 230 on the intake, the Edelbrock flows around 240 not the 268+ they claim! Rick at Edelbrock, their lead engineer, will tell you the same. He told me at the '08 PRI.

Want to guess what Joe Mondello gets to "make the head right"? $2200.00 just for the port job. You still gotta buy the heads. He has to move the ports, sleeve the bolt holes etc to "make it right" in his own words. Call him, he'll set the record straight. Or you can call Bill Travato at BTR racing. He'll echo the same. He buys the castings raw, no seats or anything and redoes them totally. The best he's published is 312cfm. Unfortunately alot of the flow numbers printed are hype, simply not true.

Your motor will produce great torque, but that's not too difficult with a 455. I'm sure it'll serve it's purpose well.

380 Racer

^^^^^^^ reality check!!!

Limey

looks like the original post to me

Limey

that was just a GENERIC pic that the site had up for they had not gotten the actual pic from performance products yet

cutlassefi

Fine but don't believe everything you read. Just because the advertisement says "1500-6500" doesn't necessarily mean that's what it will do. Depends on engine size, compression, cam, carb etc. Typially if a manifold says 1500-6500 a small inch small block would favor the upper end of that, a big inch big block the lower end. Same with cam rpm ranges. It's not necessarily one size fits all.

Limey

ok I will do that

I wont believe anything I read anymore



UNSUBSCRIBED TO THIS TOPIC FOR SOME ONE KNOWS MORE THAN THE WORLD

cutlassefi

Good. But for the record I said everything, not anything.

captjim

The following is my own opinion, take it FWIW. IMO, most carberated engines have an effective operating range of 3500 rpm or so. An engine that works at 1800 rpm generally will not at 6200. My 9 to 1 355 had best ETs shifting at 4600, high 13s. My 10.25 355 will spin up to 5500 or a little more, but is not quite as crisp at part throttle. EFI does make it better, due to infinite tuneability. An open plane intake with big runners will work well with large tube headers, big cam, converter, and gears and will make power from say 3,000 to 6500. Dual plane, small cam, small headers, less gear, might do it from 1500-5000 rpm. You get the idea.