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I know I already sort of asked this question once so I figured I would try a different angle. I have been setting money a side for my build and am passed the halfway point so I need to start getting serious and spitball some ideas off of my friends . Essentially I want to build a ZL1 with more cubes. I want to do a 540 big block with aluminum block and heads, pump gas, solid roller cam (or if I chicken out on the roller idea, solid flat tappet), I would like it to be at least 700 horsepower and I want the power higher up in the RPM range (shifting around 7000-7500RPM) and I want to do it as simple as possible. I need a cam that isn't going to be too hard on the valvetrain and will live well on the street.
I still find myself hesitating on the aluminum block idea, I guess I'm fearful because you don't see many aluminum big block motors on the streets (at least I don't see them). I will likely keep it 540ci if I go the aluminum block route, the thicker cylinder walls should help with bore distortion a little I think. I really love the idea of shedding some of that weight, I just worry about the durability of the block running it around on the street. I tend to overthink things a lot and quite often, so I guess I am just looking for some reassurance that it will live on the street.
P.S. On blocks with .600" cam position, does that just require a different timing chain set to accomodate the added distance?
Last edited by bence13_33; 01-08-2018 at 01:35 PM.
I would never do it unless you were class racing or just have $$$$$$ to burn.
Iron Blocks are always stronger and make more power.....
Yes the raised .600 cam requires a different set to run it. You do not need it....why are you doing it?
The raised cam is for serious racing setups. Un-needed at 540 inches.
Block distortion is worse with maximum effort engines than what you're looking to build. You'll still lose a few HP but it should be insignificant.
$4000 is still a pretty good priced upgrade, one most of us would take a pass on.
Why are you worried about durability on the street? Life's a piece of cake for the engine cruising around on the street. Things last forever at low speeds and low RPMs.
I'm inferring that this is going to be a straightline machine. An aluminum engine is a poor choice to spend limited resources on. Any iron block can go fast in a straight line, particularly with 500+ cubic inches.
I'm curious how thick are the cylinder walls at 540 cubes anyway?
My engine is a fuel sipping 427. I justified the aluminum because my fun thing is road course stuff, and I like my car to handle and brake well.
Jebby:
I like it for something different, 100lb off the front end is pretty substantial. I wanted to get away from just being a straight line machine and make it a better all around machine. As for the raised cam location, I believe that is how the Brodix block comes....obviously I would prefer one with a standard cam location. Maybe I mis-read their catalog, I'll have to glance over it again and get back to you.
L88plus:
I agree it comes with a pretty hefty price tag....there is just something intriguing to me about an aluminum motor like that.
69427:
Well I worry mostly about the heat of stop and go traffic. I don't want it to be just a straight line machine like it was. I want to make it more of a better handling car again. Obviously there are going to be trade-offs when dealing with the aspect of 1/4 mile racing vs a better road course car. I feel like the aluminum block is one of the few areas that benefits both (the weight reduction will be great for handling and for the 1/4 mile). I'm pretty sure you can go +.100" over on the aluminum block with no problems. So you have an aluminum block 427?
Big2Bird:
One thing at time, I am rough with car but in a gentle way lol. I don't like launching it hard (my best 60' time was like a 1.7 or 1.8). I raced my car like that and drove it on the street successfully running 12.1s @ 118mph with Mickey Thompson ET Streets (more or less to keep me from losing traction on the 1-2 shift) for quite some time and didn't break anything. I used to slip the clutch hard out of the hole. My car is an old friend and I do my best to baby her while still enjoying myself...it's no fun for her or I when things break.
calwldlife:
I know right, that block costs almost as much as the first rendition of my 468 all together.
Last edited by bence13_33; 01-08-2018 at 04:34 PM.
the price of one is more than likely why you don't see them on the streets !
if you have the $ for the build , then do it , otherwise it will be the one thing that will bug you , it will be just another awesome BB but you will be always wondering how much better it would have been in the handling AND you could have been the guy who says he had to cut his front springs as my BB car sat tooo high ! well ok maybe not that .
I was in the same situation a while back , I chickened out purely because of the $. I somewhat regret that now
If going Aluminum look at the Dart or Donovan block. The Donovan block is a 35 year old design.....but it is bulletproof and looks like an old block on the outside.
The Dart will give you a better oiling system.......
The Brodix is too much of a race orientated piece in my eyes......
There is also the Merlin......which is a damn good piece too.
Shop those three blocks and do some research on which would be best for you.......stay away from raised cams and trick stuff.
I have operated my Bowtie Aluminum small block on the street. I have it out now though, for a higher level build and tune! I have the crank journals at minimum clearance! I set my clearances up to exactly match that Mark Steilow GM Engineer guy with the hot Vintage Camaro builds recommended clearances! I can get those clearances for you! If I have to start it cold, it isn’t that tight and I have a stout 4340 fully circle crank, but will still go easy on it till warmed up! I have the best ever small block GM Performance made Profiled Bow tie Rods in 6 inch, lightweight Ross pistons and an ultra expensive Valve train with like inconel exhaust valves. I have an oil pan heater when planning on heading out from home! The car was awesome in front end handling, and less braking weight transfer. I ran synthetic oil, and the wear was good, after about 10k miles, before I started the current build. The hardest thing is keeping it raw clean. With oil or gas spills, it wouldn’t look as nice for long. So I painted the raw aluminum with Krylon silver!
Last edited by TCracingCA; 01-09-2018 at 11:01 AM.
Aluminum is cool for sure. You might consider building it with a bigger bore sicne you like to rev. Maybe a 4.600x4" stroke would be fun? It's got liners so no reason to not go big. if it hurts something you just change a liner. Not like a regular block where you run out of meat. It should dissipate heat well so heat shouldn't be an issue. You have to make sure clearances are right and as mentioned...best to let things warm up first. There's a gazillion engines out there with aluminum blocks from the OEM's and none of them are as stout of any of the aftermarket ones you're talking about.
If going this far....going to a 55MM cam core and .903" lifters would be a good thing. Costs more..but the bigger cam core helps life. A raised cam isn't necessary but it allows shorter pushrods.
None of this is remotely needed for 700 HP. You're going to have to strangle it to only make that.
Being as money is not an infinite resource, the absolute very first thing I would give up in this particular engine build is the aluminum block. There is zero gain by the change other than weight. Now...weight is worth 'horsepower', so saving 100# is nothing to sneeze at, but it seems there is another side to the coin...
Some of the armchair quarterback information is that aluminum motors give up power. I guess that makes a little sense with the heat being carried from the chamber much faster, added flexibility, and whatever other factors go into a big horsepower build.
In the end, my opinion is this: The cost difference is $4,000 just on the block. Given the concerns with aluminum, I could generate an extra 20 hp out of ANY iron big block build to counteract the additional 100# with an additional $4,000 added to the bottom line. Heck...just that one statement adds your blower and whatever other accessories there are and you're adding 40% power to your build...not just 20 hp.
New iron block. Unless you have so much money you don't know what to do with it. And EVEN THEN, I'd be 50/50 just because an iron block is so much more durable and dimensionally stable.
Last edited by keithinspace; 01-09-2018 at 08:07 AM.
I have the Gen 1- 075 Bow tie Wet Sump SB and set my Mains up at .0018 and my rear bearing clearance at .0025! I shift it at over 7K.
The iron engines I have built, I set up at .0025 on the mains and .0030 on the rear!
The block I have will support 800hp, but I went Conservative on the first install at around 525hp! I am going up to over the 600hp range next (all old school- 140 Cam, 1.6 SS roller rockers, 2.055 intakes, Bow tie air gap single plane, 285cfm flow on older Bow tie Phase 6 heads!
Here it is, when I first got it prior to install (all shiny and new!!)The two piece cover on the front is from Bo-Laws! It sure was pretty when I had it sitting in the Living room!Ps this is my C2 Car stuff! I still run a Bow tie Iron block and Bow tie heads in my C3. I just have a very well running 30-30, max ported heads, a single plane Tarantula, in the Blue one!
Last edited by TCracingCA; 01-09-2018 at 11:59 AM.
Did this a few years ago in my 1969 BB convertible. Yes, cost me an extra $3k for the aluminum Dart Block, but what the hell, can't take it with you. Dart is probably charging a little more now?? My friend is a performance engine expert and owns an offshore boat racing business in St. Louis area. Message me for contact info if you want. He can provide answers to any of your questions.
Design constraints were:
1) It has to fit under Blue Angel's stock GM L-88 hood and interface to the air chamber much like the stock approach.
2) Hooker sidepipes have to interface without cutting body or frame. That limited Head choices.
3) Multi-Port Fuel injection with coil on plug, sequential injection, cam & crank sync, Timing control, Wideband O2....leveraging the Holley Dominator EFI that I already bought.
4) Naturally aspirated running 93 octane pump gas.
5) Optimize HP & Torque while keeping it street worthy for cruising.
Did this a few years ago in my 1969 BB convertible. Yes, cost me an extra $3k for the aluminum Dart Block, but what the hell, can't take it with you. Dart is probably charging a little more now?? My friend is a performance engine expert and owns an offshore boat racing business in St. Louis area. Message me for contact info if you want. He can provide answers to any of your questions.
Design constraints were:
1) It has to fit under Blue Angel's stock GM L-88 hood and interface to the air chamber much like the stock approach.
2) Hooker sidepipes have to interface without cutting body or frame. That limited Head choices.
3) Multi-Port Fuel injection with coil on plug, sequential injection, cam & crank sync, Timing control, Wideband O2....leveraging the Holley Dominator EFI that I already bought.
4) Naturally aspirated running 93 octane pump gas.
5) Optimize HP & Torque while keeping it street worthy for cruising.
I can attest, I have heard this car run, and its a beast.
01-08-2018, 01:23 PM
Opinions On Going Aluminum Block?
. Essentially I want to build a ZL1 with more cubes. I want to do a 540 big block with aluminum block and heads, pump gas, solid roller cam (or if I chicken out on the roller idea, solid flat tappet), I would like it to be at least 700 horsepower and I want the power higher up in the RPM range (shifting around 7000-7500RPM) and I want to do it as simple as possible. I need a cam that isn't going to be too hard on the valvetrain and will live well on the street.
well ok maybe not that .
The two piece cover on the front is from Bo-Laws! It sure was pretty when I had it sitting in the Living room!Ps this is my C2 Car stuff! I still run a Bow tie Iron block and Bow tie heads in my C3. I just have a very well running 30-30, max ported heads, a single plane Tarantula, in the Blue one!
Dart is probably charging a little more now?? My friend is a performance engine expert and owns an offshore boat racing business in St. Louis area. Message me for contact info if you want. He can provide answers to any of your questions.
