Heres my combo;

Engine:
1972 454 bored .060 (supposedly)
Stock cam (i believe no lope or anything runs smooth)
Stock exhaust manifolds
770 cfm Holly Street Avenger with vac secs
Stock Intake manifold
781 heads (stock i assume)

I also have a 700cfm mechanical sec carb too.

Tranny:
m-20 4 speed
3.73 12 bolt eaton posi

I have about 500-750$ budget to do some upgrades to my car. I would like to get it in the mid 12's but i don't know where it is right now (never raced it). I know the heads have a good opportunity for improvement as they are a desirable head. My question is what should i spend the money on for the most improvement (no NOS). Heads (port/polish/enlarge?), headers, cam?

Its not a high reving block maybe redlines at 5-5500 rpm.

What's the best way to spend my money for the most improvment and to possibly get me in the 12's?

thanks tom

I would install a mild cam,headers, and an RPM intake.
$700 would cover that.

You won't get into the 12's with all the stock stuff,unless its a stock LS6 motor and its tuned very well and has traction.

Tom,you need to be a little more realisitic with you expectations for a max $750 budget for upgrades assuming your buying NEW QUALITY parts.

You ask should you port/polish/enlarge (i assume valve size) in heads,well there go'es the $750 in one shot.

Then you say cam,well cam,lifters,matching springs,t/chain,gaskets,approx $350-$450 for least exp hyd flat tappet cam.

Last you say headers,headers/gaskets fot std uncoted $200-$250,coated $350-$500 not including other ex modes needed to attach headers/collectors to your existing ex system.

Total-approx $1650-$1950 not including any exhaust work needed to attach to new headers.

Also,12's may be out of reach if your motor is an 8:5 comp motor which would limit you to a mild cam. Yes cam/headers/and more cam (even with low comp) will get you more power over stock but if your motor truely has low comp it will limit you sme on power.

Since you stated the motor idles smooth and you think it has a stock cam a very quick & dirty way to get some kind of idea on comp is if your motor is sound not real tired and burning oil etc is to do a comp test. If all clys come out to approx 120-130 psi i would say its a low comp motor but if they are in the 140-160psi range i say it would likely be at least in the low-mid 9's on comp.

Now dont all you tech guys jump in to say this will not really tell the story on comp which i know. But since he does not know his comp and has no way of knowing what pistions are in the motor or what the comp ratio is from what he said doing this would give him some idea of comp /cylender pressure for cam choice to be safe so he doesn't over cam a low comp motor and end up with a dog.

Heck,when my 396 had the stock whimpy cam with 198 deg dur@.05,.399 lift,115 deg L/S with a static comp ratio of 10:25:1 the cranking comp was approx 160-170psi just for an example. Now if for example my motor was lower comp like 9:1 comp with all else the same the comp may have been approx 130-140psi. The point i am making here is that cranking comp can tell you somthing when it comes to what comp a motor has as in his case with a stock sounding cam and not wild cam timing to deal with of any kind which was also like when i tested the comp in hte 369/325hp with stock cam.

But if it was my motor i would take the safe road and assum it's running the stock comp approx 8:5-9:0 and cam it conservatively to stay out of trouble and be happy with 13's. But,if he wants to tear down the motor to get the comp up to the 9:5:10:1 comp then thats a different story and he could cam it up some more.

scott

I agree though, realistically i think headers/intake can easily be done together for 750. Intake itself is like 200 for a Perf RPM, Headers are about the same for good ones, uncoated of course. Shoot, go with the Dynomax Blackjacks if you want a good budget header, i am happy with mine! So you are into it about 400 bucks, plus gaskets and some bolts, easily in my book...

Daniel

Not sure why you don't want to run nitrous but for the money a simple plate kit and headers should get you in the 12's assuming traction. Otherwise like everyone else said. Cam, headers and a RPM intake

Headers for sure. Then intake, and lastly cam and timing gear. The headers can be bought used so could the intake. Especially the intake. Headers are the first thing I do to my cars, they are the most bang for buck. At the same time you do the headers tune the car really well. New cap, rotor, wires, ect.....Laterman--Josh

Nice car by the way.

Yeah i didnt think it could be enough to get it in the 12s but id like to be close. I think headers, intake, and cam would be a good start. I did a compression check some time ago.

Cold across all cylinders was 120psi-125psi
warm across all cylinders was 140-150? i think, its been such a long time ago and im away from home right now. My guess was its the 8-8.5:1 motor.

Nice car by the way.
Thank you! Its nice comments that keep the hobby going!

any suggestions on a cam?

I may consider using NOS but im a little afraid of it. I have heard alot of debate about the dangers of it and some people that have no problems with it. Im studying chemical engineering so i know all the properties of nitrous and how well it ignites and burns. Im just afraid of damage to the motor.

Thanks,
tom

Yes,i would think comp #'s like that would be approx 8:5-9:1 comp max if your running a stock mild cam and not a long duration cam that bleeds of cyl pressure.

So i would definately keep your cam choice on the mild side so you dont blow what little comp you have out the exhaust.

Scott

IMO, the most bang for your buck will come from a cam swap. If it stiil has the low stock cr, look at the Lunati Voodoos and Comp XE's. Like Scott said, you have to budget for things beside the cam and lifters (gaskets, maybe timing chain, etc.). I'm assuming that you're running an adapter for the Holley. Lose the adapter and replace the intake with one that accepts the Holley (a new manifold will cost less than a Qjet to fit your stock manifold and it's going to come off anyway). Those mods will pretty much use your entire budget. When you have another budget, do headers.

Just rember if you want to race you will also need sanctioning body safty equipment bell housing flyweel driveshaft loop ect GOT TO BE SAFE. Good luck!

I'm not trying to ruffle and feathers here, but, I don't think a lot guys understand just how fast "getting into the 12s" really is.

I have a bone stock '69 390hp/427 4 speed Corvette that has been in our family since 1977.

I can remember growing up as a kid thinking that it was the fastest car in the world :D. Then, after a few trips to the local drag strip, the best I can manage with it is a 14.07 E.T. in the qrt.

It felt as fast as ever, and with some traction, could probably break into the 13's but, it obviously is nowhere near a 12 second car.

Thats when I realized and had newfound respect for honest to goodness 12 second cars. Its harder to get there than you may think.

I'm not trying to ruffle and feathers here, but, I don't think a lot guys understand just how fast "getting into the 12s" really is.

I have a bone stock '69 390hp/427 4 speed Corvette that has been in our family since 1977.

I can remember growing up as a kid thinking that it was the fastest car in the world :D. Then, after a few trips to the local drag strip, the best I can manage with it is a 14.07 E.T. in the qrt.

It felt as fast as ever, and with some traction, could probably break into the 13's but, it obviously is nowhere near a 12 second car.

Thats when I realized and had newfound respect for honest to goodness 12 second cars. Its harder to get there than you may think.

well said :thumbsup:

I may consider using NOS but im a little afraid of it. I have heard alot of debate about the dangers of it and some people that have no problems with it. Im studying chemical engineering so i know all the properties of nitrous and how well it ignites and burns. Im just afraid of damage to the motor. Thanks,
tom


Nitrous is pretty safe when used properly. The hardest thing with nitrous is fighting the temptation to put a bigger jet in it. For under $10 you can go from 100hp to 250hp and that can be hard to resist at times. You could go with a Super Power shot style kit that could be adjusted between 50 and 175hp the solenoids would keep you from going any higher. And on a 454 even a stock one those power levels would be pretty safe. Also make sure you have the fuel system for it, people have run small plate kits on mechanical pumps before but a good electric is always good insurance. And if you follow the rule of pulling 2 degrres for every 50hp worth of nitrous you could run up to 150-175hp on pump gas. And I may be biased but nitrous is way too much fun not to have anyone that has ever had a car with nitrous should know what I am talking about. Nitrous shouldn't be something people are afraid of. If you have any other queston let me know.

I decided to bring this post back up because im back to thinking what i can do to my car.

I have a holley intake on it already with a 770cfm street avenger with vacumm secondaries. I am going to put a set of headers on the car as well.

My other question is. I did a compression test today everything test 120-130psi across all the cylinders and same with oil in them so thats good. Now what combination of cams/heads can i get the most improvement from?

I would like to use my 781's but i would consider switching if it would be a smart idea. Im going to have them re-milled etc.

i'd go with a set of 1 7/8 " headers and a good 3" exhaust system preferably with an X-pipe. i went with a set of hedmans ( $200 cdn ) and Ultra-flo mufflers ( $300/pr cdn ) and picked up .7 sec in the 1/4 in my 4000 lb pick-up. i ran 781's untouched other than Comp magnum roller rockers until this year with a comp 294 solid lifter cam and 9.5-1 Trw pistons and ran in the 13's. this year i had them cut for 2.19 and 1.88 valves and spent 20 hrs with a grinder doing a decent port job. don't have any track numbers yet but seat of the pants is good. i'd vote for headers and exhaust first then cam and headwork second.

Your heads should work fine, do a little exhaust porting on them If you are adding headers. As for a cam....go with a newer style FT, The Lunati voodoo line makes great power & sound awsome. See my combo wich has not been to the track but from experience I feel is a low 13 sec or high 12 sec car....with traction

Your 781's are good heads for now..but if you feel the need to mill them, you can make a large improvment by adding bigger valves and bowl porting while you have the heads off. I'd be hesitant to dump a bunch of money into those heads though as aftermarket heads offer such an amazing power increase for the money.

Right now; I'd do Hooker comps and an extreme energy 262 due to the lower compression. Make sure you have a good set of valve springs and rockers. After that, get to a chassis dyno and spend a few hours there tuning your carb, timing etc. I think that will give you the most bang for your buck.

later on, due to your lower compression, maybe an upgrade to the 110 CC edlebrock Performer RPM head would be a good step.

Good Luck and keep us posted,

Bill

Thought I'd post my experience with a stock 454:
stock,untouched 1973 shortblock
swapped out the stock 049's for stock closed chamber #215's
compression added up to 8.9 to 1
swapped in a 228/238 @ .050 .540/.540 114 LSA cam
Performer intake (with small ports)
Holley 3310 750 cfm
HEI
Too big 2 1/8" primary headers with 3.5" collectors necked down to a 2.25" exhaust :eek:
TH350/B+M 2400 Holeshot
3.42 gear/8.5" 10 bolt posi
Combo in a 1980 Malibu,full weight (spare,interior,etc)
Ran a 13.4 @ 101.8 MPH
This is with no tuning thru a restrictive exhaust and a tiny port (peanut sized) Performer intake.
Car has a great seat of the pants feel on the street

I'm not completely certain Tom, but with a presummed "stock" cam your 120-130 cranking compression seems a bit low. What steps did you use to perform the test? All plugs out, throttle open, engine warm?

I also respectfully suggest that, givin the modest changes you are contemplating and the RPM range you are seeking, that 3" exhaust is over the top, particuarly if you are thinking about using an X pipe.

Dan

You won't need bigger than a 2.5" system IMHO and experience unless the heads are done up and you have a big cam.

130 psi is about what we got before we opened the motor up.
True compression on the motors is about 7.9 to 1/8.0 to 1 at best

Watch out,a 294 adv dur cam that may have approx 240-245 deg dur @.05 will very likely be too much cam for your low comp so beware. I would keep the cam somewhat conservative with lown 8;5 comp in your 454 and go with a cam like the voodoo hyd flat tappet 219/227,.530/.542,112 deg l/s or at the most and it may be pushing it with your low 8:5 compression is the voodoo cam with 227/233,.542/.554,110 deg l/s but to be safe i would opt for the smaller 219 deg dur voodoo cam if it was my motor.

For example,the smaller voodoo cam is stronger then the stock 70 LS5 454/360hp cam was which was spec'd @ 214/218 deg dur @.05,.461/.480/ lift,115 deg l/s angle. The smaller voodoo has more durataion,lift,and a 3 deg tighter l/s angle (gives better mid range kick) then the stock GM LS5 454/360hp hyd flat tappet cam had,it was a very mild cam for 454 cubes.

But to recap,people are saying you can do your upgrades for $700 which only covers cam/lifters,headers,& exhaust out the back. You also stated you were thinking of doing some head work like porting & larger valves,etc . All this head work could easily cost a min of $600-$700+ to do when installing new larger valves,machining for new/larger valves,porting work, new guides,springs,retainers,labor,etc ,there goe's your complete $700 budget in one shot.

I would just replace the stock/very mild cam with one of the voodoo's i listed above along with small tube headers and a good free flowing 2.5 inch exhaust system out the back and that will wake it up nicely. BBC's respond well to headers & more cam. Also make sure to setup the timing to 18 deg initial & 20 mech for 38 total with that cam. With your low comp you could try 20 deg initial & 20 deg mech for a 40 total without any detonation but listen closely for it and put the initial back to 18 deg if you hear any pinging. Dont forget to also dial in your 750 vac secondary carb to open up as quicker but not so quick you get a bog. Also,ensure the secondaries are opening all the way too which doesnt always happen especially if the secondaries are still in the untouched out of box setup state/condition,,its a trial & error dialing in thing that pays off in the end by getting this right zlong with jetting,power valve and overall timing curve that will get a you a good running mild bbc street perf motor. I just remebered you said you also had a 700 dbl pumper,i like the dbld pumps with man trans because they generally give better/quicker responce esp when rowing throught the gears then with a vac sec carb. So maybe you could try the 700 dbl pump if you want but it is 50 cfm smaller then your 750 vac sec carb which is not a huge difference. Both carbs would likely be very close on top end power but the 700 dbl pump would feel/be more reponsive with man trans on the street & would be plenty of carb for what will be a mild cam'd low compression 454 IMHO.

Scott

You can get into the 12's w/sub 9:1 compression.

Although I never broke into the 12's (tranny, and traction issues), I did run just over 107 mph (which should be good for mid-high 12's) before I did a bowl blend, intake change, and ti retainers. My tarnny was acting up last time out so I coulda ran even more mph if the d@m thing woulda let me change gears.

My motor has about 8.5:1, wrong heads, smallish cam (211/230), too big headers, and not enough gear and too tall a tire (3.31's and 28" tall) :D . Using a 770 also.

Focus on torque - it wins the fight everytime.

Also,

Since you have the right gears and carb, focus on what has been mentioned: Cam, intake, headers.

Cheapy 1.75 summit headers, some sort of free flow 2.5 exhaust

RPM intake

Cam - something XE268, or XE274, or Voodoo equiv.

I like the XE since they seem to make the most of low-compression.

You will be in the 12's IMO w/the above.

just my .02 this is in a 78 malibu with a cage and weighs approx 3300 without me.

bone stock 454
solid roller 666/623 256/260 @.50
8.1 compression (took off closed chamber put on 049's with 2.19 1.88)
4.11 gear and 3000 stall 11.55@117