Air Flow Research Heads
 

The other day I posted here about a 540 motor I am putting together. See attached link.

http://www.offshoreonly.com/forums/s...ngine+build-up

The short block parts are already ordered. I am trying to decide on the heads. I have talked to Dart and A.F.R. I like AFR better, their flow numbers are real good. However, Jason from AFR told me that they are using "REV" valves.. I never heard of them.. I thought everyone is using Manleys. Is anyone using these valves?

The other question is aluminum heads. With 9 1/2 compression, aluminum heads will not help me. Steel would be better. Also, I wanted to use my closed cooling system from my 454 Magnum. I am not certain it will keep a 540 cool enough. My 454 Magnum runs at 170*, this 540 will have a 140* t-stat in it. The cooler temperature has to help the heat exchanger deal with the extra cubes somewhat---I guess..

Re: Air Flow Research Heads
 

Well Check, I think closed cooling is the perfect match for Al heads....salt or fresh water. I would try to run your existing cc system-if it keeps the mag plenty cool, me thinks running where you run your rig-it should be plenty. Why not run your temps up a bit...that way you could run a little tighter PTW? Thats one of the big advantages of cc- things such as clearances and tunability are more constant.

Re: Air Flow Research Heads
 

You can order the AFR heads with "hard anodized" water passeges for $90 extra. Well worth the money, especially if you are going to run in the salt.

Re: Air Flow Research Heads
 

Thanks for the replies.

sutphen30,
So, you are saying that Rev valves are better than Manley. I just never heard of them..


john.s,

The next time I talk to AFR, I will inquire about the " Hard anadizing"

Re: Air Flow Research Heads
 

I'm using the AFR 315 CNC heads on my 540's and am pleased with them. I've used AFR heads on automotive SBC's, and the BBC castings are much better.

I bought them bare, except for copper-berrylium valve seats and hard anodizing. I put Del West inconel exhaust and stainless intake valves in them, along with Isky Tool Room springs (really made by PSI), and Crower titanium retainers. After giving the valves a 30* back cut, we flowbenched them and exceeded AFR's flow claims. With a Crane 741 roller cam, Victor Jr intake and Holley 850 carb, they made ~690hp (@6000rpm) and 650 ft lbs on the dyno. Other than forgetting to hook the choke connections up, they have run flawlessly since I installed them last spring.

Here are the results and comparisons to what AFR claims @ 28" H20. The heads are "out of the box" with no additional porting or epoxy.

We tested with an out of the box Manley Severe duty intake valve, and then with a backcut inconel Del West Intake valve of the same diameter which I am using.

..........AFR CLAIMS.......MANLEY SEVERE........B/C Del West
.200........169.0..................169.28......... .............177.45
.300........249.0..................248.64......... .............261.45
.400........312.0..................306.36......... .............327.60
.500........353.0..................352.98......... .............363.59
.600........380.0..................375.18......... .............391.40
.700........387.0..................390.72......... .............394.74
.800..........N/A....................391.12......................3 94.91

I would say that AFR's claims are pretty accurate. The discrepancy's are around 1% which can be accounted for by atmospheric conditions and variations between flowbenches.

The basic combo is: Dart Big M block, 9.0:1 static compression, 4.500" bore x 4.25" stroke, 9.800" deck, Crane 741 hydraulic roller cam, Crane roller lifters, AFR 315 CNC heads with backcut Del West stainless intake valve, Del West inconel exhaust valves, Isky (PSI) "Tool Room" springs, Crower stainless rockers, JE forged pistons, Crower 4340 billet 6.386 rods, Crower semi-lightweight 4340NT crank, Victor Jr intake, Holley marine 850cfm 4150 carbs, MSD Pro-Billet Distributor, etc....

RPM.......TQ.......HP
4000.....643......490
4100.....644......503
4200.....644......515
4300.....649......532
4400.....654......548
4500.....655......561
4600.....660......578
4700.....660......590
4800.....655......599
4900.....652......609
5000.....651......619
5100.....648......629
5200.....645......639
5300.....642......649
5400.....638......656
5500.....635......665

Re: Air Flow Research Heads
 

Monty, I'm sure that I told you before, but that is one sweet engine! It looks like a perfect blueprint for 1000 HP supercharged.

Re: Air Flow Research Heads
 

Monty,

Great information!! Thanks alot for the help.

Re: Air Flow Research Heads
 

If you want an indorsement in regards to REV Valves, Dean Nickerson is the person who clued me in on their existence. I would definitely go with the hard anodizing. It is a $189.00 upcharge.
My engine builder went with the AFR 305cc heads with the CNC'd chambers on my 9.2:1, Dart based 540. Manley valves. Cam is a Comp with 236/[email protected] duration, LSA is 112 and valve lift is .630/.635. 1050 Nickerson carb with a single plane Merlin intake.
706 hp@5400 rpm and 700 ft/lbs@5000 rpm on the dyno.
Hope this helps.
Russ

Re: Air Flow Research Heads
 

AFR will install the killer feria valve which is better than manley innconel ,, rev vavlves are goood if the are their best series

Re: Air Flow Research Heads
 

I had a set of Dart Merlin heads, I cleaned up the intake ports, sent them to Weston machine for a valve job and assembly, then CC'd the combustion chambers. They produced 5000 rpm and 82 mph on my boat. I made some extra money in the stock market so I sent a brand new set of Dart Merlin heads to AFR, they cc'd combustion chambers at 130 cc's, ported intakes and valve job...2.25 intake 1.90 exhaust. They produced exactly 5000 rpm and 82 mph.
I've spent more on less.