[Mo]

Just posting this to see if there is any interest for a Tall Deck version of the IA2 block. This could be done as stated by Bob C. in another post. Please vote and share any info, pro or con, that would help determine if there is a need/use for a tall deck block. Thanks

[WDCreech]

I voted no because I have two of the original Indian Adventures tall deck blocks.

[Mo]

Originally Posted by WDCreech

I voted no because I have two of the original Indian Adventures tall deck blocks.

Thanks Bill. I take that as a YES for the production but "No, I already have an aftermarket block" vote?

[NHRASuperStock455SD]

I voted no because we really need a wider bore spacing to get us up with the Chevys, Fords, and Chryslers.

Lynn

[RAIV55]

I voted no, but it's more my preference to build CI using bore size instead of stroke.

[R 70 Judge]

Voted: No, I already have an aftermarket block

[hechto]

I voted "yes", but in aluminum.

Iron is way too heavy.

[WDCreech]

Originally Posted by Mo

Thanks Bill. I take that as a YES for the production but "No, I already have an aftermarket block" vote?

Not exactly. If I only had aftermarket standard deck blocks, I would have said yes. Production of tall decks should be low key, as there won't be as much of a demand for them.

[WDCreech]

Originally Posted by NHRASuperStock455SD

I voted no because we really need a wider bore spacing to get us up with the Chevys, Fords, and Chryslers.

Lynn

I agree, but we'd need cranks to go with it, and some BIG flowing heads. (maybe a modification of the RA V in aluminum?) Or better yet, an aluminum modification of the MT hemi.

[Mo]

Thanks guys. A larger bore would be nice. But this is to help out the guys wanting a larger stroke and resonable compression by being able to have a large dish...Pump Gas. Once you reach longer strokes your compression height gets shorter. You then have to compromise on your ring package. Among other things.

Andy Mitchell built a Butler based Pump Gas 601 (4.375 bore and 5.0 in stroke) using wide port e heads. It dynoed 755 ft/lbs Tq at 4400 and 738 hp at 5800. That with only .640 lift. It was an IA1 tall deck.

For those who don't think we need one. I ask you to give us some ideas on how to get 8:1 compression on a 572 cid motor with Tiger heads so you can run a blower on pump gas. All opinions welcome. Thanks.

Keep voting!

[Steve Barcak]

Changing bore spacing makes no practical or economic sense and will not happen as a result. With that said, there should be a need for taller deck heights but, apparantely most builders aren't using the foresight to take advantage of better rod ratios with larger displacements.
I will predict that as more of the new parts are used and larger displacements are sought for more power, demand for a taller deck height block will follow. Most people now with larger engines are seemingly happy in the 530" range. As you go over 550" or so, the taller deck becomes more attractive and even necessary.
I have had a super tall deck 577" Pontiac project for years but, it has been put on the back burner since I decided to go the with small inch route with my AA/Fueler. However, the first one may be together in 2007.

My blown/injected 577s, based on early 389s, have deck heights of over a foot. One will be used in my '65 Tempest altered wheelbase funny car project and another in one of my boats.
Tall decks have advantages, esp with larger displacements.
What is the 'tall' deck height of the engine you are considering?
Stock height is in the 10.2..." area. My 577s" are around 12.200".
Running the taller height in the deck gives much more room for a better ring stack, allows longer rods, etc and is very attractive with longer strokes.
Steve Barcak www.pontiacheaven.org

"Real Pontiacs only...no corporate nonsense!"

[hechto]

Originally Posted by Steve Barcak

Changing bore spacing makes no practical or economic sense and will not happen as a result.

How can you make this claim, Steve?

Are you aware of how much (or how LITTLE) material is left between the cylinder liners on the IA2 aluminum block?

It's enough not to be stable at higher bore sizes.

Increased bore spacing offers so MANY advantages, it's crazy NOT to think about it for higher cube, carbureted motors.

[NHRASuperStock455SD]

I am talking normally aspirated, although the wider bore would help gasket seal as Hecto suggested.

The biggest limiting factor we have in the normally aspirated engine is valve size. We are struggling currently for the ability to deal with technology for a good flow 2.4 valve. The 4.40 bore just doesnt provide "easy" room for an inline valve. Let alone the 2.5 that BBCs, Fords, and Chevrolets have.

2.4 + 1.8 = 4.200 That leaves 0.100 between, and .050 on either side? Or .060 between or .070 either side? Right now we are going to sacrifice exhaust shrouding for intake, but it still isnt preferable.

We will aways suck wind to the "Big 3" current castings until we get a bigger hole. The Pro Stock guys use the biggest bore/flow ratios and then make the 500 inches with what ever stroke they need.

I remember reading an article from Darin Morgan about Rod length. He said something like it is the method of connecting the rod to the piston, and that is about it. I am sure he assumes dependibility and rod weight one optimizes.

Lynn

[Steve Barcak]

Hechto-

you asked me "How can you make this claim, Steve? "

This was in reference to my quote- " Changing bore spacing makes no practical or economic sense and will not happen as a result."

Then you stated- "Are you aware of how much (or how LITTLE) material is left between the cylinder liners on the IA2 aluminum block?"

I respond to you- Yes, I am as aware as anyone or possibly more so.

Your next statement- "It's enough not to be stable at higher bore sizes."

I agree
Your third comment was- "Increased bore spacing offers so MANY advantages, it's crazy NOT to think about it for higher cube, carbureted motors"

I disagree. your statment about- "increased bore spacing offers so Many advantages" Really? Ok, things like being able to run a bigger piston, OK, perhaps less shrounding, OK. Sure there are some advantages. How many more are they?

Next- you say- "it's crazy NOT to think about it for higher cube, carbureted motors"
I strongly disagree. It IS crazy to think about this in a practical way. If you are so determined to use very large bores, the Pontiac V-8 is not for you. the engine as a 4.62" bore spacing, that is all we have to work with. If you absolutely need bigger, then you must jump ship and run a 385 series Ford ( 429, 460 ). There is your big bore spacing.
Again, it IS crazy to think about running a Pontiac with a huge bore. Why? do you realize how much work? redisigning, etc,etc it would be to build a Pontiac with a larger bore spacing? Tell me what parts off of a Pontiac that will fit? dist? timing cover? OK.
What about, oil pan? intake manifold? crankshaft?, cam shaft? Heads? intake? NONE of that stuff will fit. THAT is why it IS crazy to think of a Pontiac with a larger bore spacing.

Now, with that said- It really doesn't matter unless you are determined to run in IHRA pro stock.
Pontiac engines, with their 4.62" bore spacing, have already made MASSIVE power. Look at Langers recent accomplishments, look at Robin Roberts, John Welter, Scott Rex, The Butlers, the Kauffmans, Cooper,Gaydosh, etc, etc, etc.
Quit thinking about bigger bore spacing with a Pontiac. Work with what we have (and we have plenty) to make power.
On the extreme high horsepower end 4 second fuel cars use a typical bore size of 4.18" and that is with 500".

Put bore spacing issues to rest, it is not going to change and it shouldn't change.
It is time to spend building excellent combinations with parts that are available as they are now, like never before. Take advantage of what we have.
You asked me, I took the time here to respond. I am not being critical of you, I am merely answering your questions.
Now is it time for me to get some work done tonight. I want to get my car together so we can run as soon as my driver, track and crew will allow.
I use a 4.18" bore in a 46 year old iron 389 block.
If you need more material between your cylinders for better ring seal, then use a smaller bore.

Steve Barcak www.pontiacheaven.org

"Real Pontiacs only...no corporate nonsense!"

[Steve Barcak]

Now with that said. If you are determined to run a Pontiac, and on gas and with just carbs only. And you want to extend the envelope, then I suggest you spend your energy building your own heads. Work on a canted or hemi design. This will allow larger valves, less shrounding and resultant more horsepower. By going in this direction, you can use existing blocks, cranks, etc, etc, etc. You may also want to consider high porting the exhaust as I have. By making the port shorter and straighter, you could run a smaller ex valve and increase your intake. A 3 valve head has promise to. Pontiac designed this in the early to mid 60s. It look doable for someone with enough ambition and abilities. On very large intake valve in the middle of the cylinder results in little shrouding and 2 small exhaust valves gets rid of the siamesed port arrangement.
These are only a few good ideas.
How fast do you want to go N/A? Faster than Scott Rex, Gaydosh, Langer, etc? Look at what they have done N/A.
Now that makes more sense than dreaming about larger bore spacing for a Pontiac V-8 and it is much more practical to do too.
Now, back to the tall deck issue that this thread is about. I like them.

You N/A guys, if you are all so "N/A happy", then why doesn't someone build a N/A fuel motor? You could run faster than I am with a set up like that.
5s are possible unblown with a Pontiac on fuel.

Steve Barcak www.pontiacheaven.org

"Real Pontiacs only...no corporate nonsense!"

[Mo]

Originally Posted by Steve Barcak

Tall decks have advantages, esp with larger displacements.


What is the 'tall' deck height of the engine you are considering?


Stock height is in the 10.2..." area. My 577s" are around 12.200".
Running the taller height in the deck gives much more room for a better ring stack, allows longer rods, etc and is very attractive with longer strokes.
Steve Barcak www.pontiacheaven.org

"Real Pontiacs only...no corporate nonsense!"

Good input Steve. You too Lynn!

Deck height would be 11.00'' as per another post by Bob C.

Raised cam tunnel option/standard?

Perhaps 2.5" main? Maybe 2.75? Bob C....

It's Christmas time.....add to the "wish" list!

Thanks for all the votes and posts. Keep them coming.

[Mo]

ttt

[Mo]

bump! some more info

Factory rod/stroke ratios:

455- 1.57

428- 1.656

400- 1.766

Modified pontiac

455 with offset crank 4.25 stroke with 6.8 rod and 1.315 CH- 1.60 R/S ratio

4.5 stroke crank with 6.8 rod and 1.19 CH- 1.51 R/S ratio

4.75 stroke crank with 6.7 rod and 1.165 CH- 1.41 R/S ratio

5.0 stroke......

BBC

454- 1.53 R/S ratio

[John Langer]

How long of a hammer do you want to put in a Pontiac? You do get to a point were you will be side loading the pistons in the cylinder pretty bad. 572" is pretty much the limit regardless of deck height.

[Mo]

572 is fine by me. So is the 15.5 to 1 compression that goes with it. I'm not sure how much of a dish you can get with only 1.16 CH. That pretty much leaves out the street guys unless we get a bigger cc head that will flow enough to make use of the cid. Maybe that will be the next poll question. Thanks