Well I'm starting off on my engine build for this summer and have 2 important questions that really aren't answered well in the searches.

1.) I ripped apart a spare LS block and found some domed pistons . They are surprisingly forged SRP pistons. They look like 10.5:1 compression since that's all they sell according to their site. Now I had to figure out if the block was over bored or anything like that. I took a piston and measured it using come calipers. They ended up being 3.171" which is 80.5434mm. Now I know that a stock block is 81mm bore so this size doesn't help me find out the actual bore of the engine .
I need help with figuring out the size of the pistons and if anyone knows for sure the compression of it through the pics and the size I took with calipers. Do I have to measure the cylinders walls for that?





2.) I'm a little confused on waht new gaskets to get for the complete rebuild. It's a simple piston/Rod and everything else stock build up. The head will be my own used 75k mile head so no gaskets above the head gasket should be needed. I've searched around and found things on e-bay and such stating complete kits.
http://www.prostreetonline.com...t_kit/
I also looked at acuraparts247.com here: http://www.acuraparts247.com/s...ch=no
Looks like the bottom end one is only $50?!?!? Does that include headgasket? I'm just looking for a one stop shop to get quality or OEM gasket sets for the buildup.
What else do I really need?:
-Headgasket
-Oil pump gasket
-Main seals?
-Eveything else like oil pan gasket is pretty safe to reuse as long as you have no leaks etc

Thanks for the help guys! Links are fine if you don't feel like writing too much.

BTW these are for sale if anyone wants them I'll let them go with or without rods for REALLY cheap $150 OBO


Modified by adseguy at 1:35 PM 4/18/2006


Modified by adseguy at 7:13 PM 4/21/2006

 

 

I got a gasket kit from Carquest (vatozone and others like it have them too)

You can get a full motor kit, just a head rebuild or just the block rebuild. I don't think the headgasket came with the bottom rebuild kit, but I would rather use OEM honda for the headgasket, everything else I used the kit from carquest, vatozone, whatever.

Once my kit was a fel pro and another time it was like Carl Reitz or something like that. All the gaskets worked perfectly.

There is a formula to mesure the bore, I think you literally measure the bore like you did but then you must mult or divide by some certian number. I'm sure there are countless sites that describe this.

 

remember forged pistons expand more than the stock hypercasts.So for a forged piston to fit in a stock cylinder they must be smaller.

 

i just did a rebuild on my single cam and used all honda gaskets.

the bottom end gasket set should include rear main seal, front crank seal, "o" ring seals for water tube on the back of the block, oil pan gasket, oil pump pickup tube gasket, water pump seal maybe something else that i cant remember. i had to order that kit and the head gasket to get all gaskets/seals from the head gasket down.

dont forget a tube of hondabond, its around 14 bucks for a tube.

 

I believe that you are correct with the pistons being 81mm 10.5 compression pistons. I had some 81.5mm for my friend ls vtec and they mearused larger if I recall correctly.


As far as the gaskets, Felpro makes a front seal kit that has the oil pump seal, O-ring, pick up gasket, and also a front cam seal kit is available for pretty cheap.
For the head gasket I would just get it from Honda separately, I dont think the kit they sell includes it but I may be wrong.
Since you have the motor apart are you planning on having the head and block resurfaced?
Let me know how it goes and if you need any help just let me know. Im pretty close to you and have built quite a few Ls engines.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by adseguy &raquo;</TD></TR><TR><TD CLASS="quote">BTW these are for sale if anyone wants them I'll let them go with or without rods for REALLY cheap $150OBO</TD></TR></TABLE>

you want $1500 for used pistons and rods? not trying to bash or anything but damn.........

I would go with a cometic and then a felpro bottom end gasket kit

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BoostedEG6 &raquo;</TD></TR><TR><TD CLASS="quote">you want $1500 for used pistons and rods? not trying to bash or anything but damn.........

I would go with a cometic and then a felpro bottom end gasket kit </TD></TR></TABLE>

150 or best offer...not 1500

BTW you need to measure the bore with a bore mic. and measure the piston with an accurate micrometer that has .0001" resolution. You may just want to have a machine shop do the measuring. a $10 dial caliper just isn't good enough for this kind of work.