Requirements:
6500 red line
600+ HP and very strong on low and midrange torque
Good street manners, 10 years of joy without need to open and inspect every now and then
Strong on strip
Easy later to upgrade to 700+ HP and 7000rpm

Plan:
BG 850 Mighty Demon
Edelbrock BB Victor Jr
AFR 315 Fully CNC ported
Valves with Undercut stems
HydRollerCam ~0.63lift and ~250 @ 0.050
11:1 CompRatio
Forged light aluminum pistons
Total Seal rings
Manley 4340 H-beam rods
Crankshaft Scat (of similar) 4340 steel 4.250 Stroke
540 Dart Big M or World III Race

Have already:
1973 Vette
2” primaries headers
All MSD (6AL, Pro billet, 8.5mm wires, Blaster2)
TH400
3.36 rear gear

What kind of habits would you guess out of this combo?
Something there popping into your mind not fitting into picture?
Where on rpm the peak HP, peak TQ and how much?

 

For a 540 cu/in engine size, the 315cc intakes are a bit small. 650HP is a lot of horsepower to put through the Corvette's differential (the weak link.) One other factor to contemplate is the possibility of gas selling in excess of $3 a gallon by next year, do you really want a monster of this size to keep fueled? (expect around 6-10 MPG at best with a large motor.) I would stick to a 454 or even buy the GM ZL-1 aluminum block and build a short stroke 4.40" bore engine (3.75" 427 crankshaft.) The 315 heads would work well on a 427-500 cu/in motor.

 

These AFR heads flow 380cfm intake 296cfm exhaust @0.6lift and @0.3lift 249/184cfm so they show quite impressive figures. The 335 CNC Heads flow 240/197 @0.3lift and 385/311 @0.6lift, but maybe the flow figures are not enough to rely on also the runner volumes count...when looking for right match...
Yes the differential/driveline may be a problem, but maybe not with street tires. Without focusing on strengthening I maybe should forget my ET Street´s
My existing 500HP BB does like 12-13 MPG and 10MPG would make no difference to me (figures on easy riding). And it is a toy - I do drive it short distances and around 500-2000 miles a year eq during 6 summer months.
Thanks for your input!!!

 

 

Note that Vesa lives in Europe so he's probably already paying way more than we do for gas.

The combo looks pretty good, but I'm not too familiar with BBC's. I'd recommend dropping the compression down to maybe around 10:1 and definitely go with a hyd roller cam.

Wanting 600+hp and reliability, a big motor like that is a good way to go. You can also go a tad conservative for reliability and maybe add a small 100-150hp NOS for those times when you want to go for a blast.

The 3.36 gear is probably ok with the torque from the big block, but if it were a small block, I'd recommend maybe a 3.70 gear instead because of the seat of the pants acceleration a simple gear change can make

 

Vesa, very similar to my combo. Mine is a 502 with the AFR 315's, Victor Junior, SRP 10.2 pistons, Hooker sidemount 2.125 headers, 4 speed with 3.70 gears. I am running a solid flat tappet cam with 258 @ .050 and .615 lift. My combo made 614 hp on an engine dyno and it is very driveable on the street. I did significantly upgrade the rear end for safety though. The horsepower peak for this combo was at 6100 rpm's and torque was 586 ftlbs at 5000 rpm. The dynoing was done with a Holley strip dominator intake and a 950 Holley HP. I now have the ported Victor Junior and an 1000 HP Holley. So I would imagine I am more around 625-630 crank horsepower. At some point I may go the solid roller route and sneak up on 700 hp. Should not be hard to do.

 

RIGHT - One litre is 1.2euros here. But driving a Vette is a hobby!!!
Why 10:1 instead of 11:1? what would the advantages/disadvantages be?
Dont know why but NOS is not for me...It is like cheating/not real...and to get the NOS here in Finland is difficult...

 

Sounds like a good combo just keep in mind while the TH400 is a builitproof tranny it has a large parasitic loss 20%+. Also you're gping to need a fairly stout stall for700hp, 3,000+.

Best of luck.

 

I have now 2200 stall. I do not understand the tranny much; what does big parasitic loss mean? and why does it then point to having higher stall?

 

Great beast you have out there!!!
There was an opinion that maybe instead of AFR315 (maybe too small for 540 engine) i should head for AFR335 - what is your opinion here based on 315/502 experience?
What upgrades did you do to your rear end?
"Sneak up on 700 HP" - sounds like this is a never ending story - one newer has enough power
Do you think that based on your figures I should expect like 5800-5900 peak HP? And also I guess the TQ peak might be 200-300 rpm loweer...

 

Vesa, I too was torn between the 315's and the 335's, but it seems the 315's are perfect on my 502. I got alot of great input on this from people on this forum like Mountainmotor and 427HotRod. On a 540 I would probably go with the 335's. I guess it all depends on how fast you want to spin it. With a hydraulic roller cam you will definitely be rpm limited. The first incarnation of my 502 had a hydraulic cam in it and although it was supposed to be good to 5800 rpm it really nosed over at 5000. If I were you I would consider a solid flat tappet. It will spin up better because of the much lighter tappets and I haven't had to adjust mine yet after 1000 miles which includes break in and 20+ dyno runs. I am running Jesel shaft rockers though which surely helps.
I ended up putting offset trailing arms in the back with the 30 spline inner/outer axles and the huge 3.5 inch halfshafts with 1480 series U-joints. I also had the posi rebuilt. I got all those goodies right from Van Steel and believe me it is great quality stuff.
I would think that your HP and Tourque peaks would be at least 300 rpm lower than mine all else being equal. Good luck on whatever you do and I would be happy to answer in more detail with anything I have done. I will say also that I spoke at length with Tony Mamo at AFR and I would suggest you give him a call as well. He designed the BBC heads and is great to talk to.

 

Exellent input! Thanks alot!!!