Really Need Piston help

[Blown68]

Hi, This is my first post. I've been reading and learning for some time. I spent many late nights learning from all of you. Great forum Lots of knowledgeable folks here. I've owned my Regal T for about a year and a half now, and I love it. It's one of my all time favorite cars. Car was stock , running 13's but now with bolt-ons running 11.40 @ 118 . Stock long block. Hoping to run 11.20's this week-end if it doesn't rain. Running 93 octane with meth 25 psi, no knock, wideband shows 10.8 afr's. So far so good.

I bought a set of T/A heads the SI ones. Also a 109 block with forged crank and rods. My question is, I need to buy pistons what do I get. I see many that run JE , Wiseco and also Diamond's . My plan is to run low 10's. Do I get an off the shelf piston or do I get some custom stuff with Gas Ports and Coated tops and skirts. I don't want to cheap out. I called Diamond and their recommendation was to get customs at $950 a set. I feel like trying out some JE's but do I go with customs with them also or is the off the shelf stuff good enough.

Thanks
Nick

 

[turboclam]

Where do you live? Wondering what kind of help is around you (vendors).

 

[Blown68]

I'm actually out of Montreal Canada. There really isn't that much around here. I have no issue ordering direct from JE, or Diamond. The only thing is what do I order, off the shelf or something with all the options. Gas ports coatings etc. It's basically going to be a stock stroke just .030 over.

 

[DSEROVY]

I'm in the same situation - looking to put together another short block with a forged crank, good rods, steel caps, ect. I've been looking at all the different options out there and it seems like ten different people have ten different opinions.

That being said, I bulit my short block back in '07 with a new GM turbo crank, stock rods, TRW Forged replacement pistons and a girdle. At the time I had been collecting parts for a few years and was not really looking to build a drag car - just a fun street car. Then I really got the bug and ordered ALL the goodies - Champion heads, intake, roller cam, TA headers, big turbo, ect, ect. When I was done, I had the feeling that I "cheated" myself on the bottom end (no forged crank, no fancy pistons).

After a ton of very "spirited" street driving and 10's at the track, I just yanked the engine about a month ago - girdle leak popped up, the Cometics always weeped just a little and I just wanted to take a peek inside anyway.

I expected to see some wear and was planning to upgrade the crank/rods/pistons, but everything came out beautiful - pistons looked perfect, bore was excellent, bearings were in good shape. I was actually a little shocked at how good it all looked and all she got were new bearings, rings and gaskets.

I guess what I'm trying to say is that the TRW's were not my 1st choice, but I ran what I had & decided to just keep beating on them. Any good quality piston should be a good choice and it really boils down to a proper tune. I'm leaning toward a set of Wiesco pistons for the next build, but that's just because I'm a Wiesco dealer (I live in the motorcycle world most of the time!).

 

[forcefed3.8's]

What is the rod length? If you go with Diamond, I wouldn't buy their shelf piston. Make sure the top ring is down. Also, I don't care for their dish design. The valve reliefs cut in close to the top ring land. If the ring is placed down far enough, it isn't a concern. There are other options like crown thickness and skirt thickness. The Diamond pistons Weber Racing sells are their custom spec, and have proper ring location and crown/ skirt thickness. I had my pistons made with a spherical dish, no sharp edges. I would think about raising the compression to 9:1.
If you have stock length rods, then the TRW's, JE's, or Wiseco's are good. I would probably put the JE's at the top of the list. The TRW's are heavy.

 

[Blown68]

So I guess an off the shelf JE should do the job. I'm probably breaking my head for nothing. I see it with the stock motor that it's all in the tune, but just like DSEROVY said I don't want to cheat myself by cheaping out. I'm not really a lucky guy. When ever I cut corners, I always end up re-doing things and paying TWICE. Lesson learnt a long time ago.

 

[Nick Micale]

Well, off-the-shelf pistons from JE, or someone else, will work IF all the rotating parts are compatible in size and fit?

If you do not have the knowledge, experience and tools to check all items BEFORE and AFTER the machine work has been done, you could end up with paper weights.

Many times we have seen projects that guys have tried to assemble after spending many $$$$ for parts and machining that will not work, so all the prior money spent was wasted.

Even the sharpest guy on a keyboard cannot spec out your pistons and be absolutely sure they will work or fit properly.

A case in point is one engine we are now doing where all the machine work was done and not assembled, BUT we have to rebalance it, check and redo some machine work and correct the problem of the pistons ending up 0.005" out of the hole which will touch the heads when installed.

Working with an experienced Buick V-6 engine builder/vendor to get things right at the start does have a price, but it is smarter than doing a second time.

 

[Just a Six??]

I'm actually out of Montreal Canada. There really isn't that much around here. I have no issue ordering direct from JE, or Diamond. The only thing is what do I order, off the shelf or something with all the options. Gas ports coatings etc. It's basically going to be a stock stroke just .030 over.

There is a guy in or around Montreal who is on the other board in the Toronto Section. he goes by JB Racing. I have never met him but others here in Toronto know him & he is a very helpful & experienced GN owner. Builds engines for a couple guys here as well as heads etc. It would be worth 5 mins to get his info & talk to him since he is local to you. he has some pretty fast GN's & seems really nice by his posts.

 

[Blown68]

Well I think the machining and engine building part should not be a problem. I have someone who has done quite a few Buick motors, and I trust him. The question was more whether a set of $600 JE's will be good enough or do I need to spend $900 - $1000 for a custom set.

 

[Blown68]

He's the one doing the motor so I have no issues with that it's simply which pistons to get. Joe had recommended the JE's at $600. I just figured, trying to not skimp out on anything should I add gas ports and coatings.

 

[forcefed3.8's]

You just have to make sure the rods are stock length and stock pin size. Has the engine already been bored? If it is standard bore, I wouldn't go .030 over. Leave some for future rebuilds. I have sonic test results on acouple standard bore 109 blocks that are pretty thin. You need the pistons before the engine can be bored/finish honed. I wouldn't worry about coatings or gas porting.

 

[Blown68]

Ok, I'll just get off the shelf JE's. Seems like not many running low 10's high 9's are running gas ports and coatings. Rods are standard length Eagles. And the block will be done at .030 over.

 

[norbs]

I have a set of JE pistons for sale if your interested slighty used.

 

[Blown68]

Thanks for the offer. I'll decide on what I'm doing in the next couple of days. Went back to the track today. Another good fun day. My Black T rand 11.30 @ 119. 1.59 sixty foot. My White T ran 11.43 @ 118 with a 1.66 time. Couldn't hold it back past 4-5 psi. Guess it's time for new brakes. Both set at 25 psi.