Pistons?

[TurboDave]

Any comments, suggestions. These are far too small for my 4.020 block, but could be made to work in my un-bored/sleeved block (3.7" rough opening), but the 1.88" cd would severely limit my stroke options.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=33623&item=2449008825

 

[KendallF]

$300 opening bid, minus pins? Pass. You can get a full set from BRC, JE, etc. with pins and rings for probably $600-700..and you'll get what you need. Find your crank and rods first, then just order the right pistons.

 

[Ron Tarabori]

Venolia. They will do a set pinfitted with spiral locks for under $400. They are absolutely identical to a JE. Also the last set I order took less than 3 weeks.

 

[86gn]

If ya want to take it out a little,I have these for a good price have pics and the spec sheet if ya want it.

http://www.turbobuick.com/forums/showthread.php?s=&threadid=107343

 

[TurboDave]

Thanks guys!! I thought they might be a little pricey!

 

[TurboDave]

Originally posted by 86gn
If ya want to take it out a little,I have these for a good price have pics and the spec sheet if ya want it.

http://www.turbobuick.com/forums/showthread.php?s=&threadid=107343

I'm not sure yet how far I can take it out. This is a sleeved aluminum block, and while the tops of the sleeves are VERY thick, the bottoms (hanging into the crankcase) are NOT.
So, I'm not sure just how much I can take these "sleeves" out

 

[turbodave231]

Kendall, said it all. Get your rods, crank, and make 100% sure you check your main bearing bore and block deck for squareness before you order pistons.

I made the mistake of overlooking the deck squareness issue. Both decks were flat but one was not square to the main bearing bores. I ended up square decking the block .015 which meant that I had to take that amount off the tops of the pistons too.

Diamond pistons did my pistons. They have alot of history with the early Stage 2 V6 development. This doesn't make them any better, but they are knowledgeable and good to work with...IMO.

Dave

 

[TurboDave]

In retrospect, of course you and Kendall are correct. If I'd have gotton a set like that, it would have restricted me to stock crank and rod size specs.
I have quite a bit of fairly good mic's etc. for varifying measurements and so on. As near as I can tell the decks on these blocks are square to the main bores, BUT, the sleeved block has been align honed (if that makes a difference in the final squareness outcome), but not decked. the Sleeves are (as near as I can measure) about 2-3 thousandths "proud" right now. So decking would have to be done with the cylinder boring and honing.

 

[Mac in SD]

Dave, if by "proud" you mean that the sleeves are above the deck by .002-.003, then hold on. I'm pretty sure that the TA blocks have the sleeves up a little, and that it's supposed to be that way for head sealing and integrity issues. Could be that that alum block you have is set up the same way. Give TA a call? Or call Don Wang...he's the one who pointed it out to me on his TA block.

 

[TurboDave]

Thanks MAC, yes that's what I meant. Using a term you coined, "proud" meaning sticking up out the top.

 

[turbodave231]

Dave,

Deck squareness can't be measured accurately without a special fixture. My machinist uses a BHJ Blok-Tru fixture which mounts to a mandrel that fits through the main bore.

I had the block checked at one shop and they said it was OK. When we bolted the BHJ fixture we found the problem. The BHJ fixture is the best way to measure your deck height because it locates off the main bores. You'll need to know exact deck height to order your pistons.

On the "proud" liners. The current generation of GM aluminum engines 2.2 and 4.2 engines use a liner pressed into the block.
The deck surfaces are machined flat after the liner is in place. That would make them zero. If you're not sure if your block was designed to run with the liners above the deck, ask some of the manufacturers who are making sleeved aluminum blocks (like Dart). You might even talk to liner manufacturers like Darton. They might be able to give you some insight.

 

[Nick Micale]

Originally posted by Mac in SD
Dave, if by "proud" you mean that the sleeves are above the deck by .002-.003, then hold on. I'm pretty sure that the TA blocks have the sleeves up a little, and that it's supposed to be that way for head sealing and integrity issues. Could be that that alum block you have is set up the same way. ... /QUOTE]

I know this is a "piston" thread Dave, but just wanted to add a comment about the liners. They do stick above the deck on the TA block and need to be seated prior to decking the block.

Since the surface to be machined is alum and steel, a normal surface cutter cannot be used. I forget the name of the machine needed, but make sure whoever does the work on your block is familiar with machining/building alum motors

 

[TurboDave]

Originally posted by Nick Micale

Originally posted by Mac in SD
Dave, if by "proud" you mean that the sleeves are above the deck by .002-.003, then hold on. I'm pretty sure that the TA blocks have the sleeves up a little, and that it's supposed to be that way for head sealing and integrity issues. Could be that that alum block you have is set up the same way. ... /QUOTE]

I know this is a "piston" thread Dave, but just wanted to add a comment about the liners. They do stick above the deck on the TA block and need to be seated prior to decking the block.

Since the surface to be machined is alum and steel, a normal surface cutter cannot be used. I forget the name of the machine needed, but make sure whoever does the work on your block is familiar with machining/building alum motors

Once I find my way to civilization, that shouldn't pose too much of a problem. There's a LOT of aluminum motors out there now days. With a little research, a LOT more than I had suspected!! There's people making LS1 alum. blocks, and of course most of the high end european cars run ALL alum blocks. Some sleeved, most not.
So finding a good machinist should be do'able.

Assuming of course I even decide to build that block. I may just build the all aluminum one. I can get a LOT more C.I. out of it.

 

[quickt]

Originally posted by Ron Tarabori
Venolia. They will do a set pinfitted with spiral locks for under $400. They are absolutely identical to a JE. Also the last set I order took less than 3 weeks.

Venolia is a great piston. I perfer them over the JEs myself.