Aluminum VS Cast Iron, Engine Blocks,,,,

[gaston 2005 502]

Just wondering of engine blocks. Specifically aluminum or cast iron. Other than the obvious being weight reduction & better handling with aluminum over cast iron, what are other benefits of Aluminum over cast iron? All of my experience is with cast iron blocks, (limited) Members comments with pros or cons, past experiences good or bad with either Aluminum or cast iron blocks? Any and all comments are requested and welcomed.

Darryl

[AR]

hey Darryl,

firstly many thanks for the SYBSTD email today . it was awesome and you are a true mate arrrrr!!

2ndly, i was talking to the Au BH dealer recently and he told me two of his customers that bought the XL frame last year have both chosen to put in iron big blocks..from memory there was a 690 merlin and the other with a 540 i guess stroker is apparently coming out for a bigger one soon. Not sure of their reasons why they went iron but it was great to hear this going on locally. Funny you said 'limited' members advice cause hearing this it kinda reminded me but how little % that goes on around the V8 world actually gets reported on line. Probably just as well they stay away these days .

But to let you know what i heard/know about aluminium blocks, when i was in Dyers in 2006 there was one of the MBH 606's. i remember that he had a substantial reflective shield lining under the tank i suppose it was to stop some kind of heat issue and when it was running. Never saw that on an iron job and it did have the tinny sound thing happening but it was a f'ken deep grunty tinny sound and he was allowed and it was cool. Maybe it was also the same year that i was riding with GAB with his 427(?) a bit, he reckoned aluminium was the way to go. obviously you got to work with what you already got and what your budget will let ya.

So you know you not alone i get silly new engine ideas whilst on remote sites,,,specially after lots of cider.


PIr

[V8Bikers]

Gents,
just wanted to revive this thread to obtain your options on this topic. Having had both, the aluminum is definitely more "flickable" and lighter on it's feet. There is more maintenance if you are anal concerning polishing he block.

[V-MAN]

My personal opinion on AL block engines is while they look awesome they require more cleaning and polishing as Bill mentioned to keep them looking good too! They are lighter weight wise, while I have not owned one in a bike I have ridden a couple bikes with AL blocks ... noticeable difference in weight and handling (for the better of course). When we built my stroker engine I considered going with an AL block for the weight savings (better weight to HP ratio) but decided against it. Even if you can get past the cost difference the iron block will disapate heat faster/better then an AL block (especially a polished AL block). I went with the iron block for cost savings but most importantly for the better cooling effect.

[SQ4MN]

Aluminum block will save approximately 80 pounds on a SB. They are great for racing but not as good as a cast iron for cruising IMO.

[hogv8]

I would have thought more like 200 lbs difference .

[SQ4MN]

Most people think a couple of hundred pounds but it is only about 80 pounds. Sometimes when I'm selling bikes and I get a fat customer that is noticeably shocked by the cost of an aluminum engine I explain plan B. Plan B replaces the aluminum engine with a case of lettuce. The weight savings are about the same with the added benefit of saving thousands of dollars along with him now being able to see his dick, something the aluminum engine can't do.

[V-MAN]

The weight savings are about the same with the added benefit of saving thousands of dollars along with him now being able to see his dick, something the aluminum engine can't do.

Now that's funny Dave ... how many AL engines have you sold!!!???

[V-MAN]

I would have thought more like 200 lbs difference .

Jack -

When building my Boss stroker the AL block weighed 95# and I believe the cast block was barely shy of 200# ... I don't remember the exact weight.

[CanuckHoss]

I have ridden and owned a bunch of 1100lb SB bikes and also about 5 - 1300 lb BBs and have ridden a few customers 1050 lb LS3 bikes.

My personal preference is the 1300 lb BB as it is longer and heavier and handles the road better than the lighter bikes and behaves better in our winds. I guess if I was racing around corners or racing in general the lighter bikes would be better but for what I do it is the BB all the way.

As a dealer I guess I am lucky because I got to spend enough time on the different versions to pick a clear winner for me. Short demo rides for customers don't always tell the picture in the long run.

PS...there is always the Kewl Metal front end that lengthens the shorter bikes and would add to their stability.

[SQ4MN]

Barry, one thing my small block Boss Hoss doesn't lack is stability. I can take my hands off the bars at any speed and it tracks straight and stays stable as a rock. Still for cruising on the freeways the heavier the bike the less winds affect it which really makes for a comfortable ride.