How much power with a two bolt main 454
 

Hi all, Looking for some advice on an engine. I am clearly aware that 4 bolt main engines are better. I am wondering if a two bolt main bottom end will support 450 horsepower. Also, is a 1995 310 or 330 horse a four bolt main or two bolt main??

Re: How much power with a two bolt main 454
 

a 2 bolt main will support 450 hp for short periods of WOT if it has a steel crank. I wouldn't recommend trying 450 with a cast crank though. The 330 should be a 4 bolt main block.

Re: How much power with a two bolt main 454
 

Lined honed and ARP studded block will handle 600 or so. Make sure its balanced real good and clearances are spot on. The 95 should be a four bolt, some of the earlier mark 4 330's were 2 bolt. Cast crank is fine if you keep the rpms below 5200 and everything is blueprinted.

Re: How much power with a two bolt main 454
 

The boat I am looking at has what I believe to be a gen 5 engine. I would like to see about 450 hp but would not run wot hardly ever.

Re: How much power with a two bolt main 454
 

check out The thread "horsepower happy" I built a 91 330 hp to about 425. It seems to run strong. Ron

Re: How much power with a two bolt main 454
 

I thought all gen5's were 4 bolt.

Re: How much power with a two bolt main 454
 

If you want some peace of mind throw some 4 bolt 'retro' caps on it. I've seen them for <$100. My machine shop talked me out of it this time, but I'll probably do it next time... if I get that forged 496 stroker crank :)

Re: How much power with a two bolt main 454
 

According to Dennis Moore, do not hesitate to use the 2 bolt main block on anything with less than 600 hp and turning less than 6000 rpm.

Re: How much power with a two bolt main 454
 

Formula31 has pretty much hit it on the head. Back in the mid 1980's a few of my friends used 2-bolt main blocks and cast cranks and made 450+hp @5500rpms. They just made sure everything was done correctly, align honed the mains, balanced the rotating assemblies, accurate clearances. Some used bolts and some also used ARP main studs. Studs will give about twice the holding power and are a good idea on a 2-bolt main block for added insurance, but not absolutely necessary. They all survived. :D

Re: How much power with a two bolt main 454
 

By the way, back then many other offshore boaters and engine enthusiats thought thought we were nuts/crazy for using cast cranks and 2-bolt mains, but like I said they all survived many, many hours with no problems. One particular friend of mine had a twin engine 30' Scarab with two 454's (bored .030") that made about 450+hp each and each had been cut to .010"/.010" on the mains/rods of the CAST cranks he used. He didn't even run engine oil coolers---just 10 quart pans with Valvoline straight 40wt oil----still no problems with either engine. He owned the boat for about 5 years and hundreds of hours after he had the engines rebuilt up until the time he sold it in 1991-1992.

Re: How much power with a two bolt main 454
 

All above are pretty much correct. We run a cast crank and 2-bolt mains in our Corvette and turn 6500 RPM and turn 11.90's. If RPM's are kept at 5500 RPM or so cast cranks and 2-bolts are fine in a pleasure HP marine engine. Racing engines that are used for racing really need steel cranks and 4-bolt mains, but most of us on here fall into pleasure boaters. :D

Re: How much power with a two bolt main 454
 

my 470hp/468 with 2 bolt & cast crank ran for 500 hrs with LOTS of time at 5400 rpm, until it's untimely death when it ran up on a beach and spun for almost an hour with no water at about 4000rpm or so till the boat caught fire -- I say bolt that stuff up right and go!

Re: How much power with a two bolt main 454
 

You're 100% correct.

Roby

Re: How much power with a two bolt main 454
 

What!!!! On the Beach.....almost an hour....4,000rpms.....no water? Full story Please, hope no one was too badly injured.

Re: How much power with a two bolt main 454
 

A well balanced cast OEM crank with a block that has good machine work will handle 600hp all day long. A 2 bolt block will handle what you want. . get into the 500 range I recommend studs, at 600 the caps start to walk and aftermarket splayed caps are really needed.

Chris

Re: How much power with a two bolt main 454
 

My engine machinist has a really slick way of using dowell tubes in conjunction with studs that keeps the cap still on 2-bolts. He has numerous 800+ HP 7500 RPM+ drag motors running 2-bolts with no problems relating to the cap moving. He charges about $250 to dowell and align hone the block and it is ready for action. :D

Craig

Re: How much power with a two bolt main 454
 

between SuperV and I we have 5 motors with cast cranks that make 500hp at 5600 and never had a crank related issue....