[phil400]

How often do you get on it really to 5k? Do you 1/4 mile it? I mean really how often do you get to get on it to 5k WOT?

I had my car out today with the wife and kids and its slow as $h/t next to all of the cars on this site and WOT in 1st gear I was well over the speed limit.

Does your car run good? Are ya having fun? **** man, with your combo I wouldn't even be thinking about it..just saying...go have fun.

[TCSGTO]

Originally Posted by phil400

How often do you get on it really to 5k? Do you 1/4 mile it? I mean really how often do you get to get on it to 5k WOT?

I had my car out today with the wife and kids and its slow as $h/t next to all of the cars on this site and WOT in 1st gear I was well over the speed limit.

Does your car run good? Are ya having fun? **** man, with your combo I wouldn't even be thinking about it..just saying...go have fun.

This guy gets it!

[Cliff R]

I had the same cam in my last 455 with unported KRE 85cc heads, compression ratio 10.48 to 1. It made peak power at 5400rpm's and peak torque at 3900rpm's. Pulled hard on the street to track to 5800rpm's and the car went as quick as 11.52 at the track in decent air and ran very consistent 11.60-11.70 ET's around 115-116mph......Cliff

[pastry_chef]

Originally Posted by PONTIAC DUDE

I Track tested the same cam profile with a different LSA. The 110 LSA ran quicker then the 112 LSA.

66 bonne with a 231@.050 Comp Cam and out of the box heads ran 11.50 in a 4000 lb car with a 110 LSA.

This was Jim Butcher's 65 Catalina (4100 pounds), hyd roller with unported KRE dports a PTC torque converter and 3.42 axle.
https://www.dragzine.com/news/more-p...s-65-catalina/

Later on with a 494 engine ported the heads, larger cam and converter and went well into the 10s.

Too bad Ken doesn't post here, he was worth listening to.

[steve25]

First off bandi400 which heads do you have the D port version or the round port?

The D ports on average only flow from what I have seen close to 260 Intake cfm @ .700" lift out of the box and that Holley Intake will not support even that 260 cfm.

For a wide power band you do not want the Intake Manifold to be the choke point, it should be the heads.

My guess is that with the lift you are running and what the heads flow at that lift point that you are making , or could make up to 500 hp from your combo when tuned right.

Your motor even now though should rev clean up to a easy 5500 rpm , but if you fuel supply system can't supply the good's it will not, so I hope your not trying to run on the factory size in tank pick up tube or the stock size fuel line from the tank?

[Steve C.]

In use KRE 72CCs heads, out of the box.

Knowing what Cliff pointed out about the higher rpm potential in his post above I personally would check the spring pressure which is unknown. If in fact it is nosing over due to weak springs would you want to continue driving it even if he was ok with 'getting on it' to only 5000 rpm. Valve float due to weak valve springs is bad not only for performance, but also for the valves themselves.

Old catalog information...

STREET DOMINATOR SERIES (SINGLE PLANE): The Holley single plane Street Dominator series was
designed for use in the idle to 6000 RPM range. Engineering designed these intakes to make maximum peak power
without sacrificing the low end torque normally only associated with dual plane designs. Large plenum volumes and
optimized runners make these ideal manifolds for use on stock and mildly modified engines.

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[steve25]

Kerp in mind that the Holley info statement of " stock or mildly modified engines " during the era that the Holley Manifold was made was in reference to factory iron heads, not the aftermarket ones that we have now which start off flowing what the best iron RA4 or 455SD iron head did back then!

[Steve C.]

Good point.


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[Cliff R]

No mention that I've seen of the compression ratio and not sure how or why 72cc heads were used for a pump gas 455 engine build?

Hopefully it's up around 10.5 to 1.

I would add here that we built one 455 with dished pistons in it and small chamber KRE heads. The original build was for #48 heads so the owner had purchased dished pistons. When the machine shop discovered the heads were cracked he order small chamber KRE heads instead.

That engine made less power than similar builds we've done with flat top pistons and their 85cc combustion chamber heads, but still over 500hp and 550tq.

Unrelated and not quite sure how LSA got thrown into the mix here but several years back we replaced a cam in a 455 that was on a 108LSA with one on a 112LSA and the car went from 12.20's to mid-11's and 7-8mph FASTER!

More recently we helped an engine "builder" with his first 455 build make a better cam choice, dyno numbers below........FWIW......Cliff

[Steve C.]

In a previous post he estimated (or guessed) compression ratio around 10.8
No mention of piston design.


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[Cliff R]

Some sort of dished piston would be needed to get it that low.

I've only rebuilt one 455 with a dished piston and it did OK but off about 30hp/40ft lbs torque from near identical builds with KRE heads, same size cam, compression, intake, exhaust, etc.

I "chased" the power a bit since we had lots of time that day for dyno pulls. Our pulls started out around 490-499hp and 530-540tq. Got it up to around 520hp/550tq by the end of the testing, but off a bit from what we typically see with those builds and the ONLY real difference was the big dish in the pistons....FWIW......Cliff

[pastry_chef]

Originally Posted by Cliff R

several years back we replaced a cam in a 455 that was on a 108LSA with one on a 112LSA and the car went from 12.20's to mid-11's and 7-8mph FASTER!

A stock heads engine with the Crower flat tappet 60213 compared to SD ported heads with a Road Paver hyd roller. This has been noted at least 10 times in past posts.

umm, ported heads are a massive bonus! Has NOTHING to do with LSA. everything about more valve area and flow. Details like this are essential.

Also I would never expect a cam with 145@ 200 duration to produce the same power as a cam with 160 @ .200. LMAO. Again nothing to do with LSA.

Originally Posted by Cliff R

A few years back we built a 455 with #48 heads and installed a 308/314, 246/254 cam on a 108LSA. To date I don't think we've built a 455 with a power curve that explosive. It idled with great authority, TONS of low end power, and would tear your head slam off in the mid-range. That engine felt like it was going to run well into the 10's if you evaluated it by the "seat of your pants". Remarkably, the car ran the very best of 12.20 @ 112mph with traction.

We replaced the cam with the Road Paver from Dave at SD, which is close in specs but 112LSA. At the same time we installed a set of his ported #62 heads, short block was untouched. The new combo idled nearly smooth, with a deep/heavy sound and barely any noticeable lope. It was no longer raspy, nor did it have the explosive power of the first set-up. Instead, power was very smooth and linear, is just pulled hard clear across the load/speed range. It really didn't "feel" like it was going to run much into the 12's if evaluated by the "seat of your" pants, the power curve was just too smooth and somewhat boring.

Track day came and the car blasted off mid 11 second runs over 116mph

[TCSGTO]

Originally Posted by Cliff R

Some sort of dished piston would be needed to get it that low.

I've only rebuilt one 455 with a dished piston and it did OK but off about 30hp/40ft lbs torque from near identical builds with KRE heads, same size cam, compression, intake, exhaust, etc.

I "chased" the power a bit since we had lots of time that day for dyno pulls. Our pulls started out around 490-499hp and 530-540tq. Got it up to around 520hp/550tq by the end of the testing, but off a bit from what we typically see with those builds and the ONLY real difference was the big dish in the pistons....FWIW......Cliff

Some designers claim the proper shaped dish will make more power than a flat top. I've done 2 455's and the 517 with dished pistons & 72cc heads and the dish shape has alot to do with how it will run. The first 455 had TRW's that I cut a simple round dish in on the lathe and it was ok but needed more total timing than normal to runs it's best. I seem to remember around 37-8 with a set of '68 #16 iron D-port heads and 42 with old style Edelbrocks.

The next 455 had Ross dishes that more closely mirrored the chamber shape. That engine ran as well as a typical flat top piston shortblock and needed 38 degrees on the dyno to make max power with the old chamber Edelbrocks.

The 517 has Icon pistons also with a dish that resembles the chamber and it seems to make the power you'd expect from such a combination. It made best power at 38 degrees on the dyno also with old style Edelbrocks although it doesn't lose much at 35-36 where I've kept it set.

[Formulajones]

Had no choice but to run a custom dish piston in the 571ci. Using old Edelbrock heads with their bathtub chambers. What I would have thought would make that scenario even worse is the fact that Tony reworked the chambers and made them even bigger, lol. Oddly, on the dyno it made best power at just 34 degrees timing. Here's a picture of those pistons and the chambers.

[steve25]

With the far greater air flow demands taking place much earlier on piston descent with the stroke of a 517 as compared to a 455 it's no surprise that a Cam with 160 duration @.200" lift makes far greater power then a Cam of 140 duration at that same lift.
This fact also shows how important Intake head flow is in that lift range even if max lift air flow numbers need to be comprised to have them!

[Cliff R]

"umm, ported heads are a massive bonus! Has NOTHING to do with LSA"....blah...blah....blah....blah

About like digging up a nearly 10 year old post that has even less to do with the topic at hand.......FWIW.....

Maybe instead of trolling all over the NET to find things that disagree with your twisted line of thinking you might want to get busy and build one of these engines with the EXACT same cam, 1.7 rockers, same heads, street, dyno and drag strip test it, then come up with some information that you have ownership in?

I for one am way past being tired of reading chit that I can google up myself that really doesn't pertain to the thread being discussed.

The OP wanted to know about what he's doing, I built, dyno and drag strip tested the same combo nearly 15 years ago. Then I exploited it for quite a few years putting several wins at the Pontiac Tri Power Nat's under my belt with it. Maybe, just maybe I know a little, just a little more about it that someone who hasn't even ported their first Pontiac head yet?.......Cliff

PS: In case you didn't google search hard enough we put that cam in a very "basic" 455 with unported #46 heads (small valve 1969 castings), different vehicle, same intake, carb, etc and it went 11.80-11.90's. So it may be just a bit more about the combination that makes for different/better end results than just the camshaft, LSA, etc....

[pastry_chef]

An engine with the OPs heads and similar cam that went faster than yours when factoring for weight. Another example was all it was until you focused on LSA.
http://forums.maxperformanceinc.com/...0&postcount=24

Funny when a man with 12 NHRA records cares less about LSA. In two hours I could advance your knowledge 10 years if you would understand what was being said.

[455TA]

I think you need to look more at the intake manifold and valve springs. I have a 462, 89cc E heads, 236/242@.050, 600/620 lift, 110 LSA Hyd Roller cam, Performer RPM intake, and FiTech EFI. My car runs 11.17 @ 120 in the Alabama heat, with a 1.49 60 ft. Easily a high 10 sec car at sea level. I think you need to utilize the torque by swapping to the dual plane. Also, make sure your cam is degreed in correctly and make sure you have enough spring pressure. I'm running comp 914 springs, which come out to 165 lbs on the seat. My engine easily hits the rev limiter at 5800, and I feel it would pull well past 6000.

[pastry_chef]

Originally Posted by 455TA

I have a 462, 89cc E heads, 236/242@.050, 600/620 lift, 110 LSA Hyd Roller cam, Performer RPM intake, and FiTech EFI. My car runs 11.17 @ 120 in the Alabama heat, with a 1.49 60 ft

I believe your heads flow around 300?

[Steve C.]

fwiw, if modified to support the cylinder head air flow in use the original Holley Street Dominator intake will support 600 hp in a 462 with little more than a proper port match and simple runner blending. Been there, done that.


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