Been toying with the idea of buying a new set of heads to replace the Edelbrock 60739's I'm currently running.

I bought the Brocks when I had a 355, and now that I'm a bit bigger, my thinking was that I needed better (bigger) heads. Guess I was caught up in the "bigger is better" mentality there for a while. Hard to resist.

Then I had a revelation!. Since I have this "way too expensive" Engine Analyzer Pro program, I decided to see what the results would be. You know, it's the program that costs $600+ and calculates well over 40 different
engine conditions. These programs are great for making comparisons; but don't necessarily accurately predict what a dyno will show.

So I sat down and plugged in the head flow numbers for the following heads:

AFR 180, 190, 210, Edelbrock Victor Jrs and my 60739s.

I entered in the different combustion chamber volumes, port volumes, intake and exhaust flow and valve sizes and recalculated the compression ratio when the chamber sizes differed from the 60739s.

I was amazed. As you might guess, the AFR 210s had the highest flow and my 60739s the lowest, but the max Tq and HP AND average Tq and HP wasn't anywhere near what I expected.

Here are the numbers; judge for yourself:

60739----------AFR 180 ----- AFR 190-----VIC JRs ----- AFR 210

Max----Avg------Max Avg------- Max Avg-----Max--Avg------Max----Avg
Tq 508--428---518--440----- 513---433---529---441----534----448
HP 460--307---467--308-----472---306---479---311----492---317

So, maximum average power increase would be 20 lb/ft Tq and 10 HP.

Yea, yea, I know, if I made a lot of engine changes, like more cam, better intake, etc., the numbers would change, but none of that was in the plan. I ONLY wanted to change heads. Not to spend another 2 grand on an engine that is never raced.

So for $1,500 or so (not to mention all the work involved), I don't think I'd be getting a lot of bang for the buck.

The max numbers for torque were in the 4200/4500 range and HP in the 5100 range (except for the 210 heads which hit 5700).

Just something for you folks to chew on.

Hey, I tried several times to get those stupid columns to align so it would be easier to read, but the way the forum formats msgs I couldn't do any better, sorry.

Jake





[Modified by JAKE, 3:35 PM 11/22/2003]

 

Looks like you just saved a bunch of money :cheers:

Once you reach a certain level there is definately a diminishing gain for the dollar spent.

Hey this is a great plug for that expensive program you bought isn't it ! The way my wife thinks, that package didn't cost you $600 it saved you $900 !!

 

Jake,
That was an excellent post.Interesting to read about that info.Having the program to run numbers can possibly come in real handy.Must be the reason its best to buy all the parts first,such as a true and tried matched/combo than to try and buy this cam now,this intake later and swap heads etc.

Interesting enough,the machine shop guy I knew told me he felt the edelbrock heads for the L98 were excellent street heads and gave a decent gain without going too big for a car that is driven on the road 95% of the time.Plus the bang for the buck for new heads wasnt too bad either.
I almost got those heads when they rebuilt my engine but my budget suffered and I kept the stock heads with some minor port work done.

Anyways,nice info.
:)
:cheers: