what kind of HP do I need

[jshirley78]

I have decided to go ahead and build a 454 for my 18' tahiti Torino (scraped the 350 idea), the question is what kind of power do I need to produce 50-60 mph top speed. Keep in mind Im on a married mans budget so 500hp is prolly out of the question, I know I can get 330hp out of a stock 454 easy. Also what kind of redline should I build into the motor.

[Jetmugg]

A stone stock 330 HP 454 will get you to 50-60 mph. Don't worry about high rpms, if you use an A impeller, you will probably only be turning somewhere between 4500 and 4800 rpm.
Of course, after you do this, you will be wanting more. It's the deadly and expensive trap.
SteveM

[BrendellaJet]

It doesn't take much to make 500 hp with a big block. Im pretty sure the 330 hp motors have really low compression. You'll want to identify your impeller size and then locate the hp chart for the impeller to determine where you want your power.

[TJS]

I have decided to go ahead and build a 454 for my 18' tahiti Torino (scraped the 350 idea), the question is what kind of power do I need to produce 50-60 mph top speed. Keep in mind Im on a married mans budget so 500hp is prolly out of the question, I know I can get 330hp out of a stock 454 easy. Also what kind of redline should I build into the motor.
I think we need more infor on what you want to "build"
There are many perceptions of "build". Are you just going to clean, hone (keep stock pistons), rings, cam, timing set, gaskets and bearings. We need some more info to go on. Also what are your plans on the heads ???
Do you have the block apart for inspection yet to see what you might need??
Or are you replacing pistons, resizing rods (or new rods), bigger cam, larger marine grade valves etc. Again to answer this you should take the motor apart and check the holes for roundness and wear.Check the crank as well. Hope this helps some.
T.J.
www.tjsperforamance.com

[jshirley78]

dont actually have the block yet, plan is to get a "junkyard" motor (I have a few resources for good cores) and do a complete teardown, have it magna fluxed and checked, if the stock crank is good I plan to keep it, no plans to overbore. Prolly going to keep stock heads and just rebuild/true as needed. More than likely Ill be adding a new cam and was considering a gear drive for timing (could use opinions). Ive built a couple of barebones small blocks in the past, usually just use a kit from summit, but those have been for farm trucks and realy needed nothing special.

[TJS]

For your sake, I hope it is a good core if you are not going to bore it out. I hope there is no taper either. I got a core LS-6 (virgin) uncut block with rect. port heads. I got it for a fair price. It had dropped a valve, so the pistons were hammerd. When I got it apart the cyl. walls had some good scratches in them so now I have to over bore. I just got the heads back from the machine shop and they had to put hardened seats and replace eight guides along with new valves and oversize the exh. valve. I have done many small blocks too, for some reason the Big block takes a lot more money to build one.
T.J.
www.tjsperformance.com

[jshirley78]

usually the cores I get are out of emergency vehicles with fairly low miles and so far I havent had any with any real cylinder problems. When I built the 350's I went ahead and bored them but according to the machine shop guy I would have been fine not to. What I end up doing realy depends on the block I end up with. I have noticed when the put big block on a part you tend to haveto dive a little deeper into the pocket book and realy not sure why

[Squirtin Thunder]

It has been my experience that 500 - 600hp is very easy to get out of a BB. With todays gas quality and high price you will want to stay around 9.5-1 so you can run reg 87 oct. Heads and port work will dictate alot of your power. Make sure everything is matched and work together for the RPM you want. If you need any help designing a platform let me know !!!
Jim
1-928-704-1158

[Squirtin Thunder]

You can trust Jim, first thing he does is take your 454 and bore it to a 460 :yuk:
No I was thinking more on the lines of a 4.500 bore !!! :cool:

[jshirley78]

The engine kit I had my eyes on for the boat is 9.78:1 with forged pistons with teh stock 116cc heads, I had figured in a .030 over bore if needed. (Im guessing most would just go ahead and bore it) with a Crane powermax Cam kit with duration of 226/236 and lift .534 int/ .553 exh... intake manifold I was up in the air prolly just use and edlebrock performer as thats what I am familiar with and I have no idea what size of carb Ill need as big blocks are new territory for me. So any help will be greatly appreciated!!!!

[BK]

You might want to concider the RPM Air gap and an 850 Holley or Demon carb.

[Squirtin Thunder]

You might want to concider the RPM Air gap and an 850 Holley or Demon carb.
Good ideas. I would shoot at the Demon for it is twice the carb at 2/3 the price in a marine application. There are also four Demon carbs made by Barry Grant that are 850's. I believe your cam is a little small to get the performance you are looking for or could want later down the road. After reading quite a few posts, if you want 500 lake HP, you must make about 600. So step up two cams in the power max series or go with a extreme marine cam from CompCams in that same ballpark. To save you some money, I would look at the powerplus hurricane intake from Profesional Products. It is about $110 less than the exact same unit from Harden Marine. As far as you heads, I would think about the aluminum edelbrock Marine head. If you have any questions, please call me.
Thanks
Jim

[SmokinLowriderSS]

It's not hard to build yourself a 400 to 500 HP big block chevy. I'd step just a bit bigger on cam (I'm runing a .565 lift) and it runs good. I'd also reccomend the Performer RPM Air Gap (It is also working well on my 454). Carb, yes arround 800CFM, maybe a bit bigger. I'm still running my 700CFM orriginal from 1978 and just redid the engine last winter. Personally, I like timing chain sets but that is just me. Running an all-billet one from Comp that has a built-in block-saver bearing on the cam gear, $100.
Lastly, to have an "out" for the poweritis disease that eventually strikes, plan on installing a nitrous plate setup at a later date and you are another 150HP ahead in the game. I been running a Marvin Miller plate setup since '79, still orriginal as dad had it installed, still works great.
Best of luck to you.