The 4 page debate on "Iron vs Aluminum Heads" got me thinking about all-aluminum setups. What must be taken into consideration when dealing with an aluminum block versus standard procedure for a iron block? I am guessing that toleranes for many things will be different, as well as torque specs and such. Anyone care to share? What kind of compression can be run (DCR or SCR) safely on pump gas? Thanks graemlins/hurray.gif

Do a search for RickWI and his all aluminum 454 SB!!

I think over at either Team Chevelle or SGCOG... He may even post here every so often??

pdq67

The bearing clearances and piston/wall clearances would remain in what I consider normal for any big block, cast iron or aluminum. At least they were on the two I built. The area that really changes on these aluminum big blocks is the valve lash. They'll "grow" .012" to .016" from cold to hot so it required a very tight cold lash. Makes them idle a little lumpier when cold, but no real biggie.

I also like to let them warm up a few minutes before driving them, where on a cast iron deal I'd fire them up and head down the road.

Jody

The only problem that I have ever encountered was head gasket failures from NOT doing what Jody has stated.......

quote: ....'let them warm up a few minutes before driving them'.....

Yup, you gotta warm'em up, before you play.

yep, what they said. the heavy street drag car i crew on is an all aluminum 632. and as stated, lots of similarities as to clearances and the like, but things like adjusting lash really needs to be done at operating temp, these puppys really grow a lot from cold to hot. we actually got the hot lash right, then checked it cold for data, and it was about .08-.010 change, but it varied. also leak down testing and compression testing, at least on this 632, needs to be done with the motor at temp. and you really do need to let them get good and warmed up before running them. we are running a dry sump and have a heater element in the tank that brings the temp up to 120, before we even fire it. other than those, mostly expansion related issues, it's similar to the iron/aluminum motors, only a whole heluva lot lighter graemlins/thumbsup.gif