Max HP a 1970 460 block can take?

[Trent]

Hi All,
Great forum here!

Could someone englighten me as to what the max hp a 1970 460 BLOCK can take with the 2 bolt mains and how much if I convert to the 4 bolt main caps.

Thanks in advance!

Trent

[Dukeofdiamonds]

It depends. Not all blocks were created equal... but most have agreed that any factory 2 bolt block is usually fine to 700 hp. There are those that have successfully pushed these blocks to 1500 hp before..... but these people are not the average builder and its only a matter of time till something breaks. Most guys will go to an aftermarket 4 bolt block or at least machine and install 4 bolt caps for anything above this level. The BBF is a strong motor, but there comes a point where there is a gray area where safety and reliability are at risk.

What really depends is, what are you wanting to do? Best bang for your buck? Stroker motor? NOS? Forced induction? That will determine how much work it will take to meet your goals, and whether or not a factory block is appropriate.

Also, don't hesitate to do a search on here, there has been lots of information posted in the past.

[Trent]

Hi Dave,
Thanks for the information. I am building a stroker 521 drag motor and looking for 850-900 hp at the crank N/A. I already have the block and would like to have it machined for the 4 bolt caps and put a forged rotating assembly into it. I was wondering if 900 hp would destroy this block... I also don't like to live on the ragged edge if you know what i mean

Thanks,
Trent

[1Bad65]

If you plan to make that kind of power....it's un-realistic to not go with a A460 aftermarket block. It's not worth the "I think it will hold pass after pass after pass".....I'd spend the $2500 and get that block if thats the power you want to make. If you stay under 850hp I think a 4bolt splayed would be ok, but any more it isn't worth the headache and pain to go through after you $$$$ is demolished over a block that could hold up to the power inside of it....jmho

[Dukeofdiamonds]

Originally Posted by 1Bad65

If you plan to make that kind of power....it's un-realistic to not go with a A460 aftermarket block. It's not worth the "I think it will hold pass after pass after pass".....I'd spend the $2500 and get that block if thats the power you want to make. If you stay under 850hp I think a 4bolt splayed would be ok, but any more it isn't worth the headache and pain to go through after you $$$$ is demolished over a block that could hold up to the power inside of it....jmho

X2.

You have the right idea not to run on the ragged edge... its always better to spend the extra for the better stuff, 99% of the time it ends up being cheaper in the long run.

[DJOHAGIN]

Trent,

While it is certainly possible to make the stock block work, and work well, you're at a point where the A460 block or an Eliminator block is a better choice. You can start off the bore at 4.5, which will help with unshouding the valves, and I'm assuming you're looking at the A460 heads. While you can get the stock layout heads to put out that kind of power, if you're starting from scratch, the A-heads would be better.

Hope that helps,

Dave

[MarkJ]

They can also split from the mains to the cam. I have one that was making around 825H.P.

V/R
MarkJ

[Lem Evans]

Originally Posted by MarkJ

They can also split from the mains to the cam. I have one that was making around 825H.P.

V/R
MarkJ

Yep...if they [2 bolt deals] break it's from a main bolt hole to the cam bearing housing .

[HEMI-HUNTER]

i wouldn't worry to much about 900hp as long as you stud the mains w/ a girdle. and use quality forged parts in the bottom end don't bore over 80 and make sure she is balanced to the T". it should hold up OK. try and keep it under 7000-7200 and make sure the block is sonic checked before you bore it 80 over.

[BBFmavrick]

Also, You have to remember that these blocks are 40 yrs. old. KISS

[Paul Kane]

Originally Posted by Trent

Could someone englighten me as to what the max hp a 1970 460 BLOCK can take with the 2 bolt mains...

Depending on engine combo, engine application, components used, compression ratio, hp generated, operating rpms, executed block modifications/preparation/treatment, power adders, tune, and more: the 2-bolt blocks can support anywhere between 300hp-1500hp. Generally, the higher the power output the riskier the use of the OEM block and the greater the maintenance (maintenace exponentially increases, so to speak). So they have lived at 1500 hp but these engines usually received complete freshening after 7500 feet worth of quarter-mile passes, and on the flipside I have known people to absolutely destroy 4-bolt blocks at just 300 hp.

Like Chuck Stevens signature line states, "Some people can break a cannonball, in their little sandbox, with their bare hands."

Paul

[1Bad65]

Originally Posted by BBFmavrick

Also, You have to remember that these blocks are 40 yrs. old. KISS

IMHO, older is better, but with today technology....it's priceless

[1Bad65]

Originally Posted by Paul Kane

Depending on engine combo, engine application, components used, compression ratio, hp generated, operating rpms, executed block modifications/preparation/treatment, power adders, tune, and more: the 2-bolt blocks can support anywhere between 300hp-1500hp. Generally, the higher the power output the riskier the use of the OEM block and the greater the maintenance (maintenace exponentially increases, so to speak). So they have lived at 1500 hp but these engines usually received complete freshening after 7500 feet worth of quarter-mile passes, and on the flipside I have known people to absolutely destroy 4-bolt blocks at just 300 hp.

Like Chuck Stevens signature line states, "Some people can break a cannonball, in their little sandbox, with their bare hands."

Paul

lol, very well stated and I can see where your coming from. BUT, to me it's just foolish to waste your hard earned dollar to make HP levals that were never really thought of when these older blocks were designed. Thats why these A460 blocks are worth the money. They have been proven to hold up to 2500hp. Now if you ask me....if I'm gonna make 900hp NA w/out gas and then plan to spray...There is no way in hell I'm going to limit my block power to 1500 when I'd much rather limit my block power to 2500hp...plus that motor making 900hp in a A460 block has room to grow and MUCH more room to play..

[Paul Kane]

Yes, if you can afford 1500-2500 hp, then hopefully you can afford to use parts superior to OEM passenger car parts.

Paul

[1Bad65]

hey I'm a poor guy....i cant afford no a460 block myself....so i just stay under 800hp.. Thats plenty for me to handle...