540 BBC
I just ordered 2 new Dart Big M 4.500" bore, 9.800" deck blocks, and 2 pair of Brodix BB-2 Plus aluminum cylinder heads. With the 119cc combustion chamber and JE forged pistons it will work out to 9.0:1 compression.
Has anyone used the Brodix BB-2 Plus heads in a marine application? Is it necessary to hard anodize the heads in a freshwater (Lake Michigan) application? With a 234/244, .527"/.544", 112 LSA hyd. roller cam, anyone think I would have reversion issues with Stainless Marine exhaust? DD2000 predicts this: RPM......HP......TQ 2000....245.....643 2500....314.....660 3000....374.....654 3500....430.....645 4000....480.....630 4500....513.....598 5000....523.....549 5500....503.....481 6000....462.....404 |
You can contact KAAMA. as he's had extensive experience with many different 540 variations.
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Sutphen30,
I got the flow numbers from the the Brodix website. I've used Dart heads in the past with good results as well, I've got Dart 18* CNC heads on my Vette's twin turbo engine. However, the machinist I use, Fast Times Motorworks, recommended the Brodix over the Darts for smaller port BBC heads. I'm not set on the cam spacs yet, that was just one that I was using for modeling. In any case, it will still be relatively mild. I'll sacrifice a few hp in return for increased reliability and lower maintenance. |
Okay, I checked out the AFR 305's and at least according to their claims, they do have better intake and exhaust flow across the lift range. I'll have them order those instead.
Do you think Copper Beryllium valve seats are a good idea? |
With the Crane 741 and AFR 305's, DD2000 predicts:
RPM........HP........TQ 2000......247.......647 2500......317.......666 3000......380.......665 3500......441.......661 4000......497.......653 4500......546.......637 5000......573.......602 5500......577.......551 6000......551.......482 Is this too much for Dollar Offshore prepped TRS and Borg-Warner Velvet Drives, assuming I'm easy on the throttles out of the hole? According to the speed calculator on go-fast.com, assuming 8500lbs, these would be good enough for 82 mph peak at 5000 rpm, and 72mph cruising at 3500 rpm. |
Could one of you computer guys run the same combination with Dart Pro-1 325's and Crane 651 cam on your DD. Cam specs. are 244,256 @ .050, .632/.632 lift. 114 sep. Thanks.
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Here's the dyno sheets from my short deck naturally aspirated 540's on Tom Earharts dyno. Holley HP950's, Dart single plane intake manifolds, Dart Pro-1 aluminum 310cc heads fully ported by JimV with 2.30" intake valves and 1.88" exhaust valves, Crower hyd roller 236*/244* on 114* lobe seps, 9.6 comp ratio, 32* timing, full length tubular dry headers, MSD billet distributors, MSD Crank Triggers with Crane Hi-6M ignition boxes.
RPM TQ HP 1500 507 145 2000 545 207 2500 539 257 3000 614 351 3500 598 399 4000 662 504 4500 692 593 5000 684 651 5250 658 658 5400 655 673 5500 651 682 5750 639 699 |
Just got off the phone with Mark ( KAAMA )
Although the engines produce HP all the way up at 5750 RPM he doesn't run it above 5500 - 5600 MAX. That is what JIM V. heads will get you. Just think what these engines would produce at 10.5 to 1 compression and a more agressive cam. And it would still run on pump gas. |
Those are some startling numbers from a small set of heads. I'll have to call Jim V. this winter.
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Monty, I have a 555 with the BB2 Plus heads with a bowl port. It has a mild cam (232/240 at 114 LSA) and MPI. Running 9.4 compression it made a little over 600 HP on the dyno. I now have over 200 hrs. on it with nothing but oil changes. I only turn it to a max of 5400 RPM.
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