Other than weight, which can be a big time pro, what are the pros and cons of an aluminum block versus that of an iron block?

 

aluminum's FAR easier to repair once damaged as TIG welding ALUMINUM is far simpler than nickle brazing cast iron, aluminum dissipates heat faster, aluminum,s far easier to machine, and if your doing some mods you can weld stuff too aluminum far easier
but the cast iron blocks USUALLY got an edge in stiffness
the big problem is COST,

http://www.brodix.com/blocks/5inchblock.html

http://www.brodix.com/blocks/4.500block.html

http://www.dartheads.com/products/en...vy-big-blocks/

http://www.dartheads.com/products/en...ig-blocks.html

http://www.cnblocks.com/

http://www.jegs.com/p/World-Products...53923/10002/-1

 

One additional pro, is that when you scrap it you get about 40+ cents a pound for aluminum verses a couple pennies per pound on the iron.

 

 

Use an iron block for a street car.

 

why do you say that? all of the new vettes use aluminum blocks...

 

Off topic, but I just want to thank you for sharing your knowledge and experience --- I learned a lot from some of your postings on another board, can't remember which. But thanks.

 

ALWAYS GLAD TO HELP!
probably my home data base, where IVE started a few months ago to complile my various hard drives full of info for everyone's easy access to data

http://grumpysperformance.com/

 

It related to CSA, velocity, etc. You had some good info and links that really helped me out a lot.

Stock LT1 heads, as far as I was able to measure have a CSA of about 1.8 squ. in. I put mine at 2.0, removing only from the top half of the port, some call it the roof. Did it according to Vizard's diagrams but using the equations in your link(s) and what else you wrote freehand.

The frickin stock heads don't have the exhaust seats completely seated in the heads, they had sharp exposed edges. So I ground them flush with the chamber as they should have been, and then did a 3-angle cut using Neway tools 31/46/60. In the chambers, there was a big wall around the intake seats courtesy of GM, which I meticulously removed, smoothing the seat to the chamber walls. Hand sanded the SSR to smoothness and bowl blended. To top it off I had the faces on the intakes cut so the total 45 seat is just 60 wide and the seating surface is at 45. Talk about time-intensive. Managed to punch a hole in one of the walls at PR pinch point, had to learn about patching that up. Hell, I'm a chemist by trade but now write patents for 15 years but really always enjoyed engine work since the days of my buddies long ago back when none of us knew squat and would have fallen for TB airfoils as ways to improve perf. I think these LT1's can run circles around even an LS6 ----- the secret is in the reverse cooling but from the factory, they screwed it up --- probably intentioanlly so as to not compete with LS5. They made LT1 run hot and that exhaust seat rim and other sharps in the chambers killed timing advance. A properly done LT1 is worth 425-475 HP @ 6000 without much more than paying attention to details. thanks again you grumpy young vetteman.

 

IM always amazed at the seeming majority of guys who it seems would rather poke their own eyes out with a burning stick than actually READ and research the basic math, basic port flow and cam timing , exhaust scavenging and compression data to figure out the way an engine functions correctly, and then read thru some bogus magazine article and repeat obviously erroneous info from some clown who used weather strip adhesive to stop leaks in his intake manifold gaskets in the same article, as if its gospel

 

Its not easy, there's a lot to it, plus a lot of mis-info out there to sift through, which makes it next to impossible for most of the consumers in the market to figure out.

 

LS1 based aluminum blocks are amazing. I don't know of any that have broken due and some guys are making tons of power. Personally, I wouldn't bother with an aluminum SBC block and would just do an LSx swap.

 

half the guys on the tech desks read from scripts on computer screens with FAQ menus , and if you've got a question they can,t locate they ignore or try to B.S. you, or sell you something rather than give you answers.
ERSON AND CROWER ARE good , CRANE GUYS WERE GOOD(I HEAR THEY WILL RE-OPEN SOON WITH SOME OF THE OLD STAFF) IF YOU KNEW WHO TO TALK TO AT EACH COMPANY,

http://www.competitionplus.com/index...11154&Itemid=6

I GAVE UP dealing with some of the others because of the consistent b.s.

 

lots of pros, very few (if any) cons

 

It is an improvement, all new Corvette engines are aluminum. If you got the money, go for it.

Me and a friend with a LS1 went driving on the mountains. My LT1 temp got to 240, his never made it to 220. Both Vettes are automatics now, the C5 A4 heats up more than the 4L60.

 

Wouldn't an aluminum block change the handling of the car. Since the GM engineers designed the car to have the iron block I would thing that it would throw off the handling. I'm not sure if it is a pro or con since im not sure if it will improve or worsen. I think it will worsen since the weight distribution would be changed but im no engineer, just a kid that took a physics class.

 

The LSx blocks have a much stronger structure than the Gen 1 especially around the mains. I approached a few machinists back when I built the motor I have now and all refused to do one for a street/strip car. (aluminum block)

 

Removing weight from the nose will make it handle better. Removing weight from the nose of a nose heavy car is a good thing. The weigh difference is around 100 lbs, and if needed, a spring rate change might be needed (but the way most people on this forum drive their cars, it would go totally unnoticed).

 

the traditional SBC alloy blocks will cost a good amount to get the machine work done. I wouldn't trust just any shop to do the machine work either. It's easy to heat up the aluminum and get the measurements wrong when machining. So it's got to be a skilled precision shop that has worked with alloy blocks before.

This is a major problem for the ford modular guys (with the 4-v mod blocks) since they are alloy, and require certain temperature purameters for given machine work (as the alloy expands and contracts much easier than iron).

 

Not all 4V 4.6L are aluminum blocks. 03-04 Cobras got 4.6L 4V with iron block.