InchUp

iTrader: (2)

I feel like I've beat to death my "Opinions wanted" thread with questions and also thought this topic may help a few other people later on during searches. Speaking of...I did search and this is why I'm starting this thread. I read a few different opinions from guys on LS1tech mainly who thought they knew what the ideal quench area is for a daily driver N/A motor. I wasn't happy at the arguing and debating by most of the threads leaving with no real answer.

I can't take any measurements at this exact moment because the machine shop still has my block and rotating assembly. However, considering that my build is more or less an all-stock LS1 with an iron block, I figure a good starting place to guess my "out of the hole" measurement to be around .006-.007" or so I've read from the LS1 guys. Assuming a .045" thick head gasket from I don't know who yet, that would leave me with a .039"-.038" quench area correct?

Would this be ideal for a 100% N/A 5.7L truck motor going into a truck, being run on the shittiest gas possible? I'm figuring a compression ratio of 10.1-10.3:1 depending on head gasket and if these heads get milled at some point before the build. But no higher, because I'm often times dumping in 87 octane gas that's months old out on the farm and want zero problems with detonation/pinging.

PappyDan

iTrader: (4)

well what do you want.
a nice DD that will move when you put your foot in it.
or a DD that will run on any thing that burns.

InchUp

iTrader: (2)

Why not both?

dirt track racer 81

iTrader: (45)

just stick a .040 gasket on..thats what most do..id like to see pics of an ls1 in your truck though..i gotta 96 s10 last week to stick a turbo 5.3 in to

InchUp

iTrader: (2)

Well it's a Tahoe 5.3L bored over .181" to 5.7L. That's why many call it the iron block LS1.

.040" gasket would bring me deep into the .030 range...what's your opinion on that?

PappyDan

iTrader: (4)

i think you gona rattle and knock running the **** gas.

PathfinderJr

iTrader: (6)

My buddy was told time and again not to go less than .040 quench on his LT4 build. He's at .044 I think. Granted its not an LSx, so I dunno if its exactly apples to apples here, but I don't see why not.

hirdlej

iTrader: (31)

measure measure measure. Never assume. My 6L ended up being .013 out of the hole, with a .052 head gasket my quench is perfect at .039. I wouldn't go any tighter than that on a street driven hot running truck engine. Save yourself a headache (patience young grasshoppa) and get your rotating assembly installed and see where you're at for the pistons being out of the hole. (you're going to be surprised). Once you know that, shoot for a .037-.041 quench area. This will give you the best balance between resisting detonation and proper/cleaner combustion. Use the sheet below to choose your head gasket when you're ready.

TXsilverado

iTrader: (19)

with my motor, 243 heads, .040 gaskets and a 226 cam everything came out to.

11:1 Static compression,8.7 Dynamic Compression Ratio and .032 quench


i was told by a reputable source that you want to shoot for 8.7 DCR and .032 quench and the SCR doesnt matter as much as the DCR and quench. i took that info to the bank and it worked out for me. picked up 5/10 and 5mph from the heads alone.

TXsilverado

iTrader: (19)

oops i didnt read that you plan on using 87 octane....dont take my advice. it wont work well with regular octane. 93 only...in your situation i would just put on the el cheapo stock gaskets and not wory about all the specific numbers. it will work out fine with stock gaskets.