Max Horse Power for Ford 302 block

[MadBill]

... the real problem with any of the production Ford small block engines is that the blocks just don't have much main webbing.

Alas, something about which we can now nod in rueful agreement. Closer inspection (it didn't hardly take a microscope.. ) of the block mentioned above reveals that the collective wisdom of S/T was right again.
It's also clear that as per Walter M.'s comment, bigger studs can make things worse. I'm sure the (#2) web would have failed even sooner with the reduced cross section resulting from 1/2" studs. It's hard to see the full extent, but the crack crosses from the broken cap down the web, across towards the opposite bank and also down to the cam bore.

Looks like we'll be brown-bagging it for lunch for a while to finance the Dart piece. Anyone have observations re their SHP Vs Iron Eagle and various mfgrs. aluminum offerings?

[EDC]

Hate to say "I told you so" but I did.

[Lem Evans]

Well.....wouldn't "filling" the block help it hold together a little better/longer?!
6sally6

It might but the real problem with any of the production Ford small block engines is that the blocks just don't have much main webbing.

Dave, it's been a good ride for the 221's big brother. They are small, light and cheap to buy.... 1.5 hp per c.i.d. and live aint a bad date for a block that can be bought for $50.
.

[347guy]

cap walk is the killer, they all break at the main bolt holes and the crack walks to the cam tunnel the the lifter valley.

[MadBill]

FWIW, not a trace of fretting at any of the cap/block joints of our 'victim', and that's with 7/16" studs.. There is a shiny spot on the upper bearing close to the crack, presumably where the web pulled away from the stud bore after it cracked.

[5.3]

The roller cam block can be fitted with four bolt main caps and will be less of a grenade at 500hp. With the dart shp and the new boss block they are just about not worth messing with anymore at those power levels for racing. It takes around a grand to machine and prep one with the cost of caps studs and machine work. The early blocks dont have a thick enough rib to support the outer bolts imo. They are slightly heavier in the upper webs and would be better for a two bolt as mentioned earlier. 351s are about the same story just handle a bit more power.

Consensus seems to be that stock block 351's are good for around 650 hp and stock 350 chevys about 450hp.
Whadya think?

[n5ifi]

cap walk is the killer, they all break at the main bolt holes and the crack walks to the cam tunnel the the lifter valley.

Is RPM the "cap walk" issue or is it something else. I never take my 347's much over 6500 and none of them are internally balanced.
Every 302 block I've ever built for racing, I've always concreted them to them bottom of the water holes and haven't had any problems.
Don't know if it helps longevity but it seems to be more consistent or it's more conducive to my operating technique.
I warm the motor up to operating temp, bring it back to the pit, and let it sit and heat soak. From that time on I take the water temps to 120 (140 or so before leaving the line) and it's super consistent that way. I think it helps to stabilize the oil temps and puts heat in the right place. It cools off super easy with all the concrete in the block.

[CREngines]

The roller cam block can be fitted with four bolt main caps and will be less of a grenade at 500hp. With the dart shp and the new boss block they are just about not worth messing with anymore at those power levels for racing. It takes around a grand to machine and prep one with the cost of caps studs and machine work. The early blocks dont have a thick enough rib to support the outer bolts imo. They are slightly heavier in the upper webs and would be better for a two bolt as mentioned earlier. 351s are about the same story just handle a bit more power.

Consensus seems to be that stock block 351's are good for around 650 hp and stock 350 chevys about 450hp.
Whadya think?

The 350 chevy seems to start breaking cylinder walls around 550+hp. You will find some guys that say more but its in that general area depending on the motor. The stock four bolt main caps themselves are only good for around 500 on circle track apps, with studs. The 351W is about the same. 650 on a 351 is borrowed time as far as im concerned, the walls are thinner then a SBC. When you stand on the production blocks you will find that they tend to leak oil pretty easy from the block flexing.

[5.3]

The roller cam block can be fitted with four bolt main caps and will be less of a grenade at 500hp. With the dart shp and the new boss block they are just about not worth messing with anymore at those power levels for racing. It takes around a grand to machine and prep one with the cost of caps studs and machine work. The early blocks dont have a thick enough rib to support the outer bolts imo. They are slightly heavier in the upper webs and would be better for a two bolt as mentioned earlier. 351s are about the same story just handle a bit more power.

Consensus seems to be that stock block 351's are good for around 650 hp and stock 350 chevys about 450hp.
Whadya think?

The 350 chevy seems to start breaking cylinder walls around 550+hp. You will find some guys that say more but its in that general area depending on the motor. The stock four bolt main caps themselves are only good for around 500 on circle track apps, with studs. The 351W is about the same. 650 on a 351 is borrowed time as far as im concerned, the walls are thinner then a SBC. When you stand on the production blocks you will find that they tend to leak oil pretty easy from the block flexing.

Any experience with LS1 or LS2 blocks? Gm rates them at 450hp max but that seems a bit low especially with 6 bolt mains.

[BrazilianZ28Camaro]

Consensus seems to be that stock block 351's are good for around 650 hp and stock 350 chevys about 450hp.
Whadya think?

A few years ago I saw with my own eyes a blow-alky-injected 370" 69' Nova (steel body but lightened) ran high eights in the quarter. I ran to the pits to see the artillery the car should have under the hood.

I was REALLY shocked when I saw a detroit 6-71 (probably came from a truck) overdriven to hell above a stock-ported factory heads and STOCK 350 block. The car had tinny summit headers also.

So I do believe the 350 blocks can take more when prepped correctly, but for how long is hard to say.

[CREngines]

I dont have enough experience with the LS to really say. That whole trend isnt really popular around here.

[needforspeed66gt]

Any experience with LS1 or LS2 blocks? Gm rates them at 450hp max but that seems a bit low especially with 6 bolt mains.

I have them quite a bit over 600 without any bottom end work and they hold up fine if the tune is good, with main studs and forged parts, I have gone way past that. Pretty sure I remember hearing that a thick sleeve 4.8L I did ended up being turbo'd to way past 1200hp and it does fine. Those blocks are quite strong.

I love them, my favorite motor to build by far.

[5.3]

Any experience with LS1 or LS2 blocks? Gm rates them at 450hp max but that seems a bit low especially with 6 bolt mains.

I have them quite a bit over 600 without any bottom end work and they hold up fine if the tune is good, with main studs and forged parts, I have gone way past that. Pretty sure I remember hearing that a thick sleeve 4.8L I did ended up being turbo'd to way past 1200hp and it does fine. Those blocks are quite strong.

I love them, my favorite motor to build by far.

I was surprised to learn that a 302 windsor engine weighs the same as the ALUMINUM LS1.
However, your experience supports my suspicion that the LS blocks are stronger than the small Windsor.
And where else can you get a brand new V8 aluminum block for $1100.00?
I still haven't decided which platform to use for my project - LS, SBC, or SBF so please elaborate on why the LS engines are your favorite to build.

[needforspeed66gt]

Any experience with LS1 or LS2 blocks? Gm rates them at 450hp max but that seems a bit low especially with 6 bolt mains.

I have them quite a bit over 600 without any bottom end work and they hold up fine if the tune is good, with main studs and forged parts, I have gone way past that. Pretty sure I remember hearing that a thick sleeve 4.8L I did ended up being turbo'd to way past 1200hp and it does fine. Those blocks are quite strong.

I love them, my favorite motor to build by far.

I was surprised to learn that a 302 windsor engine weighs the same as the ALUMINUM LS1.
However, your experience supports my suspicion that the LS blocks are stronger than the small Windsor.
And where else can you get a brand new V8 aluminum block for $1100.00?
I still haven't decided which platform to use for my project - LS, SBC, or SBF so please elaborate on why the LS engines are your favorite to build.

They're incredibly easy to build big power with using very affordable factory stock components and engine management....of course this is going to depend upon what the motor will be going into as far as affordability goes with supporting components, but I'm just focusing on the long block. Additionally HP for HP they're much more streetable as compared to the older SBC and SBF motors.

I also like the rubber "gaskets," just a dab of silicone at the corners and you never run the risk of a little leak.

[5.3]

Good point about the superior sealing of LS engines, and I agree stock for stock LS engines are more efficient.
However, the topic is blocks and I have yet to find any pump gas builds that show LS engines having any
advantage over SBF or SBC when topped by good aftermarket intake, cam and heads.
By the way, I'm comparing all three with carb and distributors.