How would you take a 1979 L-82 motor with 225hp to over 325? Engine is still stock. Looking at edelbrock intake with Holley carb. So I am thinking of a 750cfm carb and move the cam up to the next level. Also looking at placing hooker headers on the motor. Exhaust is already custom. What should I do with the heads? The car has a 4 speed manual transmission. Thanks for your input and happy new year.

 

What to do with the heads? Do you mean what replacement heads to use? Asking for another 100HP over stock is easily obtainable, but you will need to replace the heads for sure. Carb, intake, exhaust, cam can grab you 30-50HP, heads can make up the rest...but be aware you are opening a huge can of worms when you start talking about heads and cam. Everyone has their own favorite combination (and budget!)

So, what exactly is your budget?

 

Let's start around $1000.00.

 

Intake manifold, carb, cam, lifters, heads and headers for $1K? I think $2K would be a more realistic estimate. That assumes you do the installation yourself and the heads are low end, cost wise.

 

CCC (carb, cam , compression)

The good: you only want 325 hp or so...thats not much cash for engine..so no bottom end work.. how good of shape is your bottom end?

Thats not much $ for performance boost... but for sure..with your 4 speed...

1) what stock carb do you have...its prolly enough.. 650 or 670 cfm is plenty

2) Single plane manifold..you may have one..check.or pick up used...

3) Cam swap: Necessary... and that depends on what heads you can find...

4) Heads, try to find alum. heads that flow...with small intake runners.. 180cc intake runners...with small combustion chambers.. say 65cc ...and then run a thin head gasket..

5) For the cheap way...look for a used msd spark booster...

6) Agressive timing is your friend...

make sure compression ratio in the 10:1 range.. with alum. heads..you'll be ok.. run 36 total timing (approx. range)..with msd box..

Cam it right...meaning..dont listen to any old gear head...the cams will all be approx the same price... its the heads in a budget build you need to get right first (used)..and DO NOT get crazy big heads...just cause thats the used deal..the car will run horrible if there is a mis match..

try to do hyd. roller if you can afford... but flat solid is next choice for cheapo build..for max power... with the 4 speed..you're gonna like the r's... so i'd stick with roller or flat solid cam so you can feel that sucker breathe..

good luck bro !

 

I just did it on a 78 L-48.

Headers
True Duals
Vortec Heads Summit Racing® Vortec Cylinder Heads SUM-151124
Recurve Dizzy (Not more power but feels like it)
Performer 2116 Intake
Q jet
1.6 Roller tip rockers

No Dyno but feels very stout for me. BTW Heads are 650 intake 200 already had the headers and duals.

Good luck

 

Daltman4437,
I'm in same boat as you as far as budget etc. I have an 81 and I want to keep my CCC (computer controlled) setup. I am thinking about the edelbrock top end kit 2022... It basically adds everything bebezote said, just have to add in pushrods and rockers...1500.00 give or take....I need to check compression but it's decent power for price and it's got room to tweak for future enhancements.

 

Cool.
I was not going to touch the bottom end. I want more HP but don't want to race it. I still need to redo the suspension and have it painted. So if I need to push the budget for the motor I will. Is it worth it to find another block and have it bored out and replace all the parts in the bottom end. Then build the motor outside of the car so I still have the original motor?

 

You're almost there without spending a penny. Most crate engines boasting '325HP' are doing it on a dyno with open intake, exhaust and no accessories. That's called a 'gross HP' rating.

Taken that same engine, add a stock exhaust and everything else and it's now rated as 'net HP'.

As a rough calculation 325 gross HP = 243 net HP.

BTW- the Edlebrock intake is a 'copy' of a stock GM intake and your stock qjet carb is already 750 CFM. Save your money.

 

Sounds like I need to be looking more at over 400 HP then. My problem is when I mash the pedal in first gear the tires don't spin and it just seems to be a dog until I hit second and third gear. So I am thinking I need more HP to make her spin and take off. Not that I really want to do this all the time and buy new tires or anything. I want to feel the power of being pushed back in my seat while cranking thru the gears. So maybe I need to increase my budget and do some bottom end work also.

 

This top end kit looks good. What kinda carb are you going to run..

 

Going to run my stock Q-jet. It's a great carb and a 650cfm as well

 

What is your ultimate aim for the car? What is the diff ratio? If all you want is to melt the tyres at the stoplight grand prix all you need is a bigger diff ratio:-) If you want the car to get off its bum and cruise as well why not save up for a 5 speed trans? I agree with Mike Ward, keep the intake manifold and if a Q Jet is fitted and is in good condition I would keep that also. Heads, headers cam combo would be my pick. My two cents worth others may have better suggestions:-)

 

I have definitely thought about a 5 speed tranny. More of a later down the road thing. The car has 3.70 gears in the rear end. When running at 70 MPH it is running around 3200 RPM. Maybe I should stop trying to be a teenager and leave well enough alone. I take the car to work (5 miles and stop lights) a couple days a week and take my 9 year old son for cruises. I don't want to show the car...just drive it and have some fun. People are always guessing what year it is when I am getting gas. Definitely a conversation piece.

 

..Mike is dead on here...if a qjet flows 750 (i didnt know that)...its plenty...dont even think of changing that...

BUT... if your stock is a dual plane manifold... i'd swap to single plane and get the right heads and cam... your 4 speed will like a proper cam with a single plane..

those heads are ok...next step up is some dart pro1 alum heads..in a 180cc/64cc chamber... flow #'s here


The edlebrock heads flow are below:.. look at 0.500 .. its 66% efficiency...

Flow Numbers as tested by Edelbrock's SuperFlo SF-1020 flow bench @ 28" H2O
#5073, #5089
Valve Lift .100" .200" .300" .400" .500" .600" .700"
Intake 63 125 182 225 248 249 -
Exhaust 51 99 131 153 163 168 -


dart pro 1's in 180/64cc

DART PRO1 LT1 HEAD FLOW (CFM)*
Inch Lift Intake Exhaust
.100 71 69
.200 139 102
.300 190 136
.400 231 158
.500 254 175
.600 263 186

 

Also..with your qjet, single plane and some heads.. prolly little bigger than the eldebrock..but they would work... you need more cam for that 4 speed...

If you add the headers, dual exhaust..as the above posters have said..you gotta cam it or you'll leave 30 to 40 horse on the table...

and..some gear..3:55's

here is the specs on that E's cam ..the performer...

Edelbrock 2102 - Edelbrock Performer-Plus Camshaft Kits Details

Chevy

Duration Advertised 278° Intake/288° Exhaust
Duration @ .050'' 204° Intake/214° Exhaust
Lift @ Valve .420'' Intake/.442'' Exhaust
Lift @ Cam .280'' Intake/.295'' Exhaust
Lobe Separation Angle 112°
Intake Centerline 107°
Intake Timing @ .050" Open 5° ATDC
Close 29° ABDC
Exhaust Timing @ .050" Open 44° BBDC
Close 10° BTDC

 

you are dead on Haggis !!

 

you're not far off something similar to the below..your compression will knock you down..but a qjet with single plane will flow similar to a modified LT1 intake...with these heads, 1.6 rockers, thin head gaskets..this exact cam... you could make 400 (lower compression)..and feel very stout..

http://www.gmhightechperformance.com...e/viewall.html

 

Thank you for the specs. I don't have much experience with different cylinder heads and I thought the single plane manifold was more for racing. Will the car perform Ok around town with a single plane manifold?

 

you're kinda right...

the dual plane= more torque down low.. better off the line..but falls flat as your rpm rises...

The single plane = loss of low end torque, free breathing and more high end power and revs.

you're limited to 5.7 liters cause your current plans are to keep the bottom end...and thats a good choice..just keep it..

so to make your 5.7 perform better..you need to get more "stuff" through the engine between stop lights... stuff = air/fuel

Since displacement is set at 5.7.. you need more revolutions of the engine to occur between stop lights..

to get more revolutions to occur between the stop lights..you need the following..

1) quick revving.. (spin up quick)..

2) be able to hold more revs in each gear..(cause your other limit is the 3.70 rear end)

Since you have the 4 speed... VERY GOOD !!!

you can rev up the motor more as you take off...(also increasing revs between stop lights)


To make power...its always CCC (carb , cam , compression)

1) Your carb is good..but this also means correct intake...3.5" runners (single plane)... for instance..a stock LT1 manifold IS a single plane..so there are many factory (oem) applications of single plane... i.e...its not just race...

2) Heads..this is part of carb and COMPRESSION..and you gotta get alum. heads..small combustion chambers to increase compression... get rid of the irons..you lighten the load and bring in the STUFF..

3) Compression; thats the small combustion chambers of the heads..(where the STUFF explodes)..increasing that..and use a thin head gasket to also reduce space and bring compression up... (what is your compression now?)

4) CAM; proper cam for the heads, single plane, qjet and headers... makes it all come alive...

Read through the below article... check your compression... you may do something similar to this... but with your qjet and single plane..

http://www.gmhightechperformance.com...e/viewall.html