My curiosity spurred by the 2 block discussion posts ( CGI block )

[winr1]

How does one make a CGI block ??

How much more would a CGI FE block cost versus an iron FE block ??

How much stronger would the CGI block be than regular iron ??

...................................

How about a nodular iron FE block ??

Could nodular iron be poured into regular iron FE molds ??

How much stronger would a nodular FE iron block be over regular FE iron block ??

.........................

Could steel be poured into an FE block mold ??

...................................

Last:

What if one CNC'd an FE block out of a steel billet ??




Ricky.

[wowens]

I wanna know too

[GerryP]

An engineered CGI block or just a material pour difference?  A CGI in existing molds would only cost around $1k more than the current mix.  You can price Dart blocks.  They at one time offered a CGI pour.  I don't know if they still do.  My recollection is that the option was right at a grand.  But do check to be sure.

But unless you are running nitro or some outrageous boost, there wouldn't be a great advantage to CGI in existing molds.  And using existing molds gives you a pretty heavy block, which most folks don't want.

The benefit of CGI is that it allows you to drastically remove weight and get strength if you are willing to engineer a fresh-sheet-of-paper solution.  That is why OEMs are using CGI in their diesel blocks.  In that regard, a re-engineered CGI block would look a lot different from what we're used to.  Sure, everything could bolt up.  That's not a real problem.  But it would we very expensive since you are talking about a new engineering design with all the R & D associated costs.  Could be in the millions.  There would have to be a market for such a thing.  I don't think there is, but that's debatable.

I don't know about the other materials.  It seems nodular is pretty close to CGI, so there might not be a real difference there.  I'm not a chemist or metallurgist so I'm ignorant of such things.

[jayb]

This is information I got from Manitowoc Grey Iron Foundry in Manitowoc, Wisconsin, during my visit there: 

- CGI (Compacted Graphite Iron) has a tensile strength of about 70,000 psi, whereas normal gray iron has a tensile strength of about 40,000 psi.  So, it is close to twice as strong as regular grey iron.  It is machinable, but some foundries put titanium in the mix to make it easier to pour, and that results in increasingly difficult machinability.  The Dart CGI blocks are quite a bit more expensive than normal cast iron blocks because of this.

- Martensitic ductile iron is even stronger, but would be much more difficult to machine with tools typically used to machine blocks, and so is not considered usable as a block material.

The foundry people I spoke to about this thought it would be a waste of time to cast a CGI block in a grey iron mold, although it could be done.  Their suggestions was to change the block design to make it lighter, and thus take advantage of the stronger CGI material.

[mkopmani]

Grainger Worrall poured the GM, Ford and Hemi NASCAR and Pro Stock CGI blocks. CGI has some chemical alloying differences, but cooling and/or subsequent heat treat controls the final mechanical yield and tensile strength. Depending on this, strength can be as much as 4x that of gray iron. CGI is very tough in machining, and hard on tooling. For the 6.7L and 2.7/3.0L V6 which use it, we see about a 30% tool life reduction, and significantly lower speeds and feeds. Advantages are that for space constrained areas (bore bridges, main bulkheads), it offers strength otherwise unobtainable. For lower stressed areas, it enables lightening. Not only is CGI expensive, availability of casting suppliers is also limited. For the JC50 Pro Stock engine, Ford had G-W cast 75 blocks and 150pr heads. This is per the individual who ordered them. These are the ultimate Ford pushed V8, but these engine as are obviously very rare.

[Autoholic]

What if you took the FE block design that Kirkham did, and had a mold made for that to use CGI or a steel alloy? Still light weight and would be stronger than pretty much any aluminum alloy. 7075 is pretty close in strength, but you still have the thermal properties of aluminum to deal with.

[e philpott]

BBM asked on here 4 or 5 years ago if anybody was interested in bringing the FE into the modern world with CGI but there was no takers or anybody interested at that time

[Dumpling]

I too would like to know about a steel block.

Can portions of a block be cast in regular iron with high-stress areas cast using CGI? Or do the two types of iron not work well together, or is it just not possible due to the pouring process?

Really, really interested in being able to add pancake electric motor(s) between an FE and transmission. 

Something like this:

https://www.ebay.com/itm/2006-Honda-Accord-Hybrid-JNA1-OEM-IMA-Integrated-Motor-Assist-Generator-/153016222444?_trksid=p2385738.m4383.l4275.c10

Some explanation given starting at 0:50 here:

https://m.youtube.com/watch?v=-P_VChtMGK8

Or, more obviously installed, one or two of these kits:

https://www.greencarreports.com/news/1128312_electric-crate-motor-kit-is-ready-for-your-ev-project-what-would-you-make

[60sIron]

CGI is created by pouring the right mix into the mold and then a proper heat treatment of the block.  It is not possible to only make parts of the block this way unless you design it for wet sleeves.

[machoneman]

I do remember reading some time ago regarding CGI weight that (maybe a Warren Johnson Pro Stock article?) the GM Pro Stock 500 CID blocks were extensively machined to minimize weight w/o compromising strength. It also stated that the total machine time to whittle off many pounds of excess material was quite high and separate from the the usual decking/boring/honing operations.