[Speargun]

Christmas 2019 I broke a rod in my 455 so a few months later, I threw together a 400 I had sitting around. Long story short, I didn't catch that the block wasn't finished smooth enough for Cometic gaskets so compression ended up blowing past the gasket and forcing the water out of the engine and I ended up cracking the block.

Yesterday I picked up a '67 400+030 block from my machinist who I had install splayed, 4 bolt, caps. While cleaning it up today, I discovered that the bottom of the number 5 cylinder has a crack about an inch long right in line with the casting line. Lots of bad words were said and it is quite possible that there is a tool or two currently in a low Earth orbit.
Now I have TWO blocks that need sleeves.

After dropping close to $2200 on main caps, bolts, and machine work, I'm starting to think that $3600 for an IA block isn't that bad of an investment.

IA Block Questions:
What is needed to be done to the block once it arrives? (Beside drilling coolant holes) I plan on using my 400+.030 rotating assembly.

Are any other parts needed?

Other than the cost, is there any reason to not run an aluminum block?

Does the aluminum block require anything different from the iron block?


The current plan is for a 400-450hp street car, but may get upgraded to a 600+ stroker later.

[PontiacJim1959]

I think the machinist owes you a block and all the work to be redone on a replacement block for not magnafluxing it and catching that crack. Throwing tools, I'd be throwing a block through the wall of my machinists' business. Talk to him first ad see what he offers to do to fix the situation.

[Formula8]

If your interim goal is 400-450hp, In my opinion, you are way overthinking this. Sounds like you just need to get hooked up with a solid engine builder put a sleeve in your 400, add nice pistons and rods in it and be done with it. When and if you go for 600hp you can think about an aftermarket block.

[blueghoast]

You can sleeve that block and still put a lot of power to it.
There is nothing wrong with sleeving a block. Some people will
do all the sleeves for sake of mind.

GT

[Old Man Taylor]

Ditto on the sleeve. I used to be worried about it when I was faced with the same thing. The guy at the machine shop said not to worry. It was common for Bonneville cars to sleeve all 8 to get into a specific class. As for the IAII block, it should be fine, but I always check everything.

[Sirrotica]

Detroit Diesel has routinely been using sleeves in all their 2 cycle diesels for decades. During a major O/H they just replace all the sleeves, along with new pistons and rings. All their engines run blowers too.............

[Speargun]

I don't have a problem sleeving a block. I'm going to sleeve the two I have for other projects, but I like the idea of a better built block with a better oiling system, braced lifter bores, the ability to use corporate lifters, and bolt a 4L80E to it without an adapter plate. Even though I'm only looking at 400-500 hp now, there is a distinct possibility that would increase dramatically down the road.

I'm usually planning my next build long before I finish the one I'm working on and it seems that for what I would spend bringing a factory block up to the level that I feel it should be, I could build an IA block for about the same price and not have to worry about "fixing" all of the little issues in a factory block.

So... can anyone provide any advise on an IA block or answer the questions in the OP?

Oh, and HAPPY NEW YEAR!

[HWYSTR455]

Butler offers iron IA2 blocks fully prepped, ready to assembly. They have rotating assemblies for them too. $7200 plus options for a shortblock kit.

They also do select performance castings of OE blocks, the 400/455 +.030 'kits' are ready to assemble, with a forged crank, @ $4400. You can have upgrades added. If you order caps, of course they align bore.

IA2 is nice because you are never restricted by power over concerns for a block, and you are certain you will get several rebuilds out of it.

Sleeving is fine if done properly, but honestly, I've heard not many can do them 'properly' on a Pontiac block.

Adapter plates are not a big deal for adding a 4L80e, and not expensive. There's really no drawback, you just need to ensure you have the correct pull-out spec for the converter (to properly be seated in the pump). There is 2 spots that benefit from a little trimming, but you can use them as is too.


.

[ponjohn]

Originally Posted by Old Man Taylor

Ditto on the sleeve. I used to be worried about it when I was faced with the same thing. The guy at the machine shop said not to worry. It was common for Bonneville cars to sleeve all 8 to get into a specific class. As for the IAII block, it should be fine, but I always check everything.

OMT hope you are well, Happy New Year.

[ponjohn]

There is a thread in the street or race forum with a list of what needs to be finished on an aftermarket block.

[Steve C.]

And this if your not already aware of...

http://www.allpontiac.com/online_cat...ding_notes.pdf

I would suggest you pay heed to this note on that list:

CHECK ALL OIL PASSAGES AND DEBURR IF NEEDED

Example, take note that the location where the oil passages intersect within the front main can use some attention. The depth where they intersect is not the same as a factory block, it's closer to the bearing. Similar situation on the three center mains.


.

[HWYSTR455]

Yes Steve, there are areas that need checking or attention on the IA2 blocks, as well as other aftermarket blocks.

My IA2, 2nd design block, had one cyl that was a little thin, and opted to sleeve it for piece of mind.

Of course, all typical checks need to be done as would be on any performance build.

.

[Formulajones]

With a good machinist and done properly, I don't give a second thought to sleeving a block.

For your power level of just 400-450hp I personally wouldn't even be looking at an aftermarket block for that.

If you had bigger plans later on, and really want to push things, then yes I think it would be a wise investment.

Dad struggled with the same thing several years ago. It wasn't like he has a shortage of Pontiac block choices with a trailer full of them, but ultimately he decided he wanted to go with an aftermarket block and push the power level.
In the end, spending the money with good block prep of a stock block and all that is needed to start fresh, the aftermarket choice wasn't too difficult to make.

[Old Man Taylor]

Originally Posted by ponjohn

OMT hope you are well, Happy New Year.

Thank you. For an old guy I'm doing OK. I will be having my right knee replaced January 25. I already had the left one done, so I know what to expect.

Happy New Year to you too!

[Dragncar]

2 bolt block with studs = 600 HP with ease.

[455Grandville]

Originally Posted by Sirrotica

Detroit Diesel has routinely been using sleeves in all their 2 cycle diesels for decades. During a major O/H they just replace all the sleeves, along with new pistons and rings. All their engines run blowers too.............

And they survive countless hours loaded at WOT.
But, theres a lot of not so good engine machinists out there.

[steve25]

You can't sleeve all 8 cylinders in a factory Pontiac block due to how the block is cast unless you fill it completely,so drop that line of thinking real fast!

[Gary H]

I would buy the block and rotating assembly from Butler with everything done except the balancing. I would also go ahead and have them balance it if you buy the harmonic balancer and flexplate from them. That way they will have all the rotating parts.

I recently bought a finished block from KRE. Only thing I had to do is final hone it

[tjs72lemans]

I didn't know the balance included the harmonic balancer and flexplate. News to me.

[mgarblik]

For a traditional Pontiac application, having the harmonic balancer and flywheel/flexplate is not necessary for balance because they are supposed to be internally balanced. However, if using a cheap aftermarket balancer and/or flexplate/flywheel, it wouldn't hurt to spin them up as well with the rotating assembly. If it changes the balance, those added parts are crap and not made correctly. For externally balanced engines, like many Fords, 400 SBC, those parts need to be on the crankshaft for balancing as they contain counterweight.