Stock block strength

Hi All,
Currently rebuilding my 66 mustang and have installed IFS suspension so now have all the room in the world.

Looking at building myself a nice street motor which may see the odd trip to the strip. This would consist of a stock 460 block that I am yet to find.

Being new to big block Fords, I was wondering if someone could give me some info on how strong stock blocks are and what year would be the one to use? Eg, 70's, 80's and so on. I do plan on converting to a 4 bolt main. Being in Australia I haven't seen many for sale.

Would like to build a 521 stroker with a set of kaase sr71 heads. Although not ruling out a set of boss 9 heads as my dream engine is a boss 429.

Any help would be greatly appreciated.

Kind Regards,

Tim

The two best factory production blocks to use (excluding the Boss 429) is the D0VE and D1ZZ-6015-AA castings. These have the thicker main webs and can be machined for 4 bolt mains.

timhadfield wrote:Hi All,
Currently rebuilding my 66 mustang and have installed IFS suspension so now have all the room in the world.

Looking at building myself a nice street motor which may see the odd trip to the strip. This would consist of a stock 460 block that I am yet to find.

Being new to big block Fords, I was wondering if someone could give me some info on how strong stock blocks are and what year would be the one to use? Eg, 70's, 80's and so on. I do plan on converting to a 4 bolt main. Being in Australia I haven't seen many for sale.

Would like to build a 521 stroker with a set of kaase sr71 heads. Although not ruling out a set of boss 9 heads as my dream engine is a boss 429.

Any help would be greatly appreciated.

Kind Regards,

Tim

Most production blocks of any year will usually handle 800 horsepower or more if there is no detonation.

timhadfield wrote:Hi All,

...building myself a nice street motor which may see the odd trip to the strip. This would consist of a stock 460 block...

..I was wondering if someone could give me some info on how strong stock blocks are and what year would be the one to use? Eg, 70's, 80's and so on. I do plan on converting to a 4 bolt main. Being in Australia I haven't seen many for sale.

Would like to build a 521 stroker with a set of kaase sr71 heads. Although not ruling out a set of boss 9 heads as my dream engine is a boss 429.

Any help would be greatly appreciated.

Kind Regards,

Tim

Yours is kind of a loaded question. And you didn't mention your target horepower & rpm.

Although it's a unique example, I have known a 4-bolted D1VE passenger car block that held 3000 hp; on the other hand if one does not know what he is doing any cylinder block can be damaged with a mere 300 hp.

It has been our general policy to not build 2-bolt block based engines for customers beyond 800 hp (although I am breaking that policy with a build currently in the shop). On the other hand we have built 2-bolt blocked engines for our internal use (not customers) that made far greater than 1000 hp with zero issues...but they are very high maintenance.

You're from down under? Don't let the little 302 block's embarrassing weakness influence your speculation about the 429-460 block strength, as the 429-460 blocks are exceedingly strong.

I think you'll be fine with a 2-bolt block up to 800 hp. Beyond that, use a block that can be easily 4-bolted, such as the D0VE-A block.

One important caveat to all of my advice is the following: At these proposed power levels I strongly advise you to use the OEM factory main bolts in the cylinder block. Do not upgrade your main bolt fasteners to a higher tensile strength aftermarket fastener. If you do, then the likelihood of the cylinder block failing increases dramatically, and everything I just said does not apply as far as I'm concerned. Do a search on this subject for more info.

Paul Kane wrote:

One important caveat to all of my advice is the following: At these proposed power levels I strongly advise you to use the OEM factory main bolts in the cylinder block. Do not upgrade your main bolt fasteners to a higher tensile strength aftermarket fastener. If you do, then the likelihood of the cylinder block failing increases dramatically, and everything I just said does not apply as far as I'm concerned. Do a search on this subject for more info.

I am not sure I would trust 50 year old hardware for main cap bolts - thats just me.
Kaase's 521 dyno mule short block uses studs on the 2 bolt mains.
That has survived many, many tests. Good luck with your build. Should be a fun ride for sure!

68galaxie wrote:

Paul Kane wrote:
One important caveat to all of my advice is the following: At these proposed power levels I strongly advise you to use the OEM factory main bolts in the cylinder block. Do not upgrade your main bolt fasteners to a higher tensile strength aftermarket fastener. If you do, then the likelihood of the cylinder block failing increases dramatically, and everything I just said does not apply as far as I'm concerned. Do a search on this subject for more info.

I am not sure I would trust 50 year old hardware for main cap bolts - thats just me.
Kaase's 521 dyno mule short block uses studs on the 2 bolt mains.
That has survived many, many tests...

Compared to real world abuse, engine dynamometers are eeeeasy on engines.

And if we look to real world use-and-abuse high performance examples, 98% of the OEM 2-bolt blocks in high horsepower applications that I have seen which had their main webbing ripped out of them had aftermarket high tensile strength main fasteners installed. The same is true with the 4-bolted 2-bolt blocks. Frankly I would rather have those higher-than-normal stresses absorbed by the OEM bolts of steel rather than forcibly imposed upon the block webbing consisting of cast iron. Stronger fasteners belong in stronger blocks.

Generally there is nothing wrong with the fifty year old main bolts--that too has been proven over and over in the high horsepower 2-bolt blocks. But if it makes you feel better then just buy some brand new Grade 8 cap screws and use them instead of the old ones.

Thank you everyone for your input. It's greatly appreciated. So there is only certain stock blocks that can be converted to 4 bolt mains?
Sorry for not adding what I'm hoping to achieve with this build.
521 forged internals
Hoping around 750hp with sr 71 heads and max rpm being 7000rpm.
Thoughts???
Cheers, Tim

Any 429-460 block can be 4-bolted, some require more work than others, for simplicity's sake, the thick main web D0VE block is the easiest to convert. As Paul stated, all 429-460 blocks are more than adequate to handle 800 hp, more in the proper hands. Google D0VE and D1VE main web images and you'll see the difference

For being down under, by the time you purchase a D0VE block, and the aftermarket caps, and pay the shipping fee's and the import duty fee's, and then local delivery fee's....you would be better off to order a Ford Racing A-460 block, or an Eliminator block!!
Just my worthless opinion!!

Yes thinking the same way. There are a few std bore blocks on ebay out here at the moment but aren't DOVE blocks. The aussie dollar is a killer at the moment. A Ford Racing A-460 block is around $6000.

timhadfield wrote:..what I'm hoping to achieve with this build.
521 forged internals
Hoping around 750hp with sr 71 heads and max rpm being 7000rpm.
Thoughts???
Cheers, Tim

Again it depends on the build details, but assuming a solid roller cam and a double-digit compression ratio it’s pretty safe to say you can acheive 750 BHP with those heads and stroke at damn near 1000 rpm less or close to that.

If the needs from your build allow for such an engine combo (say,750 hp @ 6200 rpm) then if it were my own engjne I’d just run a well prepped 2-bolt block.  If it were a customer’s engine then I’d still be asking questions such as application, fuel, etc, but use of a 2-bolt block is certainly still a reasonable consideration.

Now if you simply want piece of mind then go ahead and 4-bolt the 2-bolt block. Lastly, a $3000 racing block for a 750 hp engine is money unwisely spent, especially from a horsepower-to-dollars ratio.

For ~ 750 hp on a 4.390" bore.......P51 would make more sense.

Lem Evans wrote:For ~ 750 hp on a 4.390" bore.......P51 would make more sense.

There you go ... trying to be sensible again.

If it weren't for the need for the 750hp number being in australia I would be tempted to play with some of the homegrown ford v8's the cleveland headed 302's and 351's can make some decent power and save some weight to boot.Did the 302 have a cleveland style block or did it use the same windsor block we have here?Either way it would still be the limiting factor for hp with the CHI heads being made down under unless they have local aftermarket race blocks also available for those apps.

timhadfield wrote:..There are a few std bore blocks on ebay out here at the moment but aren't DOVE blocks...

If you must have one then I have a D0VE-A 2-bolt block that I'd be willing to ship to you. We've shipped blocks all over the world, including Australia. But this particular example is not standard bore.

I regularly speak with customers from Australia and for some reason they, 1) believe an engine block is done at 0.030" overbore, and, 2) insist on a standard bore block for that reason. I'm really not sure why this presumption is being made about the 429-460 blocks, but perhaps it is because of other engine block designs and their cylinder wall thicknesses.

And so when it comes to the 385 Series cylinder blocks I find such beliefs misguided and in fact 95-of-100 385 Series blocks that I've sonic checked I've deemed the cylinder wall thicknesses good to 1000 hp at 4.44" bore (0.080").

If you want a D0VE-A block then give me a call and talk with me directly. I can include a sonic check sheet with the block, I can estimate how much horsepower I feel it is suitable at a given overbore, and I will even tell you whether I feel it will suit your current engine build. But it will not be standard bore...nor is that necessary.

dfree383 wrote:For a street car a factory 2 bolt block is fine

A Kaase Boss 9 Head is fine on a 4.39 bore and 700+ hp is pretty much a bolt together with a factory 460 crank, 10.5:1 and a decent small custom cam

Don’t let Pauls idiotic negative attitude about ford small blocks scare you either they make great engines and have powered many a fun street car for years.

I’d imagine in Oz you can get a Cleveland relatively easy too. They make a fantastic platform to.

I don't think Paul's comments are "idiotic", however I have beat the snot out of a .060 over 302 for over a decade in an 82 Mustang with a 5 speed. Street car.

I'm currently screwing together an A460 block with a 572 rotating assembly to run on pump gas. I'm shooting for 700ish horsepower on pump gas, but I want the option of bolting on a fogger or a couple of turbos. Everybody has their goals.

I have a nice D0VE-A block, std. bore, and I wanted to put the splayed 4 bolt caps on it and all the regular machine work, but after getting the prices for everything, it is within a few hundred dollars of the brand new A-460 block.
So I imagine how much more it would be in Australia. Plus, if one ever, for any reason wanted to go bigger and/or make a lot more power than 750, it would already be set for that.

dfree383 wrote:
...Don’t let Pauls idiotic negative attitude about ford small blocks scare you either they make great engines and have powered many a fun street car for years...

Huh? i like Ford small blocks. All of them. I drive one daily and it’s a blast.  



1995 SN95 in Saphire Blue, one of 2684 produced in this people-polarizing color.

BBFTorino wrote:I have a nice D0VE-A block, std. bore, and I wanted to put the splayed 4 bolt caps on it and all the regular machine work, but after getting the prices for everything, it is within a few hundred dollars of the brand new A-460 block.

Do you mean 4-bolting the D0VE block plus any other necessary machine work to bring the D0VE block to the same state as a new A460 block? If so, then you’re getting seriously ripped off on machining costs.

If you mean otherwise then please elaborate on your comparison to the A460 block pricing because I just don’t see how the bottom line costs/pricing can be even remotely similar between the two.

Again thankyou to everyone for your input.

Paul, I have emailed you in regards to the block.

The reason why I haven't gone the small block route is with all the room I have now, I like the idea of a big motor in the engine bay. I've had a blown 347 windsor in my old Aussie falcon before buying the mustang which was a lot of fun. Plus the big block in a 66 would be different out here.

Cheers,
Tim

Paul Kane wrote:

BBFTorino wrote:I have a nice D0VE-A block, std. bore, and I wanted to put the splayed 4 bolt caps on it and all the regular machine work, but after getting the prices for everything, it is within a few hundred dollars of the brand new A-460 block.

Do you mean 4-bolting the D0VE block plus any other necessary machine work to bring the D0VE block to the same state as a new A460 block? If so, then you’re getting seriously ripped off on machining costs.

If you mean otherwise then please elaborate on your comparison to the A460 block pricing because I just don’t see how the bottom line costs/pricing can be even remotely similar between the two.

Correct. A new A-460 block from Summit is listed as $2609.99(free shipping too!), and the local machine shop quoted me $600 for block prep and machining, which is cleaning, mag testing, bore, hone, deck surfacing, install cam bearings, and chase all threaded holes.
The steel aftermarket 4 bolt caps are $500 a set from Pro-Gram Engineering, then to have the block drilled, tapped and line bored/honed to proper size is $750. Filling the block up to the bottom of the water pump holes with Hard Block filler, letting it harden up, then rechecking the bore size and final hone if needed is $125. That all comes to $1975.

Now, I know those prices are on the high side, but its the cheapest I could find!!

BBFTorino wrote:

Paul Kane wrote:

BBFTorino wrote:I have a nice D0VE-A block, std. bore, and I wanted to put the splayed 4 bolt caps on it and all the regular machine work, but after getting the prices for everything, it is within a few hundred dollars of the brand new A-460 block.

Do you mean 4-bolting the D0VE block plus any other necessary machine work to bring the D0VE block to the same state as a new A460 block? If so, then you’re getting seriously ripped off on machining costs.

If you mean otherwise then please elaborate on your comparison to the A460 block pricing because I just don’t see how the bottom line costs/pricing can be even remotely similar between the two.

Correct. A new A-460 block from Summit is listed as $2609.99(free shipping too!), and the local machine shop quoted me $600 for block prep and machining, which is cleaning, mag testing, bore, hone, deck surfacing, install cam bearings, and chase all threaded holes.
The steel aftermarket 4 bolt caps are $500 a set from Pro-Gram Engineering, then to have the block drilled, tapped and line bored/honed to proper size is $750. Filling the block up to the bottom of the water pump holes with Hard Block filler, letting it harden up, then rechecking the bore size and final hone if needed is $125. That all comes to $1975.

Now, I know those prices are on the high side, but its the cheapest I could find!!

Ouch. I know engine machine costs are going up, but damn.

I’ve typically sold our Stage 2 prepped D0VE blocks for about half Summit’s retail price of the A460 block and the Stage 2 4-Bolted D0VE block is in the same state of machine/readiness as an A460 block.  Unless you need the A-Block you can save at least a $1000-$1300 and apply those savings elsewhere in your build.

dfree383 wrote:

Paul Kane wrote:

dfree383 wrote:
...Don’t let Pauls idiotic negative attitude about ford small blocks scare you either they make great engines and have powered many a fun street car for years...

Huh? i like Ford small blocks. All of them. I drive one daily and it’s a blast.  

Then don’t talk smack scooter

You don’t govern me or anyone else on this board.