[Speargun]

I'm looking for Pros & Cons on running an aluminum IA2 block on the street in a '67 bird.

Pro: light weight
Con: costs more than iron

I was told that the aluminum block would HAVE to run a 50mm cam journal due to the way it heats & cools. Why wouldn't a standard journal work?

[Tom Vaught]

Originally Posted by Speargun

I'm looking for Pros & Cons on running an aluminum IA2 block on the street in a '67 bird.

Pro: light weight
Con: costs more than iron

I was told that the aluminum block would HAVE to run a 50mm cam journal due to the way it heats & cools. Why wouldn't a standard journal work?

For info, By Who. I also have an Aluminum IA2 block scheduled for down the road in a street car.

Tom V.

[Formulajones]

There are a couple of them in street cars running around Arizona. No reason at all not to. If you have the pocket book I say have at it

[slowbird]

It'll run cooler also. Never heard about the cam thing and not sure it makes any sense to me

[Steve C.]

Of interest....

LPI Three Point Oiling Grooved Pontiac Camshaft Bearings

http://www.luhnperformance.com/pontiac.html


.

[Speargun]

Originally Posted by Tom Vaught

For info, By Who. I also have an Aluminum IA2 block scheduled for down the road in a street car.

Tom V.

Tom,
One of things that I haven't figured out is why you'll get one price if you ask for a quote for a "ready to assemble" short block & heads, but if you add the exact same stuff to your shopping cart via their "top end power package" & "ready to assemble" short block, you'll get a price that is about $1000 less AND you end up with more parts. ???

And to answer " By Whom"....
By a Butler employee
"The alum block will be easier to cool but you need to run roller cam bearings and a 50mm cam due to the way alum expands."

If this is the case, why are standard journals even listed and 50mm is a $550 "option"?
Why do other aluminum engines run standard cam bearings instead of roller bearings?

I have to admit that the "help" that I received via email was only "ok" at best, I would ask 3 questions and only get one answer, or short answers. When I finally got the person to actually call me, it was like pulling teeth. I would ask a question, get a terse answer and then silence until I asked another question. Zero input from his end. Zero conversation. I got the impression that he didn't want to talk to me and gave the absolute minimum assistance required.

That phone call really has me wondering whether or not I want to spend $16k+/- with these guys. If this is how they treat the customer before the sale, I wonder what it will be like after the sale.

[Speargun]

BTW, this was for an under .600" lift HR cam so we aren't dealing with crazy high spring pressure.

[Scott65]

Not to excuse the employee, but maybe you'd get better service and feel better if you spoke with one of the Butlers. I once had a 45 minute in depth conversation with Jim while ordering pushrods. I don't know their level of involvement these days, my dealings with them have always been very good. David once tried to loan me a starter when mine broke at PSN. Told me to use it and ship it back, or send him the money if I wanted to keep it. It wouldn't work with my headers but the offer was classy nonetheless.

[AG]

When I bought my aluminum block from Butler they never mentioned that I need a 50 mm cam core with roller bearings and I spoke to David Butler.

[PAUL K]

Maybe the 50mm cam thing is the "Butler way". The aluminum blocks are a great way to go. Definitely impressive when you pop your hood at the cruise night..unless you paint the block Pontiac metallic blue.

[Tom Vaught]

My understanding is that the 50mm cam machining is designed for the traditional camshafts using normal camshaft bearings.

The 55mm cam bore block is designed to run the roller bearing camshaft bearings vs the sleeved bearings.

So the quiestion is did you mike the camshaft tunnel bore and what number did you come up with if you already have the black. I assume that you do not have the block yet.

A 50 mm cam bore block should be approximately 1.969 inches when you use a caliper. No cam bearings installed


A 55 mm cam bore block should be approximately 2.165 inches when you use a caliper. No bearings installed.

If I am wrong on this ASSUMPTION, post up the correct info.

Tom V.

[ID67goat]

Originally Posted by Speargun

Tom,
One of things that I haven't figured out is why you'll get one price if you ask for a quote for a "ready to assemble" short block & heads, but if you add the exact same stuff to your shopping cart via their "top end power package" & "ready to assemble" short block, you'll get a price that is about $1000 less AND you end up with more parts. ???:

Based on personal experience, I would not recommend the "ready to assemble" option...you are better off sourcing the parts yourself and have a trusted machine shop verify the block, balance the rotating assy., etc.

If you don't get a good feeling about this kind of purchase, there are other good sources out there also. I have dealt with Paul before and thought he was a stand up guy...answered any questions that I had and communication was excellent.

Good luck with the build, sounds like it will killer....55mm cam or not...

[PAUL K]

Originally Posted by Tom Vaught

My understanding is that the 50mm cam machining is designed for the traditional camshafts using normal camshaft bearings.

The 55mm cam bore block is designed to run the roller bearing camshaft bearings vs the sleeved bearings.

So the quiestion is did you mike the camshaft tunnel bore and what number did you come up with if you already have the black. I assume that you do not have the block yet.

A 50 mm cam bore block should be approximately 1.969 inches when you use a caliper. No cam bearings installed


A 55 mm cam bore block should be approximately 2.165 inches when you use a caliper. No bearings installed.

If I am wrong on this ASSUMPTION, post up the correct info.

Tom V.

Hi Tom,

The way it worked for a while (on the first two batches of blocks we purchased) the AP cam tunnel was machined for use with a 50mm roller bearing or a 55mm slider. I ASSUME it is the same way today BUT it has been years since we have used the 50mm roller bearing set up.... Everything has been sliders with the exception of a couple original IA blocks we still service and those are 55mm rollers on the front four and a 50mm roller on the rear.

I suspect there maybe a "reason" JBP is recommending the larger cam tunnels and the next time I talk with Frank I will ask, but for now it is just a guess so I will keep my thoughts to myself on the subject.

JBP does good work.

[Skip Fix]

I asked Frank about sleeving the lifter bores-he said unless going with the big cam really no need. He did not recommend going with the big cam bore to me for my goals, and he had one in stock.

[ponjohn]

All Pontiac sells an assembled iron block at a very reasonable price.
Maybe source an assembled IA2A from them?

[Speargun]

Originally Posted by Scott65

Not to excuse the employee, but maybe you'd get better service and feel better if you spoke with one of the Butlers. (snip)

When I originally called to get the ball rolling a few weeks ago, I was told that no one was available to talk to me on the phone (due to COVID) & I would have to do everything via email.

[Steve C.]

A friend has the IA2 aluminum block on his street/strip combo with the standard cam journal size. It went into service April 2017 and has been bullet proof.

He is using a Comp solid roller cam with 254/260 at .050" It's around 0.700" lift with 1.65 ratio rockers. He is using a pac-style spring with 240lbs on the seat, somewhere around 550 open, with 1.900" install height. The engine made 656hp/632ft-lbs with a smaller carb. Currently closer to 675 hp based on traps speeds just under 130 mph @3800 lbs.

.

[Speargun]

For anyone who has an aluminum block, what head bolts/studs did you use?
The rep quoted me $350 for "special" head studs for the aluminum block. The spec sheet says ARP, but there is no number & I can only find the regular studs that cost half that.

[77 TRASHCAN]

Originally Posted by Steve C.

A friend has the IA2 aluminum block on his street/strip combo with the standard cam journal size. It went into service April 2017 and has been bullet proof.

He is using a Comp solid roller cam with 254/260 at .050" It's around 0.700" lift with 1.65 ratio rockers. He is using a pac-style spring with 240lbs on the seat, somewhere around 550 open, with 1.900" install height. The engine made 656hp/632ft-lbs with a smaller carb. Currently closer to 675 hp based on traps speeds just under 130 mph @3800 lbs.

.

Steve,
How many cubes is this engine, bore/stroke?

The advertising I’ve seen for the aluminum blocks, the max bore is listed as 4.250. Sounds logical with an aluminum block having sleeves...

Anyone know anything different?

Thanks

[77 TRASHCAN]

Originally Posted by ponjohn

All Pontiac sells an assembled iron block at a very reasonable price.
Maybe source an assembled IA2A from them?

Assembled shortblock?