Aluminum Blocks

[Tee]

Anyone had any experience with Aluminum Blocks in a fresh water cooled application. Found a smokin deal on an Aluminum Donovan Block and wondering if it would be ok to persue that direction?

[burbanite]

Shouldn't be a problem, have played with aluminum engines in jet boats before, what kind of system are you using for temp control? Just like a cast iron engine you would be best advised to keep the temps somewhat constant.

[Tom Brown]

I'm curious how much weight can really be saved by going to aluminum with a big block V8. Is the weight saving substantial? Are the aluminum blocks as durable in terms of keeping the cylinders straight and round?

[Unchained]

I'm sold on aluminum blocks. I figured it makes more sense to save weight in the engine components then the boat hull. I believe the weight savings over cast iron is 150 lbs.
The aluminum blocks are extemely strong. They hold up to top fuel use and can be repaired after a blow up.
http://www.childsdale-ind-prop.com/540Arias.jpg
http://www.ariasengine.com/ancblock.jpg
[ December 11, 2002, 04:14 PM: Message edited by: Unchained ]

[burbanite]

Tom Brown:
I'm curious how much weight can really be saved by going to aluminum with a big block V8. Is the weight saving substantial? Are the aluminum blocks as durable in terms of keeping the cylinders straight and round?Off the top of my head I can't tell you what the difference is, although it was worth the effort and I do know that anytime you save weight you effectively get handed free horsepower, and it all adds up.
Tee, are you talking big block or small block? Some guys are achieving great things with small blocks these days, if you have a big block already you might consider that as another option. Is this a direct change, i.e. big/big or small/small?
Longevity wise, they hold up fairly well, the things were rebuilt constantly anyway so it wasn't an issue.
http://free.***boat.net/gallery/Gearhead_Garage/Motors_and_Drives/Big_Block.JPG

[Tee]

Burbanite: My current system is a crossover - no thermostat. Never could get the cast motor to over 150 deg. (6-71 @ 10 psi 355 cu.in.) It is a small block I am looking at. 4.155 bore 4.00 stroke 436 cu. in. (I think?) Will use same 6-71 but go with different cam. I have been looking at building this same motor with a Dart or World block and just stumbled onto this aluminum one. For basically the same money as a new aftermarket cast. My only concern was corrosion. Other than that I know Alum blocks hold up well.
Tom & Unchained: In the small block platform I would save 100 lbs + or -
P.S. Sweet looking motors guys!!!!!!! jawdrop
[ December 11, 2002, 08:57 PM: Message edited by: Tee ]

[DogHouse]

Hey Tee, so you're going to give the Mighty Mouse another shot of steroids eh? Should be fun! Will it be ready for next season?
-brian

[Tee]

Doghouse,
Don't really know what I am doing yet, all I know for sure is there is a big empty hole in the back of my boat. Looking at a bunch of different options. I like the idea of a sleeper SBC (430 cu. in.) "Honest, its just a 350!!!!" =) The aluminum block was just a deal I stumbled onto.
Also looking at a HP500EFI take out. Either way I hope to be back under power by the spring poker run?

[Havasu Hangin']

I was told that cast rusts, and aluminum corrodes...so pick your poison. Fresh water...no worries.
I like that aluminum SBC idea...it's gotta save a couple hundred pounds minimum over a cast BBC with iron heads, and I'll bet you could easily make more power than that Merc HP500...
[ December 12, 2002, 09:34 AM: Message edited by: Havasu Hangin' ]

[DogHouse]

Yeah Tee, like your last motor was such a "sleeper", with a polished 6-71 and a pair of 750s sitting on top, surging and struggling to idle at 900rpm, right... "Really, it's totally stock." Ha!
Is there any way to coat the inside of the water jackets with some sort of paint, or would it just end up flaking off?

[burbanite]

I honestly don't think that you would have a big issue with corrosion in your fresh water environment, dissimilar metals probably causes more problems.

[West Coast Dave]

Personally I would much sooner go w/ a Donovan or Rodeck aluminum block before an aftermarket cast. Buddy had an 8-71 in an altered w/ a 421 SBC, the car ran 7.20's @ 175 turning 8200 rpm. Minimal coroding, 125 lbs and easy to weld!! Not a hard decision!!

[J540]

Havasu Hangin':
I was told that cast rusts, and aluminum corrodes...so pick your poison. Fresh water...no worries.
I like that aluminum SBC idea...it's gotta save a couple hundred pounds minimum over a cast BBC with iron heads, and I'll bet you could easily make more power than that Merc HP500...

[J540]

come on Guys you know there is know sub; fore CU.inch. think about it merc hp 500 makes what 485 HP eek! o boy thats a lot at over 10,000$ 454 std bore 12to1 629 lift makes over 550 hp.at what 6000$. alm. blocks are 150 lbs, great, a good block, you know the kind for endurance or longevity,like what you want in your boat, are dart big M 275 lbs, or merlin pro 300 lbs even merlin II at aprox, 270 lbs, but will not distort, and holds heat better, in return more HP and round cylinders.at lease get 165 temp.so how hard will you hav to push a sbc, to get 550 HP. sounds like it will last a long time, years mabe. :D alm. blocks are nice, but to run high HP hard and long and for few seasons nope.

[Unchained]

J540
but will not distort, and holds heat better, in return more HP and round cylinders.[/QB]The aluminum blocks all have iron cylinder sleeves.
You didn't think the pistons were going to run in an aluminum cylinder did you?
A lot of HP import engines have aluminum blocks, like the Lexus V8. I don't think there is any question of durability. It's just getting engine manufacturers out of the stone age/cast iron age. Just think, In a couple decades Chevy and Chrysler may discover overhead cams. eek!
[ December 14, 2002, 05:54 AM: Message edited by: Unchained ]

[J540]

And how much HP does a lexus have 2something wow thats a lot, far from 1000 to 1500 with 15 to 25 lbs of boost,running around the lake all day yha think, O aluminum blocks have steel cylinders ? you mean sleeves, wow who would have thought, :rolleyes: and how thick are these sleeves .350 thou, yep thats alot to keep the cylinders round,again a motor is a heat pump more heat (to a point)more HP over 1400 EX temp COULD be bad, alum,blocks are nice but do distort,maybe not the best choice in some cases,O what do pro-stock cars run? O thats wright steel blocks, very high dollar,maybe when they get out of the stone age they will have alum,blocks.but then again alum,blocks have been around 4 quite sometime.maybe there's a reason not to use them in some things.and just to let you know my bud has an alum, block JPII with brad water heads (brad anderson that is) runs very hard but rings and pistons dont last as long. wink Hay UNCHAINED on that cfm mph thing,got to get up at 4:00 am maybe tomaro i will get time to get back to you,but real fast who cares what the speed 100mph how much is comeing out of the hole.@100 mph in a 20" hole its alot more than 100mph out of a 1/2" hole.

[SuperWrench0166]

If you look at most racing endurance engines there are mostly all aluminum. The chev can am small block is all aluminum most all your formula one and indy cars all aluminum all yoru big drag motors all allumium if you want quick horsepower most people use alum heads it works much better if you keep the same together

[J540]

Have you ever seen an indy motor? Apart, it's not like anything you will put in your boat. As far as endurance, what do they do with the rings, valve springs etc. after the race? Oh, that's right they throw them in the trash! And alum heads...can you show me a set of steel heads that are comparable to big chief's or dart 360, brodix 2extra's,brad 4s'brad,5s? There are so many more. And keeping the same together,my 632 cu with my merlin pro block is not going to make any more HP,with merlins alum block, but with the HP,that I'm making, my steel block will last longer. If it wasn't going to make a difference, I would have used the alum block cause it sure wasn't a cost issue but their was a weight issue of 150 lbs.

[blowngas]

just a note on rodeck aluminum blocks (481t)---these blocks were originally made for fuel dragster applications---(solid blocks, no coolant)---some were modified that allowed coolant to be circulated around the (exhaust side) of the block---look for pics on some web sites---unless u really need one,or build one for strictly racing, stick with a bowtie or dart aftermarket block that doesn't have head bolt holes protruding into the waterjacket---you will be much happier----

[Unchained]

J540
my 632 cu with my merlin pro block is not going to make any more HP,with merlins alum block, but with the HP,that I'm making, my steel block will last longer. If it wasn't going to make a difference, I would have used the alum block cause it sure wasn't a cost issue but their was a weight issue of 150 lbs.[/QB]It looks like your heating up over this discussion. burningm Calm down, I understand the CFM thing. No need to rehash. I just questioned what the flow through the intercooler was at WOT and got no response no matter what the measuring stick used was. It doesn't matter now, I'm using an intercooler anyway.
On the aluminum blocks, The main reason I got one was,
#1 to save weight
#2 to have something different than the other guy.
#3 If there ever was a blow up the aluminum block can be repaired. With the cast iron block, one blow up = scrap.
#4 If I ever want to sell it the aluminum block should have more residual value.
I guess I don't understand your statement of the iron block will last longer.
In the three seasons I've run the Arias I may be ready for rings and bearings but I don't notice any thing other than normal parts wear. I probably have put over 120 hrs on it in three
seasons. Most of the time just cruising around at 3500 rpm. My cranking compression is within 5 lbs per cylinder of what it was when I started fresh in spring 2000. I thought it held up pretty good.
Post a picture of your engine and boat.
Mark
mark55@direcway.com

[J540]

Thanks for calling the fire department for me to put me out. wink lol, .I just got a digital camera let me figure it out and i will get pics, up. boat is Cole 20'v drive blown injected 540.with spare 632.short block.was going to pick up this alum block for the same reasons you just said,but had the merlin pro that i picked up 4 dirt cheep years back so y not use it but 300 lbs is kill'n me. I will get back later(mon) my head is falling off my neck sleeping

[turboz28]

i dont think that gm would have made an engine that has 400hp (severely underated) out of aluminum if they didnt think it was going to hold up. i know of more than a few people runing alot of boost from a turbo and drive these everyday. on car is in the mid 9's. did the general SCREW us? jawdrop

[Jungle Boy]

I know of many aluminum small and big block guys that race jet boats (whitewater marathons) and they hold up great. I don't think there is a tougher test in a boat than running 5500 - 6800 RPM for 500 miles over 6 days of racing. :cool: