aluminium vs. cast iron block • The Dodge Challenger Message Board

by **pior999** » 20 Apr 2008 13:22

I am new to your newsgroup, hello everybody. I own 68 Charger, and I am considering switching to 528 INDY Hemi engine. I need an advice whether I should go for alu or cast iron block. The car will be mostly used for street purposes, occasionally for 1/4 mile events.

Piotr

by **Eddie** » 20 Apr 2008 13:41

Have you ever dealt with INDY before? Welcome by the way! Here is some info on alloy blocks versus Cast iron on the street. www.moparengineswest.com then click on the aluminum Hemis and there is a tutorial on the pro's and Cons of using alloy blocks versus cast iron. If it were my Hemi and I was installing one in a street car, I would seriously consider alloy IF that block was designed from the start to run water and had cylinder sleeves installed for that purpose. The reason being, the sleeves are installed to prevent 'shifting' and leaking coolant. I believe both Keith Black blocks as well as INDY blocks are currently designed with this feature in mind. Alloy will shift a little, cast iron doesnt, but is very heavy. The OEM uses alloy blocks in their vehicles soo.... :mrgreen:

by **pior999** » 20 Apr 2008 13:52

Never so far :shock:

What's your experience?

by **Eddie** » 20 Apr 2008 13:59

pior999 wrote:Never so far What's your experience?

I walked into INDY with 12,000 in my hand and Kenny Lazzeri sent me packing down the road!!He wasnt interested in my 440SixPack and said he didnt work on 'junkyard' engines only new stuff. OK no problem. I took all my stuff to Hensley Racing and was completely satisfied. You should contact Richard Nedbal at MEW he is very friendly and will discuss your engine project with you at great length and give advice freely. If you deal with Indy all I will say is Good Luck!

by **pior999** » 20 Apr 2008 14:01

I've heard that alu hemis are installed without engine mounts, transferring therefore a lot of vibrations. Have you heard anything about that?

by **Eddie** » 20 Apr 2008 14:24

pior999 wrote:I've heard that alu hemis are installed without engine mounts, transferring therefore a lot of vibrations. Have you heard anything about that?

I think the INDY alloy blocks must be used with a motor plate. The Keith Black alloy blocks can use a set of motor mounts, according to MEW website. This would be a big advantage in my book. However, some fabbing and mods are required, such as grinding on the K-frame for clearance. Another is the external pickup for the oiling system, you must use an external oil pickup point in order to use it. There is NO internal pickup due to the long stroke cranshafts that it can accomodate. Alloy is easily repairable,(welded) as well.

by **dave-r** » 20 Apr 2008 15:35

I have heard that there have been some issues with some KB blocks holding water.

Personally I would only use an alloy block if weight was an issue. Like up front on a Hot Hod 32 Ford or something. Or a race car.

A few extra pounds on a Charger is neither here nor there. Iron is a much better material for blocks and heads anyway. I would try to find a well seasoned iron block if it were me.

Have a read of the 440 Source web site on how tto spot the best blocks.
A 400 block with a 3.75 inch or bigger stroke crank is the best combo.

by **pior999** » 21 Apr 2008 14:48

Thanks for answers, it was helpful.

Piotr