What size pistons do I need?

[Shadowjake]

Hey guys,

I have been gradually rebuilding my 89 CSX-VNT and pre ordered a bunch of parts over the last year or two. One of which was a set of .040 Wiseco pistons. In my excitement, I ordered the big ones thinking they could bore to make them fit which I am pretty sure was dumb

It is the original block (numbers match the shelby plaque) so I don't want to bore it out more than necessary. Can I determine what size I need without bringing the block to a machine shop (i.e. get a micrometer)? Or should I go through the hassle and just bring it in and have them tell me what to order?

Sorry if this is a dumb question. I am learning a lot as I go and want to do this right.

Thanks!

Jake

[turbovanman²]

If you want to rebore it, then just go .020, but you will need the pistons to have that done as they set the bore to each piston.

[Shadowjake]

Is there any chance I can get by with STD pistons? Or should I talk with TU and see if I can trade them for .020s and have the shop do whatever they need to do to get them to fit? Thanks for the help. I haven't rebuilt an engine for almost 10 years.

[My96z]

I wouldnt stick stock cast pistons back in. Those Wisecos are bada$$. I would try to trade them for 20 overs as I like to keep any overbore to a minimum for future rebuilds. But the machine shop should be able to make them fit.

[Shadowjake]

I meant STD size not the stock cast ones :-P. TU offers STD, .020, and .040 sizes for their wisecos. But I will get with Chris and see if he'll let me trade them in. Thanks!

[turbovanman²]

Is there any chance I can get by with STD pistons? Or should I talk with TU and see if I can trade them for .020s and have the shop do whatever they need to do to get them to fit? Thanks for the help. I haven't rebuilt an engine for almost 10 years.

You have no idea really what pistons will fit until you take it apart and measure, if the bores are ok, then you could get away with stock size pistons but usually, they have some form of taper after all these years so why go to all that hassle when just get some .020's, rebore and you have some nice, straight, fresh bores.

[Shadowjake]

Good point and thanks for the input.

Jake

[contraption22]

Why not find another common block engine to play with and keep the OE stock engine away for safe keeping?

[Shadowjake]

That might not be a bad idea either. If I grabbed a common block from a local junk yard, what would I expect to pay? What's a fair price just so I know if I'm getting ripped off? The local yards are sometimes shady.

[135sohc]

You pull or they pull ? if your doing all the work I wouldnt go over $100

I paid $200 for the last CB engine I bought. more than what I would have liked but they did all the work and all I did was show up with a truck to take it home.

[Chris W]

I meant STD size not the stock cast ones :-P. TU offers STD, .020, and .040 sizes for their wisecos. But I will get with Chris and see if he'll let me trade them in. Thanks!

Jake,

I have a customer with a set of Wiseco +20 2.2 pistons looking to trade you for your +40s. Give us a call or shoot us an email so we can get you two guys together.

Chris-TU

[Shadowjake]

Sounds like a good plan and thanks for keeping a look out Chris! I will give you a call tomorrow to work out the details. Thanks again!

[89sdac]

Ah yes! I am that customer. Thanks Chris! I am in the exact reverse of your situation. I have .020s and need .040s. I live in central Iowa, Polk City to be exact. If you would like to give me a call or email me that would be great! I am learning too, as I forgot to measure my block first. Turned out it was already bored .030 over and there was a slight score. It is being honed to .040 at the moment.

cweedthegearhead@yahoo.com
515-401-2425 cell

Thanks

[Chris W]

Ah yes! I am that customer. Thanks Chris! I am in the exact reverse of your situation. I have .020s and need .040s. I live in central Iowa, Polk City to be exact. If you would like to give me a call or email me that would be great! I am learning too, as I forgot to measure my block first. Turned out it was already bored .030 over and there was a slight score. It is being honed to .040 at the moment.

cweedthegearhead@yahoo.com
515-401-2425 cell

Thanks

Glad I could get you two together on this. It might be best to wait until you have the pistons in hand before you do the final hone though.

Chris-TU

[Shadowjake]

Ok, so I feel like a total idiot. I was sure I got +40s but it has been 5 years since I ordered them. I logged into my TU account to get Doug the details on them (wrist pins size, etc.) and it says I ordered standard size instead. On top of that, I ordered 2.5L pistons not 2.2L. I ordered when I was planning to build the engine in my (since sold) '91 Shadow ES.

I guess I'm in a bit of a pickle now. I'll have to try sell these and order the correct ones I guess (unless Chris would take them back in exchange them for the ones I need but I would understand if he didn't considering the time it's been and being no fault of his).

So here I sit. Sorry Doug for the let down.

Jake