Thoughts on an aluminum block

[CTsupra]

I don't know what it takes or even how to go about building a custom block, but has anybody ever thought about this or have the means and know how? What could be the pros and cons? I guess this could be good for weight savings, but I can't think of anything else.

What do you guys think? Good idea or just mindless thinking?

 

[shaeff]

if i remember correctly, outofstep proposed this a while back. i dont remember what the conclusion of the conversation was, but i'd imagine that you'd have to chop a bit of weight off the rear of the car after reducing the front weight so much, as we're already 51/49. perhaps he'll chime in.

-shaeff

 

[TONY!]

I don't know what it takes or even how to go about building a custom block, but has anybody ever thought about this or have the means and know how?…

I imagine it takes owning a manufacturing company. You would have to make the mold & pour in the molten metal etc. It does not sound like an easy operation to me.

… What could be the pros and cons? I guess this could be good for weight savings…

Pros would be that it is lighter. A 7M block weighs about 130 lbs without its guts. How much lighter would it be to deal with the following cons?

CONS

1) It would crack easier. We already have many cases of blocks cracking between the water jackets & the head bolt hole. Jjh kept running into blocks that were cracked this way. IIRC, MA71supraturbo bought 3 out of 4 blocks with this type of crack as well. I also had this type of crack. If it our block was aluminum, we would have this “problem” even more often. Cracks in other areas may possibly occur as well.

2) Stock rings are made of stainless (top compression ring) & cast (2nd compression ring). Those two rings (or 12 for the whole car) exert the most outward pressure. Many are using aftermarket chrome rings. Well unless you had a sleeve in the cylinders, the block would wear much quicker. Chrome, stainless, cast iron rings VS. aluminum--no contest.

3) Aluminum also warps much more than iron. You would have to line hone (if you could still use) the block much more often.

4) I also imagine that the big HP guys would have to deal with the limits of a block like this. So I bet that an aluminum block would be less big HP friendly.

5) I highly doubt that you would be able to torque the head bolts to what some are torquing them to (100+ ft/lbs). You may not even be able to torque to 85 ft/lbs.

I would rather my car be much lighter. But being lighter by removing “muscle” is not worth being lighter. I think the engine should be as durable as possible. Weight savings should be made in other areas.

 

[MKIIINA]

this was discussed not too long ago in the mk4 section of SF. Due to the points brought up by Tony Mawad and also costs in manufacturing it would be beyond the realm of prossibiblity and feasability. sorry man.. good idea for weight though

 

[GrimJack]

Unless you are building a drag car and can omit the water jackets.

 

[outofstep]

if i remember correctly, outofstep proposed this a while back.

Wasn't me. I asked what part folks would want cast. Other folks said they wanted a cast aluminum block. That won't happen.

Close though, it was in a thread I started.

 

[CTsupra]

Thanks guys! Oh well, it sounded good.

 

[chevyeater]

Call up Dart and ask how much they'd want for one. I'm sure they could make one as strong or stronger than the stock block. My machinist had a few of the Dart Honda blocks laying around last time I was there. They are really nice.

BTW, Aluminum blocks all have cylinder liners, thread inserts for fastner attachment, stiffening ribs etcetera. The concerns Tony Mawad listed are a thing of the past.

 

[Orion ZyGarian]

Man...if I had the technology to do that, I'd make a 90* V12 "7"M or "2"JZ...

 

[GrimJack]

"2"JZ - that would rock. I hate to think of the timing belt routing though!

 

[CTsupra]

Call up Dart and ask how much they'd want for one. I'm sure they could make one as strong or stronger than the stock block. My machinist had a few of the Dart Honda blocks laying around last time I was there. They are really nice.

BTW, Aluminum blocks all have cylinder liners, thread inserts for fastner attachment, stiffening ribs etcetera. The concerns Tony Mawad listed are a thing of the past.

Interesting.

Yeah, 'cause I was wondering...well what about the LS1? It's good for abut 550hp untill you need to start doing internals.

If somebody ( with ample funds ) will bite-the-bullet and be a test subject, that would be great. I would, but I can't afford it right now. In the future I'm going to look into it.

edit: What's Darts contact info? #, website?

 

[TONY!]

Call up Dart and ask how much they'd want for one. I'm sure they could make one as strong or stronger than the stock block. My machinist had a few of the Dart Honda blocks laying around last time I was there. They are really nice.

BTW, Aluminum blocks all have cylinder liners, thread inserts for fastner attachment, stiffening ribs etcetera. The concerns Tony Mawad listed are a thing of the past.

That is why I said “Well unless you had a sleeve in the cylinders”
Does Dart make a 7M block? IIRC Honda makes aluminum blocks, I think a machinist pointed one out to me once. So of course they get used somehow. I just never looked at one up close. I guess you would need the inserts as you mentioned.

this was discussed not too long ago in the mk4 section of SF...

Thanks for the info on that. I went & posted on that thread. They were wondering how much a block weighs so I posted the following on their thread:

If you guys don't mind an MKIII guy talking about this with you, I see you are wondering what blocks weigh. I have two complete 7M-GTE motors completely apart. A 7M block without its guts is 130 lbs. Let's assume that your blocks go for the same weight at 130 lbs also. I can't get an estimate one how much a block would be if it were composite (aluminum w/ steel sleeves & other steel reinforcements) because I really dont know how much steel would be used in this type setup. But just pretend you can make the block out of 100 cast aluminum. If the your MKIV blocks have the same mass & weight as ours (most likely very close) a solid aluminum block would weigh about 50 lbs. You would be removing 80 lbs of weight if it had the same exact dimensions to the cast one.

Here is how I calculated my numbers:
I weighed my bare block
I compared the mass from cast iron to various types of aluminum by this calculator:
http://www.alloytech.com/mmsonline/weightcalc.htm

One replied

The mass comparison isn't a good conversion as I explained earlier. You have to account for additional material to design the block to be as strong.

Then another replied

Exactly. This is part of the point he was making: 80lbs AT BEST. More likey to be sub-50lbs of savings. I think the money could be better spent on reducing the weight of chassis/suspension components, much simpler too compared to a engine block.

I wonder how much it would be to have a block made of aluminum, or to buy one as chevyeater mentioned. If you are doing it for the weight, CtSupra, do you think 50lbs of savings is really worth the money, time, and the risks that are incurred with innovation & unknown parts.
Their thread number is 274586 in SF.

 

[Furball]

I know this is rather crazy, but has anyone ever even thought of redoing the chasis in aluminum? Isn't the torsional rigidity better with aluminum? It is lighter also (as we all know). There are probably much more practical solutions, but this is at least fun to talk about.

 

[IJ.]

FB: We don't have a chassis as such it's unibody construction meaning it's a bunch of sheetmetal welded into one structure not a body over a frame.

You could possibly replace all of the subframes with aluminium replicas but it would be cost prohibitive and most times you can't just replicate a part in AL as it has a much lower yield strength than steel so needs to be overbuilt, not to mention it work hardens.

 

[Furball]

FB: We don't have a chassis as such it's unibody construction meaning it's a bunch of sheetmetal welded into one structure not a body over a frame.

You could possibly replace all of the subframes with aluminium replicas but it would be cost prohibitive and most times you can't just replicate a part in AL as it has a much lower yeild strength than steel so needs to be overbuilt, not to mention it work hardens.

Oops...you got the basic gist of what I meant. I know it's not cost effective, but it would be great on the "look what I did" scale. Kinda like how hot rodders do weird things just to say they did them and make their car special. I guess I have just been thinking wierd lately.

 

[Clinton]

"2"JZ - that would rock. I hate to think of the timing belt routing though!

it'd be the same as the 1UZ-FE, likely, with two cam gears on each side instead of one

CCC

 

[Orion ZyGarian]

Yup. It'd still be DOHC, therefore there would be 4 camshafts

 

[chevyeater]

Interesting.

Yeah, 'cause I was wondering...well what about the LS1? It's good for abut 550hp untill you need to start doing internals.

If somebody ( with ample funds ) will bite-the-bullet and be a test subject, that would be great. I would, but I can't afford it right now. In the future I'm going to look into it.

edit: What's Darts contact info? #, website?

http://www.dartheads.com/hondab.aspx
^That is the Honda block I was referring to. They are much nicer than OEM blocks and with a brand new casting, the world of possibilities is opened up. How about priority main oiling? The fitment of a better oil pump? 4 bolt or even 6 bolt mains? More crankcase clearance for a longer stroke? Special sleeves for a larger bore? All possible when somebody decides to drop some coin on this idea. Unfortunately, I don't have that kind of $ at the moment.

Anyone know a rich mk3 guy we could get interested in this idea?

 

[Orion ZyGarian]

Anyone know a rich mk3 guy?

Oxymoron :icon_roll

 

[CTsupra]

Lol.

Yeah, 50lbs of savings wouldn't be worth it, but then again, chevyeater brings up some good ideas. Chassis lightening is also something I think about. Only thing we can do is lighten the sub-frames, I guess, since we're uni-body.

Besides a complete carbon-fibre shell, I don't know how else to lose weight, other then what has been already mentioned over the years. Damnit, there has to be something more we can do with the underworkings of our cars.

Now, how did they engineer that damn Fd...