[E.Furgal]

Originally Posted by CNC BLOCKS NE

At finish size I look for minimum of .160 on the skirt sides and wrist pin side I look for a minimum of .100 at finish is size.

I have seen guys with stock builds crack the wall of a cylinder and I doubt it was 13:01

Do a search!!

no need for a search. 25 years of racing..
luck of the draw

[CNC BLOCKS NE]

Originally Posted by ss396si

Thank you all for the details on my block. So it looks like I don't need to have a sonic test done. I want a reliable street engine 350-400hp and torque.

I would get one done If you want a reliable build unless you have a crystal ball or take a guess like others have said.

Just guess by looking at a block and saying its good is kind of a joke to say the less.

Thin cylinders don't aid in good ring seal !

[CNC BLOCKS NE]

Originally Posted by E.Furgal

no need for a search. 25 years of racing..
luck of the draw

35 plus years of racing and building racing engines I see to many junk blocks because of thin cylinders.

I am a dealer for Dart and blue print blocks for a living and dealing with new Dart blocks is the way to go.

[ss396si]

guys, what if i had a big block 454 and I wanted 400hp and torque? do i need a sonic test as well?

[CNC BLOCKS NE]

Originally Posted by ss396si

guys, what if i had a big block 454 and I wanted 400hp and torque? do i need a sonic test as well?

What bore ?? I have guys bring in 454 for a 496 build and not have it pass a sonic test and on any of those blocks it was one cylinder that failed the test.

I check every block cause I don't need the practice of doing the job twice because of a split cylinder or poor ring seal.

I have seen a few guys in my small area have build another engine out of there own pocket ecause they did not pay attention to detail.


You have to remember your dealing with OEM blocks that made how much power when stock ?

[ss396si]

ive never built an engine before and looking at other options rather than buying a crate motor. If I try my luck at a big block junkyard special. Id be saving money. but its still a risk because its a junkyard motor and i could be throwing my money away. Another option would be buying a short block and putting the heads,rockers etc etc together. First start up is another nail biter..

[oldbogie]

Originally Posted by ss396si

ive never built an engine before and looking at other options rather than buying a crate motor. If I try my luck at a big block junkyard special. Id be saving money. but its still a risk because its a junkyard motor and i could be throwing my money away. Another option would be buying a short block and putting the heads,rockers etc etc together. First start up is another nail biter..

Not that I'm opposed to junk yard engine's but you really don't know if you have a rebuildable block till it's been stripped, cleaned, and Magnafluxed. That happens before you even put it on the table to check the alignment and dimensions. So by the time you find out; first, is it even a candidate you've put in a fair amount of effort and some cost. Second comes the dimensional inspection where you find out if the bearing bores for the crank and cam are straight or not, whether the cylinder bores are perpendicular to and centered on the crankshaft, and whether the head decks are equadistant from and parallel to the crankshaft also how flat and square they are. And more inspections if youre hunting big power like how centered is the cam, do the lifter bores meet the cam at the correct angle. Etcetera! This leads to what will it cost to correct the imperfections.

So there's a lot to be said for the purchase of a remachined block from the major hot rod catalogs as much, if not all, of this has been done for you and the cost is pretty reasonable as this is what they do en-mass so you save money because they can make specific inspection and remachine set ups that do blocks in quantity at each station.

The good news is that 350-400 horsepower and foot pounds of torque from a 350 is not difficult to acheive. This doesn't tax the engine structure all that much if this is a mostly hot street and occasional strip engine so the vast majority of SBC blocks are up to this. Certainly if you do enough of them you'll hit the exception and maybe the hobby builder will hit one but the odds are way in your favor that statistically you won't hit a bad block either a new GMPP or a remacined from a reputable source.

Going racing is a somewhat different propisition because compared to the street the engine is being used on the high side of its power output all the time, it sees big and sudden changes in power settings and when mounted ahead of a manual transmission has to absorb all the clutch pressure changes as it's engaged and dissengaged buy way of reaction this thrust load out of the crank at the thrust cap and putting it into the block. So racing is a situation that will quickly find marginal strength areas and bust them. Automatics are somewhat gentler in this regard but that depends on how aggressivly they are set up.

An unmolested post 1974 used block should take a .030 to .040 without having to sweat out the wall thickness even for a mild racer but especially for a good hot street motor that isn't being blown or juiced. If going to .060 I do recommend sonic testing as these things are thin wall castings. The pre 1974castings are thicker some of the early blocks like the 283 and some 307s will safely bore .120.

Bogie

[E.Furgal]

Originally Posted by CNC BLOCKS NE

35 plus years of racing and building racing engines I see to many junk blocks because of thin cylinders.

I am a dealer for Dart and blue print blocks for a living and dealing with new Dart blocks is the way to go.

my next block will be a bbc alum.. donovan..

[ss396si]

lets say i buy a 350 goodwrench crate then change the top end. which I read guys do on this site and hope the heck it will last me for years.

[CNC BLOCKS NE]

Originally Posted by E.Furgal

my next block will be a bbc alum.. donovan..

I just had a Donovan in the shop lifters bores were not straight by any means and did not have a honed finish and were over size. They don't use billet caps either!!!

If you want a better block go to a Brodix or a Dart block and by the way they use billet caps.

[oldbogie]

Originally Posted by ss396si

lets say i buy a 350 goodwrench crate then change the top end. which I read guys do on this site and hope the heck it will last me for years.

You can do that Chevy High Performance magazine did an article several years ago where they took the Goodwrench and went through a long series of dyno tests where they started stock then went through a series of tests replacing the GM intake and Q-jet with an Edlebrock Performer RPM and 750 Holley. Then stepped up the heads with stock but ported, L99/ZZx out of the box and ported, Vortec out of the box and ported, AFRs I think as well. This thing grew from stock out of the crate at 230 hp or so to about 410 with the stock bottom end. Of course a couple handfuls of dyno pulls isn't the same as honking down the street for a hundred thousand miles but it shows a 400 horse engine can be done on the Goodwrench foundation.

My biggest issue with the Goodwrench as the basis of what is approaching the level of an upper end high performance engine is the piston crown configuration. GM, who isn’t alone in this, uses those circular dished pistons to control overall compression. These things essentially cheat the engine of a considerable amount of squish/quench by reducing the flat surface of the piston that opposes the squish/quench step of the combustion chamber because the stepped down portion of the crown is too far from the head to be as effective as one would hope for. While not the end of the known universe, it does increase the engine’s octane requirement by 4 or 5 points so you can't run as much compression ratio or spark advance as would maximize fuel efficiency and power development. Still, like I said, CHP got over 400 horses from the thing with better heads and cam, and a bunch of what's considered bolt on stuff like an almost racer intake, big ol' Holley and headers. This happened under 6000 RPM if I remember this article correctly. They also didn't do anything under the oil pan either, such an engine especially as it starts getting on the 6000 RPM line could benefit from a windage tray, a rear pan baffle and a crank scraper, this would minimally insure that the oil got pulled out of spinning crank, put under the tray to lose the entrained air, and the baffle helps keep it in the sump instead of the rear crank counterweight when accelerating the car hard. These are things a dyno doesn't do so it's not so critical to have these parts in the bottom end when the engine isn't being maneuvered by the vehicle.

For a few dollars more you can buy one with vortec heads check this link out >>> 5.7 Ltr - 350 C.I.D. - GM ENGINE 1996-2002 New 12530283 <<<. This is a 4 bolt Vortec with a roller cam. The ponies can easily be pumped up with an aftermarket roller, this gets around the flat tappet break-in issues and eliminates the downstream risk of smoking lobes and tappets because you can't get high zinc oil. Since you would stick Vortec heads on the low end Goodwrench anyway the 600 bucks on top of the Goodwrench closes a lot of the cost gap and you end up with a much stouter 4 bolt bottom end. The cam, intake and headers would be the same for either, so for about 400 dollars cost delta you have a much better engine, and no extra heads taking up garage space. The only addition to get this into pre-1986 vehicle will be the purchase of a one piece rear seal mating flexplate and an electric fuel pump.

Really for an entry level upper end high performance 350 engine you've got a lot of choices and the 12530283 as a new 4 bolt block with Vortec heads a very good starting place.

Bogie

[ss396si]

Originally Posted by oldbogie

You can do that Chevy High Performance magazine did an article several years ago where they took the Goodwrench and went through a long series of dyno tests where they started stock then went through a series of tests replacing the GM intake and Q-jet with an Edlebrock Performer RPM and 750 Holley. Then stepped up the heads with stock but ported, L99/ZZx out of the box and ported, Vortec out of the box and ported, AFRs I think as well. This thing grew from stock out of the crate at 230 hp or so to about 410 with the stock bottom end. Of course a couple handfuls of dyno pulls isn't the same as honking down the street for a hundred thousand miles but it shows a 400 horse engine can be done on the Goodwrench foundation.

My biggest issue with the Goodwrench as the basis of what is approaching the level of an upper end high performance engine is the piston crown configuration. GM, who isn’t alone in this, uses those circular dished pistons to control overall compression. These things essentially cheat the engine of a considerable amount of squish/quench by reducing the flat surface of the piston that opposes the squish/quench step of the combustion chamber because the stepped down portion of the crown is too far from the head to be as effective as one would hope for. While not the end of the known universe, it does increase the engine’s octane requirement by 4 or 5 points so you can't run as much compression ratio or spark advance as would maximize fuel efficiency and power development. Still, like I said, CHP got over 400 horses from the thing with better heads and cam, and a bunch of what's considered bolt on stuff like an almost racer intake, big ol' Holley and headers. This happened under 6000 RPM if I remember this article correctly. They also didn't do anything under the oil pan either, such an engine especially as it starts getting on the 6000 RPM line could benefit from a windage tray, a rear pan baffle and a crank scraper, this would minimally insure that the oil got pulled out of spinning crank, put under the tray to lose the entrained air, and the baffle helps keep it in the sump instead of the rear crank counterweight when accelerating the car hard. These are things a dyno doesn't do so it's not so critical to have these parts in the bottom end when the engine isn't being maneuvered by the vehicle.

For a few dollars more you can buy one with vortec heads check this link out >>> 5.7 Ltr - 350 C.I.D. - GM ENGINE 1996-2002 New 12530283 <<<. This is a 4 bolt Vortec with a roller cam. The ponies can easily be pumped up with an aftermarket roller, this gets around the flat tappet break-in issues and eliminates the downstream risk of smoking lobes and tappets because you can't get high zinc oil. Since you would stick Vortec heads on the low end Goodwrench anyway the 600 bucks on top of the Goodwrench closes a lot of the cost gap and you end up with a much stouter 4 bolt bottom end. The cam, intake and headers would be the same for either, so for about 400 dollars cost delta you have a much better engine, and no extra heads taking up garage space. The only addition to get this into pre-1986 vehicle will be the purchase of a one piece rear seal mating flexplate and an electric fuel pump.

Really for an entry level upper end high performance 350 engine you've got a lot of choices and the 12530283 as a new 4 bolt block with Vortec heads a very good starting place.

Bogie

Now that vortec crate w/ the roller cam sounds like a great idea! What do I need to bring it to 400hp/tq?

[cdminter59]

Vortec bowties.

[ss396si]

Originally Posted by cdminter59

Vortec bowties.

Good choice!, pretty good price too.