online170

Just a question i got to thinking about. I didnt get much time to drive my car this summer, but next year im hoping to do a long road trip and/or hit Calabogie Motorsports park in Ottawa.

My question is, what would be smart things to do for a car running 6500-7000rpm for 15 minutes continuously?

This is my daily driver so im talking about coolers, or gauges, or sensors or addons in general, that should be installed before tackling this task.

My engine is already built for decent power, for a street strip type deal, so the internals are up to par. I just want to protect them.

The only thing comes to mind, is to install an Oil cooler. What else?

1975 010 Block with 4 bolt main.
Factory rad with electric fan.
T56 transmission.
Factory rear end.
Air gap intake, 9.8-10.1-:1 compression.

//<86TA>\\

iTrader: (14)

i would say a good healthy motor, a very good valvetrain setup and ignition to match, and an oil cooler wouldn't hurt.

do you have to rev it that high? does the motor even make power up there?

online170

The motor is built up to handle it. I dont have anything fancy like roller rockers, but i dont think that matters.

I think i have a solid cam, and hydraulic lifters. The rockers are plane jane, and springs match the cam. 4bolt main, forged pistons, yada yada, all good. Oil pump is stock, that may be worth upgrading?

MSD 6420 ignition box, and an MSD 8981 programmable timing computer in the works. The car has unbeleivable torque at 36* total up to 4500 rpm, and then not so much after that. Will chirp tires into 3rd and sometimes 4th with this config. But it has fairly good torque and alot more hp at 34*total. The MSD 8981 can give me best of both worlds.

It does make power upwards of 2500 rpm, and only stops pulling hard very very close to 7000. Ive only had it that rev that high once. But it goes to 6500 regularly when i want to play. So it does see those RPMs, and it does make power there.

Im more concerned about heat or any other culprits that i may encounter at the track.

Now that you mention it, i guess i dont really need to go up to 6500 rpm seeing as how i can manage 140mph at 3000 in 6th, but it will be full throttle around the circuit for majority of the lap. Id imagine in 4th gear, and some tmes 5th. My engine sees a good amount of abuse, but never for more than a minute at a time.

Just dont want to break anything when endurance is tested under pressure.

paul_huryk

Those rockers are going to fail - stock stamped rockers are known to either jump off the pushrods or bend when subjected to high rpms for a long time. Not like they use them on NASCAR motors, right?

online170

What do you recommend?

I relaize they arent the best rockers in the world, but lets not compare it to Nascar just yet. 8000rpm for over an hour......

They arent the best choice, but they arent made of tracing paper either.

EDIT: I started looking on summit.

How about i add some guideplates, rocker stud girdles, and a rev kit? And maybe also replace the rockers for after market ones. I dont want to get into replacing the lifters, and springs, because im not 100% sure what cam it is, and i dont want to mess with the specs. So roller conversion is out of the question.

Heres what it looks like now.

fryer1979

Roller rocker would be the best upgrade you could do as far as mechanics go. All the major manufacturers make them, Crane, Comp, and Summit even has their own, and they are all descent parts.

As far as oiling goes, do not change into a high volume oil pump unless you plan on putting a higher capacity pan on the car. The high volume oil pumps have a tendancy of pumping all of the oil out of a stock oil pan starving the engine of oil actually. An oil cooler wouldn't be a bad idea, and fresh tranny oil will help too.

For cooling, a high flow thermostat at a 160 degree rating and a hig flow water pump would be your best bet. If you think you might still have problems, you could install a switch in line for the fan power so you can manually turn the fans on and have them running the whole time you are driving.

One last trick if you are driving a Camaro (honestly I didn't even pay attention if it was a Camaro or a Firebird). You can remove the inner headlights of the Camaro to help outside air flow through the engine compartment while you are moving. I used to do it when I drag raced an '89 IROC, seemed to help.
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Scratch the headlight thing, I saw you have a firebird. If you have the turn signal/parking lights next to the headlights, that little trick might work for them.

online170

Can i just install roller rockers regardless of what cam or lifters i have? I thought it all had to match?

fryer1979

No, they are the one part of your vaivetrain you don't have to match at all. Your cam and lifters will love you for the upgrade. By reducing friction and mechanical preasure you will not only increase the durability of your engine, you will likely gain a few HP in the process. We all love that! Because of the frictional limitations on the stamped rockers they are likely to fail under higher RPM, and even more so for longer durations.

Quasi-Traction

You have a solid cam and Hydraulic lifters? How's that work?

How much lift are you running? What's the diff between your Adv duration and .05 duration? What's your LSA?

Reason why I ask is that if you plan on hitting 5000+ rpm for an extended period of time you run a risk of pulling a rocker stud. If the ramp rate is too quick on the cam too, you could have lifter pump-up troubles too.

My reccomendation if you want to sustain high RPM for more than a few minutes, is to do screw-in studs and guideplates along with your roller rockers.

The LG4 in my old Z/28 pulled 2 studs with a comp 256xe cam only running over 5000rpm for less than a minute.

online170

I didnt build the engine, so excuse my lack of knowledge on the cam. Probably a hydraulic cam....

All i was told, was the engine has a "284-H" cam. Its been a few years now since the engine was rebuilt, so with the help of some members here, we determined it was an older grind.

Theres are 2 284-H that it could be, with very very similar characteristics. Heres the one from crane.

http://www.cranecams.com/?show=brows...07&lvl=2&prt=5

The only difference between the COMP cams version i think is 110 LSA vs. 112 LSA.

It says i make power from 2800-6200 which seems bang on from what i can feel while driving.

Saculia

iTrader: (1)

How well balanced is your engine? That would also determine how fast you can run it and for how long.

5678TA

that is going to build tremendous heat.. this is what i would do:

upgrade radiator
engine oil cooler
HIGH quality oil (royal purple, valvoline race, etc)
definitely look into roller rockers and good quality pushrods
pushrod guideplates
make sure you have NO oil leaks anywhere
higher volume oil pan (around 7 quarts)
high volume oil pump
GOOD tuning (if i leans out, your toast)


do your heads have screw-in rocker studs?? if youre getting anywhere near 6000rpm, you should have them for safety.. and you dont need a stud girdle or rev-kit unless youre running a roller up past 6500rpm..

online170

What do you mean by this? When the engine idles warm, it just purrs. Doesnt shake or anything. It was balanced and blueprinted when it was rebuilt about 5 years back.

5678TA, THANK YOU! Thats the sort of answer i was looking for. Im not necessarily going to see these RPMs, but incase i do, i want insurance.

Im not sure i will go with the oiling mods, or the aluminum rad just yet. I get good oil psi, and i almost never have to use my fan, because the airdam does alot of cooling. As long as im moving, with the fan on, i should be ok. If i was to go with the 7qt oil pan, do 3rd gens have clearance issues with them? I have a 3" y-pipe running pretty close to it, will that matter?

Thanks for the heads up on the revkit. I did some research on it, and it seems only people with boost seem to need it.
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How can i tell? Are you able to judge from the pix?

DIGGLER

iTrader: (1)

looks like a stock set of rockers and springs to me...
chances are, that motor is actually not making any power past 5k-5500ish.

5678TA

and no, you will not be able to use shorties with the larger oil pan.. long tubes only.. i had to sell my shorties for that exact reason.. the only issue i have with the oil pan is installing my headers.. the motor has to be off the mounts to slip them in..


and from what i guess, you have press in.. screw-ins have an integrated nut toward the bottom of the stud..

online170

Im not so sure about this statement. I did alot of trial and error tuning to see what the car likes this summer. I was able to quantify it twice at the drag strip. This is only taking into account tuning differences in the timing, there is still some carb tuning to be had.


EDIT: TRANSMISSION = T56 in all these cases. Therefore 4th Gear = 1:1
But i left my stock distributor in, and had a total timing of 34* with a holley 650 dp. At the begining of the summer, i ran a best of 97.416mph trap speed. (ETA was 14.760) but thats not relevant taking into account i didnt "launch" the car. 60 ft time was something like 2.5, pretty slow. This is shifting at 6500rpm. and trapping in 4th. I also ran 1 run in 3rd gear, pretty close to 7000rpm, just to see what happens. I trapped the same MPH, and a tenth quicker ETA(14.60x i didnt get this slip, so i only have speed and ETA from what a freind saw on the board). Heres the slip:
I1 - 60ft - 2.542
I2 - 330ft - 6.757
I3 - 1/8mi - 9.674
I3(mph) - 76.355mph
I4 - 1/4 - 14.760
MPH - 97.416 mph


After the paint job, i installed an adjustable vacuum canister from Accel, without a limiter plate (so it didnt actually do anything), and i locked out my mechanical advanced. Total timing was 36*. This time, the car launched and pinned me hard in my seat, it was torquey as hell, ive never had it run like that. Squacked tires into third consistently. However, it fell flat on its face at 5000ish rpm. So i know what it feels like when it falls on its face. The trap speed in this case, was much slower. Like 88mph or something. However my 1/8 mile speed went up from 76mph, to 78 or 79mph. (id have to dig up the slips).

Finally, i got a crane cams' vacuum adjust kit with the limiter plate, and limited vacuum advance to 12* (thats irrelevant at WOT). I also, backed the timing off to 34* total. I didnt get to see how this behaves on the strip, but it felt much better right up to about 6500rpm. It didnt fall on its face anymore. It didnt seem quite as torquey below 5000, but much quicker in the upper band for sure.

Long story short, it definately makes power past 5000, and probably drops off around 6200. Theres the numbers, you be the judge.

Ill post the times when i dig up that slip.

RedHawkLB9

the rpms dont need to go that that high