This thread looks very suspiciously like a set up to try and discredit RayMac, by a few that are motivated for a some reason .
Most people don’t understand why speed cost, it take a skilled craftsman about 50 hours to finish a cylinder head correctly, it also take some very expensive equipment, close to half a million to open a engine shop And it looks like some people don’t understand cutting edge parts, you truly get what you pay for , and Chris at RayMac dose some incredible work . The retail price for a CR/24 valve head is $7400 this includes a $500 core charge that is refunded if you send in a good core. This price also includes an O-ring that is done on a CNC mill not with a ice cream grinder. Is this head for everyone? no, but it is not the most expensive, a top head from Buddha Power brings $12,500
I will clarify that Project X currently has a RayMac cylinder head, Burt at Manuel Auto Group is an incredable head porter and his head may find its way on X some day . But he is is able to do only one head a month and the head in the picture belongs to Brad at Fass.
RayMac turns out 6 to 10 heads a month, along with a shop full of pulling engines and drag race engines. The prices they charge are compliable to other reputable engine shop such as Doug at Woodward and Dan Schieds.
I have been on the flow bench with a good number of heads and the head I flowed for Burt, flowed great numbers, around 235 cfm The head that RayMac dose flow even more 255+ cfm , but requires a lot more time and work. , and the Buddha power head flows even more than that???? .
A stock Cummins head flows 144 cfm of air. The area of work in a 24 valve head doesn’t weaken it in any way, that area of smallest cross section is about 2 inches in to the port and not accessible without removing the intake manifold.
With regards to ZZ custom fabrications intake, the air flow to the end cylinders is absolutely restrictive and it makes for the last cylinder to run richer with a stock intake, this is even worse with you port the head and do not address that area . The ZZ manifold fixes a lot of these problems
People that are saying that air flow doesn’t matter in making power are correct, you can make 1000 hp with a stock head and cam, but you will need big boost numbers, and big drive pressure numbers , and this equates to retained heat, this retained heat will also require you to reduce compression to keep from melting parts .Reducing compression reduces mechanical efficiently, and slows spool anytime you reduce compression it is a crutch to make something else work .
so you have two engines side by side that make 1000 hp, one requires 80 psi + boost , the other requires 45 psi . How long does it take to spool an 80 psi chargers, vs., a 45 psi charger. In sledding pulling it might not be a factor, but in drag racing it’s everything. In drag racing you can leave at lower boost numbers, because the chargers will ramp up quicker, this allows for less broken drive line parts. Now if you put twins and big boost, on this type of engine the results will be 20% lower boost and as in Brian’s truck 1300+ hp
Brian, You and Ray currently have a disagreement, and there are two sides to every story, but I did see you time slip at Drag Week and the 11.17 pass was an easy 10.70 judging from the splits I saw, and the terrible 60 you had on that pass. You were down 3 tenths on 60 ‘and the injectors you received that morning from your friend popped on the top end , and as a experienced drag racers who lives and dies on math , I will tell you , you lost about a tenth to .15 hundredths . So that is a solid 10.7? . So why complain. I would talk to Ray if you think you have a problem.
There is a point when people ask for a maximum effort engine and this requires compromised on the street ability , light weight ring packages require a dry sump or a vacuum pump , this is a fact . Now that ring package is worth about 40 to 80 hp, which is already paid for in the combustion chamber. But it also has its down side, blow by at part throttle.
I am sold on the precision that is RayMac, Ray has many years at NHRA Pro Stock, NASCAR , GTP and other high end engine development programs . It where Ray excels and it doesn’t matter what fuel it burns. The fundamental point is any racing engine is just as good as it is an air pump. So you that want to slam Ray, might look around, There are a lot of engines out there that are winning, with his parts
So whether you get a head from RayMac, Burt , or John Russin and Buddha power , it is the future of Diesel performance . Curtis Halverson is doing my engine program , assisted by some of the creations from Greg at ZZ, He does have individual runner manifolds and several big pullers are using them, I am not allowed to show pictures of these , but some are going to big name engine shops in the pulling world