Selecting a manifold for AFR 265's - single versus dual plane - thoughts anyone?
02-25-2014, 06:56 PM
#51
I am a big fan of the as cast 305 afr's on a typical 500" and under bbc. they just work, for not a lot of money...
I like how they proved ovals work better, by putting a modern designed aluminum oval, up against a 1960's designed GM iron rect head. Not to mention the GM iron headed combo was 9.7:1, with a major port mismatch, and the AFR combo was 10.5:1 port matched. HMM, I guess all rectangles suck. I would have like to see them do a back to back, with a 265 OVAL, VS a 305 Rect on that build. I bet the numbers would have been alot closer. Heck, a 308 Summit brand Iron head will walk away from those vintage 088 GM heads. They could have done a little better in trying to compare oval vs rectangle design.
02-25-2014, 07:00 PM
#53
02-25-2014, 07:36 PM
#54
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Since we are posting magazine article info, I was just reading an old one on the crapper.
Budmans
454 with AFR 265s. 10.5:1 compression. 242/248 110LSA cam. Single plane. (10.5:1 is pushing the limit imo on pump gas in a boat)
3,300 317 506
3,600 361 526
3,900 393 531
4,200 425 543
4,500 455 564
4,800 516 569
5,100 552 566
5,400 582 556
5,700 603 556
6,000 617 540
6,300 622 518
6,600 620 493
Engine Masters
454 stock 454HO crate bottom end with Dart 310 Pro 1. 8.5:1 compression. 236/242 110LSA. Single plane. (this thing will run on 87 octane all day).
3200 287 472
3400 312 483
3600 333 485
3800 352 487
4000 373 489
4200 396 495
4400 422 504
4600 447 511
4800 473 517
5000 493 518
5200 509 514
5400 519 505
5600 524 491
5800 524 475
6000 520 456
Now you may see that the AFR 265 Combo, made 51 ft lbs more, and 98HP more. But, it also had two full points more compression, and a larger camshaft. Id be willing to bet, that you bump that compression on the Dart headed engine up to 10.5:1, the numbers would be real close. Even still, a 8.5:1 454 making 525HP and 518FTlbs, on 87 Octane, is not exactly a turd, and would make someone a nice long lasting marine engine. The 310 Rectangles they used, might not be theoretically the right head for a small, sub 6000RPM, 454 inch engine. But, sometimes ****t just works.
Budmans
454 with AFR 265s. 10.5:1 compression. 242/248 110LSA cam. Single plane. (10.5:1 is pushing the limit imo on pump gas in a boat)
3,300 317 506
3,600 361 526
3,900 393 531
4,200 425 543
4,500 455 564
4,800 516 569
5,100 552 566
5,400 582 556
5,700 603 556
6,000 617 540
6,300 622 518
6,600 620 493
Engine Masters
454 stock 454HO crate bottom end with Dart 310 Pro 1. 8.5:1 compression. 236/242 110LSA. Single plane. (this thing will run on 87 octane all day).
3200 287 472
3400 312 483
3600 333 485
3800 352 487
4000 373 489
4200 396 495
4400 422 504
4600 447 511
4800 473 517
5000 493 518
5200 509 514
5400 519 505
5600 524 491
5800 524 475
6000 520 456
Now you may see that the AFR 265 Combo, made 51 ft lbs more, and 98HP more. But, it also had two full points more compression, and a larger camshaft. Id be willing to bet, that you bump that compression on the Dart headed engine up to 10.5:1, the numbers would be real close. Even still, a 8.5:1 454 making 525HP and 518FTlbs, on 87 Octane, is not exactly a turd, and would make someone a nice long lasting marine engine. The 310 Rectangles they used, might not be theoretically the right head for a small, sub 6000RPM, 454 inch engine. But, sometimes ****t just works.
Never popped a TRS until this year. I wonder what changed... 5700RPM!
02-25-2014, 07:42 PM
#56
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I wonder why I snapped TRS like twigs with 600hp. Maybe it was the 5 blades and 5200RPM in a 40' tank ! I should have ran royal purple lube.
Last edited by MILD THUNDER; 02-25-2014 at 07:44 PM.
02-25-2014, 08:12 PM
#57
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iTrader: (1)
02-25-2014, 08:13 PM
#58
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iTrader: (1)
So...I've been gone for a few hrs. Enough time to have that Dart oval installed. Is it on yet ?
Now where's that piece of paper with the lengths written on it?
02-25-2014, 08:52 PM
#60
So you own Dart oval port single plane intake and you are wondering which intake to use 
..Why don't you put on the one you own and try it .If you aren't satisfied with midrange by an rpm airgap .Gaskets may be expensive .but less so than a new intake...Especially if you are happy with the dart and game over .....
..Why don't you put on the one you own and try it .If you aren't satisfied with midrange by an rpm airgap .Gaskets may be expensive .but less so than a new intake...Especially if you are happy with the dart and game over .....
