[Dragncar]

Here is that Rollermaster .005 short IWIS chain with nitrided gears and Torrington bearing.
https://www.summitracing.com/parts/rmr-na-cs7051

Will have to be ordered because I just bought their last one.

[Stan Weiss]

Originally Posted by Schurkey

How was the existing cam installed? Was it degreed, or was it crammed-in "dot to dot"? What is the cranking compression pressure for all eight cylinders?

That 750 carb and intake is not too small for a 455...at low RPM. If that car doesn't launch hard, it's something else. I don't know how a 700 trans can take the torque of a properly-running 455 even with "billet everything".

What is the fuel pressure after several seconds of WFO?

Was this ever done?

Stan

[jhein]

Originally Posted by blueghoast

You Know after listing to all of this I'm wondering if his secondaieres is
opening at all, It kind of sounds that way. I wonder if the diaframis blown.
I would check to see if it is working and also change the spring in it too.
I always run the lite spring or you could go with the next one down?

GT

Wouldn't that be something.

I've had carb, tuning and fuel problems that have all given similar symptoms to varying degrees..

Otherwise, my "AI" diagnosis is that the cam is small but maybe not small enough to cause what you're describing. The intake is definitely a suspect.

I'd make sure the carb and throttle linkage are all working properly. If that's all OK and you're confident the carb is otherwise calibrated reasonably close, then change the intake to a factory iron or RPM and maybe that's all it's missing.

[Gach]

Originally Posted by General Z

Current 2802 cam was not degreed. Installed dot to dot and I was surprised at the amount of slack in the chain. Exhaust is Hedman headers true duals with Magnaflow mufflers and an H pipe. The torque converter is supposedly extreme duty and probably only has 1500 miles on it. I've tuned the carb to the best of my ability. I put the bigger accelerator pump and power valve on it. Bigger front jets. Haven't changed the rear jets. Have the lightest spring, I think for the vacuum secondary too.

The car pulls, but it feels like a locomotive building up steam and just doesn't pull as hard as I think it could/should.

This should answer a few questions some times got to go back and read. I know its a pain. So he tired the lighter spring. With his earlier description for me, it runs good, put doesn’t pull kind of lays down. After the initial putting his foot into it. He wants more. He needs more cam. The Crower 60919 cam will wake that baby right up. Can he put more jet in the secondaries, sure its been a while since I worked on that crab, So I’m not sure you can just change the jets. The way the come. With out having to change the metering block. So yeah he could do a compression check. I doubt thats and issue but it won’t hurt I guess to do one.
Z getting back to timing chain being real slack. If it wasn’t when you installed it but is now, thats kind of normal. If you would have saw mind after I freshen the Motor, it was real slack. I’m not saying not to try the .005 shorter one. Hell you can even try jetting up the secondaries. First I mean I have no idea whats in there now. See if that helps, I don’t think it’ll make much difference, that cam your running is a very weak cam, its just not the power your looking for.

[Gach]

By the way, when I freshen my motor timing chain had allot of slack, just out of curiosity before I pulled it apart I degreed the cam in again just to check.
I installed it at 112, when I check it it was at 114 perfect because that’s exactly where I wanted it. I’m just betting if you check yours now it be about 2 degrees, from where they say to install it, if you have the capabilities of degree in a cam, if and when you make the cam change. Check it see what its in at, that will answer a lot of questions for you. If you’ve never done on, I can walk you through it, its easy, maybe a little investment on The proper stuff to do it.

[Gach]

The other thing about checking to see where the cam is at before you pull it apart is this…let’s say they wanted it installed ( just for example) at 108, you check and find its at 112, well that 4 degrees off. Trust me you’ll learn allot by checking it, plus it’ll answer that big question was it installed severely retarded. Which would make down on mid range power.

PS: its not unusual to fine a cam that ground wrong. Dot-dot sometimes works out, but there’s always that chance its not, and could have you chasing your tail. Still from what you’ve described I don't think thats the issue.

[Schurkey]

The main point of suggesting a cranking compression check, is that if the cranking compression is way off, it's likely that the cam timing is way off.

It's a simple, nothing-but-spark-plug-removal way to verify cam timing. Another method would be to check the rocker arm position on #1 at TDC-Exhaust (overlap) to see if the intake is open just a bit more than the exhaust. Problem with that is that hydraulic lifters may bleed-down making the check unreliable.





The simple fact is that with the info provided, it's fookin' near impossible to determine what (if anything) is wrong, because there's been NO TESTING DONE. A bunch of impressions, and some (vague) listing of parts used, and no real diagnosis. It's hopeless trying to list all the possibilities this could be. With regard to parts installed, what does "bigger" accelerator pump, "bigger" power valve, and "bigger" front jets mean? We know the timing chain has slack, but not where the cam was installed to begin with. We know that it's got an electric fuel pump and a pressure regulator, but we don't know what the fuel pressure is. "Roller rockers" that "might be Magnums" which are not roller rockers. (roller TIP rockers.) A "custom curved" distributor but not what initial timing, and the rest of the curve is. We don't know if it's got vacuum advance. The list goes on and on.

Now, a '67 Firebird is a relatively light car, with 3.73 gears, a deep first gear, a "high stall" converter, a "too small" carb, and a "too small" intake manifold. That thing should launch like it had JATO rockets. Maybe the power tapers off as the revs build, but stab the gas from a stop, and it should be nearly uncontrollable. Until the transmission shatters, anyway.

[SD455DJ]

Originally Posted by Jay S

Does the performance meter you have show MPH times? That maybe would be the better indicator of what HP the engine is making. Mid 14s on the street could be mid 13s on a prepped track.

A 2802 in a 455 is a small cam, so, if the cam timing was retarded, my guess is the engine would actually like it. So I rather doubt cam timing is your issue.. As is I think the 750VAC that has the metering blocks on the secondaries is your biggest issue for your combo, not the performer intake or the cam. Pretty limited on tuning with that carb. If the timing chain was loose when it was installed, was most certainly retarded some. But the 2802 comes with 5* of advance built into it, it has room for some retarding.

Maybe he will comment, but Dennis Jensen on here dyno’d his 70 455 with small valve heads and 9.8 SCR, all stock, no headers, and I think it made 390HP@4800. Best I recall anyway, I think it runs in the 13s in his stock A body. I think he later swapped over to stock round ports with the same short block and it made around 420 HP @5200. The current 112 LSA 60919 with that same set up peaks a few hundred rpm higher, if you are looking for big gains, I think you would be disappointed. I have ran in the high 12s with a completely stock Oldsmobile 455 and headers with the smaller 2801. No question there are better cams for a 455, but it seems like there is something going on more than just the small cam.

Just leaving the 1.52 and swapping from the 2802 to the 60919 is not going to be a big improvement. Both those need 1.65 rockers. The 60919’s that had 112LSA’s I have had do not need Rhoads lifters in 455s. Bigger rockers require the intake pushrod to be clearanced, So if your stuck with 1.52s, i would pick a cam that has more lift, like a Lunati voodoo 704. There are some Bullet grinds that are similar to the Lunati also that provide a lot more lift without a rocker change.

Good memory Jay! Yes, the ’70 YH 455 (+0.040” so a 464) made 390 hp @ 4600 rpm and 512 lbft @ 3400 rpm with the small valve #15 heads (9.94 static compression ratio with 0.040” quench) with the Summit 2802 cam & lifter kit, factory 1.50 stamped rockers & push rods, and factory log exhaust manifolds. It made over 500 lbft of torque from 2800 rpm to 3800 rpm (1000 rpm range). No doubt it was hamstrung with the small cam and log exhaust manifolds, but we were curious what a ’70 small valve 455 would make in the real world with just a cam upgrade. The 2802 is too small and any 10 to 1 compression iron headed 455 needs a 230+ intake duration cam with tight quench and a wider LSA (112+) to manage 93 octane fuels, along with sharp jetting and timing and a good cooling system. Similar engines with this power at the Pure Stock Drags run high 12’s @ 105 mph in a 3900 lb. race weigh A-body with 3.55 – 3.73 gears. This engine was explosive off idle in a ’70 Lemans with an M20 and 3.08 gears. (I found out real quick that the original 3.23 Safe-T-Track 8.2 rear axle couldn’t handle the first full throttle blast!!!)

With the same 464 short block (and 2802 cam) and stock #197 HO heads (8.61 compression with 0.040” quench) and factory exhaust manifolds made a best of 431 hp @ 5000 rpm and 535 lbft @ 3500 rpm. It made over 500 lbft of torque from 2900 rpm to 4400 rpm (1500 rpm range). The cam was pretty good, but the engine could have managed a bigger cam as well. It idled with a little bit more lope than the higher compression heads as expected. It is easier to control detonation and isn’t as fussy from the lower compression but makes more power from the higher flowing heads and exhaust. Similar Pure Stock builds run easy mid 12’s at 108+ mph. The “HO” is just as explosive at a slightly higher rpm, but not much. You really have to be careful when playing around on the streets because you can swap ends before you know it!

There is definitely something amiss in the OP’s 455 as it should be making at least 430 hp and 530 lbft of torque with his combination. I would check the cam install position, timing curve, and fuel calibration and delivery, as it seems there is a lot of horsepower to be found yet without changing anything. Certainly, a factory iron intake and properly built Q-jet (or the 750 Holley) will be better (Q-jet is my preference) than the Performer. Change the cam to one that Cliff recommends is a must for your 9.5 compression and the high piston speed of the 455 stroke. I’d also change the rear gears to 3.08 with the 700R4 trans super low 3.06 first gear, or change out the trans for a TH400 or 4L80 with the 3.73’s.

Sorry for the long post…Dennis

[ta man]

The last paragraph sums it up.

[Gach]

Personally I think Z has done excellent job on explaining exactly how its performing. Just got be a good listener. If any of the things question here were off it wouldn’t have the bottom end he described. Thing has no mid range, its a learning curve for him and I’m sure all those possibilities he will check out. Until then we can argue now until cows come home. Well we’re are not really arguing just suggestions. My feeling he wants more power and its not going to happen with that cam and intake and some crab tuning. All the other things he can check compression, cam timing as he goes along, and secondary jetting in the carburetor. Then bingo the light will come on as to what he finds. My feelings thats a weak @ss cam for what he’s expecting. Hey it’s probably making close to 400 hp but seeing the factory show room GTO’s made 350-370 hp and were basically 13 sec cars far cry from 475-500 hp potential. It’s not going to happen with that cam. OK I will check my attitude. LOL

[b-man]

I can remember reading about one of the cars that was featured in High Performance Pontiac about a second-gen ‘77 or ‘78 T/A running a 455 in their 1/4 mile Shootout series

I distinctly remember that he was running the Summit 2801 cam, an auto (TH350?) trans and 3.23 rear end gears and was clocking 12.90s in the quarter.

There’s a major tuning issue here at the very least, that 2802 cam is more than plenty for a street 455.

As another point of reference a good friend was bracket racing a +.030 455 powered ‘69 GTO (3650 w/driver) equipped with TRW flat top pistons and stock no porting or port match #16 big-valve high compression heads, probably around 11.25:1 compression. He ran the RAIV cam w/1.5 rockers, an untouched regular Performer intake (I loaned him the intake) topped by a Holley 750 double pumper straight from the box, a 3000 stall converter/TH400 and a 4.10 12-bolt w/29.5-10.5 slicks.

It was running 12.20s at 2700 altitude LACR which usually had air quality in the 4000s, this car no doubt would have easily run in the 11.70s or better at sea level. The real killer detail was the Pep Boys stock fuel pump and stock 3/8 fuel line feeding it.

A Performer intake would not be one of my choices for any 455 but there you have it, they’re not as bad as you think.

In my own bracket racing 3550 w/driver ‘64 GTO 8.6:1 ‘74 455 (stock original factory 2-bolt short block) with lightly cleaned up ‘71 #197 HO heads I ran the HC-03 cam and 1.65 rockers and an untouched Torker II topped by a meager 650 double pumper, 10” Continental 3500 stall/TH400/3.89 Ford 9”/10x28 slicks and ran consistently about 2 tenths slower than my friend’s ‘69 GTO with his high compression and smaller cam and what most consider a lousy intake manifold.

1964 GTO bracket car combo: https://forums.maxperformanceinc.com...5&postcount=19

In regards to the OP’s lackluster performance I’d say at the very least there’s a problem with your ignition timing and timing curve. Adding a RAIV cam ain’t gonna fix it, although that’s not a bad choice at all.

My daily driver for about 5 years was a heavy ‘64 Tempest (4000 w/driver) 462 topped by stock #66 455 heads (8.2:1) and a stock ‘66 Tri-Power, 068 cam/1.65 stamped RAIV rockers/RA manifolds/13” Continental/TH400/2.56 peg-leg/25.3” tall 235-45/17 tires. The distributor was a stock single point equipped with an H-O Racing curve kit fired by an old stock coil. On 87 octane it clocked 13.899 at 101.85 mph at Famoso in Bakersfield, running the quarter in first and second gear only and shifting to third across the line.

Details on Tempest engine/drivetrain combo: https://forums.maxperformanceinc.com...22&postcount=4

Something’s wrong and it ain’t the cam or intake.

[ponjohn]

I ran a similar combo, 240/248 HFT made 450 crank / 532 t. Car went 11.98 @ 109 @ 3720 bs.

[Stan Weiss]

I see some people wanting the OP to install a Crower 60919 cam. Just how much more HP do you think that will make over the 2802?

Stan

[SD455DJ]

Stan, I think at least in the 20 – 25 hp range (conservatively) all things the same. He has headers which could allow more gains.

Dennis

[b-man]

Another 455 combo I recall from my bracket racing days from ‘93 through ‘02 was installed in a full weight ‘64 Le Mans (surely at least 3800 with driver) belonging to another friend. Back then I would pick everyone’s brain about the specifics of their combo and especially take note of mild combos that would perform outstandingly.

462 running stock 6X-8 heads for 8.6:1 compression, a regular old restricted junk Performer intake and whatever 750 or 800 Quadrajet which really makes no difference. H-O Racing HC-01A cam which is in the same category as the Summit 2802 and 3-tube headers which we all know are nothing special. Backed up by a 2500 stall converter, a TH350 and 3.08 gears running 10x28 slicks.

It ran 12.90s all day at our local high desert 2700 foot altitude LACR, take your best guess at how it would have run at sea level.

Sometimes you can get a lot out of nothing special.

[Stan Weiss]

Originally Posted by SD455DJ

Stan, I think at least in the 20 – 25 hp range (conservatively) all things the same. He has headers which could allow more gains.

Dennis

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

[b-man]

Whoops, here’s yet another fast street 455 with the 2802 cam.

This time in a heavy ’69 Le Mans convertible running 13.1s in the quarter with ‘71 #96 heads and log exhaust manifolds no less:
https://forums.maxperformanceinc.com...51&postcount=5

The 2802 cam is clearly capable in a street 455, it sure looks like it might be one of the best cams for moderate builds and at the right price.

The OP’s ‘67 Firebird convertible isn’t exactly a lightweight either, likely to weigh in close to 3800 w/o driver. My brother once owned a heavily optioned ‘69 Firebird 350 coupe with A/C, power discs, windows, steering and drivers seat weighing in at 3750 w/o driver.

Cam timing/installation - questionable and needs to be addressed.
Rocker adjustment - verify that the valves are not adjusted too tight holding them off of their seats.
Carb tuning - also questionable. You have a good carb.
Ignition timing - critical and not just the total timing but the timing curve itself.
General engine health - perform a compression test.
Valve springs - if they’re worn out that’s a performance killer.

I’d address the leaking oil pan and main seal, replace the valve springs and degree the cam while replacing the timing chain set. Then pay for some time on a chassis dyno with a reputable tuner in your locale. You don’t need to throw a bunch of money at it changing things for it to be a strong runner.

[Gach]

As long as we’re giving examples of 2802 cam car combinations, here’s one. With the Crower 60919 cam, 67 GTO weighs 3600+… 461 with a Q’jet.. performer rpm intake. Turbo 400 trans, 3.73 gear… pump gas. Closed exhaust. Ran 11.60 at Norwalk there’s a video of it on this site. If you take the weight and mph it works out to 500 hp. The kicker is, no roll bar, so to keep it from going faster then 11.60’s he actually put a block of wood under the gas pedal. Perfectly street able.

So just showing Z the potential his combo has with Crower cam. Thats what at least I thought thats what he’s asking. ( Different cam ? Chain ? Should be Faster ) then with 2802….answer definitely. Dose he have some things to address sure, but he’s pulling motor because of oil pan leak. Now knows he has to degree the new cam in, and should definitely take a compression test before pulling the motor. Even if everything it correct with 2802 cam it definitely will run faster with the Crower 60916. It’s pretty obvious he’s not happy with the performance. There’s no way in hell 2802 cam will make same power as the Crower 60916.

For me anyway to keep beaten to death how well 2802 performs, is just crazy. I just don’t get it. Even if there’s issue and those issues are corrected ain’t gonna happen. So while its down why not go with the Crower, thats up to him to decide. Just me 2 cents.

[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.

[Gach]

his quote: On my little quarter mile test tool, it will do mid 14 seconds. I feel like the car should be quite a bit faster.

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