On the talk of building a 600 HP 440 or larger stroker, several posts questioned the strength of the stock engine block?

I thought 600 HP was not all that hard on the stock 440 block, but other than the mild 505" in the Convertible, my other strokers were 400 blocks. All have 1/2" oil pickup mods, and ARP main studs. Only the 500" 400 block has the BCR aluminum caps and 1/2" Girdle.

What modifications to the block are normally done for 600 HP?

The Jensen engine may be close to this power level, and I was just planning on using the ARP main studs, and maybe the 1/4" 440 source girdle?

I don't plan to modify the block for full time rocker oiling, I never had issues with the rocker oiling before?

Just depends how long you are going to beat on it. The typical engine puts out about 30 hp driving down the freeway at 65 mph. Maybe if you're pushing a C body up over the Rocky mountains you might eat up 75 or 100 hp but that is about it. So unless you are WOT for an extended period of time the engine will never see 600 hp.

Having said that, Mopar engineers quickly found out that the wedge block couldn't handle 600 hp for more than a few laps at Daytona so they had to go back to the drawing board and design the cross bolted mains.

My old 440 made about 625 hp or so at the flywheel (10.40 @ 129.1 mph at 3700 lbs.) and put 508 hp to the rear wheels on the local chassis dymo.
That block has nothing done to it other than ARP main bolts. I ran the crap out of it for about 3 years w/ no trouble, street and strip.
I personally think the limit for stock blocks is closer to 700 hp than 600 hp. I base that simply on what I've done personally and what I've seen others get by with.

Now my old 440 has fully ported heads, a bigger intake, and a lot more cam. Should be right at 700 hp. Have a few chassis updates to do to the car it's in now, but it will be hitting the track again soon.

Think it was a better than that>...650hp@3700-lbs
60 Foot E.T. : 1.45
1/8 Mile E.T. : 6.56
1/8 Mile Trap Speed : 103.58
1/4 Mile E.T. : 10.40
1/4 Mile Trap Speed : 129

rb446...the 60' was always a little sluggish, best was a 1.49. It wen 6.62 at 104.1 mph in the 1/8.

I think the altitude here (Denver) will save me
If I build it for 600 HP, I'll be luck to see 500 actual, more like 480 HP?

Yup, the factor is almost exactly 0.8 times sea level air.

R.

Tuning for no detonation and good main caps and studs wil be your best freind Keeping it under 7000 RPM is a good thing also

I ran my 446 for 7 years with no issues at 615 hp.
ARP main studs, alum rods is all that was done to it over
the normal stuff. I dropped a valve in my indy sr heads and that
did it in.

is this for a driver? I think a stock 440 block can take 600. I'd definitely clean up the oil returns and go w/ a the larger pick-up. If you aren't going to routinely beat on it at the track you probably don't need the girdle. Any ideas on the build? Boost? roller?

Stay in Denver, build for 700, make 580, live forever. 😉

The current build is for the Jensen Interceptor. Really over kill for that car as there is no room for decent sized tires on the rear.
The car has the original 1973 440, that I will do a 505" stroker kit, most likely from 440 source, and maybe get the light weight crank option? Plan to use the stock mains with ARP studs (align boring the mains for new caps is fairly expensive.)
The mains will be align honed.
Reason I was thinking of using the main girdle is I want to use the Jegs composite windage tray and the girdle will space it 1/4" out so it will fit without modification. I used that windage tray on the 505" 440 in the Coronet Convertible (mild hydraulic roller and 440 source stealth heads, so maybe 550 HP max? at sea-level.) On that engine I had to do a little modifying of the windage tray for it to fit (no girdle.)
Back to the Jensen Engine, This is getting the trick Flow heads, 1.6:1 HS rockers, and a solid roller Lunati Voodoo 40230732LK cam 243/249 duration @ 0.050".
I was thinking this might be around 575 HP? at sea-level, but reading the thread on the trick flow heads, this seems close to some of the other builds reporting around 600 HP?

Yesterday, I got shipping tracking numbers for a few of the back ordered parts I have been waiting for, so some day I might have the parts needed to do this project.

I use a 440 block on my 493 build. I am using ARP main studs and steel billet main caps. I also am using the 1/2 pickup and I drilled the passage to 1/2 in the block to the pick-up. And I use a solid flat tappet cam. And thats about it really but it is a street car that I just race every now and then when I can. The last few years I am lucky to get to the track once a year. I would guess it makes about 600 flywheel hp as it has pushed my 3700 lb 63 to 10.70's on 92 pump and through the full exh as I race it just as I drive it. I put this eng together and in the car in 2011 and its holding up great. I dont street race so when I drive it on the street which I normally drive it alot I dont hammer it hard. I also just use the stock rocker shaft oiling and it has worked great as everything under the valve covers still look like new. I use the basic Indy EZ heads that use the stock rocker oiling and it seems to work fine for how I use the car. Course if I was racing every weekend I would have done more to it but for a mild street car that only gets raced once or twice a year it has worked great. Ron

Man, more delays! Got UPS shipping update that delivery will be delayed due to a traffic accident.

Summit called Lunati, and they are waiting for solid roller lifters from their supplier, est another two week delay in shipping.