Is anybody here familiar with the Wiseco Pro Tru pistons? Good, Bad? Would be for a mostly street motor/car. Thanks, in advance, for any input you may have.
We built my son's 464 with them about a year ago for his '85 Regal. It's his everyday car with several trips down the dragstrip, we've had no problem with them. Ken
I have a used set with about 4k miles on them. They are the dished version, netted about 10.5:1. If interested PM me.
If you are building a big block Buick, you'll want a piston you can get to zero deck with. Most pistons will end up .050" or so in the hole at TDC. Then you have to deck the block to get to 0 deck. With the availability of custom pistons at decent prices, it pays to go that route IMO. You can change the compression distance and the dish/valve relief volume to dial in your static compression ratio for the cam you want to run. Don't some Wiseco pistons tend to slap when cold?
Wouldn't one want to deck/square the block anyway? If so & if Joe has a nice set of used ones & depending on Matt's intended use/budget seems like it could be a pretty reasonable way to go IMHO.
There is a big difference between decking/squaring a block and milling .050" off the deck which is not cheap. Custom pistons can allow for a cleanup cut off the deck. We don't know anything about Matt's intended use/budget. I would rather pay a little more and do it right to begin with. It costs less in the long run, and you get a more versatile short block.
What does it usually takes to square a block? I have no idea but I do mill parts & .050" doesn't seem like much to me nor like it would cost much more once it's set up in the machine. Maybe 1 extra pass depending on doc (e.g. .023"/.023/.004 finish cut). I don't necissarily disagree w/your approach of doing it right the 1st time but intended usage/budget could also be real considerations, idk. I'm no engine/455 expert but maybe slightly in the hole isn't a huge problem either depending on the desired SCR (?) and then the full .050" wouldn't have to come off.
I'm basing my comments on what I have read in the past. Specifically, Jim Weise's posts. Read post number 4 in this thread. It deals directly with the issues/considerations we are talking about here, https://www.v8buick.com/index.php?threads/your-new-diamond-pistons.181425/ Jim also talks about Wiseco pistons.
With the Autotec and Diamond custom piston choices we have today, does it make sense to go with used or off the shelf pistons? Only Matt can answer that. Oh, and today, we even have better drop in rods. Lots of choices when building a BBB today.
Sure there are endless advantages to custom order pistons and rods. The costs add up. Putting a "normal" 455 together is still a real viable engine and will run just fine and be plenty fast.
The Wiseco piston piston comment was in 2009. The pistons have changed a bit for the better in the 12 years since that post.
Thanks for all the input. This is the discussion I was hoping would happen with my inquiry. I'm not looking for maximum effort race engine, but, rather a dependable and stout street engine that will live on pump gas and can be beat on every now then. My thoughts were to get a set of Molnar connecting rods and some nice pistons that will yield 10:1 compression ratio. Assembly would be balanced. Plans are for St2 Street Eliminator Heads and shorty headers, B4B intake & Q-Jet carb. Camshaft choice is not yet determined, however. not looking for too radical as I'd like to have a reasonably streetable combo. Switch pitch T-400 is on the table, too. I'm thinking the alloy heads along with a good aluminum radiator and proper tune will help keep detonation down. So, if the Wiseco slugs are .050 in the hole at TDC + a .040 gasket the quench area will not be a good set-up(?). Where should piston like to live for most desirable flame behavior? How far down in the bore do stock pistons live at TDC? Also, if I have the block decked so much won't I need to have the intake and heads machined to accommodate the new deck height? Perhaps custom pistons or just plain more expensive pistons will be the right answer.
Go to the AutoTec website and download/print their piston order sheet. Take that to your machinist who has your engine and have him fill out the info after he measures everything
With aluminum heads, you'll want 10.5:1 static compression. Zero deck makes that much easier to attain, and makes the engine the most resistant to detonation. A cam with about 230* of intake duration will have nice street manners. That is what I have. It idles very nicely at 750 RPM in gear, makes 14-15" of vacuum at a 900 RPM idle, 12" in gear. Part of that is the roller cam, they make more vacuum. It runs very nicely on 93 pump gas. Stock pistons sit anywhere from .040-.090 in the hole depending on the year of the engine. My advice is to get the custom pistons, better all the way around.
I think you need to firm up your goals/expectations. Do you have an ET/HP goal? Are you looking for a serious street car or do you want a cruiser that will fry the tires? I would suggest that you take your block to a reputable machine shop and have them clean and blueprint it. This is step one. See what you are working with and then make decisions. There are a plethora of options out there.
It took .058 to zero my deck and the cost almost doubled. With cutting the deck so far the intake needed a large cut to line up with the ports on the heads. More money. Plus I had to get new pushrods because the stock one were too long now. For all the extra money and time, I could have had a good set of lighter pistons and Molnar rods. Just wanted to share my experience with you.
