Let's say you have a stock 81mm GSR shortblock that you want to build.

How can you tell if it's possible to do just a hone and run 81mm aftermarket pistons?

What factors come into play when deciding whether or not to do a stock-bore build? I know most B-series blocks are higher-mileage when torn down, and the cylinders might be out of round. But if they are still good & the crosshatch is still showing, why waste an extra potential build by boring the stock sleeves out to 81.5mm (which = the only/last build you can do on stock sleeves)?

Thanks in advance for the input.

 

I'm in the same boat with the same question.

I plan on just taking my block to a reputable machine shop / engine builder to take a look at the block to see if any scratches/gouges in the sleeves can be taken care of with a hone or if further machining will be necessary.

 

You need to check for out-of-round mainly. Also if there are any scratches in the cylinder walls. In this article about 1/4 way down, Jeff Evans gives a very in depth description of how to check the cylinders with a dial bore gauge.

http://www.evans-tuning.com/te....html

 

A couple engine builders Ive talked to always say to go oversized when rebuilding, so that the cylinder is perfectly round without and imperfections. But regardless there's plenty of people running serious power on 81 mm, as long as it checks out at a machine shop I guess.

 

Personally Fnan, i would overbore to 81.5mm....i am

 

Theres not gonna be any major difference in 81 or 81.5mm. I personally would get it bored to the 81.5mm so that everything is perfectly round, the pistons can be fit to the cylinder and you get a nice tight seal. Stock head gaskets are actually 81.5mm.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SpoolnG2 &raquo;</TD></TR><TR><TD CLASS="quote">Theres not gonna be any major difference in 81 or 81.5mm. I personally would get it bored to the 81.5mm so that everything is perfectly round, the pistons can be fit to the cylinder and you get a nice tight seal. Stock head gaskets are actually 81.5mm. </TD></TR></TABLE>

My point in making this thread is, why waste a potential 81mm build if the cylinders are good, you know? If the cylinders check out, that way you can have two builds before you have to sleeve the block.

 

^^although that is a good point, i dont see you blowing up a built bottom end when the sleeves are stock. In this case, they are the weakest link and IMO more likely to go before the bottom end. With aftermarket sleeves, its a different story.

 

Agreed with the poster's above. Most engines will either have too much piston to wall clearance of be out of round. If you are spending the money to put pistons in the block, insure that the rest of the engine is like new as well. Sure it works and might run, but who showers and puts their dirty socks and underwear on?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ninesecrx &raquo;</TD></TR><TR><TD CLASS="quote">Sure it works and might run, but who showers and puts their dirty socks and underwear on?</TD></TR></TABLE>

I do

lol...also with the price of stock blocks, i wouldnt chance the current build on the off-chance that it blows and you are able to rebuild on the stock sleeves.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ninesecrx &raquo;</TD></TR><TR><TD CLASS="quote">Sure it works and might run, but who showers and puts their dirty socks and underwear on?</TD></TR></TABLE>

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ninesecrx &raquo;</TD></TR><TR><TD CLASS="quote">Agreed with the poster's above. Most engines will either have too much piston to wall clearance of be out of round. If you are spending the money to put pistons in the block, insure that the rest of the engine is like new as well. Sure it works and might run, but who showers and puts their dirty socks and underwear on?</TD></TR></TABLE>

I planned on finding out if the P/W clearance would be suitable with the current condition of the cyl. walls, and then doing a proper hone before installing the 81mm pistons. But I hear what you're saying.

 

I thought you were resleeving that blown ITR for your new setup...what happened??

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Schister66 &raquo;</TD></TR><TR><TD CLASS="quote">I thought you were resleeving that blown ITR for your new setup...what happened??</TD></TR></TABLE>

I'm throwing together a stock-sleeve GSR block for this season...I can't pass on the deal I'm getting

Sleeved ITR block = 2009

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by boostincoupe &raquo;</TD></TR><TR><TD CLASS="quote">

I'm throwing together a stock-sleeve GSR block for this season...I can't pass on the deal I'm getting

Sleeved ITR block = 2009 </TD></TR></TABLE>

You could pass it on to me and then bump up the sleeved ITR build to 2008. That's your best bet