iron versus aluminum

Posted By: mayhem148

iron versus aluminum - 08/19/09 08:34 AM

for the after market blocks what would be a better choice. what holds up better. advantages and disadvantages. can aluminum blocks really be rebuilt after some explosions or catostrophic failure.

Posted By: chryco

Re: iron versus aluminum - 08/19/09 11:29 AM

Ally blocks KB at least have superior strength as well as optimized oiling compared to iron . They are easier to repair not to mention the weight savings.

Attached picture 5426832-MVC-005S.jpg

Posted By: blownzoom440

Re: iron versus aluminum - 08/19/09 11:56 AM

the budget then intended use determined my decision to get an iron block and the quality of the KP440.thanks for posting the question.it should be technicly interesting.

Posted By: an8sec70cuda

Re: iron versus aluminum - 08/19/09 12:57 PM

Aluminum is light, easily repairable if windowed, and you can resleeve if you hurt a cylinder. The ONLY downside is the cost.

Cast iron is heavy, it's a boat anchor if you window it, sure you CAN sleeve it, but not like an aluminum block.

In my opinion, if you have the money...there is only one way to go. That's why I have a KB block in my cuda. CHIP

Posted By: BobR

Re: iron versus aluminum - 08/19/09 01:35 PM

Quote:

Aluminum is light, easily repairable if windowed, and you can resleeve if you hurt a cylinder. The ONLY downside is the cost.

Cast iron is heavy, it's a boat anchor if you window it, sure you CAN sleeve it, but not like an aluminum block.

In my opinion, if you have the money...there is only one way to go. That's why I have a KB block in my cuda. CHIP

I agree. There may be some here chime in about thermo/power loss. That's all BS. There may be some cylinder movement that can slightly affect ring seal but it's minimal compared to the advantages aluminum has over iron.

Posted By: BIG BEAR

Re: iron versus aluminum - 08/19/09 06:51 PM

Quote:

Aluminum is light, easily repairable if windowed, and you can resleeve if you hurt a cylinder. The ONLY downside is the cost.

Cast iron is heavy, it's a boat anchor if you window it, sure you CAN sleeve it, but not like an aluminum block.

In my opinion, if you have the money...there is only one way to go. That's why I have a KB block in my cuda. CHIP

Do you think that alumium is as strong as iron?

Posted By: juicedcuda

Re: iron versus aluminum - 08/19/09 06:57 PM

And is there any problems just cruising an aluminum block on the street?

Posted By: Cab_Burge

Re: iron versus aluminum - 08/19/09 08:05 PM

Quote:

Quote:

Aluminum is light, easily repairable if windowed, and you can resleeve if you hurt a cylinder. The ONLY downside is the cost.

Cast iron is heavy, it's a boat anchor if you window it, sure you CAN sleeve it, but not like an aluminum block.

In my opinion, if you have the money...there is only one way to go. That's why I have a KB block in my cuda. CHIP

I agree. There may be some here chime in about thermo/power loss. That's all BS. There may be some cylinder movement that can slightly affect ring seal but it's minimal compared to the advantages aluminum has over iron.

If your running a N/A motor with NO power adders then the aluminum may be the way to go, maybe not if you can't afford to lose a certian amount percentage wise of the total HP attainable. MY example is Pro Stock, they can run any block material they want, once they lobby NHRA for it, and all of them are using Compact Graphite Iron blocks not aluminum

Posted By: Hemiroid

Re: iron versus aluminum - 08/19/09 08:15 PM

Quote:

Quote:

Quote:

Aluminum is light, easily repairable if windowed, and you can resleeve if you hurt a cylinder. The ONLY downside is the cost.

Cast iron is heavy, it's a boat anchor if you window it, sure you CAN sleeve it, but not like an aluminum block.

In my opinion, if you have the money...there is only one way to go. That's why I have a KB block in my cuda. CHIP

I agree. There may be some here chime in about thermo/power loss. That's all BS. There may be some cylinder movement that can slightly affect ring seal but it's minimal compared to the advantages aluminum has over iron.

If your running a N/A motor with NO power adders then the aluminum may be the way to go, maybe not if you can't afford to lose a certian amount percentage wise of the total HP attainable. MY example is Pro Stock, they can run any block material they want, once they lobby NHRA for it, and all of them are using Compact Graphite Iron blocks not aluminum

If you're running a n/a motor that's not heads up, then the aluminum is probably the way to go. Even in a heads up situation, taking that weight off of the nose of the car and the overall weight savings coupled with repairability probably make aluminum the best choice even with the slight loss of hp in the ring seal. The new world iron blocks, without cnc lightening weigh like 200 lbs more than a alum block!

Posted By: Irun5snd8th

Re: iron versus aluminum - 08/19/09 08:19 PM

A very smart class racer tells me that a iron block with aluminum heads will always make more power than an aluminum block and heads with the same parts because the aluminum acts as heat sink for the iron. That being said he says the aluminum block goes faster in the car cause it weighs less. This may explain the pro stockers cause they have a minimum weight and just need the power.

Posted By: an8sec70cuda

Re: iron versus aluminum - 08/19/09 09:01 PM

No problems cruising an aluminum block on the street. Most of the cars on the road today have aluminum blocks. Mine's been on the street and strip for 3+ years w/ no problems.

All the pro mods I've seen run aluminum blocks. They are billet, but still aluminum. My good friend has a big NASTY BB Chevy ex pro mod motor that's a cast aluminum block. Another good friend has a 540" Jim Oddy blower motor that made some ridiculous power... aluminum block.

The CGI blocks may be the best for making power, but the majority of the time you'd rather have the weight savings of aluminum.
Regular cast iron really shouldn't be an option for you unless cost is a factor.

CHIP

Posted By: mayhem148

Re: iron versus aluminum - 08/20/09 02:12 AM

i just dont know about the natural-A situation. ive seen alot boost put to LS blocks. and they hold up just fine. i kinda feel if you put this much money into a hotrod than you shouldnt be to worried about cost. im worried about goin faster. and i belive in the weight saving deal. if im gonna spend a couple grand on a block than im gonna get the best i can. its not how "reliable" can you make your hotrod its how FAST can you make your hotrod.
aluminum=less weight=faster=

Posted By: blownzoom440

Re: iron versus aluminum - 08/20/09 02:29 AM

Quote:

And is there any problems just cruising an aluminum block on the street?

and just because a handfull of people did it does not mean it is reliable.

Posted By: an8sec70cuda

Re: iron versus aluminum - 08/20/09 12:11 PM

Quote:

Quote:

And is there any problems just cruising an aluminum block on the street?

and just because a handfull of people did it does not mean it is reliable.

Why isn't it reliable? Please, do tell?

CHIP

Posted By: blownzoom440

Re: iron versus aluminum - 08/20/09 01:07 PM

Quote:

Quote:

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And is there any problems just cruising an aluminum block on the street?

and just because a handfull of people did it does not mean it is reliable.

Why isn't it reliable? Please, do tell? CHIP

my point was about the pressed in sleeves possably leaking if nothing else over time.

Posted By: BobR

Re: iron versus aluminum - 08/20/09 01:14 PM

Quote:

Quote:

Quote:

Quote:

And is there any problems just cruising an aluminum block on the street?

and just because a handfull of people did it does not mean it is reliable.

Why isn't it reliable? Please, do tell? CHIP

my point was about the pressed in sleeves possably leaking if nothing else over time.

Aluminum blocks are every bit as reliable as iron. All the GM LS1, LS2, LS6 and LS7 blocks are aluminum. Many of the import high perf blocks are aluminum as well. I have an aluminum block on my Cobra replica-4 years and running with zero problems. The NHRA pro stock guys use compacted graphite blocks but the IHRA guys all use aluminum for their mountain motors.

Posted By: blownzoom440

Re: iron versus aluminum - 08/20/09 01:27 PM

Quote:

Quote:

Quote:

Quote:

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And is there any problems just cruising an aluminum block on the street?

and just because a handfull of people did it does not mean it is reliable.

Why isn't it reliable? Please, do tell? CHIP

my point was about the pressed in sleeves possably leaking if nothing else over time.

Aluminum blocks are every bit as reliable as iron. All the GM LS1, LS2, LS6 and LS7 blocks are aluminum. Many of the import high perf blocks are aluminum as well. I have an aluminum block on my Cobra replica-4 years and running with zero problems. The NHRA pro stock guys use compacted graphite blocks but the IHRA guys all use aluminum for their mountain motors.

you did not name 1 mopar block[aluminum aftermarket].i am not trying to argue but learn from this post.

Posted By: BobR

Re: iron versus aluminum - 08/20/09 01:37 PM

Quote:

Quote:

Quote:

Quote:

Quote:

Quote:

And is there any problems just cruising an aluminum block on the street?

and just because a handfull of people did it does not mean it is reliable.

Why isn't it reliable? Please, do tell? CHIP

my point was about the pressed in sleeves possably leaking if nothing else over time.

Aluminum blocks are every bit as reliable as iron. All the GM LS1, LS2, LS6 and LS7 blocks are aluminum. Many of the import high perf blocks are aluminum as well. I have an aluminum block on my Cobra replica-4 years and running with zero problems. The NHRA pro stock guys use compacted graphite blocks but the IHRA guys all use aluminum for their mountain motors.

you did not name 1 mopar block[aluminum aftermarket].i am not trying to argue but learn from this post.

Holds true for these as well. A couple have vouched for their aluminum block's integrity. My post was just vouching for the integrity of aluminum in general.

http://www.jimsautoparts.com/mopar_performance_blocks.htm

Posted By: blownzoom440

Re: iron versus aluminum - 08/20/09 02:02 PM

to cover a viable % of people who can vouch for there leak resistance i dont think there are enough people on this site who will chime in with the info.naturaly we hear of the 1s that have problems on the net.thanks for the link.

Posted By: an8sec70cuda

Re: iron versus aluminum - 08/20/09 02:02 PM

Quote:

Quote:

Quote:

Quote:

And is there any problems just cruising an aluminum block on the street?

and just because a handfull of people did it does not mean it is reliable.

Why isn't it reliable? Please, do tell? CHIP

my point was about the pressed in sleeves possably leaking if nothing else over time.

The old aluminum blocks had wet sleeves with O-rings that sometimes leaked. Not anymore, they now use dry sleeves and have done so for many years. So no worries about leaking water.

CHIP

Posted By: Bob_Coomer

Re: iron versus aluminum - 08/20/09 02:04 PM

Have owned both, nothing wrong with running a aluminum blocks on the street, yes some of the old KB water block, due to there design, and sleeve construction would typically find water in the ol etc.
Those days are over with.
It really a matter of preference. Yes, for a fact the aluminum block gives up some power over the same iron brother. Some top engine builders say this approaches 50+hp. Some say 25-30hp. Its easy to understand just by looking at the lash growth between iron vs aluminum. Aluminum blocks lash grows near 100% more than iron. For example, my last iron block aluminum head engine, lash would grow .005-.007 from cold to hot. Keeping everything else the same, same heads, same rocker arms, even the same pushrods, the Indy maxx block grew .012-.014 inch. I would say this would effect ring seal etc.
IMO
Power loss almost offsets, weight gain. The repearability of aluminum makes it a nice choice. If your building a dragster or a 2200 lbs tube chassis car, then the weight diff shouldn't be much as a factor.
Stripping weight off our old Mopars really isnt a problem, just takes a phone call, and for one to open his wallet.
This debate will never end, and we all have diff idea's what works, and which is better and why.
Its really a matter of preference.
But on a side note, you dont hear about to many aftermarket block failures today. Even with the added community of forums like Moparts. These aftermarket blocks are made to handle about anything the average Joe can throw at it.
In other words, which every block you have, even a nice a nice repairable KB block, a catastrophic engine failure suxs big time regardless of block type.

Posted By: blownzoom440

Re: iron versus aluminum - 08/20/09 02:07 PM

The old aluminum blocks had wet sleeves with O-rings that sometimes leaked. Not anymore, they now use dry sleeves and have done so for many years. So no worries about leaking water. CHIP

this is the info i was missing.i had old information.a dry sleeve is 1 pressed inside of another,correct?

Posted By: blownzoom440

Re: iron versus aluminum - 08/20/09 03:23 PM

Quote:

for the after market blocks what would be a better choice. what holds up better. advantages and disadvantages. can aluminum blocks really be rebuilt after some explosions or catostrophic failure.

advantages iron is 3,000$
and disadvantages aluminum is 6,000$

Posted By: sdaurity

Re: iron versus aluminum - 08/20/09 03:37 PM

Quote:

Quote:

for the after market blocks what would be a better choice. what holds up better. advantages and disadvantages. can aluminum blocks really be rebuilt after some explosions or catostrophic failure.

advantages iron is 3,000$
and disadvantages aluminum is 6,000$

So thats your only disadvantage?

Posted By: gregsdart

Re: iron versus aluminum - 08/20/09 03:46 PM

I did the math on hp loss versus weight loss, and with a loss of 40 hp, it is a wash at 8.80 and 3000 lbs.
The biggest advantage of all is the loss of 100+ lbs up front! This weight removal can really be an advantage, especially if you want to stay anywhere near the stock engine location. Want to buy a slightly used mega block, 4.501 bore?

Posted By: blownzoom440

Re: iron versus aluminum - 08/20/09 03:53 PM

Quote:

Quote:

Quote:

for the after market blocks what would be a better choice. what holds up better. advantages and disadvantages. can aluminum blocks really be rebuilt after some explosions or catostrophic failure.

advantages iron is 3,000$
and disadvantages aluminum is 6,000$

So thats your only disadvantage?

i am not sure i dont have any experiance with the aluminum blocks.

how about availabillity?
how about lifter bore sleeving?[any issues?
can barings spinning?block growth?
maintainance with valvetrain?block and head growth with heat?
are there any drawbacks in these areas?

Posted By: an8sec70cuda

Re: iron versus aluminum - 08/20/09 04:50 PM

Quote:

Quote:

Quote:

Quote:

for the after market blocks what would be a better choice. what holds up better. advantages and disadvantages. can aluminum blocks really be rebuilt after some explosions or catostrophic failure.

advantages iron is 3,000$
and disadvantages aluminum is 6,000$

So thats your only disadvantage?

i am not sure i dont have any experiance with the aluminum blocks.
how about availabillity?
how about lifter bore sleeving?[any issues?
can barings spinning?block growth?
maintainance with valvetrain?block and head growth with heat?
are there any drawbacks in these areas?

They don't cost $6,000. My KB was $4,850 plus $150 for shipping to SC from CA. So it was $5,000.
I figured at the time a Mega Block was about $2,600 or so plus another grand in corrective machine work to fix the usual Mopar Performance junk, it was only about $1,500 difference. I'll gladly pay an extra 1500 bucks for a block I can repair if I grenade it and not have to start all over with another new block. The World blocks weren't available yet when I built my hemi a few years ago. It was either KB, Indy, or a big pile from MP.

KB has a few months of wait time, but I think it's worth it. Indy has them in stock as far as I know.

My lifters don't get any oil at all (solid roller) and there is no lifter bore sleeve. The only oil they get is drainback from the heads and what gets splashed on them. No trouble here. I sent my lifters back to Isky for a checkup after 2 years of use and they sent them back saying they were in perfect condition and needed nothing.
They can gundrill oil passages if you're going to run hydraulic lifters though.

The block is gonna grow since it's aluminum. My lash changes .012" from cold to hot. Again, no problems.

CHIP

Posted By: BobR

Re: iron versus aluminum - 08/20/09 05:08 PM

Another thing not being talked about is if you do nick a sleave either N/A or nitrous assisted you can pull it out and put another one in pretty easily.

Posted By: blownzoom440

Re: iron versus aluminum - 08/20/09 05:22 PM

good info.thanks for posting.the cost between them for me is getting a safe block or not 1 yr sooner.others needs may very.

Posted By: juicedcuda

Re: iron versus aluminum - 08/20/09 08:20 PM

So if I was to purchase an aftermarket aluminum block and build a street friendly 500" stroker with up to a 400 shot of spray, what would be my best choice in aluminum blocks? INDY, World, KB?

Posted By: an8sec70cuda

Re: iron versus aluminum - 08/20/09 08:33 PM

Quote:

So if I was to purchase an aftermarket aluminum block and build a street friendly 500" stroker with up to a 400 shot of spray, what would be my best choice in aluminum blocks? INDY, World, KB?

All 3 are quality blocks, I chose to stay away from Indy b/c they are A-holes. If you do buy an Indy block, get it from a dealer and not from them directly. I'm 100% happy with my KB block.

CHIP

Posted By: juicedcuda

Re: iron versus aluminum - 08/20/09 08:39 PM

Is there any huge differences in machining of any of the aluminum blocks?

Posted By: BIG BEAR

Re: iron versus aluminum - 08/20/09 09:03 PM

Quote:

Is there any huge differences in machining of any of the aluminum blocks?

IMO the biggest difference in machining is the sleeve and how it fits into the block, but that is a manufacturing step so as far as anything else goes I would think it would'nt be to hard. But I would have to think you may lose some of your bore size due to the sleeve in the cylinder wall

Posted By: 540dust

Re: iron versus aluminum - 08/20/09 09:30 PM

Don't get me wrong, I would pick Al for sure, but the HP loss is real. When I bought my Al block I used the same rotating assembly, same compression, heads, clearances, everything to do a back to back comparision to the iron half filled block. The weight differece was 90lbs the et loss was 2 tenths, I got to within about 1.5 tenths tightening the lash and leaving with some more heat. That being said, the advantages of durability, repairability, and lightening the front end in my opinion outweigh the HP loss.

Posted By: blownzoom440

Re: iron versus aluminum - 08/21/09 01:57 AM

Quote:

Quote:

Quote:

Quote:

Quote:

for the after market blocks what would be a better choice. what holds up better. advantages and disadvantages. can aluminum blocks really be rebuilt after some explosions or catostrophic failure.

advantages iron is 3,000$
and disadvantages aluminum is 6,000$

So thats your only disadvantage?

i am not sure i dont have any experiance with the aluminum blocks.
how about availabillity?
how about lifter bore sleeving?[any issues?
can barings spinning?block growth?
maintainance with valvetrain?block and head growth with heat?
are there any drawbacks in these areas?

They don't cost $6,000. My KB was $4,850 plus $150 for shipping to SC from CA. So it was $5,000.
I figured at the time a Mega Block was about $2,600 or so plus another grand in corrective machine work to fix the usual Mopar Performance junk, it was only about $1,500 difference. I'll gladly pay an extra 1500 bucks for a block I can repair if I grenade it and not have to start all over with another new block. The World blocks weren't available yet when I built my hemi a few years ago. It was either KB, Indy, or a big pile from MP.

KB has a few months of wait time, but I think it's worth it. Indy has them in stock as far as I know.

My lifters don't get any oil at all (solid roller) and there is no lifter bore sleeve. The only oil they get is drainback from the heads and what gets splashed on them. No trouble here. I sent my lifters back to Isky for a checkup after 2 years of use and they sent them back saying they were in perfect condition and needed nothing.
They can gundrill oil passages if you're going to run hydraulic lifters though.

The block is gonna grow since it's aluminum. My lash changes .012" from cold to hot. Again, no problems. CHIP

the cost of the ali block was takin from the link posted above.
["P5153868
Block, Aluminum, Wedge, Siamese-bore, Finished Bored at 4.50"
$ 5,695.95 "]