Friend of mine is going to run a 588 wedge motor he just bought next year in his street/strip car, current spec is>
Mega Block, 572-13's, Jesel rockers, small s/roller .620/.620, on 112lsa, don't know the @.050 dur.,....its only 10:1CR
I don't know much about the motor whether they are CNC385's or the smaller version as motor was originally built as a 605 with a 4.625 crank, its now got a 4,5 crank in it he's been told, I would've thought they were the 385's with those cubes. We are going to run it as is next year, this is not a drag car only but will see 6>7 meetings@SPR, he will be driving quite a bit on the street also.perhaps not as much as this year?.

It made an average of 700hp/735ftlbs on 2 dyno pulls with an 850DP and his 950DP., max power came in@5700 with the 950DP which showed 1.9 vacuum@ WOT. My thoughts are of an upgrade to the lift and an 1150 Dom carb at some stage later, thats a very small cam for those heads, and I understand they need lift to get air in through those big ports for it to work well with a bigger carb, CR will stay the same I reckon, which won't help things on CP.

He will be running 4.10's and 10x29 bias slicks which will mean around 6300 rpm@the stripe in his weight, which will work with the cam he has, so what would you guys suggest would be a good cam upgrade considering that if he goes up to .700+" the duration will go up in the 280's@.050 but that may not be an issue for the size of motor, I've no experience with such big motors only stock stroke stuff I raced. He may need a 1 off grind?....is there a 700+ lift roller with easy lobes that will live on the street without much maintenance as I don't think he's going to be into that after running a more or less stock 440, this will see him go 2+ sec faster@mid>low 10's but I'd like to see him run 9's.

All thoughts advice welcome...thanks

I've never driven this on the street. But driving around the pits at low speed its fine. Easy on springs. Its put my 572, -1s to 9.00@3350. Run it with both 4.10 and 4.30, 10.5wx31 M/Ts. Comp int lobe RX1718 exh lobe XCX1862 on 112LCA. I do run 15-1 comp though.
Doug

I guess before I got too far along with a cam swap, I’d try and figure out exactly what you have.

The “popular” 604”’combo is 4.50 bore with a 4.75 stroke.
In order to get that many cubes from a 4.625 stroke the bore would have to be 4.560....... I’m not so sure that fits in a mega block.

“If it were me”, I’d want to nail down what I have, and measure/calculate the actual CR.

Frankly, I don’t feel that more duration with 10:1 CR is going to do much for it.

If the heads have been CNC ported by Indy(in the last 15 years or so), it will be CNC’d right into the intake mounting surface what they are.

Do a cranking compression test on it now to see where you’re at.

Engine/car is at race shop where its getting sorted to handle the motor, will pass info on to my mate and try and get more info on it, 4560x4.500=587.92ci, ..4.500x4.625= 588.45, it was actually sold as a 589
I did some research and found this>


CAST IRON BIG BLOCKS (Mega Block)

• Brand-new castings made from high nickel alloy cast iron
• Thicker deck surface for improved rigidity and gasket sealing
• Ductile iron main caps which are cross-bolted on the 3 center caps on all the Siamese 440 blocks
• Stock 10.72" deck height
A. Cast Iron Siamese-Bore Blocks
These blocks can be bored to the stock size of 4.25", but are specifically designed to be bored larger. Mopar recommends that you sonic check each block if you approach or exceed the 4.50" bore diameters.
*P5007625AB 440 Big Block Cast Iron Siamese Cross-Bolt Block- Rough Bored at 4.50"
*P5007626AB 440 Big Block Cast Iron Siamese Cross-Bolt Block- Raised Cam, Rough Bored at 4.498"
*P5007624AB 440 Big Block Cast Iron Siamese Cross-Bolt Block- Rough Bored at 4.19"
Note: P5007626AB Requires special UGL cam P5007714, special oil pickup, and intermediate shaft modifications. Higher cam location allows (0.250" higher) longer stroke for more cubic inch displacement up to 4.50" stroke. Some clearancing of the pan rail and other areas will be required.

Cast Iron Wedge Blocks
Wedge Blocks feature factory-size bores, water flow between the cylinders (not siamesed) for improved cooling and sealing durability. These blocks are fully water-jacketed.
*P5007671AB 426 Max Wedge Cast Iron Block- 2-Bolt Mains, Finish Bored at 4.25"
*P5007815AB NEW! 440 Wedge Cast Iron Block- 2- Bolt Mains, Finish Bored at 4.32"

So we'll see what he has for crank/compression currently and take it from there. @the current hp level it will do what he wanted and that was to run a min of 10.5 and drive on the street, he didn't want an all out high CR race motor.

Not wanting to be a party pooper but I'd be sonic testing the thrust sides on those bores. I've had 2 Mega blocks and I wouldn't run them over 4.505 bore, one of them 4.350 was all we could safely go. They had some core shift for sure.

Hi Tig, I think you know who I''m talking about, he's a nice guy, and yes I've been reading the same and its got me a bit concerned about what he's bought as I suggested it to him as a perfect way of doing what he wanted to next year. I was thinking I should talk to you about this as you have run this type motor for some time..Perhaps we can discuss things more. I doubt if Dave would knowingly sell him something thats not very good.

Do you know if it is the raised cam block? Not being that familiar with the Megs block, if it is raised cam version, is lifter bank angle changed, and are they 55mm cam bearings? I may have a Bullet Roller that cam out of my 588 for you. I’ll dig out cam card. Jim

We are going to get the block P no. and take things from there

thanks