Quote:
Originally Posted by mgarblik
I have built Indian Adventures first gen blocks, IA II iron and IA II solid aluminum blocks in that order, 8 blocks total. Yes, each generation of casting gets better and better and the machining also has better finish and is more accurate. This is all very true. However, they are all castings, either iron or aluminum and the level of accuracy before assembly and running it is the decision of the end user, the intended use and horsepower/durability they expect. Since these blocks are a huge upgrade from a stock block and the initial cost is significant, I would think the end user would want a block as close to perfect as possible. An example might be deck height. I have seen Pontiac factory blocks .015" out of square and .017" variation in deck height. These blocks all messed up like this have run possibly hundreds of thousands of miles like this. 8 different compression ratio's. In a 300 HP street engine, it would go unnoticed. The last 2 IA II aluminum blocks I prepared had the deck height +-.001". Almost perfect as delivered. Very impressive. Line hone was +- .0003". also well within factory specs. My equipment can line hone +-.0001, so I went ahead and closed the tolerance a little. It's all up to "how perfect" you want them to be. IMO, The IA blocks can be honed, cleaned and run as delivered for the most part. For peace of mind, I still want to check and measure everything to verify.
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Thanks for that. It was just confirming what Frank told me how the new blocks were turning out. Mine is a 2016 block so I expect what you said as far as how close they are. Lewis Racing has one of those big do it all block CNC machines that indicates where its at from some locating lugs on blocks. The latest IA2 is in its computer files so mine will get checked out on that machine.
I know what you are saying about stock blocks. My 455 putting out 550+ HP for many years was never decked or line honed and it is still doing fine. The factory marks on the deck are still there. Its a 4 bolt block and I just installed main studs without a line hone. Its been "good enough" to get its intended job done and be very durable. Way back when I originally had the block done and asked Dan about line honing the block he told me Pontiacs were generally pretty good and he had seen quite a few good blocks messed up line honing over the years. So I left it as is.
The 461 I am doing right now was line bored and honed by Dan fitting the splayed billet caps. After he passed and I got the block and had it checked out by the best local shop here and was told it was dead on the nuts. He was impressed So I just had it tq plate bored and zero decked. This engine will get a bit more attention than my old 455. Really looking forward to how it turns out. Dan's last engine.