434 SBC Custom Engine Build
 

I would like to ask for your help in putting together a "bill of materials" list to build a new engine for my boat this winter.
This will be a freash water only engine so I am fine using alum. heads if needed.

Here are the goals that I want to obtain.

Small Block Chevy
475 H.P. at the Crankshaft
Sustained WOT of 5,600 rpm, not to exceed 6,000 rpm.
Straight Plug Heads
Ability to run on 92 octane pump gas.
Good idle and broad torque curve.

I do not mind having to buy a World Products or Dart engine block to obtain cubic inches up to 434 cubic inches if necessary. I definately do not want to use a blower or turbo on this engine.

I will definately be using the following:
Aftermarket EFI system, closed cooling system that maintains around 175 degree F water temp and a Wet 4" Exhaust system.

Where I need some help is in selecting the crank, rods, pistons, heads and camshaft.

Thanks for your input on this fun winter project. My budget is around a maximum of $10K.

Thanks,

DonCig

Re: SBC Custom Engine Build
 

That will not be easy on that budget. Maybe this link will give you some help. He has some good deals on short block kits.

http://www.shafiroff.com/

Re: SBC Custom Engine Build
 

Don, I have an aftermarket EFI (4 bbl type intake) that I used on a customers boat prior to installing a Whipple. It has the intake, 1100cfm throttle body, fuel rails, adjustable regulator and 42 lb. injectors. It is drilled for traditional heads and Vortec. You would just need an aftermarket ECU/harness and fuel pump. It could save you quite a bit of money compared to new parts, and it is just like new. Let me know if you're interested.
Bob

Re: SBC Custom Engine Build
 

Don,
What do you want included in your 10K budget ? Are you including EFI system and exhaust, or only the basic engine ?

Re: SBC Custom Engine Build
 

What compression ratio are you looking for. I have 475HP 383 crate engines in stock. If you are interested in buying a complete long block, with warranty, call me. 903 786 3797, Matt

Re: SBC Custom Engine Build
 

"There is no replacement for displacement" in a boat of your type. Invest your money in a big block, you will get more bang for your buck! and the marine parts will be cheaper.
Ray @ Raylar

Re: SBC Custom Engine Build
 

Here is what I have placed on the "BOM" as of today.
Price on the following comes up to around $6,200

Dart Little M Block w/Nodular Splayed Caps for 434 c.i.
210 CNC Ported AFR Cyliner Heads Aluminum Straight Plug
Eagle 4340 Nitrided Crankshaft
Callies Compstar 4340 Steel Rods 6"
JE Forged 9.6-1 Pistons

I have set aside $2,500 for the Holley Stealth EFI which includes the intake manifold. The short block will come assembled to my specs so it apprars that the $10k budger was not to far off the mark.

Do you guys think that the Crane Cam #HR-284 will
produce 475 H.P with a decent idle if the engine is properly assembled?

Don

Re: SBC Custom Engine Build
 

Well, I would splurge on a better crank, perhaps a Callies or Lunati crank, and would definately go with a larger cam. I would also go with the World block since it will supposedly go .015 ;arger on the bore (even more with sonic testing I hear). I have the HR-284 in a 355 and it will idle around at 500 rpms in my small motor. In a larger motor it will behave like an even smaller cam. I would go with the next size up which will give you about 12 more degrees at .050 if I remember correctly. Keep us informed on what you decide to go with. I myself will most likely stick with a stock block and a Lunati 3.750 stroke crank and try to get a 383 to make that number, but it is always easier with more cubic dollars, I mean inches.

Re: SBC Custom Engine Build
 

Thats a hole lot of money going into a SBC just for 475 hp.It would make a very dependable bottom end

This is a little 355ci I built. Stock bottom end.Pump gas made 528hp.I have Been running it in my 70 Chevelle 4040lbs street/drag car for 3 years and also has a 200 shot of NOS.

I know a marine motor has a pretty good load all the time ,also has a lower RPM range.I also would like to have the good parts in the bottom end and on some of my other motors I have had in the car had the Crower billet crank/rods etc. IMO my 355 has been doing fine w/ stock crank/rods/block. :D

Good luck

Rob :drink:

Re: SBC Custom Engine Build
 

I built mine for half the money your planning on spending. Mine runs on 110 octane, has around 550-560 hp. all from a little 383....