Dart Iron Eagle SBC Casting Defect Opinions

[Kurshuk]

Hello everyone,

Have an Iron Eagle SBC with a casting defect in the #4 main saddle. Just looking for opinions on if this needs to go back to Dart. Noticed it as soon as I opened the box. Thanks!

[The Radius Kid]

Send it back.

[Norris Marshall]

Little bit of porosity breaking through at a machined surface. Not a defect. Its fine.

[Zmechanic]

send it back/exchange it

the Dart blocks have had a reputation for CRACKING in the main saddles...

http://forums.corral.net/forums/11440663-post22.html

Wow... alldart akhbar? I can appreciate if you have concerns, but that's about the most unprofessional attempt ato bashing a reputable product as I've ever seen.

[Kurshuk]

Thanks for the replies so far... first block I have seen with this porosity in the mains and looking for feedback, with some concern that this could turn into a crack. As this is going to be a large cubic inch sbc, naturally aspirated but pushing the rpm a little. I have no issues with Dart products, nor do i care to hear any bashing, as we all have our moments. Just looking for feedback from the people that build many more engines than me, if this should be left alone or take it to the shop and see if it can be machined out. It would probably cost more to send it back than to machine it anyway.

Thanks!
Tom

[The Radius Kid]

Thanks for the replies so far... first block I have seen with this porosity in the mains and looking for feedback, with some concern that this could turn into a crack. As this is going to be a large cubic inch sbc, naturally aspirated but pushing the rpm a little. I have no issues with Dart products, nor do i care to hear any bashing, as we all have our moments. Just looking for feedback from the people that build many more engines than me, if this should be left alone or take it to the shop and see if it can be machined out. It would probably cost more to send it back than to machine it anyway.

Thanks!
Tom

I'm not sure where your dilemma is?
Internet talk aside:

1.You paid for a new block.
2.The block has a casting flaw.
3.The flaw could propagate into failure under the loads it was designed for.
4.Why should you risk a lot of your time and associated money/parts using a block that could bite you in the a** down the road?

If they sent me that,they'd be getting it back and shipping me a new one ...... on their dime.

[SchmidtMotorWorks]

If your concern is that the defect is indicative of the casting, you can polish the side of the main web until it has a similar finish as the main bore.

Then look for similar defects on the areas that you polished.

Also look in the bores.

[mag2555]

I regardless of the defect I really do not like that those oil feed holes ( or any holes in high stress places!) are not chamfered, talk about a invite for a crack to start off!!!

[Kurshuk]

Thanks again, I know I would feel better with a block that didn't have the defect in the #4 main saddle, but I also didn't want to over react. So, this is why I am soliciting the opinions of the vast knowledge and experience at SpeedTalk! Thanks to everyone for your observations and suggestions about other areas to check and to chamfer holes.

For the engine builders out there with the machines to make the corrections, would you send the block back or try to machine the defects out if time was not an issue?

[MadBill]

I'm no machinist, but I think 'machining it out' would be like reparing a ripped shirt by snipping out the tear.

[The Radius Kid]

Thanks again, I know I would feel better with a block that didn't have the defect in the #4 main saddle, but I also didn't want to over react. So, this is why I am soliciting the opinions of the vast knowledge and experience at SpeedTalk! Thanks to everyone for your observations and suggestions about other areas to check and to chamfer holes.

For the engine builders out there with the machines to make the corrections, would you send the block back or try to machine the defects out if time was not an issue?

Send it back.
You have no idea how far that flaw goes into the block.

[mag2555]

Seing as some 3/32" of material was already machined off that Jurnal between the ruff bore and the hone job and the pitting / defect is still there I would send it back pronto!!

[Cubic_Cleveland]

What's the application? What kind of RPM?

I don't think it will be an issue. But being the 4th main, if the crank counterweight layout was average, the balance job average with heavy parts in a max effort endurance application continually changing gears or an offshore powerboat type deal I might investigate further. I would think heat transfer would worry me more in a lower stressed application, but I can't see that ever being a problem either.

If you're still worried do as Jon suggested...

If your concern is that the defect is indicative of the casting, you can polish the side of the main web until it has a similar finish as the main bore.

Then look for similar defects on the areas that you polished.

Also look in the bores.

As for sharp edges in oil feed hole etc., in my experience I have never come across a part no matter how high end that couldn't benefit from some deburring/detailing to some extent.

[Cubic_Cleveland]

Hello everyone,

Have an Iron Eagle SBC with a casting defect in the #4 main saddle. Just looking for opinions on if this needs to go back to Dart. Noticed it as soon as I opened the box. Thanks!

send it back/exchange it

the Dart blocks have had a reputation for CRACKING in the main saddles...

http://forums.corral.net/forums/11440663-post22.html ...

As for this clown, do yourself a favour and do some checking of his posts on here, and what professionals have to say. Also do some research into why those cracks probably occurred.

[pamotorman]

now this guy has real block cracking problems