I guess I missed the part about the headers and rockers.

More compromises.

Looks like it’s probably a candidate TF270’s....... and then “iiwii”.


You made 750 with them, so it appears that power level is attainable.

the low deck with SR heads, is my combo, and uses Hooker 5209 headers, just like Dave’s. Simple, proven, and works. No need to reinvent the wheel for a combo.

Oh, tell Dave to put the car on a diet. Can be done without making the car look gutted.

Yeah I pushed the 270 heads up to 780 hp on my pump gas 470 but that was a super expensive engine. Gas ported pistons, narrow rings, belt driven wet sump, belt drive, belt drive distributor, Wilson intake, custom T&D rocker arms, etc. More than $25K to build that engine from scratch. Plus I had 50+ dyno pulls on it which cost another $5K so it was a $30K project. Most bracket guys dig deep to come up with $10K for a new engine so my build probably isn't super helpful other than to say it can be done.

Something i have always wondered about , but never found an absolute answer to? Given the limits of a stock 440 block, and a given power goal that is right at the edge of that limit, which is better; a max stroke with less rpm' or. More rpm and a few less cubes? My guess is max stroke, since it reduces rpm needed and allows lighter pistons. Opinions?
About as big as you can go would be 4.375 bore by 4.625 stroke for 556 cubes. That would only require 6200 rpm to equal a 500 inch motor at 6800 rpm. Advantages would also include more average hp produced in the first half of each gear. Go from say a 4.56 rear gear down to a 4.10 to maintain proper rpm range for the big motor. The big motor also gains time duration in the induction cycle.
If a 4.75 stroke will fit, a 7.10 rod and light 1.225 ch piston work for 571 cubes. Rpm limit, 6,000 for safety.

For a stock block, I wouldn’t go any more than a 4.250 stroke, whether it be a low deck or RB.

One thing everyone needs to know, that is giving advice, is that Greg’s friend Dave, races EVERY single weekend in the summer. He double enters the car every chance he can get, and enters every gambler race he can enter. He flat out puts many laps on in a year. Having a super short piston, from a too long of a throw crank, just isn’t going to be good for long term.

No need to reinvent the wheel, and use an oddball combo. The 512ci combo is proven over and over, and works.

Another possible combo that will offer better block life;
Find a center weighted long stroke used crank, from a blown alky motor. Choose the shortest pistons that will give long ring life.( Ross ft 1.238 ch?)
Offset grind the rod journals to 2.100 sbc rod journal size. I am not sure what is out there, but would think a good crank capable of going to 4.500 stroke with a 2.100 bearing should be out there somewhere. Custum BME 396 forging aluminum rods is what i used when i built a 2.1 journal stroker years ago. The rods will end up being 7.212 long. Or you could opt for a shelf piston with a touch more ch and run a 7.10 rod. The bob weight should very light for a 4.5 stroke. 6200 rpm max should allow this 4.500 stroke 4.350 bore 535 cube motor live quite a good life with a max of 13/1 compression . a zero deck height and 76cc heads will get you to 13.1 to 1 compression with a flat top piston. Reaching 725 hp by 6200 should be doable with max wedge ports.
My 535 4.5 stroke motor used a heavier 6pak rod, taller piston, stock main caps . it lived a good life till the cracked crank finally broke. The block never broke though.
Advantages of this combo-
Light bob weight
Low rpm
Shelf stock pistons
Very easy on valvetrain
Hi torque


Disadvantages-
Needs 4.10 gear
Probably needs external oil line.
I went to a kinetic energy calculater to figure stress from the balance weight and rpm of two combos
500 cube 4.15 stroke and 535 cube 4.5 stroke.
With a 2200 bob weight for the 500 at 6800 rpm and 2100 bob weight for the 535 at 6200 rpm, the calculater shows 10 percent LESS stress for the longer stroke due to slightly less bob weight and the reduced rpm. I assume they would be equal at approximately 6500 rpm for the 535 and 6800 fir the 500.

That's what I built. 4.25 stroke 4.37 bore RB. Will use standard port Indy EZ's. 10.3ish comp.

Mild 500 inch'r with a ProCharger

That would be the main criteria I would be basing the build on.
Then, after you decide on the best way to achieve that...... it just makes what it makes.
Might make 750....... might not.

If I was building a car to run round after round then I'd tone down the tune a little bit, put a big cooling system in the car, add an alternator, and bolt on a Holley Sniper. What you give up on in power you would gain in reliability and consistency.

Daves car and his driving skills are well known.NOT someone you want to meet in the first round! The car is a PRESTEEN 1970 Charger, runs 10.60s now. I think Dwaynes' and your thought of dialing the goal back a bit to 10.20s would be a good move. That is still a great improvement over 10.60s and would reduce stress significantly on the block.

If a guy like that switches to EFI then he would become super hard to beat. At the local track one of the regular winners switched to a Holley Sniper and became deadly consistent.

Andy, i am guessing the sniper system is able to compensate for weather changes more accyrarely than a carb?

What exactly is the current combo that’s running 10.60’s?

Sure and it changes immediately without having to pull the hood off. Sometimes you get stuck in the lanes for an hour and the engine cools down or the track gets hot or who knows what. But the data logger is also important. I've had racers call me from the track with questions. I look at their data log via email and tell them what I think. One time the guy's throttle linkage shifted and he wasn't full throttle going down the track. Another time the car was laying over and the guy thought it was running lean. Turns out he was into the rev limiter and didn't know it.

A weather station and log book do wonders

[quuote=fast68plymouth]What exactly is the current combo that’s running 10.60’s? [/quote]
440 based 500 cubes, eddy heads

440 based 500 cubes, eddy heads [/quote]

TF270 heads took my 505 stealth head from 10.50 best to 10.25 .@ 3690lbs 28" pro bracket radial
BUT
Split the block at that time , actually split before i fitted the TF270s . Thought/hoped it was a head .
That motor raced once a month sometimes twice and drove daily to work etc .
My engine machine shop actually said " i knew it would break but didnt think it would break in 15 months "
My opinion for what its worth , get an aftermarket block . Mine was shifted @ 6000 , trap 6700 with Stealth head .
It was footbraked first 12 months thereabouts . At start of 2nd year went transbrake .


Tex

TF270 heads took my 505 stealth head from 10.50 best to 10.25 .@ 3690lbs 28" pro bracket radial
BUT
Split the block at that time , actually split before i fitted the TF270s . Thought/hoped it was a head .
That motor raced once a month sometimes twice and drove daily to work etc .
My engine machine shop actually said " i knew it would break but didnt think it would break in 15 months "
My opinion for what its worth , get an aftermarket block . Mine was shifted @ 6000 , trap 6700 with Stealth head .
It was footbraked first 12 months thereabouts . At start of 2nd year went transbrake .


Tex
[/quote]

What rod length?

Harry ,

4.25 stroke , 7.1 rod

Tex