Uglylspower

Ok. This is my first LS build. 6.0, howards cam, 317 heads from texas speed, stage 1.0, stock bottom end except for studs etc.
how do i check quench? I got a bridge tool the dial indicators, i need to figure how this is done.. ive built may engines but none where pistons come out of the hole. New to me! Once I figured this out i can degree the cam and move on with final assembly. .040 seems to be the number ppl look for on quench.. how do I find this?
thanks

pantera_efi

iTrader: (1)

Hi LSpower, UNDERSTAND that the LS crankshaft HAS 90* throws.
TWO pistons will be in MIDDLE stroke EQUAL distance from the deck, USE THESE for your TDC of #1 & #6.

Once TDC is found, measure the TDC piston's center (+ ???), then "rock" the piston LH/RN to the limit with measurement observed.

Provide that report here, many will help.

I like a .030" to .032" Squish

Lance

Uglylspower

I indicated TDC, then set my two indicators at 0 on the deck, put them across the piston top and bottom and rocked piston back and forth. Is this what im looking for? And to i check every cylinder? This is an interesting thing to learn.

pantera_efi

iTrader: (1)

Hi, LSP, USE my method, PROVIDE THAT report.

I would check each cylinder.

Lance

Che70velle

iTrader: (6)

Yes, use your deck bridge to find top dead center. Take your time and be very precise here. Once TDC is found, using the deck bridge, record how far out of the hole your piston is. Measure at 12 o'clock, and 6 oclock. Rock the piston carefully, until your measurements are the same, at 12 o'clock, and 6 o'clock. This is how far out of the hole you truly are. I write my numbers on the block deck with a sharpie. Do this on all 8 cylinders. You'll use the piston that is out of the hole the most, on each bank, to determine your head gasket thickness. Hopefully you'll have a flat deck. Make sure that piston tops are clear of carbon, and block deck is clean, hopefully freshly cut.
Squish preferences will vary greatly here among folks. .035" is safe with an aluminum engine. Using that number as an example for you, if your biggest number is, say .020" out of the hole, you'd look for a .055" head gasket. This would give you .035" squish.
The process is fun, and really only takes 15-20 minutes.

Uglylspower

Ok thanks.. so i was close. I couldn't get a straight answer on any site on this issue. Its always fun to learn something new. The deck was cut .005 and pistons are clean. So im working with a clean engine for good measuring.

pantera_efi

iTrader: (1)

Hi Guys, I NEED to KNOW how, the measurement method, the both of you used to find TDC / "0" degrees Crankshaft Position ?

Lance

Che70velle

iTrader: (6)

Lance, top dead center, or "zero degrees" as you state, is found when the dial indicator on the deck bridge stops climbing, and begins to descend. This is with the deck bridge held firmly in place on the deck. This is the absolute most accurate way to find tdc with the heads off the engine.

pantera_efi

iTrader: (1)

Hi LSPower, your posted picture states the BEST Tech for LS members.
SO I ask, when you measure the piston position of the #3 AND #5 pistons FROM the deck, are they EQUAL ?

This is the BEST method to use for Crankshaft TDC position measurement AND just too simple !
This measurement is taken at TOP speed, when position change is greatest.

NOW, I mark the rear Crankshaft Flange AND the Oil Seal Cover for that observed TDC measurement, you WILL use this mark when you degree the Camshaft.

WHEN you "bridge" for TDC your resolution is 2* (4* camshaft) NOT GOOD.

NEXT, when the front pulley is installed, I mark the pulley/crankshaft with an electric pencil.
Then I MARK the Front Pulley OD to the Timing cover, a TDC alignment.

GM doesn't not provide this type of mark on OEM engines.

Lance

Che70velle

iTrader: (6)

Lance, this info you've given can be misleading. Due to variances in deck height, from bank to bank, and from front to back, it's very unlikely that those two cylinders will ever be out of the hole, or in the hole the exact same amount, although I'm not sure what type of micrometer you prefer to use. I'm building a engine currently, that has been sleeved, and decked by one of the best in the business, and there is .0044" difference between my #3 and my #5 cylinder at their individual TDC's. This is not uncommon at all.
The bridge method, when done correctly, will not have an error. It's a very precise, and certain way to find exact top dead center of a cylinder, with a quality micrometer.
I'm not sure why your using a mark that you've written on the rear cover to degree a crankshaft....

pantera_efi

iTrader: (1)

Hi 70, let us use YOUR MATH in YOUR FAVOR.

The 3.625" stroke Crankshaft WILL move the piston .125" from 88-92 degrees.
The Crankshaft position in that area (90* .ish) degrees/travel distance.
NOW divide by 100 = .00125 OK
Multiply by YOUR .004"-.005" measurement error = a 4X OR 4 x .00125 = .005". (YOUR TECH)

YOUR OWN MATH STATES a 1/4* possible error at 90* Crankshaft Position with YOUR .005". (YOUR MAX, YOUR TECH)

Lance

Che70velle

iTrader: (6)

I get what your saying. Not going to argue with you on this, but I use this method to degree my camshaft son all my ls builds, and it's always worked perfectly. Tony Mamo himself taught me this method.
The 1/4 degree error is likely closer than relying on a miscut deck to find in the hole dimensions, like your using.
I'd bet that the wire sent out with most cam degreeing kits, that we bolt to the front of our blocks to point at the degree wheel, gives up more than a 1/4 of a degree of inconsistency.
I'm not gonna lose any sleep over 1/4 of 1 degree...

pantera_efi

iTrader: (1)

Hi 70, so I ask next, do you use Split Overlap as a common position for Cam Timing ?

Lance

Che70velle

iTrader: (6)

No, I use the intake centerline method to check my camshafts.

pantera_efi

iTrader: (1)

Hi Scott, OK the Intake Center Line of 108

Now lets set the cam specification 247/259 650"/.650" with a 111 C/L +3 advanced installed position.

This camshaft is a common request, recommended by many.

Your method ICL of 108 = OK

What do we call this Camshaft/Crankshaft position ?

Lance

Che70velle

iTrader: (6)

Game over lance...
I've been doing this too long for you to play teacher with me.
Sorry Uglylspower!