[pmd400]

When I say its not that fast I'm comparing to cars such as my mates 393 alloy headed Cleveland stroker with 4.3 gears and 4500 stall. I have yet to rev the engine past about 4200rpm. Even so I can't imagine it will ever rip my head off.

[pastry_chef]

Originally Posted by Cliff R

IF it doesn't rip literally tear your head off and throw it out the window going quickly to full throttle in any gear from any rpm....

550 HP makes for a nice 'street' ride, sorry won't tear my head off. Not even close. For the size of engine I'm MORE impressed with my V6 daily.
A 10 min drive from me a buddy runs high 8's with a twin turbo 406. Now that is a beast! Whisper quiet on the street, he built his car from Google connections.

[Cliff R]

If you are ever in the area let me know and we'll get the Ventura out for a drive. Make sure to take your hat and sun glasses off before we leave, because the first time I go to full throttle they are going to be up in the back window!.....LOL....

[pastry_chef]

Originally Posted by Cliff R

If you are ever in the area let me know and we'll get the Ventura out for a drive. Make sure to take your hat and sun glasses off before we leave, because the first time I go to full throttle they are going to be up in the back window!.....LOL....

Umm, I have another friend of 20 years with 455.
SD 310 CNC heads. We built his engine and he is FASTER than you.

You should upgrade for 10s,,

[pmd400]

I did read an article recently showing dyno results for a SBC with different intake/carb combos. A low rise dual quad was well of the pace. Iv been thinking the intake could be holding my engine back more than the cam

[pastry_chef]

Originally Posted by pmd400

I did read an article recently showing dyno results for a SBC with different intake/carb combos. A low rise dual quad was well of the pace. Iv been thinking the intake could be holding my engine back more than the cam

I've known Chris Straub nearly 20 years. His understanding of valve timing is top five of anyone in my book. As he always says, the cam is one part of a combination.

[Steve C.]

Intake testing on a combo that is similar to Cliff's.....

http://www.sdperformance.com/newsStory.php?newsID=44

But only dyno numbers and not actual track testing and important to note often the difference will only be a few MPH.

.

[Skip Fix]

Friend's 72 HO had an Ultradyne 280/288 from Butler(so probably on a 110) and runs well for a stockish low compression 455

[pastry_chef]

Originally Posted by Skip Fix

Friend's 72 HO had an Ultradyne 280/288 from Butler(so probably on a 110) and runs well for a stockish low compression 455

280/288 .0045
223/231 @ .050
132/143 @ .200
110 LSA
.463/.485 with 1.5 ratio

[TCSGTO]

Originally Posted by pastry_chef

Umm, I have another friend of 20 years with 455.
SD 310 CNC heads. We built his engine and he is FASTER than you.

You should upgrade for 10s,,

Come on Chef, don’t keep us in suspense. With a teaser like that you have to spill the beans on this combo.

[Cliff R]

+2......I would LOVE to see something from your own efforts, in lieu of all this useless regurgitated info from others.

BTW, the goals for my car never including running 10's, just to be able to run at the roll bar rule in any weather, which the car does with ease. In the WORST possible conditions, hot/humid, etc I ran 7.18 @ 96 mph. Most runs for the car in the heat of the summer will be 7.20-7.30 in the 95-96mph range, so it's fast enough for what I built it for, and no plans to change anything anytime soon......FWIW......Cliff

[Interceptor]

Originally Posted by Cliff R

Thinking back to all the 455's I've built, dyno'd, street and track tested, the mildest one was topped with a set of untouched #46 heads with 96cc chambers from a 1974 350 engine. Even with unported 350 heads on it that engine made 440hp on the dyno and 530ft lbs torque and the car it went into was an absolute ANIMAL on the street!

Even the first 455 that went into my Ventura was very similar with 6X-4 heads with a little bowl work that flowed 232cfm and it cranked out 455.4hp on the dyno and my car ran 12.0's at 112mph in full street trim.........FWIW.......Cliff

Cliff, what was the compression on that combo? And what cam? Your info from experience is detailed as always, but by low compression I think we're talking 7.8:1 whereas everything you've mentioned I would consider mid-compression (9-9.5:1.) What cam specs do you suggest to wake up a true dog-low compression 455? Or are they the same?

[Cliff R]

Even our "low" compression 455's get camshafts with at least 230 degrees duration @ .050". The exact choice will depend on whether it is flat tappet or roller, manual or auto transmission, and other drivetrain parameters plus the intended use of the vehicle.

In other words a "max-effort" 455 build, even low compression will get a different cam as in most cases it's going to have considerably more head flow, more converter, gearing, etc to compliment the engine power and make the vehicle much quicker than something that's more a less a "daily driver".

Anyhow, the 455 we did that made 440hp/530tq was very "basic", "N" crank, 4340 forged rods, Ross pistons, zero decked and untouched #46 heads (96cc chambers) other than having them opened up for the larger 2.11/1.77 valves. A grinder or sanding roll never touched them anyplace otherwise. I used the Crower 60919 cam, topped with Rhoads lifters and high ratio rockers, stock intake, q-jet and factory HEI.

My engine was very similar but I did a little bowl work and gasket match but nothing in the intake ports more than just smoothing them up if/as needed. Those heads flowed 232cfm, and 89cc chambers so compression was 10 to 1. Same 60919 cam, Rhoads lifters, high ratio rockers, iron intake/qjet/factory HEI. The same dyno recorded an additional 15hp and 11 ft lbs torque, so the big 455 liked the added compression and a little more head flow.

I attached a dyno sheet below to show how much power a "low" compression 455 can make with the right cam, and still enjoy smooth idle, excellent throttle response off idle, good efficiency for "normal" driving, and plenty of power across the loaded rpm range. Also notice in that dyno chart that even though we used a HR cam with 230/236 @ .050" specs it's done just a big past 5000rpm's. So imagine how much power you leave on the table with some of the smaller cams on tighter LSA's that we frequently see being recommended for the big 455 engines.......Cliff

[Interceptor]

Originally Posted by Cliff R

Even our "low" compression 455's get camshafts with at least 230 degrees duration @ .050". The exact choice will depend on whether it is flat tappet or roller, manual or auto transmission, and other drivetrain parameters plus the intended use of the vehicle.

So 70 Firebird, 455 w/6H-6 heads, 3.23 auto, street/touring. I know, I know, I could change the heads for better compression but it's a clean, non-leaking freshened engine and I'm lazy. I'm sure there are lots of guys out there with big-car low-comp 455's that could use a simple cam swap to wake things up. Easy to do while the intake is off for the EFI swap. What's my best bet?

[pastry_chef]

Originally Posted by Interceptor

So 70 Firebird, 455 w/6H-6 heads, 3.23 auto, street/touring. I know, I know, I could change the heads for better compression but it's a clean, non-leaking freshened engine and I'm lazy. I'm sure there are lots of guys out there with big-car low-comp 455's that could use a simple cam swap to wake things up. Easy to do while the intake is off for the EFI swap. What's my best bet?

Flat tappet? Or are you willing to invest in a roller?

Stock torque converter?

Headers or manifolds?

No port work on the heads?

Here is an example (400 HP with a flat) - 9.2 compression. same rear gear you run.
http://forums.maxperformanceinc.com/...d.php?t=776169

This was the cam - http://www.lunatipower.com/Product.aspx?id=1776&gid=287

[Interceptor]

Originally Posted by pastry_chef

Flat tappet? Or are you willing to invest in a roller?

Stock torque converter?

Headers or manifolds?

No port work on the heads?

Flat tappet, 2500 stall, headers, dead stock.

[pastry_chef]

Originally Posted by Interceptor

Flat tappet, 2500 stall, headers, dead stock.

I'd go Voodoo 703 - see above link.

Adv Dur (Int/Exh): 268/276
Dur @ .050 (Int/Exh): 227/233
Valve Lift (Int/Exh): .489/.504
LSA/ICL: 110/106