I've talked with quite a few marine engine builders and am not sure which direction I should go with the intake. I had finally narrowed it down to either the Merlin or the Dart with the Merlin inserts because the boat runs in salt water so that's why it came down to these two. In the final hour I decided that I'm going to ceramic coat the intake and the exhaust manifolds. This opens the door to many other manifolds. The with the right intake and exhaust, the builder said it will produce 525hp without going to a full wet header. Here's some specs on the motor.

JE Dome Top Pistons CR: 10.2:1
Bored .030 over (468?)
Cleaned up Retangular Port Heads
Crane Hydraulic Cam, full roller setup (don't have the specs but it will be spinning up to 5800rpm.)
Gear Drive
Single Plane Intake with 850cfm Carb
Revolution Marine Exhaust

I've herd good things about the Brodix HV2000. I've built my fair share of engines years ago and have always been impressed with their products. I've also been told the Edelbrock Super Victor with a 2" spacer/adapter from 4500 series to the 4150 series carb is probably the best setup. Not sure if I room for the spacer. Was hoping some of you other Senza Spectre guys out there could tell me if I'd have the room or not.

Looking forward to your feedback.

I'd go with the dart. But I would be more concerned with exhaust. Look for a true header with individual runners 30"+ in length. Revs are basically a manifold and will rob a lot of power in the upper rpm range on a n/a engine.

BT

You won't get 10.2 to 1 compression with flat top pistons. It will be closer to 8.5 to 1. I agree that the Dart is a good choice for your engine. The Brodix and Super Victor would be better on a larger engine or one that spins more rpm. Remember, drag race guy spin big inch big blocks to 8000 rpm's. That's the market the Super Victor was designed for.

I have 454's that have been massaged, 10:1 compression, and I have Merlin intakes on them. A mechanic I used to use in St Pete said he had a set of Merlins on two engines he built, and couldn't get them to stop leaking water from the front of them, so he switched to Dart intakes. I asked him if it fixed the problem and he said, "Yeah, no water leaks, but lost 400 rpm".

Are you building the engine yourself? Talk to Dean over at Gellner Engeering if your looking for a builder. It's amazing how much HP he can extract out of a NA 454. The setup works well, Their work is like no others. I have roughly around 230 hard hours on her and It is still running solid. Recently did a compression check, still running 150PSI each cyl.

My Setup:
454 Block
Stock Bore
JE 9.6:1 Compression
Stock Rods
Blue printed & Balanced
CMI Headers
Roller Rocker Lifters
Hdyro Cranscam
Holly 850CFM Carb
Dart Hi Riser intake manifold
Dart 454 Heads

Dyno 514hp (conservative tune)

They are domed pistons. I had that wrong. Will I have problems with the brass inserts when I have the intake ceramic coated? Thanks for your help.

Also, do these hp numbers sound right?

[QUOTE=Senza Spectre Man;2060860]Also, do these hp numbers sound right?[/Q

I think it's possible. The high compression and a good hyd. roller cam will help. You will need a good exhaust system, probably dry also. If you want to rev to 5800, I'd use a cam like a HP500 efi cam or the HP525 cam. You'll make as much hp as those engines but at a higher rpm because of your smaller cubes. Remember to always use good gas. 10.2 is high when you use iron heads.

[QUOTE=PatriYacht;2061014]How much hp do I give up using the RM's vs dry headers? Isn't engine compartment heat an issue with dry headers? The additional money needed for headers I'm planning on using to buy hydraulic steering. For as fast as she should run, I'm not sure it's a good idea without hydraulic steering. I keep the boat on the trailer and fuel up onshore, so that shouldn't be problem. I've built high C/R street engines in the past and jetted them a touch rich. It seems to keep the combustion chamber cooler. How ever, I will keep my ears open and back off the timing if I need to. I really appreciate all the help!

Thanks for the input. I'd love to go with a true header but I need to put hydraulic steering on this boat. It should run in the high 70's, maybe low 80's.