Clerance and tolerances Do's and dont's for Aluminum Blocks

[maybrfd]

Hi All,

My freinds and I have built several strokers, but want to try something different this time.  We're looking at building a 512 out of an Indy Max 400 aluminum block.  Am hoping to hook up with a couple of folks on this site who know a bit more about clearances using an aluminum block, and have had the trials and tribulations of the "this is what works well, and the don't do this"; or can point me to some good reference materials.  Target build is 750-800 Hp.  Will be using the 572 Indy heads.  Shooting for the 10.7 CR range.  Am in the process of designing the build. So open to part selection too.  Squeezing this one into an A body, thus combination desccribed above.  Have done some homework, but most builds I've seen are with Hemi's and not Wedge - most references found deal with the parts and a few details on gasketing, but not on tollerances, clearance issues, ect.  Any info greatly appreciated.

Thx!
Scott

[Cooter]

Not sure bout today, but a buddy built one years ago using an aluminum block and had all kinda of trouble with oil/coolant leaks due to the expansion of the metal. Was a PITA to seal up IIRC.

[maybrfd]

Cooter,

Thanks, have heard similar.  Most references I have say to high temp silicone the water jackets.  Also I miss quoted my own build - will be a 528 not 512 (was looking at some rotating assemblies as I was typing).  Min bore on the larger heads is 4.5".  If he is still around ask him what he did for valve clearance and keeping quench.  My understanding is the aluminum blocks can grow .010, so most, I hear, are running a steped dish to allow initial start and then as the engine warms it comes into running spec.  Would be interested to see how he dealt with lifter clearances too.

[Cooter]

Not a big Fan of Aluminum blocks unless they are factory and have allthat crap sorted out.


For high HP builds, can't beat a good 'ol fashioned Iron block. The amount of weight you'd save wouldn't be worth the extra cost IMO.

[Fred]

Not a big Fan of Aluminum blocks unless they are factory and have allthat crap sorted out.


For high HP builds, can't beat a good 'ol fashioned Iron block. The amount of weight you'd save wouldn't be worth the extra cost IMO.

 

[firefighter3931]

Hi Scott 

The aluminum block shaves quite a bit of weight off the front end so it's worth it for a serious street/strip or all out race build. Given your target compression i'm thinking you're looking for a dual purpose engine ?

There are a few little quirks when building an aluminum based shortblock but not anything insurmountable. You do have to account for some thermal expansion but the blocks have become more reliable on the street over the last several years. 

Why the 572-13 heads ? You can achieve those power goals with something more user friendly and less expensive.  The -13's use the complicated Jesel rocker system (spray bar oiling) and need a high rocker arm ratio to access the high lift area where these heads start to shine. In other words ; unless you're willing to open the valve to .800 lift....you won't be seeing the full potential. These heads have a pretty big port cross section and are better suited to a larger displacement build. Think port velocity and how it would differ in a 528ci vs a 572ci. 

A better head casting for a 528 would be a 440-1 cnc 345. Those heads will easily support the power you're looking to make and be more user friendly & less expensive. A Harland Sharp or T&D shaft system is easier to work with than the Jesel rocker system.

I'd give Dwayne a ring (802-951-1955) if you're serious about this build. He's built several aluminum big cube combos using all of the available aluminum castings (Indy/World/KB) and knows the intricate details of each one and they all have their strengths/weaknesses.

As for the heads & cam ; you won't find a better head porter or cam spec adviser. 

His latest all aluminum 572 using a mildly worked set of 345 cnc 440-1's made 911hp/800tq. That combo just went 9.12@146 in a 68 Charger at 3650 raceweight in the summer heat....it'll see a high 8 second pass when the weather cools off !!



Ron

[maybrfd]

Ron,

Always glad to hear from you!  As usual your are correct in all areas.  As you remember when we put the 470 together, met out numbers, but underestimated the weight.  Mine, between the 518 and associated tunnel mods, roll bar, and frame ties, is coming in at 3800, despite pulling most features out of it.  Really suprised us.  The 470 will make the numbers, but we are at block limits even with the girrdle, which BTW has been a source of leaks from day one. Also, pretty agressive cam to make numbers.  Weight distro is off too, thus thought of going to the aluminum block.  Will be looking chasis over reall hard while we have her down.  Other than a little cap walk the 470 has served us well.  Kyle may inherent some goodies.

On heads, thanks for advice.  Have been toying with both heads and either can make the numbers.  The larger heads make the numbers "easier", but as you say at the higher lifts, forcing to a higher rocker ratio ( was playing with some mild hemi grind numbers last night) and higher flow through intake.  It also will not like low RPMs every much; can you say gasp.  I see the spray bar as a plus and may run them on either head.

Will post as we build, like we did with the 470.


Please send me a private on Dwayne.  Seen his name pop up quite often, but would like to know at bit more about him before I make the call.

Have a great day up on top of the world!

Thx!
Scott

[firefighter3931]

Scott, I hear ya on the weight issue    There's a reason mine has been named the "Black Pig"....i'm at 3950 static and 4200 raceweight ! 

I have the iron World block but the aluminum block would have shaved 150lbs off the nose.  At the time of purchase the cost was double : 6k vs 3k so i opted for the iron unit because this is not a serious racecar, just a street/strip bruiser. The goal was mid 10's on pump swill and i should be there this year with a little luck. Major Tq converter issue has been resolved....

Those -13's will really push the powerband into the stratosphere with 528 cubes. Those heads might make more power but the peaks will be pushed up high and you'll need to run  lots of cam and compression to make the "Big Number". Personally, if i had the choice....a shaft rocker system would be my preference. The T&D/Harland Sharp stuff is very reliable and the ICH oiling system is far better than stock with direct lube to the valvetrain via external lines. Just my opinion, others may differ 

PM sent 


Ron

[Challenger340]

Right now I'm doing an Aluminum KB Block based 572 / on Stage V Heads ...pump gas, should be Dynoíng it sometime in August....so I'll keep anybody interested posted on the results.
It is an expansion on the last Iron HEMI we did using the Stage V's on pump fuel, albeit using alot smaller Engine underneath which was good for 864hp,but winging it very high.

KB Blocks  but very slow deliver times.

World Aluminum Blocks....wouldn't touch another one with a frozen stick.(IMO), nothing myself and others haven't communicated to Rich Gorlie at World personally.

[maybrfd]

Challenger,

Thank you and keep us posted.  Agee on the World Block.  Everyone is indicating a lot of work and machining before they can be used even though supposedly fully machined.  Indy and KB both came with high praise.  Been talking to many different folks from many different backgrounds, the 572 build keeps coming up.  Others recommended the 540 build.

If you don't mind sharing, would be interested in rotating assymbly (especially piston specs)/CR/Cam profile you chose for your 572.

Plan to simulate all three builds with a few variations here and there to see which build works best.  So far, still leaning towards 528, but the 572 is very tempting.

Thx!
Scott

[firefighter3931]

Challenger,

Thank you and keep us posted.  Agee on the World Block.  Everyone is indicating a lot of work and machining before they can be used even though supposedly fully machined.  Indy and KB both came with high praise.  Been talking to many different folks from many different backgrounds, the 572 build keeps coming up.  Others recommended the 540 build.

If you don't mind sharing, would be interested in rotating assymbly (especially piston specs)/CR/Cam profile you chose for your 572.

Plan to simulate all three builds with a few variations here and there to see which build works best.  So far, still leaning towards 528, but the 572 is very tempting.

Thx!
Scott

Scott ; I think Bob is referencing a Hemi RB build so not sure how much in terms of rotating assembly/piston choice would translate over to your proposed low deck wedge ?

I guess you could conceivably build a 572 into a lowdeck block but that's not what i would consider street-friendly. Personally, on a big bore build the piston skirt depth is one of my concerns in terms of bore stability/piston rock etc... so the 4.15 stroke makes more sense for that type of dual purpose application in a low deck. 



Ron

[maybrfd]

Ron,

We would use a 440 block if I went to 572 build - would go back to large EZ's instead of the 440-1's to make combination work.  Thank you for catching the misread on challenger's post.

[firefighter3931]

Ron,

We would use a 440 block if I went to 572 build - would go back to large EZ's instead of the 440-1's to make combination work.  Thank you for catching the misread on challenger's post.

The 325cc EZ's are nice heads and would work fine on a 572 build. Should be no problem hitting the target power level on pump gas. It'll definately be lower revving than a 528. Mine makes peak HP at 5800-6000 and idles clean at 900rpm. 


Ron

[MxRacer855]

Hey Ron, Scott, Challenger340, and Cooter!

I've mentioned in a few threads a couple of different pre-built crate motors that I wanted to drop in my '68. I was researching an aluminum block from Indy when I came across this thread. Since a lot of the really good engine builders seem to be backed up right now (like yourself Challenger340), I was just going to grab a crate from Indy.

I wanted something in the 600-750hp range for street/extremely light strip use. Indy offers a 500" street wedge 400 block w/ 440 EZ-1 Heads that's good for 600hp/600ft (I'm a little confused on the difference between the 400 block and a 440? They're both big blocks and will drop in the same and mount correctly to my built 727, right?). With that, They offer a "PHR" (Popular Hot Rodding Version) model with offers a variety of upgrades including an aluminum block. Outside of the aesthetic factor (this thing looks amazing and has that cool "racey" look to it), it brings the overall power to an even 650hp/650ft. There's definitely a little bit of a price upgrade, but at this point in my build I really don't want to sacrifice performance or "bling" based on a restrictive budget.

With that being said, will this 400 block drop in and mount up the same way as the 440 that came out? Also, should I steer clear of the aluminum block and go the original cast iron route again? As much as I want performance, the overall goal really is functionality and reliability. I'm obviously willing to sacrifice some of that, but NOT to the extent of having to rebuild a motor yearly.

Any input you guys have would be much appreciated! 

Thanks!
Jeff

[John_Kunkel]

Millions of dollars spent on billet aluminum blocks and heads and they still can't get a head gasket to seal reliably in Top Fuel. 

[Challenger340]

Yep, a 400 B-based build will drop in place anywhere an RB based 440 will.

Personally, imo
for 500" pump gas based builds at 600/600, that's pretty anemic but SAFE on the "stock" 400 Block, and requires pretty much NO EFFORT by the builder, hence why I think INDY would advertise that at an attractive price ?
BTW,
What ARE INDY asking these days anyways ?

I can't wait until you phone them...
then get the Flagle "spiel" of all the upgrades/options until the FINAL price !... for something you would actually want ?

INDY MAXX Aluminum Blocks W/572-13 Heads on "528" cubic inch engines are good for 850-900hp in "middle of the road" Race Trim, very reliable.
But yes... you gotta watch the MAXX block expansion moreso than others... or you DID anyways, ain't played with one lately ?

I'll go dig up a Dyno Sheet on a 528 MAXX based from years gone by... might be from 15 years ago... but same-same today.

I lied.... here is one from 2004, only 10 yrs back !
528" @ 866hp.... still going higher yet at 7,000 rpm.... but that was enough, because if I remember correctly ?... it was a wounded Block that came in and we had to weld it to repair it ?
The guy was the NHRA division 6 points champ 2 years running in 2005 & 2006 with it.

[c00nhunterjoe]

The engine in my signature picture is an aluminum indy low deck block. Shes 572 inches of fun. 12.5:1, 440-1's and a "mild" cam for the size. I cant recall the specs off the top of my head but it dynoed a touch over 800hp and runs 155 mph in a 3500lb super gas car. The build is.... oooo... im gonna say almost 9 yrs old now. It gets freshened up about every 2 years and typicly gets rings, bearings, valve springs and pushrods. All replaced parts show little to no signs of wear.

[Mike DC]

The engine in my signature picture is an aluminum indy low deck block. Shes 572 inches of fun. 12.5:1, 440-1's and a "mild" cam for the size. I cant recall the specs off the top of my head but it dynoed a touch over 800hp and runs 155 mph in a 3500lb super gas car. The build is.... oooo... im gonna say almost 9 yrs old now. It gets freshened up about every 2 years and typicly gets rings, bearings, valve springs and pushrods. All replaced parts show little to no signs of wear.

Sounds like a seriously fun engine to throw in a street car.  Take out a bit of compression, probably reduce a the cam a bit more, and start going through rear tires. 



Just curious, have you ever weighed that complete engine?  

Engine weights are like whole vehicle weights - everyone has an educated guess for their combo based on a set of known stock baselines for things.  But I'm always interested in directly measured figures.  

 

[c00nhunterjoe]

I will look through the paperwork, but I dont think we have ever weighed it.