2G Question for you guys

[AlmightySo]

I have the Wiseco Forged Pistons (8.3:1 C.R.) 6-Bolt, does anyone not recommend going 1mm+ on the exhaust valves? I was doing a bit of reading and came across something that mentioned "piston valve relief" will the valves hit the piston? What do I need to do to tell the machine shop once I get the valves?

 

[AlmightySo]

Anyone?

 

[DJRace]

Measuring your deck height is a pretty crucial part of blueprinting the bottom end. I don't know if there will be any need for this though with the valves you are choosing. You should measure it all yourself first.

 

[Boomdeeze]

What is your reason for going oversized valves? I did it on my first build but I have not done that since. Unless you are trying to make a large amount of power (600+) and squeeze everything out of a high flow system, I don't feel it is necessary.

Now, if you already have the items purchased it is a different story. Is the machine shop assembling your engine? If so, they should check clearance when assembling the engine. I ran 1mm oversized valves with a stock style(flat) piston and never had any clearance issues. Unless your deck has been milled a few times with a large amount of material taken off, I wouldn't worry about it.

 

[1990TSIAWDTALON]

If they require more room on the piston, then the machine shop will need to "flycut" the valve reliefs so there will be NO interference problems.

 

[AlmightySo]

My reasoning is for quicker spool. I have the option of either 1g or 2g head. I chose the 6bolt head and figured it has bigger intake ports so ill just go over sized on the exhaust. I didn't buy the valves yet due to me wanting to know more before I do. My machine shop is assembling the block as we speak, I didn't get a chance to send the head so once I get the block back ill give them the head to work on and tell them what I want as we go. The block was milled, I don't have the exact measurements. & would a thicker head gasket help clearance as well?

 

[AlmightySo]

Just got an email from the machine shop. My deck height is 9.034"

 

[AlmightySo]

Anyone? Sorry I just need to know because im on the last few steps to get it back together. And the info im finding isnt helping me. Id be fine with a link to some info
I was looking into the hks 1.6 headgasket, my bore is 85.5 and the gasket is 86mm

 

[1990TSIAWDTALON]

For reference: the 2.4 blocks have a deck height of 235mm and the 2.0 blocks have a deck height of 229mm.
9.034 = 229.4636

This came from this article which may or may not be helpful to you:
http://www.dsmtuners.com/threads/stroker-destroker-and-long-rod-engine-basics.461017/