[b-man]

Originally Posted by Gach

Doesn’t mean it actually only runs 14’s in 1/4 mile.

Doesn’t mean it doesn’t either.

He knows his car is a turd, the fact that he doesn’t have an actual quarter mile time slip doesn’t change that.

[Gach]

Originally Posted by b-man

His car is stuck in the mid 14s.

A cam swap isn’t the only answer, there’s too many other issues to address before you say the cam is too small being the main reason.

He has a potential 12 second car with some tuning/adjusting keeping the same cam, intake and carb.

Sure a bigger cam will make more power but that’s not why his car is a dog.

To keep saying he needs the RAIV cam seems crazy when his 2802 cam is plenty capable.

Isn’t that up for him to decide

[b-man]

Of course it’s his decision.

Major tuning issues.

Cam swap optional.

[Gach]

Originally Posted by b-man

Doesn’t mean it doesn’t either.

He knows his car is a turd, the fact that he doesn’t have an actual quarter mile time slip doesn’t change that.

Are you serious

[Gach]

Originally Posted by b-man

Of course it’s his decision.

Major tuning issues.

Cam swap optional.

I agree

[b-man]

Originally Posted by Gach

Are you serious

Arguing for the sake of argument here now?

Appears so.

Time for us to bow out of this thread now, we have both stated our opinions here.

[Stan Weiss]

Originally Posted by Gach

Doesn’t mean it actually only runs 14’s in 1/4 mile.

Gach,
What did you GTO run stock?

It depends on what his test tool is. A Draggy has been shown to be very close to a drag strip time slip on the same pass.

Stan

[Gach]

Originally Posted by b-man

Arguing for the sake of argument here now?

Appears so.

Time for us to bow out of this thread now, we have both stated our opinions here.

I agree

[Gach]

Originally Posted by Stan Weiss

Gach,
What did you GTO run stock?

It depends on what his test tool is. A Draggy has been shown to be very close to a drag strip time slip on the same pass.

Stan

My 68 GTO..Off show room. 13.2’s….. 400 4 speed

[Dragncar]

The 2802 is a good cam. Its not like the 6019 is WAY bigger, its not. About the same lift 112 vs 114 and its only 7 deg less on the intake duration.
At best that 6019 is only going to be a couple tenths quicker, big deal.
He has some major tuning issues, that thing should be in the high 12s.
And its a "buttmeter". Take it to the track, it might be quicker than he thinks.
His 96s have a little portwork, it should be EASY 12s.
Carb, degree, intake, timing-curve.......... combination of them.

[grandam1979]

I didn’t read every post but has anyone suggested checking timing initial and full? I did see checking carb secondary for full pull would be next and easily checked.

[Stan Weiss]

It is interesting looking at the numbers from the Summit 2802 verses a Pontiac 744. It hard to compare Adv. duration and overlap because of how Pontiac measured these numbers. But here are 0.050 and 0.200 duration numbers for the 744 that I got from Rocky Rotella and numbers I got from someone who actually measured a Summit 2802.

744 duration at .050" is 224/236 degrees.

744 duration at .200" is 128.5/140.5 degrees.

744 lobe lift is .2716/.2716".

Rocky Rotella


2802 duration at .050" is 225/235

2802 duration at .200" is 131.5/143

2802 lobe lift is .310/.330

Stan

[SD455DJ]

Originally Posted by Stan Weiss

Dennis,
Thanks. Based on the OP's description of the car performance and what he is looking for do you think that will do it?

I am still waiting with the OP to do a cranking compression test. I believe something is a miss here, and the present combination is leaving more than that amount of HP on the table to be found.

Stan

Stan, the only engine we have (built by the previous owner in Virginia) that compares closely to the OP’s is a 0.030” over 400 (4.15” bore) with a 4.25 stroker crank, so a 460 (actual, not 461) with a good forged rotating assembly (Butler w/ Ross pistons) with SD Performance CNC ported 6x-8 (245 cfm intake/205 cfm exhaust @ .500” lift) heads with 96 cc chambers (9.45 static compression ratio), RAIV clone cam (from Bullet I believe) with .510” lift with 1.50 rocker arms & Hylift Johnson regular bleed-down lifters (quiet), RA D-port manifolds with the small outlets, RPM intake with an 850 DP Holley carb. It wasn’t dyno’d by the builder, but ran consistent 11.80’s at 114 mph (best of 11.75 at 116 mph) in a 3800 lb. ’70 Tempest (with driver) with full exhaust (2.5” mandrel system with MagnaFlo straight through mufflers), TH400 with a tight 10” Continental convertor, and 3.42 gears in a 12-bolt on drag radials, stock suspension.

I think the OP’s combination is really pretty good and if he’s rebuilding the engine and has the budget, I would switch to a RAIV-type cam with either standard Hylift Johnson lifters, or the Rhoads. With his headers, it should scavenge better and make more power. With a better intake, like the RPM, with a change of trans and/or rear gear to match the huge early torque and with good tires, it should be a high 11 sec. car with the proper suspension set up. We have early Birds at the pure stock drags running low 12’s/high 11’s on F70 Wide Ovals no problem on stock suspensions.

Dennis

[Stan Weiss]

Originally Posted by General Z

Seeking opinions:

My oil pan and rear main seal are leaking. So, I was going to pull the engine. I’ll need a new pan, one piece gasket and was going to do the one piece rear main seal.

While the engine is out, I was curious about making upgrades. Personally, I feel like the car is a dog for the size of the engine and the combination of parts and drivetrain. I understand that this is subjective. On my little quarter mile test tool, it will do mid 14 seconds. I feel like the car should be quite a bit faster.

I’m curious if a different cam would give me more power, without sacrificing street manners? The car currently has perfect street manners. It drives like any modern car. But, when I punch it, I’d like it to be faster. I don’t have a big desire to switch to a roller cam.

The springs are pretty old and I was thinking of going to the Crower 68404.

Also, the last time the engine was out, I feel like the timing chain had quite a bit of slack in it. Seeing as how the block has been line honed at least once, I was thinking maybe I should run one of the undersized chains?

Looking for any advice on cam, lifters, pushrods, timing chain, if there is more power to be had, without sacrificing street manners.


The car is a 67 Firebird convertible.

The engine is a 1970 455, bored .060. It’s been line honed as well.

It has a factory crank ground .010 on rods and mains.

Forged pistons and rods.

The heads are 1971 Pontiac 400 heads, Code 96. Mildly ported, stainless valves. I’ve got Comp Cams roller rockers, ration 1.52. I think they are Magnum. The springs are some tired Comp 988 springs. I was thinking of switching to the Crower 68404.

Compression Ratio should be 9.53:1.

Intake is Edlebrock Performer, port matched.

Car is a Holley 750 with vacuum secondary.

Distributer is Performance Distributors HEI, custom curved.

Trans is a 700R4 with a 2600 stall lock up converter.

Rear end is 3.73 Chevy 12 bolt.

It’s got headers and dual exhaust.

The cam is a Summit 2802.
Cam Style:Hydraulic flat tappet
Basic Operating RPM Range:2,200-5,500
Intake Duration at 050 inch Lift:224
Exhaust Duration at 050 inch Lift:234
Duration at 050 inch Lift:224 int./234 exh.
Advertised Intake Duration:298
Advertised Exhaust Duration:303
Advertised Duration:298 int./303 exh.
Intake Valve Lift with Factory Rocker Arm Ratio:0.466 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio:0.488 in.
Valve Lift with Factory Rocker Arm Ratio:0.466 int./0.488 exh.
Lobe Separation (degrees):114

Thanks in advance

Originally Posted by SD455DJ

Stan, the only engine we have (built by the previous owner in Virginia) that compares closely to the OP’s is a 0.030” over 400 (4.15” bore) with a 4.25 stroker crank, so a 460 (actual, not 461) with a good forged rotating assembly (Butler w/ Ross pistons) with SD Performance CNC ported 6x-8 (245 cfm intake/205 cfm exhaust @ .500” lift) heads with 96 cc chambers (9.45 static compression ratio), RAIV clone cam (from Bullet I believe) with .510” lift with 1.50 rocker arms & Hylift Johnson regular bleed-down lifters (quiet), RA D-port manifolds with the small outlets, RPM intake with an 850 DP Holley carb. It wasn’t dyno’d by the builder, but ran consistent 11.80’s at 114 mph (best of 11.75 at 116 mph) in a 3800 lb. ’70 Tempest (with driver) with full exhaust (2.5” mandrel system with MagnaFlo straight through mufflers), TH400 with a tight 10” Continental convertor, and 3.42 gears in a 12-bolt on drag radials, stock suspension.

I think the OP’s combination is really pretty good and if he’s rebuilding the engine and has the budget, I would switch to a RAIV-type cam with either standard Hylift Johnson lifters, or the Rhoads. With his headers, it should scavenge better and make more power. With a better intake, like the RPM, with a change of trans and/or rear gear to match the huge early torque and with good tires, it should be a high 11 sec. car with the proper suspension set up. We have early Birds at the pure stock drags running low 12’s/high 11’s on F70 Wide Ovals no problem on stock suspensions.

Dennis

Dennis,
The OP has not been on PY in a couple of days. So getting any answers from him will have to wait, as to what he used to come up with mid 14's. But for me that indicates that there are some serious problems that just a cam change will not fix.

Stan

[Gach]

Drag daddies used at the strip have been known to be very accurate. So no argument there. But the track is treated for traction. So marketing videos, show, and no doubt they sold a ton of them…hence reputation being super accurate.

Drag daddy on street no treatment for traction is a whole Nother story.

Now how about some back to back test, first on street, then at a treated track guaranteed won’t be the same ET.

Long ago, when I had a money race, against a Nova on the street for $200.00 I bought one long before the drag daddy became available still have it. But for life of me can’t remember the name and I to lazy to go dig it out.

My purpose for buying one was to make sure my car was hooking best I could. It definitely work for that purpose by changing the rpm I was coming out. It was the quickest $200.00 I ever made and shut the chevy boys up. Still have video of the race only problem is it on VHS.

[General Z]

Sorry guys, I've been down with the flu. I'll post more info when possible. So much great information being shared. Thank you

[kingbuzzo]

Oh that sucks...it's going around

That is how I plan my performance upgrades in this tuff economy, by how much weight I can lose from the Flu...lol

[General Z]

Sorry, been down with the flu. Okay a few answers:
The fuel pump is an Edelbrock 1792, "160 GPH, enough to feed a 1,000+ hp engine".
Regulator is set to 7 psi, per Holley specs.
The accelerator pump on the carb was changed from the 30cc to the 50cc one. It's the 20-11 kit.
The car is currently put away for the winter, but I can probably still do a compression test at some point.

I need to confirm that the secondaries are opening correctly. That could be a factor. I suppose I could mount my go pro under the hood with my magnet and view the regulator gauge when I floor it to make sure I'm not running out of gas, but I doubt that's it.

With all this good information, I'm starting to consider swapping the intake, making sure the secondaries are working right and taking it for a spin before pulling the engine for the oil leak. Might save me a whole lot of money compared to tearing everything apart and replacing a bunch of stuff that's already working "fine".

[General Z]

Oh, what I've used to gauge acceleration is an old G-Tech meter I had laying around.

Yes, a lot of my observations are butt o meter. The car has PERFECT street manners, its just when you floor it, I "feel" like it should get up and go faster, instead of feeling like it's building up like a locomotive.

Like I said before, my tuned Solstice GXP, 5 speed "feels" MUCH faster for comparison.

I think I'll also pick up one of those quick swap vacuum solenoid kits from Holley to experiment with the springs

[Gach]

Wake that thing up with Crower 60916 cam !! LOL