IA1 block question
 

I have a IA1 block that I’m going to assemble this winter my question is do I need the taller roller lifters with this block? Thanks

My understanding is that it uses/accepts the same parts as the factory cast iron blocks do... unless you have modified it from the factory specs of course.

make sure to verify that they drilled the oil holes in the lifter bores... They shipped mine to me missing the oil holes. I had to send it back to them to have that corrected.



SPEED SAFE, NICK

Not fully understanding what is meant by "IA1" block. Presuming it might relate to the early first run of blocks I offer this for a FWIW.

Here is a thread from 2005 where there was a discussion regarding the lifter tie bar making contact contact with the lifter bore pad on the block. This was first run, block number 17.

Note comment in post #9

https://forums.maxperformanceinc.com...d.php?t=425138

Later blocks were changed to correct the situation. In addition the website assembly notes were changed.


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I think the reference to "IA1" is when Dick Duclow was first casting the blocks. He was the person who made it happen.

I asembled 1 of the early blocks this year. I used standard Comp roller lifters with no issues.

The First Dick Duclow and Tom? sourced blocks were cast right off the GM Block Blue Prints. Mark H and I still have info on those early blocks.

There were several design changes by Bob and Frank after they bought the rights to casting up the All Pontiac blocks vs the IA (Indian Adventures) blocks.

Tom V.

I thought you could tell a IA1 block by the Indian head on the front?

If this helps, but at least on my IA2 I had to clearance the bottom ends of the tie bars because of lack of clearance to the block, its all about checking everything over on assembly...

In mid 1997 when I first read about Dick Duclow and Tom Piecewicz designs for the new aftermarket block and then up thru Jim Butlers first use of it in late 2000 it was known only as the "Indian Adventures" block to me. That was what Jim Butler advertised it as back then. At times there also were references of "Chief Many Horses". I never paid much attention after that and never knew of it with the number one involved, as in IA1. Makes since though with ALL Pontiac involvement and then calling it the IA2 block.


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I don't know what this means, but the Dick Duclow IA1 blocks were not cast as exact GM replacements. They were based off GM blueprints with improvements for strength. Then Dick sold off the rights to All Pontiac who made further improvements. I spoke to Dick about this at his house in Massachusetts.

The Indian Adventures blocks are now referred to as IA1 since the time they sold to All Pontiac and they made their changes and began casting their own blocks. I too, received 2 Indian Adventures blocks without lifter bore oil holes. Made a fixture and drilled them myself. They do not have the pan rail extension for registered main caps. They also have drive-in freeze plugs. They may have been cast from GM/Pontiac plans but they have a completely closed lifter valley and the tops of the lifter bores are raised. Some lifters, such as Crower lifters may need a little massage on the bottom of the tie bars as mentioned for some camshaft profiles. Or mill the bores down a little as needed. As far as I know, all Indian Adventures Blocks had Indian Chief Art engraved into the front face of the block. Some blocks did have various machining issues, typical of first run stuff. Some blocks did not have lifter bores drilled for oil as mentioned, some had the Ball Crank stud hole needed for a manual transmission drilled into water. Some had several bellhousing holes drilled into water. Some timing cover attaching holes were into water. Several other little snags I can't remember . Even with their flaws, they were a HUGE step forward from a stock block and we greatly appreciate all the effort that went into them.

My suggestion if you have an Indian Adventures block, IA 1, and don't have a full history in it: Do yourself a favor and have it pressure tested to find any flaws or breakthroughs. Then repair them typically with a short set screw with sealer. Also make sure there are no breakthroughs between oil and water passages. A pressure test will find them as well. Better safe than sorry. Good luck with the build.

My point was they were cast up to the basic dimensions of the Pontiac block.
Sorry if I did not make that clear.
The enclosed lifter valley was done from the beginning as it was identified in the early 60s
by racers that the blocks were weak in that area. Racers like Joy Fair, in Michigan made
"connection bars" that attached to the heads to keep the blocks from spreading.

Same deal as far as the lifter braces. The enclosed lifter valley fixed a bunch of those issues.

But the basic dimensions were based off the GM Pontiac block blueprints.

The thicker front face of the block, a slightly taller pan rail, taller lifter bores.

The tall deck blocks, short deck blocks, and the versions of the aluminum blocks came later.

Tom V.

I think I recall that on these early blocks that besides the clutch ball stud hole going into water that the front 2 lower head bolt holes are not blind like the factory blocks either!

So these need to be sealed off from the coolant also as on a Chevy, and also in water only race motors so the fastener does not rust to the block threads and eat those up when removal time comes about.

Spray it down with come bubble mix or soap and water during the pressure test. May find interior and exterior leaks along the v and transmission area.

Luckily for me the block was in use for a good period of time it was removed from car due to a balancer problem and was running when removed. The balancer welded itself to the crank snout. Long story I won’t get into. I will check everything when reassembling the engine but you never know what you can learn. Thanks everyone

Have a Happy Holiday.

Tom V.

Iirc I was told the taller lifter was to allow for a shorter pushrod.

I’m pretty sure I bought my block in 04 and it has chief many horses on the front. Tall deck with raised cam. Lifters came from Crower but I don’t remember how much taller they are

"Iirc I was told the taller lifter was to allow for a shorter pushrod."


In another topic I posted this in a related topic....

Why Longer Lifters Live Longer
https://rehermorrison.com/tech-talk-...-live-longers/

"We recognized that the longer bosses would stabilize the lifters in their bores – a real advantage in big-block Chevy engines with angled pushrods."



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