Fellas,

I really am 4-6 Months from being ready to install my Engine (at least), but I ran into a deal today and wanted opinions. I have had it in my mind to build a 496 for my Car, and have a lot of the Parts. I am concerned about finding a good Machine Shop that I can use (the old one I used closed), and, a few around me have a bit of a dubious reputation.

Anyway, I ran into a pretty good deal on a Bill Mitchell 540-it's at a Bill Mitchell Dealer, and I can get for at least a couple of grand off of new. It still comes with a 2 Year Warranty, and, I was day dreaming the other day as to which Engine would I buy if I didn't build my 496, it was a toss up between a Bill Mitchell 540 and a GM 572-this is the 540 I day dreamed about.

I am looking for experiences on Bill Miller stuff-a search here doesn't reveal much, and, a Google search doesn't bring up much more. The one thing that does come to mind is that this engine is rated for 600 h.p. (Aluminum Heads), and comes with the World Products Rectangular Port Heads (I think 315cc?) and Single Plane. It is billed as a "Street" engine, and a call to their Tech Line says the same. Conventional wisdom says this setup is good for high RPM-any knowledge there?

They don't reveal Cam Specs, and, it appears to be a Flat Tappet Cam. I don't want something that I will hate e to drive, so I am looking for a little insight there too-we all hear the stories of guys saying that they have 900 h.p. that is streetable, but is it really?

Any thoughts would be appreciated-

I have no experience with Bill Mitchell 540's, but will toss in my 2 cents for what it's worth.

I wouldn't lay out this kind of money for a flat tappet cam motor. Being dyno'd at 600 with a single plane intake tells me that it was probably rated at a fairly high rpm. If that's the case, then it would take quite a lot of spring pressure to control the valvetrain. In my opinion, there are two things that don't belong in the same sentence....
1. flat tappet cam
2. quite a lot of spring pressure

Bill Mitchell builds quality stuff and can make a ton of HP,I know 2 guys at the race track with the 540's and have held up great and YES the HP ratings are accurate from what I have seen,They haul!!!!!

A good buddy bought the 572 and put it in a prostreet car,It's a serious deal!! As far as streetable, everyone has a different thought on that,Yes he drive's it to all the cruise in's and car show's with no troubles, but it is a rowdy one.

Buy the engine and stab in a hydraulic roller suitable for the eninge's size and compression ratio.

If you hate driving just give me a call, I'll substitute drive a 600hp hotrod any day of the week.




Larry

The minor question you have to answer is if your trans, drive train and chassis will handle the power without tearing them apart.

Then answer how much maintenance you are willing to do on the engine.

I know a few guys that have a real 900+ hp cars and the expense of the drive train and chassis is way up there to hold the power.

Mine has a tad more HP and I have 20K in upgrades, with me doing a lot of the work, including the cage, frame, and rear end parts to keep the body in one piece, not including 8K in the trans and clutch system.

Buzzing a BIG 580 inch full roller Hemi, up to 7.5-8K, really wakes up the crowd, on the street.......or anywhere..and with proper gearing and chassis can be driven, limited, on the street.

Bill Mitchell Hardcore uses World Products blocks, which are inferior to Dart blocks. The BMH engines I have seen have block and balance issues, as well as assembly problems.

As long as you don't mind disassembling the engine to correct casting, machining, assembly and balance problems overlooked by BMH, they aren't so bad.........

tom

Thanks for the replies everyone-

Tom,

Guess your answer tells the tale (I was hoping you'd weigh in)-alrighty then, I have everything to make a 540 (except a GM 502 Block, everything I've collected is for the Gen VI 454 Block I have, so it will fit a new style Block)-

I guess the Heads are the question-will the Edelbrock RPM Oval Port Heads (#6045) support a 540? I already have them, so I hate to change horses in the middle of the stream-I was thinking the options last night, if I did build it this combination (502 Block, 4340 Eagle 4.25", Eagle 6.385" 4340 "H" Beam, Edelbrock Air Gap, Comp Cam in the 240 (or so) range, it would have good turbulence, correct? (meaning it should have good throttle response?)-top end would be the concern? If that is correct, maybe I should stick to my 496-

Running the numbers through my head, in the end it would have been cheaper to buy the BMH engine, and I'd hoped it would be the answer to my concerns regarding quality and warranty. Oh well-

Seems to me that the Edelbrock heads you have are pretty much at the limit with your 496. Going bigger cu/in-wise would dictate more head..........

tom

Must be in the internal components or the assembly as I have been in the plants that machine both Dart and World blocks and heads here in MI and they use the same CNC machines to machine them. Interesting.

Could the Edelbrock heads be ported to achieve flow that would feed the larger motor?

I know you're looking at a 502 block....
But I JUST yesterday spec'd out a 540 using a Dart Big-M block and SCAT forged rotating assembly that comes out to about the same, or just under the 502 short block.
http://www.jegs.com/i/Dart/301/31273444/10002/-1
http://www.jegs.com/i/Scat/942/1-42370BI/10002/-1
It's actually about $550 cheaper...but by the time you add the oil pan, balancer, and timing set/cover...it's about the same...maybe a $100 or so cheaper depending on what you choose.
BUT...you're getting an aftermarket Dart block instead of a production GM piece. Dart also offers that block in a short block configuration...but me personally, I don't like the cast crank and pistons they put in it to keep it at a reasonable price. I'd rather just stuff my own good forged stuff in there.

After I put all the pieces down on paper, I posted it to an engine building forum elsewhere and the owner did a Dynomation run on it. ....670ft lbs and 612 hp

But, if you're spending that much on a motor, you might as well go ahead and spend the extra little bit and keep stroking it up to a 572. The guy went ahead and did that to show me...and it ended up being 720ft lbs and 660 hp....better than the GM Street 572....and with a more "street friendly" curve.
Also QUITE capable of a 250 shot plate....which bumped it to 1100ft lbs/800hp on the virtual dyno.

If you want, I'll pm you the specs since there's no way in hell I'm putting that in my little 2600lb car. That'd be VERY low 10's/high 9's....depending on what I had for breakfast. haha!

Same CNC machines doesn't mean same quality of castings, tooling, operators, programmers, and/or quality control.

And I still spend time in my shop fixing what either of them let get by, although Dart still looks better to me.

Right now, I'm fixing the valve job on some Motown heads.

tom