Blown 516....finally getting close!
 

Still working on the new motor for my warlock. Hope to have it done by late May. I just shipped my dominator to Nickerson Performance today to have it reworked. I've gone from a mild 454 that I assume put out around 450hp to a 516 (ported merlin grumpy jenkins heads, rm builder hyd. roller cam, b&m 250 blower, nickerson dominator, msd ignition, etc...) Quite a bit more horsepower to expect....so I'm told. I'm looking forward to seeing how the boat responds to this new power plant. I have had a few "unexpected" upgrades along the way. Such as an ati super damper, arp main & head studs, double keywaying the crank snout, the high flow oil filter pad adaptor from cp performance and having the oliver rods I picked up on here rebushed but it's all in the name of building a stout motor!

I'll be posting some pics on here as I am putting it together. I haven't bought an oil cooler yet but it's on the list as the stock one is clearly to small for this new motor and the numbers I've been told it should put out.

I really want to send a big thank you out to Bob at Marine Kenetics...for all his guidance and recommendations through out this build! He is great to deal with and extreamy knowledgable!

If this helps, If anyone building a gen 6 is looking for an adjustable billet timming pointer for different size dampers (they are almost impossible to find!). gen 6 502's runs a 8" diameter balancer and my ati is 7".....Unleashed Custom Maching / 818-312-6217 makes them! They are a bit pricey at $65.50 but they are out there if you need them.

a 250 blower on a 512? Sounds a little small int the blower department. I hope you are going to run an intercooler because to make any boost, you will be spinning that little bugger pretty fast and generating a lot of heat and it appears you have iron cyl. heads. Scary combination in a marine application.

MUSTANGMARK,what hp are you expecting to see with your new build?

I am thinking around 700 is a safe bet. I am running this blower for one summer then going to sell it and the carb so I can move up to a bigger blower. That's one of the reasons for double keywaying the crank snout right now.

Mark, I will tell you that to make 7psi of boost on my 460CI engines, with roller cams and dart heads, I turned the B&M 250 to 1.86:1 ratio. So at 5500, I was spinning the blower at 10000 rpm. It did sound cool.

A buddy of mine did a 598CI, dart heads, 256 blower, no chiller. He only makes about 3psi of boost, at the same ratio I spun mine to get 7psi. He made a little over 800HP dynoed with all his accessories. However, the engine without the blower probably would have made 700-725 N/A.

Another buddy of mine did a 509, 250 b&m, 7psi, 695HP. He also had merlin iron heads with a hyd roller. However, with the iron heads, i'd keep it at 5psi with your combo, or blower speed under 10000 at wot or you'll probably kill the blower bearings and make gobs of heat on prolonged runs at wot.

If you havent dynoed it yet, I'd consider selling the 250, and getting a 420 at least. Realistically, you can get into a 420 megablower for probably beer money after selling your 250.

The 420's are plentiful used and very reasonable. A 6-71 is 411, and a 871 is 436. The 420 is like a 7-71 if they made one! According to some charts, ive seen the weiand 871 rated at 50 or 55% effieciency, while the 420 was 60% effiecient.

Ask airpacker about his 509 420 Mega setup.

[QUOTE=MILD THUNDER;3649647]Mark, I will tell you that to make 7psi of boost on my 460CI engines, with roller cams and dart heads, I turned the B&M 250 to 1.86:1 ratio. So at 5500, I was spinning the blower at 10000 rpm. It did sound cool.

A buddy of mine did a 598CI, dart heads, 256 blower, no chiller. He only makes about 3psi of boost, at the same ratio I spun mine to get 7psi. He made a little over 800HP dynoed with all his accessories. However, the engine without the blower probably would have made 700-725 N/A.

Another buddy of mine did a 509, 250 b&m, 7psi, 695HP. He also had merlin iron heads with a hyd roller. However, with the iron heads, i'd keep it at 5psi with your combo, or blower speed under 10000 at wot or you'll probably kill the blower bearings and make gobs of heat on prolonged runs at wot.

Mild Thunder, Thank you for the great info! I am going to stick with the 250 for this season because I have to much on my plate at the moment and have my eyes set on picking up an 8-71 next winter. I will take your advise and keep the boost around 5 psi though! I have 2 pulleys for the 250 at the moment. One's around 3 1/2" in diameter and the other is just under 2 1/2" in diameter. I think the smaller one is going to be a bit much for it though. Thanks, Mark

Good info Mild. I might need to pick your brain on 454 blower setups next winter. :party-smiley-004:
And mustangmark can't wait to see how yours turn out. :)

Thanks Rookie! I hope to be running in late May at this point. My machinist is taking his sweet ass time, I still need to do assemby and I keep running into unexpected expenses. I'll post some pics when I start putting it together. The old motor was a lot different and wasnt anywhere near the horsepower this new one should be so it will be interesting to see how much mph the boat picks up.